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paqs345(at)gmail.com
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 Posted: Wed Jan 29, 2014 8:13 am Post subject: Wing tanks in wood wing? |
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Hello Group,
Has anyone made wing tanks for a Pulsar 1 (wood wing)?
Sonja
Matt,
I suggest we ask the group if anyone has made wing tanks for a wood
wing before. Maybe it is not necessary to reinvent the wheel.
Sonja
---------- Forwarded message ----------
From: Matthew Brock <mattbrock777(at)gmail.com>
Date: Mon, 27 Jan 2014 21:15:34 +0400
Subject: RE: Results
To: Sonja Englert <paqs345(at)gmail.com>
Wow Sonja,
That was nice and fast!
I'll put together what I'm thinking of doing regarding a wing tank upgrade/
modification of the wood-wood wing, so you can let me know your thoughts.
Would you be happy to have a similar arrangement as we had for the Fuselage/
Wing structural modifications, as perhaps there are guys out there with kits
who would like this option also?
Again thanks so much for your work and input.
Regards,
Matt.
--
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everettmcollier(at)yahoo.
Guest
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| Posted: Wed Jan 29, 2014 9:04 am Post subject: Wing tanks in wood wing? |
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I have a 582 Pulsar I with wing tanks. I have the wood spar with the xp type glass skins. Had to make new ribs to do this. The spare is coated with 45 degree S glass to strengthen it and protect it from the fuel. Coated with Jeffco 9700. Okay so far as I know.
Everett
Sent from my iPad.
[quote] On Jan 29, 2014, at 8:13 AM, Sonja Englert <paqs345(at)gmail.com> wrote:
Hello Group,
Has anyone made wing tanks for a Pulsar 1 (wood wing)?
Sonja
Matt,
I suggest we ask the group if anyone has made wing tanks for a wood
wing before. Maybe it is not necessary to reinvent the wheel.
Sonja
---------- Forwarded message ----------
From: Matthew Brock <mattbrock777(at)gmail.com>
Date: Mon, 27 Jan 2014 21:15:34 +0400
Subject: RE: Results
To: Sonja Englert <paqs345(at)gmail.com>
Wow Sonja,
That was nice and fast!
I'll put together what I'm thinking of doing regarding a wing tank upgrade/
modification of the wood-wood wing, so you can let me know your thoughts.
Would you be happy to have a similar arrangement as we had for the Fuselage/
Wing structural modifications, as perhaps there are guys out there with kits
who would like this option also?
Again thanks so much for your work and input.
Regards,
Matt.
--
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
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gregsmi
Joined: 01 Jan 2011
Posts: 268
Location: Topeka, KS
|
| Posted: Wed Jan 29, 2014 10:44 am Post subject: Wing tanks in wood wing? |
|
|
The wood wing Pulsar uses a spruce wood spacer with uni-directional glass spar caps. The strength of the spar is in the spar caps which were bonded with room temp cured structural adhesive. This wing was never intended to carry fuel, and as we have found out now, the room temp cured structural adhesive will not stand up to any type of fuel. Failure of the bond in the spar cap is a failed wing.
In using Jeffco we have found that as it cures it has small pin holes due to off gassing. We applied several coats to try to make sure all holes were filled, and then covered the tank in PRC, but still, there is a chance of a leak which could penetrate the structural adhesive on a wood wing Pulsar. Another thing to think about is that the wing flexes and twist in flight. Jeffco sets up very hard and may be subject to cracking. For that reason I would never attempt to put fuel in a wood wing Pulsar. It is possible for a leak to go undetected until the cap fails, not a good thing.
The glass spars were made with high temp epoxy and cured in a oven and do resist fuel, although the new formulations of fuel and ethanol may be an issue so checking the seal often is a great idea.
Be safe,
Greg
In a message dated 1/29/2014 10:13:50 A.M. Central Standard Time, paqs345(at)gmail.com writes:
| Quote: | --> Pulsar-List message posted by: Sonja Englert <paqs345(at)gmail.com>
Hello Group,
Has anyone made wing tanks for a Pulsar 1 (wood wing)?
Sonja
Matt,
I suggest we ask the group if anyone has made wing tanks for a wood
wing before. Maybe it is not necessary to reinvent the wheel.
Sonja
---------- Forwarded message ----------
From: Matthew Brock <mattbrock777(at)gmail.com>
Date: Mon, 27 Jan 2014 21:15:34 +0400
Subject: RE: Results
To: Sonja Englert <paqs345(at)gmail.com>
Wow Sonja,
That was nice and fast!
I'll put together what I'm thinking of doing regarding a wing tank upgrade/
modification of the wood-wood wing, so you can let me know your thoughts.
Would you be happy to have a similar arrangement as we had for the Fuselage/
Wing structural modifications, as perhaps there are guys out there with kits
who would like this option also?
Again thanks so much for your work and input.
Regards,
Matt.
-----Original Message-----
From: Sonja Englert [mailto:paqs345(at)gmail.com]
Sent: Monday, January 27, 2014 7:46 PM
To: Matt Brock
Subject: Results
Hi Matt,
I have completed the analysis and the summary of the changes you need to
make to your kit to upgrade it to the higher gross weight. Most of it is for
the wing, not much needs to be done to the fuselage and nothing for the tail
since you already have the correct HT spar tube.
