Which Epoxy!

[JohnC]

I am assembling materials for my project and I see there is a huge difference in cost between different brands of epoxy (I plan to use epoxy for transom layup and for sticking cured parts together. I was planning to use E-Bond 1285 (about $35/Gal @ Merritt). I have used WEST 105 in the past for small projects but I would not want to pay that much for a larger project (about $85/Gal @ Merritt). Fiberglassflorida.com has their own brand for around $48/Gal and I have heard good things about Raka, available from Gulfstreamcomposits.com (about $65/Gal, also happens to be a CSC Vendor).
I realize that viscosity plays a role in different types of layup processes and for that reason, one size may not fit all. Could someone please enlighten me on the good/bad/watch out things to consider with different epoxies?

[flyingfrizzle]

Don't forget about US composites, That is what I use sometimes. Their Thin 635 resin

[shine]

I will only add that we have the "tropical" hardener as an option, this time of year its really nice on big layups!

[JohnC]

Thanks Shine. I was just wanting to know the differences in general. I don’t want to step on any toes, just gather/disseminate information. The differences in cost are +/- 250% or more; that seems like a bizarre spread if all else is equal. If all else is not equal I would just like to know that so that I can make an informed decision.

[JohnC]

Originally Posted by flyingfrizzle

Don't forget about US composites, That is what I use sometimes. Their Thin 635 resin

Thanks, that's about $45/Gal.
I thought I would get some advice about why one is better/more $ than the other. It looks like E-Bond is the best value I can find.

[flyingfrizzle]

Originally Posted by JohnC

Thanks, that's about $45/Gal.
I thought I would get some advice about why one is better/more $ than the other. It looks like E-Bond is the best value I can find.

I think there are some diffrences in the diffrent epoxys, main thing is to get a product that is 1) used for marine applications 2) made for laminating fiberglass cloth 3) correct viscosity for what you are doing. Resin like west system is a great product but you pay for the name as well. A little over priced in my opinion. Some of the eBay or discount epoxys are super cheap but may be old or out of its self life period. They may not be designed for marine applications or for laminating cloth. It may be just for gluing or bonding. Some stuff has slow work times some cures in just 5 minutes. Table top epoxy and marine epoxy have diffrent chemistry makeups. A good reasonable priced product that is listed for marine laminating can be found for less than west system brand pricing. Stay away from the super cheep stuff and make sure it is not old from sitting on a shelf for a long time. I haven't used a lot of diffrent brands but someone that has may be able to tell you more info.

[shine]

It looks like E-Bond is the best value I can find.

you will not find anything cheaper than that for sure. For bonding, its just fine. FOr wetting out glass, its not as nice to work with.

You can get very good epoxy for under $60

[FishStretcher]

You posted about a vacuum pump elsewhere? Viscosity is important.

There are a couple good threads at boatdesign.net forums. More than a few trolls, too. But legit Naval Architect types hide there.

You can try a vinylester epoxy, too. I am a big fan. All the mechanical properties I can find say that the stuff I buy is better than a few big name epoxies. And it is compatible with chopped strand mat. Tuning the cure rate is a different beast, as is the smell.

And if you really want thin resin, you can play with adding styrene monomer. Or even more styrene and cobalt , but for that one, check to make sure you paid the insurance on the shop first.