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Installing a windshield.

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teamgrumman(at)YAHOO.COM
Guest

Posted: Sat Jun 12, 2010 8:27 pm Post subject: Installing a windshield.

For years, I have preferred the C. Bailey windshield because they fit better.  But, I've had a few complaints about distortion in the windshield.  My windshield has a slight distortion in it if I look for it.  It's been so long since I installed an LP Aero windshield that I really don't know if they have any distortion.  

Garner is always chiding me for using C. Bailey windshields.  But, let's face it, if LP Aero made a superior windshield, I'd use theirs.

SO . . . . I had a customer request an LP Aero windshield.  Garner packed it up and sent it.  

I put it on the frame today for a trial fit.  

For the best bond (using RTV 732) I need a bond of  around .015 inches.  On a C. Bailey, I can get it to around .010 at the tightest edge on the trailing edge of the windshield bow and still have it within .025 at the leading edge at the tightest spots.

Just sitting on the bow, the LP Aero windshield has a gap greater than .125 in the two upper corners.  It sits flat across the middle.  No mater how I do it, it's going to look like shit.

C. Bailey windshields come trim-to-fit.  That means, there is a trim line about 1/2 inch around the windshield; too much windshield.  Trimming is a pain in the ass.

LP Aero windshields come trimmed to the size.  Let's hope it fits.

C. Bailey windshields can be shimmed along the front edge using a washer held in place by a screw through the double bead seal holes.  I can shim all around the front edge without interfering with windshield  mounting and keep my .015 inches gap all around the bow. 

There is no place to do the same on the LP Aero.  So. . . .  .   I'm trying something new to keep my spacing.   We'll see.  Keep your fingers crossed.

Someone needs to make new tooling that actually fits the windshield bow curve.  That would be nice.  



   



                [quote][b]

rdp123(at)verizon.net
Guest

Posted: Sat Jun 12, 2010 10:46 pm Post subject: Installing a windshield.

Gary, my fingers are crossed and I'm sure you can work out a good installation with the LP.  Let me know -



Rick



On Jun 12, 2010, at 9:19 PM, Gary Vogt wrote:

 	  Quote: 	
		  For years, I have preferred the C. Bailey windshield because they fit better.  But, I've had a few complaints about distortion in the windshield.  My windshield has a slight distortion in it if I look for it.  It's been so long since I installed an LP Aero windshield that I really don't know if they have any distortion.  

Garner is always chiding me for using C. Bailey windshields.  But, let's face it, if LP Aero made a superior windshield, I'd use theirs.

SO . . . . I had a customer request an LP Aero windshield.  Garner packed it up and sent it.  

I put it on the frame today for a trial fit.  

For the best bond (using RTV 732) I need a bond of around .015 inches.  On a C. Bailey, I can get it to around .010 at the tightest edge on the trailing edge of the windshield bow and still have it within .025 at the leading edge at the tightest spots.

Just sitting on the bow, the LP Aero windshield has a gap greater than .125 in the two upper corners.  It sits flat across the middle.  No mater how I do it, it's going to look like shit.

C. Bailey windshields come trim-to-fit.  That means, there is a trim line about 1/2 inch around the windshield; too much windshield.  Trimming is a pain in the ass.

LP Aero windshields come trimmed to the size.  Let's hope it fits.

C. Bailey windshields can be shimmed along the front edge using a washer held in place by a screw through the double bead seal holes.  I can shim all around the front edge without interfering with windshield mounting and keep my .015 inches gap all around the bow. 

There is no place to do the same on the LP Aero.  So. . . .  .   I'm trying something new to keep my spacing.   We'll see.  Keep your fingers crossed.

Someone needs to make new tooling that actually fits the windshield bow curve.  That would be nice.  



 	  Quote: 	
		  



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href="http://forums.matronics.com">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/contribution



	


	


 [quote][b]

flyadive(at)gmail.com
Guest

Posted: Sun Jun 13, 2010 1:40 am Post subject: Installing a windshield.

Hello Gary:



It has been quite a few years since  did two sets of windows.  And I

will probably be doing one

in the next year or so.  AND you have millions of more maintenance

hours compared to myself.

I can give you my experience...  Both windows were LP.  They were

purchased through Fletcher.