I don't know what the layup of your horizontal and vertical tail skins is,
so I am assuming it is at least 2 plies of 9 oz/sqyd fabric. If it is
thinner, you need to add this.
I am attaching the 2 files with the sp; the ies ay - MATRONICS WEB FORUMS - List Contribution Web Site p;
|
[quote][b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
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pulsarbob(at)comcast.net
Guest
|
| Posted: Wed Jan 29, 2014 10:55 am Post subject: Wing tanks in wood wing? |
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SonjaI built a set of wings with fiberglass spars with fuel tanks in both wings.
My question is, Can I use these tanks with a 582 engine, providing I stay in the
weight and balance using the 582 for power ? Your thoughts , Thanks
Pulsarbob, Bob Taylor
From: "Sonja Englert" <paqs345(at)gmail.com>
To: "pulsar-list" <pulsar-list(at)matronics.com>
Sent: Wednesday, January 29, 2014 11:13:02 AM
Subject: Wing tanks in wood wing?
--> Pulsar-List message posted by: Sonja Englert <paqs345(at)gmail.com>
Hello Group,
Has anyone made wing tanks for a Pulsar 1 (wood wing)?
Sonja
Matt,
I suggest we ask the group if anyone has made wing tanks for a wood
wing before. Maybe it is not necessary to reinvent the wheel.
Sonja
---------- Forwarded message ----------
From: Matthew Brock <mattbrock777(at)gmail.com>
Date: Mon, 27 Jan 2014 21:15:34 +0400
Subject: RE: Results
To: Sonja Englert <paqs345(at)gmail.com>
Wow Sonja,
That was nice and fast!
I'll put together what I'm thinking of doing regarding a wing tank upgrade/
modification of the wood-wood wing, so you can let me know your thoughts.
Would you be happy to have a similar arrangement as we had for the Fuselage/
Wing structural modifications, as perhaps there are guys out there with kits
who would like this option also?
Again thanks so much for your work and input.
Regards,
Matt.
--
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
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barry(at)connisbeare.com
Guest
|
| Posted: Wed Jan 29, 2014 11:34 am Post subject: Wing tanks in wood wing? |
|
|
Greg,
This isn’t quite correct. I have a Pulsar XP supplied with wing tanks AND WOOD wings from Aero Designs. The wings had to be strengthened with 6” wide glass on both sides of the spar (to within about 6” of the tip) and with plenty of resin on the fuel side to ensure complete sealing. One of my wings has long since lost all of the old ‘Kreem’ sealant yet close inspection reveals no degradation of the glass structure inside the wing, or of the structural adhesive around the fuel cap. Of course, it may be that UK fuel has a different make-up to you stuff but my wings are fine after 22 years.
Barry
G-XPXP Pulsar XP R912 Taildragger 1050 hrs.
From: GREGSMI(at)aol.com (GREGSMI(at)aol.com)
Sent: Wednesday, January 29, 2014 6:44 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Wing tanks in wood wing?
The wood wing Pulsar uses a spruce wood spacer with uni-directional glass spar caps. The strength of the spar is in the spar caps which were bonded with room temp cured structural adhesive. This wing was never intended to carry fuel, and as we have found out now, the room temp cured structural adhesive will not stand up to any type of fuel. Failure of the bond in the spar cap is a failed wing.
In using Jeffco we have found that as it cures it has small pin holes due to off gassing. We applied several coats to try to make sure all holes were filled, and then covered the tank in PRC, but still, there is a chance of a leak which could penetrate the structural adhesive on a wood wing Pulsar. Another thing to think about is that the wing flexes and twist in flight. Jeffco sets up very hard and may be subject to cracking. For that reason I would never attempt to put fuel in a wood wing Pulsar. It is possible for a leak to go undetected until the cap fails, not a good thing.
The glass spars were made with high temp epoxy and cured in a oven and do resist fuel, although the new formulations of fuel and ethanol may be an issue so checking the seal often is a great idea.
Be safe,
Greg
In a message dated 1/29/2014 10:13:50 A.M. Central Standard Time, paqs345(at)gmail.com writes:
| Quote: | --> Pulsar-List message posted by: Sonja Englert <paqs345(at)gmail.com>
Hello Group,
Has anyone made wing tanks for a Pulsar 1 (wood wing)?
Sonja
Matt,
I suggest we ask the group if anyone has made wing tanks for a wood
wing before. Maybe it is not necessary to reinvent the wheel.
Sonja
---------- Forwarded message ----------
From: Matthew Brock <mattbrock777(at)gmail.com>
Date: Mon, 27 Jan 2014 21:15:34 +0400
Subject: RE: Results
To: Sonja Englert <paqs345(at)gmail.com>
Wow Sonja,
That was nice and fast!
I'll put together what I'm thinking of doing regarding a wing tank upgrade/
modification of the wood-wood wing, so you can let me know your thoughts.
Would you be happy to have a similar arrangement as we had for the Fuselage/
Wing structural modifications, as perhaps there are guys out there with kits
who would like this option also?
Again thanks so much for your work and input.
Regards,
Matt.
