Hello Everyone,

This is my very first post here in this great site and I was just wondering (since I crash a lot and am on a tight budget) if maybe I should use resin and hardner (that comes with fiberglass, ofcourse without the fiberglass) insted of the normal 30 minute epoxy?

Are they the same in terms of strenghth?
Epoxy's are soooo expensive for a 25ml bottle, and resin+hardner are really cheap for a gallon.

Is there any downside to this?

Thank you again in advance.

FatBoy. [&o]

epoxy comes in 2 parts. you dont have much choice. unless you want a lump of plastic the slower it cures the better (stronger it is)

Do you mean the 2 tubes that come with the epoxy?

You'll need to use both...

I think you mean Polyester Resin. it's not meant for a glue, but pretty well any wood glue would be fine if you don't mind waiting for it to dry.

Goop?

Use it for what? If it's a matter of mixing up 1/4 oz to glue in the firewall, then no, use the epoxy. If you're talking about using it to fuel proof the engine and tank compartments, or for fiberglassing the wing joint, then it will work fine, and save some money.

If you crash a lot, you might want to look at spad.org .

note that if you dont have an adversion to mesureing, fibreglast.com has good epoxy for reasonable prices. (40 bucks for a galon i think) and its extreamly strong when mixed well, but it has to be mixed near perfect or as was said earlier you get a glob of jelly.

its also the best epoxy for fiberglassing ive ever used.

For any construction or repairs you want epoxy. Resin is not a glue. 1 set of 4 oz epoxie tubes goes a long way. You just have to put enough to coat 2 parts together. If you get epoxie oozing out of a joint you used too much. Learning how much to use is a learned thing. Use it some and you will get the hang of it. Good luck.

Mark Shuman

Fiberglass (FRP) is merely epoxy adhesive with a glass weave or strand incorporated into it to create a structural element rather than simply bonding 2 things together. Adhesives called epoxies are mostly 2 part systems....resin plus hardener or catalyst. There are many...many types of epoxies that vary in strength and intended use. So, when you buy a fiberglass kit you're getting epoxy and the glass. Or you can buy them separate. I agree with one of the other replies to your post that the difference that may be in cost may be so small that you are better off getting the epoxy adhesive for repairs of joints. Usually, making a section of fiberglass requires more epoxy than a bonded joint...depending on how many layers of glass are used.

You can replace epoxy with polyester resin for any of the places you are COATING something, not for BONDING parts.

You can replace epoxy for bonding with other glues in some instances. Where and when is a matter of experience. until you have experience with the various adhesives, it is best not to experiment on a model.

I tend to replace epoxy as much as possible when building. I also avoid using CA as much as I can and use yellow carpenter's glue for most of my construction. (it works fine, its light and strong, and I can build a 4*40 in 3 days easilly with no CA except for putting in the CA hinges.) I find I save an average of $4 in glue using the yellow vs using the CA on a .40 size aircraft. (and I always come out below the kit's listed weight...)

Thank you to all for all the informative answers. I'll stick to epoxy for the time being untill I'm more experianced in this hobby.

Thanks again.

FatBoy

Where do I buy a fiberglass kit (resin, hardner and glass cloth)? Under which name it is sold?

Nilo

Too fast?

I just did it again - mixed up about an ounce of 30 minute epoxy-- equal parts. And BAM - in abuout 5 minutes it started to set.
I very nearly lost major parts of a 1/4 scale extral.

The first time it happened with Hangar 9 epoxy, I though I might have a bad batch. -- Called 'em they said it couldn't happen - must have mixed it too much. (the label says mix well).

This batch was from Tower Hobbies. Same problem.

The room temperature was 70.

The slower epoxy cures, the stronger it is. Will these two parts come apart?

How can I slow down 30 minuted epoxy enuff to have 30 minutes to get it right.

Less hardner?

Put it in the fridge prior to mixing?

Thanks for your help

robinr767 - if you're mixing more than about about a tablespoon, you have to mix it in a shallow container. If it's in a tall container, it will heat up and set way too fast.

Also, Tower (I think) mis-labeled some 5 minute epoxy as 30 minute epoxy which might be what happened to you. They are recalling it so you might give them a call. It might be Great Planes instead of Tower though. I'm not sure, but I read something about it here at RCU just yesterday.

CafeenMan,
Thanks for the reply.

1. It was mixed in a small disposable cup about 1.5" dia X .75 deep.
I have never seen any epoxy mentioning shallow container.

2. Will this effect the strength of the bond?

3. What's the fix? Would Tower be liable?

Thanks

Most of us learn this the hard way. Next time you need to mix that much epoxy try a plastic lid or tuna can or something similar. That's a lot of epoxy, by the way. I recently glassed an entire plane having a 600+ area wing with a fuse 48" long. I used about 2 ounces altogether for everything.

Probably, but I can't say if it would affect it enough to make it not airworthy.

A question for your lawyer.