And shipped directly from the LP factory to me or my customer.  The

biggest problem I had was

removing the old sealant, especially from around the leading edge.  I

used an air powered drill

and a STIFF wire wheel.  The fit in both cases was perfect, no

trimming needed.  I did dress

the edges of the front window with a file to remove and burrs which

could become a stress crack.

I did NOT use the 732.  I did use the 832.  The difference being 732

is only a sealant and

the 832 is an Adhesive/Sealant.  A bit more bonding and hold.  Around

the bow I used ONLY

a 1/8" thick foam tape.

The only other 'trick' I did was to mount the bow to the window BEFORE

I secured the bow

to the airframe.  This way the bow has a uniform fit all around and

the foam filled the gap.

Actually I would have to say There Was No Gap.  The foam was there to

weather seal the edge.

And I know you know this... Do not tighten the screws, only snug them up.



Hope this helps,



Barry

"Chop'd Liver"



On Sun, Jun 13, 2010 at 12:19 AM, Gary Vogt <teamgrumman(at)yahoo.com> wrote:

 	  Quote: 	
		   For years, I have preferred the C. Bailey windshield because they fit

 better.  But, I've had a few complaints about distortion in the windshield.

  My windshield has a slight distortion in it if I look for it.  It's been so

 long since I installed an LP Aero windshield that I really don't know if

 they have any distortion.

 Garner is always chiding me for using C. Bailey windshields.  But, let's

 face it, if LP Aero made a superior windshield, I'd use theirs.

 SO . . . . I had a customer request an LP Aero windshield.  Garner packed it

 up and sent it.

 I put it on the frame today for a trial fit.

 For the best bond (using RTV 732) I need a bond of around .015 inches.  On a

 C. Bailey, I can get it to around .010 at the tightest edge on the trailing

 edge of the windshield bow and still have it within .025 at the leading edge

 at the tightest spots.

 Just sitting on the bow, the LP Aero windshield has a gap greater than .125

 in the two upper corners.  It sits flat across the middle.  No mater how I

 do it, it's going to look like shit.

 C. Bailey windshields come trim-to-fit.  That means, there is a trim line

 about 1/2 inch around the windshield; too much windshield.  Trimming is a

 pain in the ass.

 LP Aero windshields come trimmed to the size.  Let's hope it fits.

 C. Bailey windshields can be shimmed along the front edge using a washer

 held in place by a screw through the double bead seal holes.  I can shim all

 around the front edge without interfering with windshield mounting and keep

 my .015 inches gap all around the bow.

 There is no place to do the same on the LP Aero.  So. . . .  .   I'm trying

 something new to keep my spacing.   We'll see.  Keep your fingers crossed.

 Someone needs to make new tooling that actually fits the windshield bow

 curve.  That would be nice.

flyv35b(at)minetfiber.com
Guest

Posted: Sun Jun 13, 2010 6:33 am Post subject: Installing a windshield.

Barry,



Are you saying that you are NOT bonding the windshield to the bow at the 

rear and just trying to bond it around the front edge?  That seems opposite 

of what has historically been the accepted practice.  732 is more than just 

a sealant when spread over a large area.  A bonded windshield/bow serves as 

a pretty good roll over protection when combined with a latched canopy.



Cliff

---

teamgrumman(at)YAHOO.COM
Guest

Posted: Sun Jun 13, 2010 8:24 am Post subject: Installing a windshield.

First of all, never wire wheel the windshield bow.  

(1) Steel and aluminum don't mix.

(2) it tears up the aluminum

(3) the bow is anodized.  the anodize is only a few thousandths deep.

I use a flat exacto knife blade and DX 330.  It takes of the old RTV732 pretty easily.

I wasn't aware of RTV 832.  I'll look into it.

I've tried foam.  It doesn't work as well as canopy bow seal glued to the windshield.

The gap to which I was referring is the gap between the windshield and the windshield bow.  If the windshield is not formed correctly, there is no fix for that.  I can stack to AN970 washers in the leading edge  gap in the corners with the windshield tight against the aft edge bow (i.e., 0.0 inches gap) 1 inch away.  Six inches toward the center of the windshield, there is 0.0 inches gap at both the forward and aft edge of the windshield bow.  Short of heating and reforming the windshield, there is no cure for that.  



From: FLYaDIVE <flyadive(at)gmail.com>

To: teamgrumman-list(at)matronics.com

Sent: Sun, June 13, 2010 2:32:45 AM

Subject: Re: Installing a windshield.