-----Original Message-----
From: Sonja Englert [mailto:paqs345(at)gmail.com]
Sent: Monday, January 27, 2014 7:46 PM
To: Matt Brock
Subject: Results
Hi Matt,
I have completed the analysis and the summary of the changes you need to
make to your kit to upgrade it to the higher gross weight. Most of it is for
the wing, not much needs to be done to the fuselage and nothing for the tail
since you already have the correct HT spar tube.
I don't know what the layup of your horizontal and vertical tail skins is,
so I am assuming it is at least 2 plies of 9 oz/sqyd fabric. If it is
thinner, you need to add this.
I am attaching the 2 files with the sp; the ies ay - MATRONICS WEB FORUMS - List Contribution Web Site p;
|
[quote]
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
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gregsmi
Joined: 01 Jan 2011
Posts: 268
Location: Topeka, KS
|
| Posted: Wed Jan 29, 2014 1:56 pm Post subject: Wing tanks in wood wing? |
|
|
Barry, I can only tell you what I have tested and the facts are very clear, room temperature cured structural adhesive will dissolve if exposed to fuel. If it were mine I would cut an access to the tanks, clean the spar and apply several coats of Jeffco followed by a good thick coat of PRC. All of those coats would cover the spar and lap at least two inches onto the tank skin. I would also make sure the end plates were sealed in the same way.
I am not sure if we have different additives in our fuel and ethanol is the worse, but when a room temp cured piece of glass tape was put in a jar of fuel, it totally dissolved the adhesive. Who knows how long it will take for fuel going through a pin hole or crack to dissolve the adhesive, did not test a pin hole.
Over the years we have learned a lot more about composites and adhesives. I know we applied real thick coats of epoxy to the inside of the header tanks and set the fuel cap with structural adhesive and we have heard of several cases of the fuel cap developing leaks due to the adhesive dissolving. Maybe the epoxy helps seal the rest but we have heard of some leaks developing when ethanol fuel was used.
The critical factor here is the spar caps are attached to the spruce spacer using room temp cured structural adhesive and we know that if room temp cured structural adhesive is soaked in fuel, it dissolves. Given what we know now, are there things we can do to make the plane safer?
Greg
In a message dated 1/29/2014 1:35:08 P.M. Central Standard Time, barry(at)connisbeare.com writes:
| Quote: | Greg,
This isn’t quite correct. I have a Pulsar XP supplied with wing tanks AND WOOD wings from Aero Designs. The wings had to be strengthened with 6” wide glass on both sides of the spar (to within about 6” of the tip) and with plea nty of resin on the fuel side to ensure complete sealing. One of my wings has long since lost all of the old ‘Kreem’ sealant yet close inspection reveals no degradation of the glass structure inside the wing, or of the structural adhesive around the fuel cap. Of course, it may be that UK fuel has a different make-up to you stuff but my wings are fine after 22 years.
Barry
G-XPXP Pulsar XP R912 Taildragger 1050 hrs.
From: GREGSMI(at)aol.com (GREGSMI(at)aol.com)
Sent: Wednesday, January 29, 2014 6:44 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Wing tanks in wood wing?
The wood wing Pulsar uses a spruce wood spacer with uni-directional glass spar caps. The strength of the spar is in the spar caps which were bonded with room temp cured structural adhesive. This wing was never intended to carry fuel, and as we have found out now, the room temp cured structural adhesive will not stand up to any type of fuel. Failure of the bond in the spar cap is a failed wing.
In using Jeffco we have found that as it cures it has small pin holes due to off gassing. We applied several coats to try to make sure all holes were filled, and then covered the tank in PRC, but still, there is a chance of a leak which could penetrate the structural adhesive on a wood wing Pulsar. Another thing to think about is that the wing flexes and twist in flight. Jeffco sets up very hard and may be subject to cracking. For that reason I would never attempt to put fuel in a wood wing Pulsar. It is possible for a leak to go undetected until the cap fails, not a good thing.
The glass spars were made with high temp epoxy and cured in a oven and do resist fuel, although the new formulations of fuel and ethanol may be an issue so checking the seal often is a great idea.
Be safe,
Greg
In a message dated 1/29/2014 10:13:50 A.M. Central Standard Time, paqs345(at)gmail.com writes:
| Quote: | --> Pulsar-List message posted by: Sonja Englert <paqs345(at)gmail.com>
Hello Group,
Has anyone made wing tanks for a Pulsar 1 (wood wing)?
Sonja
Matt,
I suggest we ask the group if anyone has made wing tanks for a wood
wing before. Maybe it is not necessary to reinvent the wheel.
Sonja
---------- Forwarded message ----------
From: Matthew Brock <mattbrock777(at)gmail.com>
Date: Mon, 27 Jan 2014 21:15:34 +0400
Subject: RE: Results
To: Sonja Englert <paqs345(at)gmail.com>
Wow Sonja,
That was nice and fast!
I'll put together what I'm thinking of doing regarding a wing tank upgrade/
modification of the wood-wood wing, so you can let me know your thoughts.
Would you be happy to have a similar arrangement as we had for the Fuselage/
Wing structural modifications, as perhaps there are guys out there with kits
who would like this option also?
Again thanks so much for your work and input.
Regards,
Matt.
