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Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

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rlowe(at)speedway.ca
Guest

Posted: Wed Jan 30, 2008 7:20 pm Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

Hi, I've purchased a partially complete Europa a little over a year ago and had to put it storage until my garage/workshop was re-vamped in order to build the kit. It is now to a point to where I can start moving my kit into it and start working on it. 



I have question about the different devices used to measure the epoxy and wondering what most builders have done in the past. The cheapest of course is to make the Europa mechanical balance which should be no problem (is it quick and easy to use during a layup?) but I'm leaning towards either a Ohaus / Sartorius digital scale with a resolution of 0.01gm (do I need that much precision or can I get away with a lower cost 0.1gm unit?) OR a ratio pump like a Glenmarc Portionator MBT-JR from A/S which is the most expensive of the all the options (is it worth the cost for ease of use?).



I live in Canada so I will be using Aeropoxy resin (100:27 by weight or 3 to 1 by volume).



I would appreciable any feedback/experience that you have that would help me make up my mind!



Thanks, Roger

Visit -  www.EuropaOwners.org

jimpuglise(at)comcast.net
Guest

Posted: Wed Jan 30, 2008 8:37 pm Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

Roger-

  

 I think you'll find that most people use a scale.  I have an Ohaus which read to 1/100 of an ounce.  Your mixing needs to be very precise and you will do it often, so an easy to use and accurate scale is important.  I throw a sheet of plastic over it to protect it and put the cup on before it is turned on and use bottles like ketchup is served in in restaurants to dispense epoxy and hardener.  If I go a bit over, a paper towel can be used to "wick" a little until it is just right.  I think the scale is a little over $ 100 but well worth it. 

  

 Jim Puglise, Punta Gorda, FL 

  

 [quote]-------------- Original message -------------- 

From: "Roger Lowe" <rlowe(at)speedway.ca> 



[quote] --> Europa-List message posted by: "Roger Lowe" 

 

 Hi, I've purchased a partially complete Europa a little over a year ago and had 

 to put it storage until my garage/workshop was re-vamped in order to build the 

 kit. It is now to a point to where I can start moving my kit into it and start 

 working on it. 

 

 I have question about the different devices used to measure the epoxy and 

 wondering what most builders have done in the past. The cheapest of course is to 

 make the Europa mechanical balance which should be no problem (is it quick and 

 easy to use during a layup?) but I'm leaning towards either a Ohaus / Sartorius 

 digital scale with a resolution of 0.01gm (do I need that   much   nd muc  [quote][b]

fklein(at)orcasonline.com
Guest

Posted: Wed Jan 30, 2008 8:48 pm Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

 	  Quote: 	
		   The cheapest of course is to make the Europa mechanical balance which 

 should be no problem


	


 	  Quote: 	
		   (is it quick and easy to use during a layup?)


	


Roger,



I've used the standard balance design with, I believe, excellent 

results. E04 will give you the proper lengths for Aeropoxy proportions. 

I excercised some care in building mine to minimize friction. I find it 

works like a charm.



I like the fact that I can pour out as much resin as I think I'll need 

and easily match it up with the correct amount of hardener...the 

balance registers to an accuracy (of say, a couple drops of hardener) 

which I find astonishing.



Happy building...welcome to the list,



Fred

-- 

This message has been scanned for viruses and

dangerous content by MailScanner, and is

believed to be clean.

fklein(at)orcasonline.com
Guest

Posted: Wed Jan 30, 2008 10:38 pm Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

Roger...one further thought re: my post.



I've not attempted to reuse resin cups as I found early on that as the 

weight of the used but (somewhat) empty cup varied enough to upset the 

balance point...rather than futzing w/ the location of the add on 

balancing piece (I've used a large flat washer) every time I do a mix, 

I zero out the balance w/ clean resin and hardener cups and once done, 

it remains balanced.



Fred



On Wednesday, Jan 30, 2008, at 20:45 US/Pacific, Fred Klein wrote:



 	  Quote: 	
		   



> The cheapest of course is to make the Europa mechanical balance which 

> should be no problem



> (is it quick and easy to use during a layup?)



 Roger,



 I've used the standard balance design with, I believe, excellent 

 results. E04 will give you the proper lengths for Aeropoxy 

 proportions. I excercised some care in building mine to minimize 

 friction. I find it works like a charm.



 I like the fact that I can pour out as much resin as I think I'll need 

 and easily match it up with the correct amount of hardener...the 

 balance registers to an accuracy (of say, a couple drops of hardener) 

 which I find astonishing.



 Happy building...welcome to the list,



 Fred

 -- 

 This message has been scanned for viruses and

 dangerous content by MailScanner, and is

 believed to be clean.






