'Craig,
The two most common Epoxy resin glues currently used by most wood builders
are System 3 T-88 and West Systems 105. Both are excellent glues.
The Classic Waco factory uses West System 105 under Engineering Approval.
Neither products have PMA approval by the FAA. I have spoke with both
companies and they see no need to obtain FAA approval.
With that said, the FAA did a complete rewrite of the following section of
AC 43.13-1B Chapter 1 Parg 1-4. It pretty much explains the FAA position. My
FAA counterpart has no issues with either products. In fact he supports my
use these two over the old Casein and Resorcinol glues.
I have used T-88 for 30 years for spar splices and rib build up on aerobatic
and non-aerobatic aircraft with great success. I test them daily on Pitts
type aircraft. Lately I have used West Systems for plywood laminations.
Works great due to being thin. I coat the surfaces and then place in press.
During LE install, I pour and brush/feather out inside. Then I use the
thickener additive to dab on ribs and spar caps. The West Systems provides
protection like varnish. You also have a complete line of additives to
thicken for all operations. I also know that West Systems has better
penetration (based on testing) into the wood fibers.
As for long life, the T-88 has a longer pot life. You can slow it down by
placing in fridge. I only mix up what I need. Don't know why you would need
hours for working life. Mix, glue and go.
www.westsystem.com
www.systemthree.com
As an IA I sign my own FAA 337s for repair using the above glues. You do
need to check with your IA and make sure is on board with the usage.
Hope this helps. Feel free to contact me in person.
JST
Jamie S. Treat A&P/IA
Aircraft Restoration & Repair, LLC
Fairchild Club DVD Editor
IAC 5, Chapter President
http://iac5.org
Kelly Airpark (CO15)
http://www.kellyairpark.org
24201 David C. Johnson Loop
Elbert, CO 80106
Hm 303-648-0130
Cell 303-304-7937
Quote of the Month: The emergencies you train for almost never happen. It's
the one you can't train for that kills you. - Ernest K. Gann, advice from
the 'old pelican'
-----Original Message-----
From:] Re: Glues
Two questions for the collective... What glue(s) are the current replacement
for casein and UF glues used during WW2? Use will be in fabrication of new
wings for a airplane with a TC.
Secondly, are there any good structural adhesives for aircraft wood use that
have a very long work life? I'm talking hours, not minutes. The structure on
my AT-21 was all done with radio cured adhesives. I'm not investing hundreds
of thousands of dollars to build an rf curing system for this project.
Craig'