-----Original Message-----
From: Sonja Englert [mailto:paqs345(at)gmail.com]
Sent: Monday, January 27, 2014 7:46 PM
To: Matt Brock
Subject: Results
Hi Matt,
I have completed the analysis and the summary of the changes you need to
make to your kit to upgrade it to the higher gross weight. Most of it is for
the wing, not much needs to be done to the fuselage and nothing for the tail
since you already have the correct HT spar tube.
I don't know what the layup of your horizontal and vertical tail skins is,
so I am assuming it is at least 2 plies of 9 oz/sqyd fabric. If it is
thinner, you need to add this.
I am attaching the 2 files with the sp; the ies ay - MATRONICS WEB FORUMS - List Contribution Web Site p;
|
| Quote: |
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
ef="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronics.com/Navigator?Pulsar-List
s.matronics.com/">http://forums.matronics.com
p://www.matronics.com/contribution">http://www.matronics.com/contribution
|
|
[quote][b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
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barry(at)connisbeare.com
Guest
|
| Posted: Thu Jan 30, 2014 12:04 am Post subject: Wing tanks in wood wing? |
|
|
Hi Greg,
My comment was not directed at whether structural adhesive is fuel proof or not but you made a comment “This wing was never intended to carry fuel” and this is not correct since Mark Brown sold kits with wood spars and wing tanks so he must have intended it to carry fuel! Maybe in hindsight we can say that this was not an ideal solution but the fact is that it was done intentionally. That was the point of my post.
Cheers,
Barry
From: GREGSMI(at)aol.com (GREGSMI(at)aol.com)
Sent: Wednesday, January 29, 2014 9:55 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Wing tanks in wood wing?
Barry, I can only tell you what I have tested and the facts are very clear, room temperature cured structural adhesive will dissolve if exposed to fuel. If it were mine I would cut an access to the tanks, clean the spar and apply several coats of Jeffco followed by a good thick coat of PRC. All of those coats would cover the spar and lap at least two inches onto the tank skin. I would also make sure the end plates were sealed in the same way.
I am not sure if we have different additives in our fuel and ethanol is the worse, but when a room temp cured piece of glass tape was put in a jar of fuel, it totally dissolved the adhesive. Who knows how long it will take for fuel going through a pin hole or crack to dissolve the adhesive, did not test a pin hole.
Over the years we have learned a lot more about composites and adhesives. I know we applied real thick coats of epoxy to the inside of the header tanks and set the fuel cap with structural adhesive and we have heard of several cases of the fuel cap developing leaks due to the adhesive dissolving. Maybe the epoxy helps seal the rest but we have heard of some leaks developing when ethanol fuel was used.
The critical factor here is the spar caps are attached to the spruce spacer using room temp cured structural adhesive and we know that if room temp cured structural adhesive is soaked in fuel, it dissolves. Given what we know now, are there things we can do to make the plane safer?
Greg
In a message dated 1/29/2014 1:35:08 P.M. Central Standard Time, barry(at)connisbeare.com writes:
[quote] Greg,
This isn’t quite correct. I have a Pulsar XP supplied with wing tanks AND WOOD wings from Aero Designs. The wings had to be strengthened with 6” wide glass on both sides of the spar (to within about 6” of the tip) and with plea nty of resin on the fuel side to ensure complete sealing. One of my wings has long since lost all of the old ‘Kreem’ sealant yet close inspection reveals no degradation of the glass structure inside the wing, or of the structural adhesive around the fuel cap. Of course, it may be that UK fuel has a different make-up to you stuff but my wings are fine after 22 years.
Barry
G-XPXP Pulsar XP R912 Taildragger 1050 hrs.
From: GREGSMI(at)aol.com (GREGSMI(at)aol.com)
Sent: Wednesday, January 29, 2014 6:44 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Wing tanks in wood wing?
The wood wing Pulsar uses a spruce wood spacer with uni-directional glass spar caps. The strength of the spar is in the spar caps which were bonded with room temp cured structural adhesive. This wing was never intended to carry fuel, and as we have found out now, the room temp cured structural adhesive will not stand up to any type of fuel. Failure of the bond in the spar cap is a failed wing.
In using Jeffco we have found that as it cures it has small pin holes due to off gassing. We applied several coats to try to make sure all holes were filled, and then covered the tank in PRC, but still, there is a chance of a leak which could penetrate the structural adhesive on a wood wing Pulsar. Another thing to think about is that the wing flexes and twist in flight. Jeffco sets up very hard and may be subject to cracking. For that reason I would never attempt to put fuel in a wood wing Pulsar. It is possible for a leak to go undetected until the cap fails, not a good thing.
The glass spars were made with high temp epoxy and cured in a oven and do resist fuel, although the new formulations of fuel and ethanol may be an issue so checking the seal often is a great idea.
Be safe,
Greg
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
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kdpalmer(at)mweb.co.za
Guest
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| Posted: Thu Jan 30, 2014 12:44 am Post subject: Wing tanks in wood wing? |
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|
Well I received cowl tank instructions and materials and also received wing tanks without instructions, these were later telexed to me ??? so all three were installed ???
