Speedbird66

Most people are aware of the risks involved using Epoxy glue or paint or just sanding an epoxy surface. Allergic reactions !
People are affected very differently. Some unfortunate people will eventually end up being over sensitive to epoxy in any form.
I still haven't developed any problems my self but I know a few people who suffer from this problem.

My questions to this Forum is simply if there are any good and useful alternatives to epoxy? A good example is when you are fixing plywood formers in a glass fibre fuselage. Normally I would use epoxy and micro balloons to get a nice fillet. What else are available on the market?

/Johan Tinde
Sweden

Propwash in Pa

This a a great question Johan. Unfortunitly I do not have any answers. I would suggest that you post the same question in the ARF and boating forums.

John 373786

SST

My Feedback: (2)

For high stress wood-to-wood joints that I can clamp, I've switched almost entirely from epoxies to polyurethane glues.

Hydro Junkie

Being a boater, I can tell you that the poly/glass hulls are generally laid up thicker than the epoxy/glass hulls. The epoxy hull is as strong, if not stronger than the thicker poly. Is there a real susbstitute? Not that I know of, but if you can't work with epoxy, poly would be my next choise. I would also stay away from the LHS epoxies. They are more brittle than the good marine types like West Systems, which is what I use. Just my .02

Speedbird66

Thank you all for your suggestions. I will do some tests with polyurethane glues. I’m also going to test polyester (styren) with micro balloons to investigate how brittle it is and how well it bonds to epoxy (the inside of a fuselage). Another unconventional idea would be to use silicon (ether based). Terrible smell but quite harmless. It bonds great to almost everything and has the right consistence for making nice fillets. It is also a fact that an elastic bond can take more load than a stiff. Silicon would not be good for a general purpose of course but could work fine for fixing formers in glass fibre fuselages.

Let me hear your opinions.

/Johan

SST

My Feedback: (2)

Polyester resin will not bond to cured epoxy. However epoxy will bond to cured polyester (go figure). When in doubt about the resin you're working with, always use epoxy. The West system stuff is superior.

khodges

My Feedback: (1)

For high strength bonds such as firewall to fuse, resorcinol would be as strong as epoxy, but it is not available in smaller containers that I am aware of. Aliphatic resin wood glue is good for most all other constuction, drying time on it is slower.