	




-- 

This message has been scanned for viruses and

dangerous content by MailScanner, and is

believed to be clean.

davedeford(at)comcast.net
Guest

Posted: Wed Jan 30, 2008 11:06 pm Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

 	  Quote: 	
		   

 

 Hi, I've purchased a partially complete Europa a little over 

 a year ago and had to put it storage until my garage/workshop 

 was re-vamped in order to build the kit. It is now to a point 

 to where I can start moving my kit into it and start working on it. 

 

 I have question about the different devices used to measure 

 the epoxy and wondering what most builders have done in the 

 past. The cheapest of course is to make the Europa mechanical 

 balance which should be no problem (is it quick and easy to 

 use during a layup?) but I'm leaning towards either a Ohaus / 

 Sartorius digital scale with a resolution of 0.01gm (do I 

 need that much precision or can I get away with a lower cost 

 0.1gm unit?) OR a ratio pump like a Glenmarc Portionator 

 MBT-JR from A/S which is the most expensive of the all the 

 options (is it worth the cost for ease of use?).

 

 I live in Canada so I will be using Aeropoxy resin (100:27 by 

 weight or 3 to 1 by volume).

 

Roger,
	




You will find people who swear by each of these approaches, so I won't try

to tell you which is best.  We used digital scales with 0.1 gram resolution

and found them to be quite satisfactory, though I wouldn't recommend less

resolution.  Our original scale (an Ohaus Scout) died after a few years of

excellent service, and we have used a couple of cheaper models since.  For a

staggering selection of scales, check out www.americanweigh.com.



Even the cheapest pocket-size scales would probably have good enough

accuracy, but you need a large enough weighing platform to hold your mixing

cups easily.  (You will often be in a hurry when weighing epoxy, and spills

are a real pain.)  Be sure that the scale stays on for long enough to zero

the cup weight, weigh the resin, and then weigh the hardener (even with some

interruptions) before it turns off to save its battery.  Not a problem with

AC power, but some of the small scales with tiny batteries get in a hurry to

shut down.



Keep in mind that absolute accuracy is not needed for mixing applications,

only good linearity.  This can be tested precisely even without accurate

calibration weights.  Just weigh anything and note the result.  Then replace

the first item with something else, and zero out the reading.  Adding the

first item to the platform should result in exactly the same reading that

you got when weighing it by itself.  The two objects together need only to

remain within the scale's range.



Remember also that you will frequently have to mix Redux/Araldite 420/???

with good precision, and it's ratio will be different from the layup epoxy,

so a mixing pump or fixed 100:27-ratio balance won't do this job.  A digital

scale is a bit like the digital level or close-quarters drill that you buy

for one specific job, and then find that you use it for many other things.



Dave DeFord

N135TD

craigb(at)onthenet.com.au
Guest

Posted: Thu Jan 31, 2008 3:13 am Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

I have used digital scales with great success also, but ran out of Ampreg

and so switched to West Systems and it came with

ratio pumps that replace the caps on the bottles. Personally I have found

the two separate pumps much faster and easier than

using the scales, but i am past the really big layups and for big lots the

pumps may be a pain, you will need the scales or balance

for the araldite 420, just dont forget the different ratio required.



craig



--

ptag.dev(at)tiscali.co.uk
Guest

Posted: Thu Jan 31, 2008 3:56 am Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

Hi! Roger.

I exclusively used a Ohaus digital scale.

For me it was easy since I decided how much of combined epoxy I wished

to make at one mix (Not more than say approx. 25gm because of exotherm

likleyhood).

 Zero the unit with my mixing cup and mixing stick on the bed. Carefully

pour say 5gm of hardener in, follow by pouring in epoxy to make up to

25gm this way, so long as you know your 5X table, is foolproof. For

subsequent mixes following immediately on I used the same mixer cup and

stick  but re-set the scale before starting each mix and be sure to

re-mix any dregs of the original mix with the new mix. So you are using

as clean a new mix every time.

I'm quite sure someone is going to tell me I was incorrect by method but

there you have it.

Have fun

Regards

Bob Harrison G-PTAG  (Europa Kit 337 originally 3300 Jabiru now with

Rotax 914 and intercooler 600 hours)



--

rampil

Joined: 04 May 2007
Posts: 870

Posted: Thu Jan 31, 2008 6:57 am Post subject: Re: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pum

Tenth of a gram is more than adequate for mixing resin.  Most batches

for layups will be between 30g and 100g, mixed.  More than that

may exotherm in the cup.   A scale that gives you 0.5% is way better than necessary since 5% is probably just fine.  A scale with 0.01 gram resolution

is a fragile lab instrument, not a working shop instrument useful for 

production work. It would waver with air breezes.

_________________
Ira N224XS

loboloda(at)execulink.com
Guest

Posted: Thu Jan 31, 2008 7:26 am Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

Hi Roger,



I'm located in London, Ont, and have a completely refurbished epoxy  

pump, that was used by Chris Staines

in his build, I would be happy to sell it for about the same price as  

a scale.

