Not that I am overly cheap, but the cost of epoxy is starting to sap the fun out of boat building.
However, yesterday I was at the local woodworking store and found a 1 gallon kit of "pour" on finish. The one bottle say it's epoxy resin the other a bunch of words I cann't say/understand. The kit was $50, half what I am paying for epoxy. Last night I tried two experiements, one wetting out a piece of fiberglass cloth, which worked great. The second a lamenated two boards together, again worked great.
Now it does say, not for exterior use, but they suggest using it on bars and tables. So is the not for outside because of UV rays?
THe product (forgot the info at home today) took along time to cure, but seems to be rock hard now.
My plan is to use it inside my duck boat, with fiberglass cloth. I will then paint over it with Interlux 2000 and then camo paint.
What are everyone's thoughts on this? Has anyone tired it before?
I've used table top "pour on" epoxies before and they are a far cry from the marine epoxy we generally use.
There are several formulations of epoxy, for many uses, each having a set of physical properties that are suited or matched to the intended tasks it must perform.
In boat building, repair or restoration we generally use two different types of epoxy, both are marine environment compatible. Laminating resin and the hardener to fit the conditions (fast in the cold and slower in the heat of summer). Laminating resins can be broken down into different strengths in many cases, but for the average amateur builder, a single laminating resin and a hardener to fit their location is normal. Then there is penetrating resin. One company's product called CPES has become a generic name for all penetrating epoxy. It's the Kleenex of nose tissue, in the epoxy world.
When wetting out cloth, you need a laminating resin. Pour on types of epoxy are usually a 1:1 ratio activated epoxy with UV inhibitors. These are very clear, high gloss, not particularly strong and poor wet out epoxies, that serve their purpose well, but shouldn't be asked to perform what a laminating resin does. These are not designed for the moisture changes commonly found in the marine environment. They are much less flexible and generally will crack or other wise de-laminate from a substrate or reinforcment (like cloth) pretty quickly.
Epoxy is formulated for a variety of duties.
The custom mixture of laminating resin I buy from my supplier has these properties; 12 minutes pot life @ 77 degrees for a 1/2 pound mass, is tack free (77 degrees) 60 minutes, recoat in 3 hours, shore D hardness 80, barcol hardness 38, heat distortion 130 degrees, tensile strength 15,800 psi, tensile modulus 499,500 psi, tensile elongation 2.9%, flexural strength 17,900 psi, flexural modulus 700,120 psi, compressive strength 15,300 psi and water absorption (30 days) .03%.
The same manufacture's table top epoxy has these properties: pot life (1/2 pound @ 77 degrees) 60 - 70 minutes, tack free 6 - 8 hours, recoat time 24 hours, shore hardness 69, barcol hardness 22, heat distortion 119 degrees, tensile strength 7,800 psi, tensile modulus 275,050 psi, tensile elongation 7.9%, flexural strength 12,900 psi, flexural modulus 300,100 psi, compressive strength 11,200 psi and water absorption (30 days) .4%.
This may seem like a bunch of gibberish to most, but I was a ChemE major at the U of Delaware (you know DuPont) and these are huge differences in product formulation. Very clearly the laminating resin is designed to a much different standard then the pour on, table top epoxy. In the end, it boils down to luck, when employing these types of experiments. I truly hope your luck is different then mine, which usually sucks.
Andrew,
I've been using Raka epoxy for 6 or 7 years now and have been very pleased with the quality, and being a Scotsman :lol: I really like the pricing too. It is in line with the prices you are talking about, less than $50 a gal.
www.raka.com
The owner, Larry (not sure of his last name), is a great guy to deal with, and is very helpful if you have any questions.
I'm not affiliated with Raka, as a matter of fact I'm about 3,000 miles north. Good stuff, good pricing.
Be well, happy building,
Ken
Paul and Rick, thanks for the posts.
Paul, I am just a little late reading my posts, it's about 9:30 PM now and I laid the epoxy and cloth at about noon. Seemed to go better doing the inside than it did doing the outside, but maybe I am learning a little as I go. So time will tell how it holds up. Now this boat won't see alot of action, it's a duck hunting skiff, so for three months a year it get used 3 times a week.
Rick, your right, Larry @ Raka is good to deal with and his prices are good too. Have you ever tried
www.shopmaninc.com. Prices on epoxy is even cheaper, but doesn't have the selection that Raka has. If you buy in bulk, with shipping you can get it down to about $35 - $45 a gallon, but it's alot of upfront money and then there is the wait to get it. Sometimes I don't do the best at planning ahead.
Andrew