 --> TeamGrumman-List message posted by: FLYaDIVE <flyadive(at)gmail.com (flyadive(at)gmail.com)>



Hello Gary:



It has been quite a few years since  did two sets of windows.  And I

will probably be doing one

in the next year or so.  AND you have millions of more maintenance

hours compared to myself.

I can give you my experience...  Both windows were LP.  They were

purchased through Fletcher.

And shipped directly from the LP factory to me or my customer.  The

biggest problem I had was

removing the old sealant, especially from around the leading edge.  I

used an air powered drill

and a STIFF wire wheel.  The fit in both cases was perfect, no

trimming needed.  I did dress

the edges of the front window with a file to remove and burrs which

could become a stress crack.

I did NOT use the 732.  I did  use the 832.  The difference being 732

is only a sealant and

the 832 is an Adhesive/Sealant.  A bit more bonding and hold.  Around

the bow I used ONLY

a 1/8" thick foam tape.

The only other 'trick' I did was to mount the bow to the window BEFORE

I secured the bow

to the airframe.  This way the bow has a uniform fit all around and

the foam filled the gap.

Actually I would have to say There Was No Gap.  The foam was there to

weather seal the edge.

And I know you know this... Do not tighten the screws, only snug them up.



Hope this helps,



Barry

"Chop'd Liver"



On Sun, Jun 13, 2010 at 12:19 AM, Gary Vogt <teamgrumman(at)yahoo.com (teamgrumman(at)yahoo.com)> wrote:

 	  Quote: 	
		   For years, I have preferred the C. Bailey windshield because they fit

 better.  But, I've had a few complaints about distortion in  the windshield.

  My windshield has a slight distortion in it if I look for it.  It's been so

 long since I installed an LP Aero windshield that I really don't know if

 they have any distortion.

 Garner is always chiding me for using C. Bailey windshields.  But, let's

 face it, if LP Aero made a superior windshield, I'd use theirs.

 SO . . . . I had a customer request an LP Aero windshield.  Garner packed it

 up and sent it.

 I put it on the frame today for a trial fit.

 For the best bond (using RTV 732) I need a bond of around .015 inches.  On a

 C. Bailey, I can get it to around .010 at the tightest edge on the trailing

 edge of the windshield bow and still have it within .025 at the leading edge

 at the tightest spots.

 Just sitting on the bow, the LP Aero windshield has a gap greater than .125

 in the two upper corners.  It  sits flat across the middle.  No mater how I

 do it, it's going to look like shit.

 C. Bailey windshields come trim-to-fit.  That means, there is a trim line

 about 1/2 inch around the windshield; too much windshield.  Trimming is a

 pain in the ass.

 LP Aero windshields come trimmed to the size.  Let's hope it fits.

 C. Bailey windshields can be shimmed along the front edge using a washer

 held in place by a screw through the double bead seal holes.  I can shim all

 around the front edge without interfering with windshield mounting and keep

 my .015 inches gap all around the bow.

 There is no place to do the same on the LP Aero.  So. . . .  .   I'm trying

 something new to keep my spacing.   We'll see.  Keep your fingers crossed.

 Someone needs to make new tooling that actually fits the windshield bow

 curve.   


	


          [quote][b]

flyadive(at)gmail.com
Guest

Posted: Mon Jun 14, 2010 4:24 am Post subject: Installing a windshield.

Good morning Cliff:



Correct - I have bonded the lower edge of the windshield all

around.... From port to starboard.  I did NOT use any bond on the bow.

 ONLY the screws and the one-side'd sticky foam.



I remember doing a lot of reading and some may still exist in the GG

archives about the "Special" bonding supplied with the install kit.

The issue was: Difficult to work with and it did not bond well,

BUBBLES between the bow and the plastic.



I have heard and read about the bonding helping to make a ROLL BAR out

of the window and bow.  I do not know if that is realistic or not.  I

was also taught to OPEN the canopy in an emergency landing to

facilitate egress.  I DON'T KNOW!

What about the expansion and contraction of dissimilar materials due

to temperature changes?  I'm thinking that might be the cause of

bubbles between bow & window?

The good points I have experienced are:

Ease of install.

No bubbles.

Ease of clean up.

No gap between bow and window.

