epoxy vs vinyl

[lprimina]

Ok here is the question
Epoxy price is going out of sight so vinyl is looking better but!!
epoxi flexes roughly 10 to 15% while vinyl flexes 7 to 10% (depending on the quality)
With cost difference would you guys switch to vinyl or stay with epoxy?
(I build one boat a year SO?)
Thanks guys
Ben

[seamonkey]

really you have to be going for a 'cost be damned' high performance boat ,to go epoxy all the way-you'd be amazed how low-grade ,some high-perf sailboats go.

[JR-Shine]

Epoxy is "tougher" than vinyester (I think thats what you are getting at), but thats not the only thing to consider. The secondary bonding of epoxy is much better than vinyester. Also the ease of use. A lot of vinyesters come pre-accelerated and have short shelf life.

If you are vacuum bagging or using infusion - thats where vinyester has an advantage (lower viscosity and longer pot life). But there are even epoxies designed for this now.

Also, vinyester is not much cheaper

[lprimina]

Thanks for the coments guys. I still have about 10 gals left of epoxi but will need about 25 gals to finish project. so it looks like I will get another 55 gal of epoxi.And no I dont vacume bag (yet)but I beleive and hope that is in the near future.
ONE DAY (drreaming!) I will build boats full time and quit my present job.
Thanks again
Ben

[goodwrch]

Iprimina, I visit Beaufort frequently, where are you loacted and what projects are you working, I am in a similar situation with building boats in So. florida, I build a 16 ft bay and a 26 ft deep V center console. I have a lace on back creek that I stay at when I visit. Please email ... Goodwrch@bellsouth.net.
Good Luck

[JEM]

I'm looking for a good laminating epoxy resin. Got my eye on some Sys Three products but they are pricey for a production environment. Where do you get yours from?

[seamonkey]

Originally Posted by lprimina

Thanks for the coments guys. I still have about 10 gals left of epoxi but will need about 25 gals to finish project. so it looks like I will get another 55 gal of epoxi.And no I dont vacume bag (yet)but I beleive and hope that is in the near future.
ONE DAY (drreaming!) I will build boats full time and quit my present job.
Thanks again
Ben

Vinyl resin propoerties are sooo much better than ortho/ISO resins,,and if you research the properties/prices equally,,you'll find the vinyl a better balance,,I bet!----I'd suggest that you save the epoxy you have for side projects,,,,after buying a barrel of vinyl for significantly less ,,,it would be like getting the epoxy for free!
Also,if you're building your boat in a mold over gelcoat,,it'll be crucial to address the bonding issues between the epoxy and gelcoat.

[Phil Locker]

Originally Posted by seamonkey

...Also,if you're building your boat in a mold over gelcoat,,it'll be crucial to address the bonding issues between the epoxy and gelcoat.

When molding, an epoxy laminate will bond directly to a vinylester gelcoat with no need for a bonding agent. Downside is that vinylester gelcoats can be brittle.

Phil

[Karsten]

If you design highly loaded composites structures you have to make sure that the elongation of the resin is larger than the elongation of the fibres at breaking point. Otherwise you can load the structure only up to where the resin breaks which is a waste of fibres. You have to add material so that the deformations are in a range of what the resin can handle. From that point of view epoxy is definitely the way to go.

Cheers,
Karsten