Keith
From: owner-pulsar-list-server(at)matronics.com [mailto:owner-pulsar-list-server(at)matronics.com] On Behalf Of Barry J Edwards
Sent: Thursday, January 30, 2014 10:00 AM
To: pulsar-list(at)matronics.com
Subject: Re: Wing tanks in wood wing?
Hi Greg,
My comment was not directed at whether structural adhesive is fuel proof or not but you made a comment “This wing was never intended to carry fuel” and this is not correct since Mark Brown sold kits with wood spars and wing tanks so he must have intended it to carry fuel! Maybe in hindsight we can say that this was not an ideal solution but the fact is that it was done intentionally. That was the point of my post.
Cheers,
Barry
From: GREGSMI(at)aol.com (GREGSMI(at)aol.com)
Sent: Wednesday, January 29, 2014 9:55 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Wing tanks in wood wing?
Barry, I can only tell you what I have tested and the facts are very clear, room temperature cured structural adhesive will dissolve if exposed to fuel. If it were mine I would cut an access to the tanks, clean the spar and apply several coats of Jeffco followed by a good thick coat of PRC. All of those coats would cover the spar and lap at least two inches onto the tank skin. I would also make sure the end plates were sealed in the same way.
I am not sure if we have different additives in our fuel and ethanol is the worse, but when a room temp cured piece of glass tape was put in a jar of fuel, it totally dissolved the adhesive. Who knows how long it will take for fuel going through a pin hole or crack to dissolve the adhesive, did not test a pin hole.
Over the years we have learned a lot more about composites and adhesives. I know we applied real thick coats of epoxy to the inside of the header tanks and set the fuel cap with structural adhesive and we have heard of several cases of the fuel cap developing leaks due to the adhesive dissolving. Maybe the epoxy helps seal the rest but we have heard of some leaks developing when ethanol fuel was used.
The critical factor here is the spar caps are attached to the spruce spacer using room temp cured structural adhesive and we know that if room temp cured structural adhesive is soaked in fuel, it dissolves. Given what we know now, are there things we can do to make the plane safer?
Greg
In a message dated 1/29/2014 1:35:08 P.M. Central Standard Time, barry(at)connisbeare.com writes:
| Quote: |
Greg,
This isn’t quite correct. I have a Pulsar XP supplied with wing tanks AND WOOD wings from Aero Designs. The wings had to be strengthened with 6” wide glass on both sides of the spar (to within about 6” of the tip) and with plea nty of resin on the fuel side to ensure complete sealing. One of my wings has long since lost all of the old ‘Kreem’ sealant yet close inspection reveals no degradation of the glass structure inside the wing, or of the structural adhesive around the fuel cap. Of course, it may be that UK fuel has a different make-up to you stuff but my wings are fine after 22 years.
Barry
G-XPXP Pulsar XP R912 Taildragger 1050 hrs.
From: GREGSMI(at)aol.com (GREGSMI(at)aol.com)
Sent: Wednesday, January 29, 2014 6:44 PM
To: pulsar-list(at)matronics.com (pulsar-list(at)matronics.com)
Subject: Re: Wing tanks in wood wing?
The wood wing Pulsar uses a spruce wood spacer with uni-directional glass spar caps. The strength of the spar is in the spar caps which were bonded with room temp cured structural adhesive. This wing was never intended to carry fuel, and as we have found out now, the room temp cured structural adhesive will not stand up to any type of fuel. Failure of the bond in the spar cap is a failed wing.
In using Jeffco we have found that as it cures it has small pin holes due to off gassing. We applied several coats to try to make sure all holes were filled, and then covered the tank in PRC, but still, there is a chance of a leak which could penetrate the structural adhesive on a wood wing Pulsar. Another thing to think about is that the wing flexes and twist in flight. Jeffco sets up very hard and may be subject to cracking. For that reason I would never attempt to put fuel in a wood wing Pulsar. It is possible for a leak to go undetected until the cap fails, not a good thing.
The glass spars were made with high temp epoxy and cured in a oven and do resist fuel, although the new formulations of fuel and ethanol may be an issue so checking the seal often is a great idea.
Be safe,
Greg
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BobP
Joined: 16 Aug 2013
Posts: 10
Location: UK
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| Posted: Thu Jan 30, 2014 4:56 am Post subject: Re: Wing tanks in wood wing? |
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I guess that if ethanol had been present in mogas when the early Pulsars were designed the tank design would have been different. My MK1 582 pulsar has wooden spars and an integral fuselage tank, and I am concerned that the fuel could weaken the integrity of the fuselage bulkheads and result in structural failure - especially if I were to run out of runway, (that glue is the only thing separating me from 60 litres of fuel).
I ponder from time to time whether wing tanks could be fabricated and retrospectively fitted into my wings. As the weight of the fuel would then be in the wings the stress on the spars would be reduced (the maximum weight of the fuselage being lifted by the wings would be 40kg lower). CofG movement with fuel load would also reduce.
It seems to me that it would be possible to fabricate some ethanol proof wing tanks as follows:
1 fabricate some aluminium wing tanks, profiled so that they will slide inside the wing leading edges. Incorporate rib baffles for increased strength and to stop fuel sloshing about.
2 Set the wing leading edge profiles in temporary external "plaster casts" to prevent stress and distortion (casts made from plaster, weak cement mortar mix or expanding foam - all contained in a wooden frame).
