Epoxy comparisons

:?: I have built several cedar strip canoes in the past and covered them with West System epoxy. I am getting the urge to build another one but I am looking at different resins. My devotion to WS is simply familiarity, nothing more. Aeromarine Products, out of California, advertises on ebay, their pitch is basically the same as everyone else's, but pricing is better, even with S&H. Am I wrong in assuming that epoxies are pretty much comparable across the board?

 

This is a great question. I second it.

Is there anybody out their that knows about epoxy formulation?

Is their a big enough diffrence?

Seem to me that they would all buy the components from the same companies, Du Pont, Dow whatever.

So are inexpencive epoxies good enough to use in boat construction>

Ray

 

The epoxies are family of resins with wide scale of different characteristics. So yes! You are wrong..

 

Ok then. What are they?

What is a good inexpensive epoxy.

I like levi's cheap and get the job done. Kid's these days like Luckie jeans about 200 bucks. Both still denum.

Ray

 

My experience with epoxy is only limited to two brands, MAS and West Systems (including their ProSet line). If it were up to me I would use West System over nearly anything else every time. There is something to be said for familiarity, if you know the product and the mix ratio then there is a comfort level, and that can be very helpful. One other reason I would choose West System over the others is the sheer amount of research and support that the Gougeon Brothers offer. The publish a free magazine that discusses various uses for their products as well as some interesting articles on the research and testing they do on their products. I find it very interesting and helpful. I'm sure their is a website or magazine out there that has compared the various brands, I do seem to recall something of that sort. If i locate it I'll be sure to post it.

 

If there one would everyone use it? Believe me, the only way to get good epoxy cheaper is to buy in barrels. Got one, hope to get the rest used next summer

 

www.bandbyachtdesigns.com

$42/gallon + s&h.

 

the epoxy test results

ONE OCEAN-kAYAKS showed the epoxy test results for 6 well known epoxies.
I am unable to forward a link to the forum but you can find this data. most interesting. stan

 

epoxy test results

Raka came out on top so you might get a lead off their site. stan

 

Epoxy can be formulated to a wide variety of physical properties. The major brands all have similar properties in their standard laminating resins, though there are some differences.

The real differences so up in the special purpose resins and hardeners. The average laminating resin/hardener mixture will have a pot life of 20 minutes at room temperature. I personally have a mixture that just barely kicks off at room temperature (low 70's) and have used hardener formulations that provide several hours of pot life (10 hours) at room temperature.

Viscosity, working time and physical strength properties can by dramatically altered with different formulations. With the great variance of formulations, a reasonable list would be more then this format is best at providing. Is there something specific you're interested in understanding?

 

A cedar strip canoe is at best a mid or even 'low-end' use for an epoxy resin. Please don't take offense to that statement; it's just a purely technical fact. A racing boat hull made of oven or autoclave cured pre-preg carbon or a carbon sailboat mast or a golf club shaft or tennis racket are more demanding uses. Aerospace (not plain ol' airplanes like most Piper and Cessna singles but the REAL stuff like commercial and military jets) and high-end auto racing use the highest performance resins available. And then there's floor coatings and casting resins which are even a notch or two below cedar canoes

For this less demanding stuff, the off-the shelf products are very serviceable. Since this is true, shopping on price is OK, as long as there are no trade-offs on performance. This isn't hard to do, as the cured-state properties and handling properties of the 'big name' epoxies are not hard to duplicate; it ain't rocket science.

If you've run into a specific limitation with the off-the-shelf stuff, a search for something a little more exotic or a custom formulation that addresses the limitation might help. Otherwise, just stick with what works

 

If you go to Epon's web site; you can get a lot of technical data for their various formulations. I noticed the Epon resin that US Composites sells isn't Epon's strongest; but it's pretty strong and it's water absorption is among the lowest (pretty important on a boat).

 

Cudashark,

After all the effort you have put into the wonderful vessel you are building, please don't tell us you favour saving a few bucks with the epoxy. Elsewhere, I posted a summary of ISO 12215. When you come to sell, if you do, the fact that you used WEST SYSTEM or another top brand will contribute to you earning top dollar.

http://www.ibinews.com/ibinews/ebb/tech_10.html

By listing all the materials and saving the invoices, you maximise your returns.

Regards,

Pericles

 

Hi Pericles,

You make an excellent point. Been using System Three Gell Magic which I tested at FAU here in Florida.

I'm at the point of sealing the ribs and internal structure w/ a laminating epoxy and then I'm ready for the skin.

I absolutly need a high preformance laminating epoxy for the 4 layer skin.

Ray

 

System Three is my new epoxy of choice over WEST by far. I will say the newness of the system had a few rocky points. However the pros are strong: low VOC...don't need a respirator unless doing a large glass job, easier to use that I get more consistent results...no need for adding fillers which also means I don't need a mask to avoid breathing in fillers, the ratio is more user friendly 1:1 and 1:2 ratios make for a more forgiving epoxy, Gel Magic comes in a tube and can be dispensed with a caulk gun and a mixing tips and get perfect mix every time, and the best for your case is that the laminating resin is blush free...the epoxy stays "open" for a long time...much less need to sand. I hardly ever sand epoxy now until the time for primer. The con with this epoxy: you have to pay attention and follow directions carefully when you switch over since it is new. I use this with my students...I have 4-5th graders glueing boats together with epoxy. I'm on my last batch of WEST: when I mix it I notice that it is much stinker...a big con in my book.

Cheers,
Clint