AND I PRAY I will never find out if I need a roll bar or not.

NOW - There is a job for an STC ... STEEL ROLL BAR.



Barry

"Chop'd Liver'



================================

On Sun, Jun 13, 2010 at 10:29 AM, flyv35b <flyv35b(at)minetfiber.com> wrote:

[quote] 



 Barry,



 Are you saying that you are NOT bonding the windshield to the bow at the

 rear and just trying to bond it around the front edge?  That seems opposite

 of what has historically been the accepted practice.  732 is more than just

 a sealant when spread over a large area.  A bonded windshield/bow serves as

 a pretty good roll over protection when combined with a latched canopy.



 Cliff

 ---

flyv35b(at)minetfiber.com
Guest

Posted: Mon Jun 14, 2010 5:40 am Post subject: Installing a windshield.

 	  Quote: 	
		   Good morning Cliff:



 Correct - I have bonded the lower edge of the windshield all

 around.... From port to starboard.  I did NOT use any bond on the bow.

 ONLY the screws and the one-side'd sticky foam.


	


I think this is backwards.  The WS needs to be bonded to the bow and the one 

sided sticky foam doesn't provide any bonding.  What happens if you grab the 

bow at the 45 degree spot and pull yourself up out of the seat.  The bow 

wants to pull away from the WS, twists and stress the glass at the screws, 

possibly starting a crack.



 	  Quote: 	
		   I remember doing a lot of reading and some may still exist in the GG

 archives about the "Special" bonding supplied with the install kit.

 The issue was: Difficult to work with and it did not bond well,

 BUBBLES between the bow and the plastic.


	


RTV732 was and still is the recommended adhesive and sealant.  It is messy 

to work with but there is no problem with bubbles or voids if you apply 

enough of it - the excess will squeeze out.  It bond well and over a large 

surface area of the bow it is very strong.  But the bow needs to be cleaned 

very well and the plexiglass scuffed with Scotchbrite or sandpaper and Dow 

Corning 1200 primer applied on both the WS and bow before applying the 732.



I know of a couple of WS installations where 3M very high bond tape (double 

sided adhesive) was used very successfully for many years to bond the WS to 

the bow.  No messy installation, you just have to make sure the parts are 

mated where you want when they are stuck togather as you won't get them 

apart.



 	  Quote: 	
		   I have heard and read about the bonding helping to make a ROLL BAR out

 of the window and bow.  I do not know if that is realistic or not.  I

 was also taught to OPEN the canopy in an emergency landing to

 facilitate egress.  I DON'T KNOW!

 What about the expansion and contraction of dissimilar materials due

 to temperature changes?  I'm thinking that might be the cause of

 bubbles between bow & window?


	


A roll over in a Grumman (or and RV) is always going to be a problem no 

matter what you do with the canopy!  If the baggage compartment is full then 

getting out the baggage door will be impossible.  Breaking out a back window 

or canopy window may be the only way.  With 4 different large exits out of 

my Bonanza that's one thing I don't have to worry about!



Nope, bubbles are due to poor technique and not enough RTV applied to the 

joint.  The front of the WS is free to float so there is no 

expansion/contraction problems.  The 3 screw holes in the front edge should 

be oversize so the glass does not bind on the screws and crack.  Proseal can 

be used externally to seal the leading edge as it is a good sealant and is 

flexible enough to allow movement and not tear away.  The factory used a 

body seam sealer inside the lip of the coaming skin to seal the leading edge 

of the WS and this can still be done this way.



Cliff



 	  Quote: 	
		   The good points I have experienced are:

 Ease of install.

 No bubbles.

 Ease of clean up.

 No gap between bow and window.

 AND I PRAY I will never find out if I need a roll bar or not.

 NOW - There is a job for an STC ... STEEL ROLL BAR.



 Barry

 "Chop'd Liver'

flyadive(at)gmail.com
Guest

Posted: Mon Jun 14, 2010 2:02 pm Post subject: Installing a windshield.

HI Gary:

What is the DX330 you speak of, is it the cleaning material by PPG?

The anodizing on sheet aluminum is way less Than a few thousandths...

It is in the range of 1 to 3 ten-thousands...0.0001 to 0.0003" .  And

yes, the wire wheel will remove the that thin a coating in a second.

Are there steel particles left behind or embedded into the aluminum?