3 cut/scrape out the leading edge foam wing ribs where the tanks are to fit.
4 Slide the wing tanks into the leading edges bedded into a thin layer of expanding foam. Then progressively fill the voids between tank and wing skin with several small applications of expanding foam (so the expanding foam will not balloon the wing skin/crush the tank.
Just an idea but any thoughts (good or bad) would be appreciated.
BobP
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mjb777
Joined: 11 Aug 2012
Posts: 54
Location: Dubai UAE
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| Posted: Thu Jan 30, 2014 6:27 am Post subject: Wing tanks in wood wing? |
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Gudday,
Ive been thinking about this as an option for my build, and am interested in all options, except rediculously expensive, or complicated options.
My humble 2 cents regarding a welded metal tank is that I would be concerned that it will be very rigid, and Aero Designs literature mentions that the wood spar and wing skin combination is quite flexible.
If a foam medium were to be appropriate to support and contain metal tanks in the leading edge, it would have to be flexible and have an infinite memory, or over time it wouldnt support the tank properly anymore?
I have a West System document that pertains to fuel tanks and discusses testing and feild experience with gasoline and ethanol and also coveres their recomendations with the epoxy resin application to acheive an appropriately sealed surface.
If the post cured products that were used for some components on the pulsar are fine, then maybe we can develop a post curing regime for a specific resin system that will solve our problems?
Regards,
Matthew Brock.
+971 50 7052665.
| Quote: | On 30 Jan 2014, at 16:56, "BobP" <matronics(at)panth.co.uk> wrote:
I guess that if ethanol had been present in mogas when the early Pulsars were designed the tank design would have been different. My MK1 582 pulsar has wooden spars and an integral fuselage tank, and I am concerned that the fuel could weaken the integrity of the fuselage bulkheads and result in structural failure - especially if I were to run out of runway, (that glue is the only thing separating me from 60 litres of fuel).
I ponder from time to time whether wing tanks could be fabricated and retrospectively fitted into my wings. As the weight of the fuel would then be in the wings the stress on the spars would be reduced (the maximum weight of the fuselage being lifted by the wings would be 40kg lower). CofG movement with fuel load would also reduce.
It seems to me that it would be possible to fabricate some ethanol proof wing tanks as follows:
1 fabricate some aluminium wing tanks, profiled so that they will slide inside the wing leading edges. Incorporate rib baffles for increased strength and to stop fuel sloshing about.
2 Set the wing leading edge profiles in temporary external "plaster casts" to prevent stress and distortion (casts made from plaster, weak cement mortar mix or expanding foam - all contained in a wooden frame).
3 cut/scrape out the leading edge foam wing ribs where the tanks are to fit.
4 Slide the wing tanks into the leading edges bedded into a thin layer of expanding foam. Then progressively fill the voids between tank and wing skin with several small applications of expanding foam (so the expanding foam will not balloon the wing skin/crush the tank.
Just an idea but any thoughts (good or bad) would be appreciated.
BobP
--------
BobP
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=417870#417870
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paqs345(at)gmail.com
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| Posted: Thu Jan 30, 2014 8:25 am Post subject: Wing tanks in wood wing? |
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Hi Group,
Interesting comments on the wood wing fuel, thanks.
If anyone has read the early XP wing assembly manuals (like mine)
closely, it says to bond the composite wing skins to the composite
spar in the fuel tank area with micro, which to me is absolutely
scary. Any pinhole will admit fuel to the micro and that stuff softens
and crumbles. The 'structural' adhesive does not seem to be much of an
improvement. The bonding area is only half the spar width (15 mm /
0.6"), which is by any standard very little.
Care to think about what happens if your wing skin separates from the
spar over a large area? I have pointed this and a number of other
scary things out in my "annotated" manuals. I can only recommend that
anyone still building their Pulsar get them and make the improvements.
Those who have read them found it very useful.
Sonja
On 1/30/14, Keith Palmer <kdpalmer(at)mweb.co.za> wrote:
| Quote: | Well I received cowl tank instructions and materials and also received wing
tanks without instructions, these were later telexed to me ??? so all three
were installed ???
Keith
From: owner-pulsar-list-server(at)matronics.com
[mailto:owner-pulsar-list-server(at)matronics.com] On Behalf Of Barry J
Edwards
Sent: Thursday, January 30, 2014 10:00 AM
To: pulsar-list(at)matronics.com
Subject: Re: Wing tanks in wood wing?
Hi Greg,
My comment was not directed at whether structural adhesive is fuel proof or
not but you made a comment "This wing was never intended to carry fuel" and
this is not correct since Mark Brown sold kits with wood spars and wing
tanks so he must have intended it to carry fuel! Maybe in hindsight we can
say that this was not an ideal solution but the fact is that it was done
intentionally. That was the point of my post.
Cheers,
Barry
From: GREGSMI(at)aol.com
Sent: Wednesday, January 29, 2014 9:55 PM
To: pulsar-list(at)matronics.com
Subject: Re: Wing tanks in wood wing?
Barry, I can only tell you what I have tested and the facts are very clear,
room temperature cured structural adhesive will dissolve if exposed to fuel.