I used a scale for my build,and found it to be quick and easy to use.

The cheapest place to find an electronic scale is in a drug  

paraphernalia store!



A few years ago I spoke to the Aeropoxy reps at Oshkosh, they were  

clearly amused by anyone

bothering to measure to the nearest tenth of a gram -  off the record  

they indicated that the tolerance

levels for a proper cure are quite high. I tended to end up a little  

short of hardener in each batch, their

suggestion was to just short a bit on the hardener, on each mix.



Dave A061



519-666-0480

On 30-Jan-08, at 9:53 PM, Roger Lowe wrote:



 	  Quote: 	
		   



 Hi, I've purchased a partially complete Europa a little over a year  

 ago and had to put it storage until my garage/workshop was re- 

 vamped in order to build the kit. It is now to a point to where I  

 can start moving my kit into it and start working on it.



 I have question about the different devices used to measure the  

 epoxy and wondering what most builders have done in the past. The  

 cheapest of course is to make the Europa mechanical balance which  

 should be no problem (is it quick and easy to use during a layup?)  

 but I'm leaning towards either a Ohaus / Sartorius digital scale  

 with a resolution of 0.01gm (do I need that much precision or can I  

 get away with a lower cost 0.1gm unit?) OR a ratio pump like a  

 Glenmarc Portionator MBT-JR from A/S which is the most expensive of  

 the all the options (is it worth the cost for ease of use?).



 I live in Canada so I will be using Aeropoxy resin (100:27 by  

 weight or 3 to 1 by volume).



 I would appreciable any feedback/experience that you have that  

 would help me make up my mind!



 Thanks, Roger

 Visit -  www.EuropaOwners.org

europa flugzeug fabrik

Joined: 13 Feb 2006
Posts: 65
Location: North Coast, USA

Posted: Thu Jan 31, 2008 4:31 pm Post subject: Re: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pum

One thing about "strength" verses mix accuracy is the current Europa design does not have us building many (or any?) strength-critical components.



Fred F.

hagargs(at)earthlink.net
Guest

Posted: Thu Jan 31, 2008 6:50 pm Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

I have been using a standard triple beam balance for years.  Very

mechanical and reliable,  Ohaus makes a  nice one with taring capability. 

Just like they used in  high school science class.  Or by the stoners in

the Air Force barracks.  This was the 70's



Steve Hagar

A143

Mesa AZ

 	  Quote: 	
		   [Original Message]

 From: Roger Lowe <rlowe(at)speedway.ca>

 To: <europa-list(at)matronics.com>

 Date: 1/30/2008 8:24:24 PM

 Subject: Epoxy Measuring - Balances vs Digital Scale vs

Ratio Pump
	


 	  Quote: 	
		  

 



 Hi, I've purchased a partially complete Europa a little over a year ago

and had to put it storage until my garage/workshop was re-vamped in order
	


to build the kit. It is now to a point to where I can start moving my kit

into it and start working on it. 

 	  Quote: 	
		  

 I have question about the different devices used to measure the epoxy and

wondering what most builders have done in the past. The cheapest of course
	


is to make the Europa mechanical balance which should be no problem (is it

quick and easy to use during a layup?) but I'm leaning towards either a

Ohaus / Sartorius digital scale with a resolution of 0.01gm (do I need that

much precision or can I get away with a lower cost 0.1gm unit?) OR a ratio

pump like a Glenmarc Portionator MBT-JR from A/S which is the most

expensive of the all the options (is it worth the cost for ease of use?).

 	  Quote: 	
		  

 I live in Canada so I will be using Aeropoxy resin (100:27 by weight or 3

to 1 by volume).
	


 	  Quote: 	
		  

 I would appreciable any feedback/experience that you have that would help

me make up my mind!
	


 	  Quote: 	
		  

 Thanks, Roger

 Visit -  www.EuropaOwners.org

rlowe(at)speedway.ca
Guest

Posted: Thu Jan 31, 2008 7:48 pm Post subject: Epoxy Measuring - Balances vs Digital Scale vs Ratio Pump

Everyone,



Thanks for the overwhelming response to my query.  From the response the majority of you have used or are using a digital scale, so I will most likely go that route. I really appreciate the extra time and effort for the responses you gave as to the use of each apparatus and especially the digital scale. Looks like I don't have to spend as much money as I thought. Very very helpful!

 

On a final note, I've sort of been lurking in the background in this user group for a while now, trying to learn all I can before I take the first stab at making the "wheel chock", I have to say that I'm always amazed at the wealth of knowledge and experience that exists here. Much better than a text book!



Thanks again.



Roger

A252

Visit -  www.EuropaOwners.org

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