Well from my experience in the metal coating industry NO.  BUT!  that

is with a NON-Rusted wire wheel and ... This is where I think the

issue of not mixing Ferrous Steel and Aluminum came from:  YOU NEVER

USE THE SAME (SAND OR BEAD) BLASTING BOOT FOR STEEL AND ALUMINUM.  The

extremely small particles of of ferrous steel under high

pressure/velocity become embedded into the aluminum and that begins a

corrosion/pitting spot.

And not to be nit-picky... But steel is steel... The X-Acto knife is

made of steel.  But, not an issue.

We are talking about the same issue... The gap between the window and

bow. But, are you referring to a specific area, like where the bow

come into contact with the fuselage sides?

Barry

On Sun, Jun 13, 2010 at 12:15 PM, Gary Vogt <teamgrumman(at)yahoo.com> wrote:

 	  Quote: 	
		   First of all, never wire wheel the windshield bow.

 (1) Steel and aluminum don't mix.

 (2) it tears up the aluminum

 (3) the bow is anodized.  the anodize is only a few thousandths deep.

 I use a flat exacto knife blade and DX 330.  It takes of the old RTV732

 pretty easily.

 I wasn't aware of RTV 832.  I'll look into it.

 I've tried foam.  It doesn't work as well as canopy bow seal glued to the

 windshield.

 The gap to which I was referring is the gap between the windshield and the

 windshield bow.  If the windshield is not formed correctly, there is no fix

 for that.  I can stack to AN970 washers in the leading edge gap in the

 corners with the windshield tight against the aft edge bow (i.e., 0.0 inches

 gap) 1 inch away.  Six inches toward the center of the windshield, there is

 0.0 inches gap at both the forward and aft edge of the windshield bow.

  Short of heating and reforming the windshield, there is no cure for that.

 ________________________________

 From: FLYaDIVE <flyadive(at)gmail.com>

 To: teamgrumman-list(at)matronics.com

 Sent: Sun, June 13, 2010 2:32:45 AM

 Subject: Re: Installing a windshield.

 Hello Gary:

 It has been quite a few years since  did two sets of windows.  And I

 will probably be doing one

 in the next year or so.  AND you have millions of more maintenance

 hours compared to myself.

 I can give you my experience...  Both windows were LP.  They were

 purchased through Fletcher.

 And shipped directly from the LP factory to me or my customer.  The

 biggest problem I had was

 removing the old sealant, especially from around the leading edge.  I

 used an air powered drill

 and a STIFF wire wheel.  The fit in both cases was perfect, no

 trimming needed.  I did dress

 the edges of the front window with a file to remove and burrs which

 could become a stress crack.

 I did NOT use the 732.  I did use the 832.  The difference being 732

 is only a sealant and

 the 832 is an Adhesive/Sealant.  A bit more bonding and hold.  Around

 the bow I used ONLY

 a 1/8" thick foam tape.

 The only other 'trick' I did was to mount the bow to the window BEFORE

 I secured the bow

 to the airframe.  This way the bow has a uniform fit all around and

 the foam filled the gap.

 Actually I would have to say There Was No Gap.  The foam was there to

 weather seal the edge.

 And I know you know this... Do not tighten the screws, only snug them up.

 Hope this helps,

 Barry

 "Chop'd Liver"

 On Sun, Jun 13, 2010 at 12:19 AM, Gary Vogt <teamgrumman(at)yahoo.com> wrote:

> For years, I have preferred the C. Bailey windshield because they fit

> better.  But, I've had a few complaints about distortion in the

> windshield.

>  My windshield has a slight distortion in it if I look for it.  It's been

> so

> long since I installed an LP Aero windshield that I really don't know if

> they have any distortion.

> Garner is always chiding me for using C. Bailey windshields.  But, let's

> face it, if LP Aero made a superior windshield, I'd use theirs.

> SO . . . . I had a customer request an LP Aero windshield.  Garner packed

> it

> up and sent it.

> I put it on the frame today for a trial fit.

> For the best bond (using RTV 732) I need a bond of around .015 inches.  On

> a

> C. Bailey, I can get it to around .010 at the tightest edge on the

> trailing

> edge of the windshield bow and still have it within .025 at the leading

> edge

> at the tightest spots.

> Just sitting on the bow, the LP Aero windshield has a gap greater than

> .125

> in the two upper corners.  It sits flat across the middle.  No mater how I

> do it, it's going to look like shit.