If it were mine I would cut an access to the tanks, clean the spar and apply
several coats of Jeffco followed by a good thick coat of PRC. All of those
coats would cover the spar and lap at least two inches onto the tank skin. I
would also make sure the end plates were sealed in the same way.
I am not sure if we have different additives in our fuel and ethanol is the
worse, but when a room temp cured piece of glass tape was put in a jar of
fuel, it totally dissolved the adhesive. Who knows how long it will take for
fuel going through a pin hole or crack to dissolve the adhesive, did not
test a pin hole.
Over the years we have learned a lot more about composites and adhesives. I
know we applied real thick coats of epoxy to the inside of the header tanks
and set the fuel cap with structural adhesive and we have heard of several
cases of the fuel cap developing leaks due to the adhesive dissolving. Maybe
the epoxy helps seal the rest but we have heard of some leaks developing
when ethanol fuel was used.
The critical factor here is the spar caps are attached to the spruce spacer
using room temp cured structural adhesive and we know that if room temp
cured structural adhesive is soaked in fuel, it dissolves. Given what we
know now, are there things we can do to make the plane safer?
Greg
In a message dated 1/29/2014 1:35:08 P.M. Central Standard Time,
barry(at)connisbeare.com writes:
Greg,
This isn't quite correct. I have a Pulsar XP supplied with wing tanks AND
WOOD wings from Aero Designs. The wings had to be strengthened with 6" wide
glass on both sides of the spar (to within about 6" of the tip) and with
plea nty of resin on the fuel side to ensure complete sealing. One of my
wings has long since lost all of the old 'Kreem' sealant yet close
inspection reveals no degradation of the glass structure inside the wing, or
of the structural adhesive around the fuel cap. Of course, it may be that UK
fuel has a different make-up to you stuff but my wings are fine after 22
years.
Barry
G-XPXP Pulsar XP R912 Taildragger 1050 hrs.
From: GREGSMI(at)aol.com
Sent: Wednesday, January 29, 2014 6:44 PM
To: pulsar-list(at)matronics.com
Subject: Re: Wing tanks in wood wing?
The wood wing Pulsar uses a spruce wood spacer with uni-directional glass
spar caps. The strength of the spar is in the spar caps which were bonded
with room temp cured structural adhesive. This wing was never intended to
carry fuel, and as we have found out now, the room temp cured structural
adhesive will not stand up to any type of fuel. Failure of the bond in the
spar cap is a failed wing.
In using Jeffco we have found that as it cures it has small pin holes due to
off gassing. We applied several coats to try to make sure all holes were
filled, and then covered the tank in PRC, but still, there is a chance of a
leak which could penetrate the structural adhesive on a wood wing Pulsar.
Another thing to think about is that the wing flexes and twist in flight.
Jeffco sets up very hard and may be subject to cracking. For that reason I
would never attempt to put fuel in a wood wing Pulsar. It is possible for a
leak to go undetected until the cap fails, not a good thing.
The glass spars were made with high temp epoxy and cured in a oven and do
resist fuel, although the new formulations of fuel and ethanol may be an
issue so checking the seal often is a great idea.
Be safe,
Greg
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simongoozee(at)tiscali.co
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| Posted: Thu Jan 30, 2014 8:34 am Post subject: Wing tanks in wood wing? |
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Wouldn't recommend trying to build wing tanks into an existing wing, I'm
actually building my Xp wings at the moment, but why not do the same thing
with the fuse tank, from alloy or polyester after all it's aft c of g that's
usually the problem ps currently fitting merin tanks in g-rman , mike redmans
aircraft who sadly died last year now owned by g Hawkins.
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mjb777
Joined: 11 Aug 2012
Posts: 54
Location: Dubai UAE
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| Posted: Thu Jan 30, 2014 11:59 pm Post subject: Re: Wing tanks in wood wing? |
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Anyone investigated just carrying a few of these or similar in your Aircraft in case you need to fill up and only E10 is available?
http://www.bunnings.com.au/briggs-stratton-advanced-formula-fuel-treatment-stabilizer_p3400256
I wonder if the Ethanol neutralisation will make it inert to the resin issues.
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mjb777
Joined: 11 Aug 2012
Posts: 54
Location: Dubai UAE
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| Posted: Fri Jan 31, 2014 12:27 am Post subject: Re: Wing tanks in wood wing? |
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Everett,
If you still have not built your wings, what is the thickness of the foam core in the fuel tank leading edge section?
Regards,
Matt.
[quote="everettmcollier(at)yahoo."]I have a 582 Pulsar I with wing tanks. I have the wood spar with the xp type glass skins. Had to make new ribs to do this. The spare is coated with 45 degree S glass to strengthen it and protect it from the fuel. Coated with Jeffco 9700. Okay so far as I know.
Everett
Sent from my iPad.
| Quote: | On Jan 29, 2014, at 8:13 AM, Sonja Englert <paqs345> wrote:
Hello Group,
Has anyone made wing tanks for a Pulsar 1 (wood wing)?
Sonja
Matt,
I suggest we ask the group if anyone has made wing tanks for a wood
wing before. Maybe it is not necessary to reinvent the wheel.
