Looks like this thread has died down, so..
Thankyou Brian and Nev. This is good information. Nev, the description on
your test results was refreshingly invaluable. It is info that is hard to
come by. I saw the original thread from Brian on the Matronix server
concerning the independent testing being done by Andy Draper, but never saw
the results on the server.
I had a personal email response from Andy about a year ago, that I just
looked at, concerning the different epoxy manufactures (I had almost
forgotten I had this). In there, was the same response in the structural
adhesive section of the email: " We have found that none of the Aeropoxy or
Hysol products compare favourably with Araldite/Epibond 420 (formerly Redux
420)."
Because of the cost and hassle in getting the A/E 420 here in the states, I
had been starting to lean towards Aeropoxy 6228, but it now seems that until
I can get an adhesive that is known to be at least equivalent or better in
all tests, its going to have to be Araldite/Epibond for me. My order of
1.4Kg 2-part Araldite 420 kits (QTY 3) is now in process. (albeit it is
back-ordered) Hopefully, it will be enough. If most everyone has used
more, let me know now, to avoid multiple export/import tariffs and taxes
that would be on the second order (and to help keep me from being tempted to
going back to Aeropoxy 6228 (which has been used successfully by at least
one (and I suspect many) builder already, on parts of the wing or
windscreens, not to mention the Velocity).
Hopefully soon, the stalled sections of the build can commence.
Thanks again. I know all this will be useful to future builders, since I
beat myself up, over this decision.
Greg Fuchs (A050)
Tigard (Portland), Oregon
Tail Kit, looking ahead, but not yet moved to wing/fuselage (transporting
them to my build location tomorrow)
Subject: Re: Europa-List: Aeropoxy 6228 ~ NEV?
In a message dated 13/04/2007 16:00:08 GMT Standard Time,
EuropaXSA276@aol.com writes:
I have been most interested in this product. The Aeropoxy rep at Sun N Fun
had told me the it was under testing by Europa as a replacement adhesive a
few years back.
I talked with Andy a year later, at Sun n Fun inquiring about the testing.
He replied that the product did not hold up to his expectations. Therefore
it was never "approved".
I most certainly would like to know more about the testing and what issues
were found. The 6228 has cost and accessibility benefits.
Perhaps Nev could fill us in on the subject?
Hi Brian et all,
The Aeropoxy adhesive is NOT suitable as a replacement for Redux / Araldite
420 in use on a Europa.
Tests I carried out way back when , back to back, with Aeropoxy and 420
showed the Aeropoxy to be far too brittle.
Lap joint test samples were made useing the pre preg laminates as in the
fuselage / wing skins, same materials / same sizes / same surface
preparation / same cure cycle / with both adhesives. Did 10 of each from
memory?
Didn't need to get them scientifically strain tested [ by Slingsby, which is
what we had done with various lay up resins] a simple blow with a hammer on
one end of the tab , with the other end clamped in a vice showed that the
Aeropoxy bonded ones let go every time, whereas the 420 bonded ones would
take one hell of a beating before eventually the pre preg would fail.[ Same
hammer ! ]
The make up of the 420 includes rubber granules, so there is a fair amount
of '' give '' in the bond.
This is allways a good test to check if the 420 has '' time lifed ''. [ in
spite of the very conservative expiry date set by the manufacturer ] If the
bond fails, bin it, if the glass fails, it is still good.
I also tested a couple of other adhesives [ at different times ] against the
420, similar results.
If there had been a suitable replacement to 420, it would have been used in
the U.S.A. as we had a lot of hassle getting the 420 shipped over [
Dangerous Goods and all that !]
Don't experiment and risk your life, just to save a few bucks ?
Cheers,
Nev.
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