> C. Bailey windshields come trim-to-fit.  That means, there is a trim line

> about 1/2 inch around the windshield; too much windshield.  Trimming is a

> pain in the ass.

> LP Aero windshields come trimmed to the size.  Let's hope it fits.

> C. Bailey windshields can be shimmed along the front edge using a washer

> held in place by a screw through the double bead seal holes.  I can shim

> all

> around the front edge without interfering with windshield mounting and

> keep

> my .015 inches gap all around the bow.

> There is no place to do the same on the LP Aero.  So. . . .  .   I'm

> trying

> something new to keep my spacing.   We'll see.  Keep your fingers crossed.

> Someone needs to make new tooling that actually fits the windshield bow

> curve.

grumpyparts

Joined: 28 Jan 2009
Posts: 65
Location: EGHH

Posted: Mon Jun 14, 2010 2:04 pm Post subject: Re: Installing a windshield.

Back in the early days did not Grumman/Gulfstream supply replacement windshields already bonded to the bows.

 

If so wouldn't it be nice to have True Flight use the jigs they have to supply pre-bonded replacement windshields. Would no doubt be expensive, but probably no more so than the labour in the filed trying to get this task done properly.

flyv35b(at)minetfiber.com
Guest

Posted: Mon Jun 14, 2010 2:52 pm Post subject: Installing a windshield.

I'll bet it would be cheaper!  Sure would save a lot of labor and those 

mechanics without specific experience would have chance to get it done 

right.



Cliff

---

jamey

Joined: 10 Jan 2006
Posts: 124

Posted: Mon Jun 14, 2010 3:16 pm Post subject: Installing a windshield.

Could even send your old bow in for credit.



Jamey

--

teamgrumman(at)YAHOO.COM
Guest

Posted: Mon Jun 14, 2010 7:41 pm Post subject: Installing a windshield.

The flat blade I use on the Xacto knife never even scratches the aluminum.  All it does is slice off the majority of the RTV.  DX330 and a 3M scrubbie removes the rest.  Quite easily too.  

DX330 is a very high grade Naptha.  It's used to clean surfaces prior to painting.  I also use it in the fuel tanks prior to resealing.  It's quite expensive.  I doubt the average mechanic would be inclined to use it for that reason.  It removes all traces of wax and grease and it doesn't touch the plexiglass.  Unlike MEK or acetone, it leaves no residue and is not going to eat up gloves or the windshield.  

Years ago, I put a bead of RTV around the base of a windshield on a plane I knew  leaked.  I did a quick and dirty job because it was going to rain and I had no place to put the plane.  Some 3 months later I scraped off the majority of the RTV and then went to work on the windshield with DX330.  It gets under the RTV and releases it.  It took about 30 minutes and it was all clean.

Funny how difficult it is to describe how fucked up this windshield is.  I'll try to simplify it.  

(1) OK boys and girls, let's pretend we are sitting in the airplane, in the pilot's seat, with the canopy open.  

(2) Pretend to run your hand along the side of the cockpit, on the top of the canopy/fuselage opening, where the window track is.

(3) Pretend to slide your hand to the windshield.  Stop.

(4) You are now at the windshield.  The windshield is attached to the windshield bow.  

(5) Let's further pretend there is  no double bead windshield bow seal on the on the face of the windshield bow.

(6) At this point, you can touch, go ahead, pretend to touch the flat face of the windshield bow that is facing you, it's OK.

(7) This surface, the windshield bow, has another surface attached to it that is 90 degrees to the face you're touching.  You won't be able to touch it because the windshield is in the way.

( You can, however, lean over and look through the windshield and you will most likely see cured RTV holding the windshield to the windshield bow.

(9) This windshield "bow" goes up from this corner and makes an arc as it curves up and over toward the center of the windshield bow.  (We'll only do one side, the right side is the same.

(10) Just for the sake of argument, let's call the halfway point, the middle of the arc, the UPPER CORNER.

(11) Now, run your fingers along the face of the  bow so you get an idea that this is a FLAT surface.  

(12) Remember boys and girls, you won't be able to touch the surface of the windshield bow that is "under" the windshield.  