Sonja
---------- Forwarded message ----------
From: Matthew Brock <mattbrock777>
Date: Mon, 27 Jan 2014 21:15:34 +0400
Subject: RE: Results
To: Sonja Englert <paqs345>
Wow Sonja,
That was nice and fast!
I'll put together what I'm thinking of doing regarding a wing tank upgrade/
modification of the wood-wood wing, so you can let me know your thoughts.
Would you be happy to have a similar arrangement as we had for the Fuselage/
Wing structural modifications, as perhaps there are guys out there with kits
who would like this option also?
Again thanks so much for your work and input.
Regards,
Matt.
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kdpalmer(at)mweb.co.za
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| Posted: Fri Jan 31, 2014 2:00 am Post subject: Wing tanks in wood wing? |
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Matt,
Mine were straight glass fiber with no core.
K'd
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mjb777
Joined: 11 Aug 2012
Posts: 54
Location: Dubai UAE
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| Posted: Fri Jan 31, 2014 2:22 am Post subject: Wing tanks in wood wing? |
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Interesting Keith. It is surprising how many different combinations of skins, spars and fuel tanks there are in the 'fleet'!
It would seem the biggest issue overall is the ethanol problem. There must be a product out there that is 100% suitable for sealing fiberglass tanks against ethanol. I know that boat manufacturers are now claiming to be building 100% ethanol resistant fiberglass tanks. Google Hightide Marine for example. I have asked them if they will share details of the resin system they use.
Regards,
Matt Brock.
+971507052665.
Original Message
From: Keith Palmer
Sent: Friday, 31 January 2014 18:02
To: pulsar-list(at)matronics.com
Reply To: pulsar-list(at)matronics.com
Subject: RE: Re: Wing tanks in wood wing?
Matt,
Mine were straight glass fiber with no core.
K'd
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Captain B777.
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BobP
Joined: 16 Aug 2013
Posts: 10
Location: UK
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| Posted: Sat Feb 01, 2014 3:58 am Post subject: Re: Wing tanks in wood wing? |
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I posted a suggestion as to how aluminium wing tanks might be retro fitted into a wood spared Pulsar wing. Someone suggested this solution might fail if the tank could not accommodate wing flexing. Good point - some work would be required to find out if this is a problem and then design it out (thicker layer of more spongy material between tank and wing skin?)
I suggested aluminium because 1) its suitable for one off construction and 2) I have a friend who is a professional aluminium welder.
But if there were sufficient demand, custom moulded plastic (flexible) retrofit tanks could be made. I'm in touch with a company that makes (amongst other things) plastic petrol tanks by rotational moulding. Powdered plastic is loaded into a cavity of the required shape and the cavity is tumbled and heated. This results in the plastic melting onto the surface in an even layer. The process is best suited to low production runs and the tooling costs are relatively low.
Would it be possible to retro fit plastic tanks into MK1 and M2 Pulsar wings? (slid in from the end). If so and if someone could advise the approximate tank dimensions, I'll make further enquiries and report back.
BobP
as its a one sided tool wsuitable
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mjb777
Joined: 11 Aug 2012
Posts: 54
Location: Dubai UAE
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| Posted: Sat Feb 01, 2014 4:49 am Post subject: Wing tanks in wood wing? |
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Bob I have wing rib templates here so could get you a rough drawing quickly.
Would be interesting to see a price and how many out there are interested.
Not sure it would be a feasible retrofit for wood skinned pulsars as I'd imagine the skin and it's attachment to the spar would have to be beefed up to take any loads from the tank? Fortunately we have some experts among us who are capable of analysing such things.
Regards,
Matt Brock.
+971507052665.
Original Message
From: BobP
Sent: Saturday, 1 February 2014 16:00
To: pulsar-list(at)matronics.com
Reply To: pulsar-list(at)matronics.com
Subject: Re: Wing tanks in wood wing?
I posted a suggestion as to how aluminium wing tanks might be retro fitted into a wood spared Pulsar wing. Someone suggested this solution might fail if the tank could not accommodate wing flexing. Good point - some work would be required to find out if this is a problem and then design it out (thicker layer of more spongy material between tank and wing skin?)
I suggested aluminium because 1) its suitable for one off construction and 2) I have a friend who is a professional aluminium welder.
But if there were sufficient demand, custom moulded plastic (flexible) retrofit tanks could be made. I'm in touch with a company that makes (amongst other things) plastic petrol tanks by rotational moulding. Powdered plastic is loaded into a cavity of the required shape and the cavity is tumbled and heated. This results in the plastic melting onto the surface in an even layer. The process is best suited to low production runs and the tooling costs are relatively low.
Would it be possible to retro fit plastic tanks into MK1 and M2 Pulsar wings? (slid in from the end). If so and if someone could advise the approximate tank dimensions, I'll make further enquiries and report back.
BobP
as its a one sided tool wsuitable
--------
BobP
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http://forums.matronics.com/viewtopic.php?p=417972#417972
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kdpalmer(at)mweb.co.za
Guest
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| Posted: Sat Feb 01, 2014 5:11 am Post subject: Wing tanks in wood wing? |
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Take a mould off a left and right wing in the area of the tank put sizing
in, to the thickness you want to reduce it by (internal), then put a back on
it to go against the spar, you should land up with a well shaped and tapered
tank to just slide in .
K'd
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