(13) Now, stand up and look out over the windshield.  Notice how it is formed such that it goes forward and DOWN to the fuselage (Boot cowl)

(14) Look along the edge of the windshield where the windshield is attached to windshield bow.  You can look through the windshield and see where it's bonded to the windshield bow.

(15) OK, here is where it gets tricky.  Remember the face of the windshield bow you ran your fingers along in step 11?  Let's go back to that.

(16) The surface of the windshield bow under the windshield doesn't stay perpendicular, 90 degrees, to the face of the bow as in step 7.  It's close though.  Let's leave it at that.

(17) So, that means, that for at least an  inch or so along the open side of the windshield, that windshield needs to be 90 degrees to the face of the windshield bow also.

(1 OK boys and girls, are we all on the same page?  I hope so.

(19) The windshield I got from LP Aero only maintains 90 degrees to the face of the bow at the SIDES and at the TOP, which is also the middle of the windshield bow.

       NOTE: this is not to be confused with the middle of the arc between the side and the top.

(20) The worst portion of this LP Aero windshield is "IN THE UPPER CORNER" or middle of the arc.  In this area, the windshield has absolutely no flat portion.  It just falls away.

(21) In the ideal world, the windshield and the windshield bow have the same shape and the bonding surface is uniform and provides a uniform thickness for the bond.

(22) I don't know how ya'all do this bonding,  particularly with the windshield in the plane, but, I use a feeler gauge and shims to get as close to a uniform .020 inch gap as I can for the entire bonding surface.  

(23) On a C. Bailey windshield, the worse I've seen is .035 inches.

(24) I don't care how many clamps you use, I don't care how you tighten the clamps, there is nothing that is going to close the .125 inch between the face of the bow and keep the forward edge of the bow from digging into the windshield.

       With a minimum of .010 inches gap at the tightest location along the forward edge of the windshield bow, the gap at the face of the bow varies from .010 to .150.  

I've included some pics, I hope they come through.  

1316:  This is the gap on the right side.  The bottom of the windshield is tight against the bow.  I.e., no gap.  The gap you see a result of the  windshield being misformed.  The windshield is TIGHT against the forward edge.  No amount of clamping is going to fix this.  Short of heating and reforming, there is just going to be .130 inches of gap at the UPPER CORNER.  

1317: This is the left side with clamps.  The gap at the forward edge of the bow is .010 inches.  The gap at the face of the bow is .140 inches.  

1324: This is a shot through the edge of the windshield.  It will hidden by bonding BUT, it's still a pretty bad distortion.  

From: FLYaDIVE <flyadive(at)gmail.com>

To: teamgrumman-list(at)matronics.com

Sent: Mon, June 14, 2010 2:57:35 PM

Subject: Re: Installing a windshield.

 --> TeamGrumman-List message posted by: FLYaDIVE <flyadive(at)gmail.com (flyadive(at)gmail.com)>

HI Gary:

What is the DX330 you speak of, is it the cleaning material by PPG?

The anodizing on sheet aluminum is way less Than a few thousandths...

It is in the range of 1 to 3 ten-thousands...0.0001 to 0.0003" .  And

yes, the wire wheel will remove the that thin a coating in a second.

Are there steel particles left behind or embedded into the aluminum?

Well from my experience in the metal coating industry NO.  BUT!  that

is with a NON-Rusted wire wheel and ... This is where I think the

issue of not mixing Ferrous Steel and Aluminum came from:  YOU NEVER

USE THE SAME (SAND OR BEAD) BLASTING BOOT FOR STEEL AND ALUMINUM.  The

extremely small particles of of ferrous steel under high

pressure/velocity become embedded into the aluminum  and that begins a

corrosion/pitting spot.

And not to be nit-picky... But steel is steel... The X-Acto knife is

made of steel.  But, not an issue.

We are talking about the same issue... The gap between the window and

bow. But, are you referring to a specific area, like where the bow

come into contact with the fuselage sides?

Barry

On Sun, Jun 13, 2010 at 12:15 PM, Gary Vogt <teamgrumman(at)yahoo.com (teamgrumman(at)yahoo.com)> wrote:

 	  Quote: 	
		   First of all, never wire wheel the windshield bow.

 (1) Steel and aluminum don't mix.

 (2) it tears up the aluminum

 (3) the bow is anodized.  the anodize is only a few thousandths deep.

 I use a flat exacto knife blade and DX 330.  It takes of the old RTV732

 pretty easily.

 I wasn't aware of RTV 832.  I'll look into it.

 I've tried foam.  It  doesn't work as well as canopy bow seal glued to the

 windshield.

 The gap to which I was referring is the gap between the windshield and the

 windshield bow.  If the windshield is not formed correctly, there is no fix

 for that.  I can stack to AN970 washers in the leading edge gap in the

 corners with the windshield tight against the aft edge bow (i.e., 0.0 inches

 gap) 1 inch away.  Six inches toward the center of the windshield, there is

 0.0 inches gap at both the forward and aft edge of the windshield bow.

  Short of heating and reforming the windshield, there is no cure for that.

 ________________________________

 From: FLYaDIVE <flyadive(at)gmail.com (flyadive(at)gmail.com)>

 To: teamgrumman-list(at)matronics.com (teamgrumman-list(at)matronics.com)

 Sent: Sun, June 13, 2010 2:32:45 AM

 Subject: Re: Installing a windshield.

 --> TeamGrumman-List message posted by: FLYaDIVE <flyadive(at)gmail.com (flyadive(at)gmail.com)>

 Hello Gary:

 It has been quite a few years since  did two sets of windows.  And I

 will probably be doing one

 in the next year or so.  AND you have millions of more maintenance

 hours compared to myself.

 I can give you my experience...  Both windows were LP.  They were

 purchased through Fletcher.

 And shipped directly from the LP factory to me or my customer.  The

 biggest problem I had was

 removing the old sealant, especially from around the leading edge.  I

 used an  air powered drill

 and a STIFF wire wheel.  The fit in both cases was perfect, no

 trimming needed.  I did dress

 the edges of the front window with a file to remove and burrs which

 could become a stress crack.

 I did NOT use the 732.  I did use the 832.  The difference being 732

 is only a sealant and

 the 832 is an Adhesive/Sealant.  A bit more bonding and hold.  Around

 the bow I used ONLY

 a 1/8" thick foam tape.

 The only other 'trick' I did was to mount the bow to the window BEFORE

 I secured the bow

 to the airframe.  This way the bow has a uniform fit all around and

 the foam filled the gap.

 Actually I would have to say There Was No Gap.  The foam was there to

 weather seal the edge.

 And I know you know this... Do not tighten the screws, only snug them up.

 Hope this  helps,

 Barry

 "Chop'd Liver"

 On Sun, Jun 13, 2010 at 12:19 AM, Gary Vogt <teamgrumman(at)yahoo.com (teamgrumman(at)yahoo.com)> wrote:

> For years, I have preferred the C. Bailey windshield because they fit

> better.  But, I've had a few complaints about distortion in the

> windshield.

>  My windshield has a slight distortion in it if I look for it.  It's been

> so

> long since I installed an LP Aero windshield that I really don't know if

> they have any distortion.

> Garner is always chiding me for using C. Bailey windshields.  But, let's

> face it, if LP Aero made a superior windshield, I'd use theirs.

> SO . . . . I had a customer request an LP Aero windshield.  Garner packed

> it

> up and sent  it.

> I put it on the frame today for a trial fit.

> For the best bond (using RTV 732) I need a bond of around .015 inches.  On

> a

> C. Bailey, I can get it to around .010 at the tightest edge on the

> trailing

> edge of the windshield bow and still have it within .025 at the leading

> edge

> at the tightest spots.

> Just sitting on the bow, the LP Aero windshield has a gap greater than

> .125

> in the two upper corners.  It sits flat across the middle.  No mater how I

> do it, it's going to look like shit.

> C. Bailey windshields come trim-to-fit.  That means, there is a trim line

> about 1/2 inch around the windshield; too much windshield.  Trimming is a

> pain in the ass.

> LP Aero windshields come trimmed to the size.  Let's hope it fits.

> C. Bailey

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n32romeo(at)aol.com
Guest

Posted: Mon Jun 14, 2010 8:20 pm Post subject: Installing a windshield.

Back in the mid '80s I purchased a new canopy and windshield for my AA-1B from Wag-Aero that came from the Gulfstream surplus auction.  These came bonded to the bow.  I still have the old original bows, and found much later they come in handy in helping to bond the next replacement windshield and canopy to the bow, by clamping the old surplus bow on the outside.  Helps provide an even clamp.

   Rich Harrison

 

 

 

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