over the years, i have been using raka epoxy and have had good results in most cases. the only time i got my butt kicked was on my first boat and it could have been my fault. it never kicked. that boat is now 6 years old and is still peeling gooey paint chips in the back yard but hey, it's water proof as grease! :roll: stickier too.
a few of you have mentioned a preference to a 5 to 1 type of epoxy? i don't remember too well. the stuff i have been using is 2 to1 of course. is there a place i can take advantage of the byyb discount with? i am not too picky but i would like to try something new. push the envelope as it were. now that the weather is starting to cool a little, i am starting to look at that naked hulk in the back yard that will some day be called a vacationer. when i start the finish work, i intend to use all thickened epoxy instead of the standard bondo this time. bondo worked ok on the weekender but i would like to see better results over a long term. looks like i am going to be using a lot of goo this time.
There are several different fillers you can use (four different types of balloons alone) to fair up the hull. I use a mixture of fillers which is dependant on the job I'm asking of it. On a hull bottom, that will see rough treatment loading on a trailer or beaching, I want a denser filler. This means I'll use quartz microspheres (Q-cells) and silica. It's much more difficult to sand, but it takes compression very well, which is what the task demands.
A light weight, easy to sand filler might be some phenolic microballons and some silica to thicken it up to prevent sagging. For the budget mined, use glass bubbles instead of phenolic microballons.
Generally, the lower the mixing ratio with epoxy, the less "refined" the resin/activator system is. This means you get different physical properties, when compared to more highly refined goo. Think of it like oil. Crude oil is unrefined, heating oil is refined, but not highly, diesel fuel is more refined, gasoline more still, etc. Each gets more powerful as it's further refined. Epoxy's physical properties get enhanced with refinement. Things like tensile strength, elongation, hardness, cure times, temperature tolerances, etc. can be "doctored" up to suit specific needs.
I've taken advantage of this particular trait and have a warm weather epoxy made for me, that has a pot life of 45 minutes in 90 degree heat. Try that with the plane Jane laminating resins most of you use. You'd be lucky to get it mixed in the cup, before it started to "kick". I also have a super thin and a super strong (and brittle) formulation, for other special needs.
For the most part, you just don't need these fancier version of stick-um. The domestic varieties of epoxy, easy handle the chores we ask of it.
Can you get better stuff. Yep, you sure can and you'll pay for it. System Three and West System both charge considerably more for their brands then others, but they also have to stand up to higher scrutiny then Joe Blow's repackaged mix (like GetRot for example, which is Smith Brothers goo). In fact, most of the lower priced epoxies available are little more then repackaged bulk product, purchased from wholesale suppliers. They're buying below wholesale (because of the purchase volume), re-badging the product, then selling at what seems like a discount, because it's cheaper then full retail price (West Marine is full retail).
The big boys don't permit this and more importantly their products are more durable, stronger, more waterproof, etc., etc., etc. and this is what you're paying for.
A broker will be able to jack up the price of a wooden boat if he can say "West System bottom", but he'll have difficulty trying to sell a "Raka bottom", even though Raka does make a good goo (I think it's too thin).
In the end, on small, lightly load applications, such as our little boats, the highly refined stuff isn't necessary.
Now if you're building a Swift Solo or other high performance, go fast boat and need to keep weight down, strength up and insure things don't pull apart when you crash jibe in building winds, then you should seriously consider a more highly refined epoxy.
Awhile back I tried calling RAKA whose product I have used on several boats but the number on their webpage wasn't working. Are they still in business? Anyway, I went to duckworksmagazine.com, which I enjoy reading and purchase boat hardqare from, and ordered their economy epoxy. Used it and loved it! I ordered a new batch and both orders were delivered quickly. Besides, Chuck and Sandra, owners of Duckworks, are great people and builders like us.
My first exposure, to what I call "real epoxy", meaning not the 5 minute in two tubes types, was Duckworks marine epoxy. I used 3 gallons of it. The last gallon I used I bought MAS epoxy instead. Both are 2-1 mixtures and both gave me plenty of time, even at 80+ F, if I use the slow hardener. The MAS seemed to be a bit clearer and slightly thinner.
i think it was bill olney that was telling me that he preffers a 5 to 1 mix but i don't remember why. the summers here in utah average in the 90s and 100s. fortunately, we have not seen too many tripple digits this year. i have gotten good at controlling how much epoxy i mix at one time. i have even been using the "fast" stuff alot more lately. for the general construction of the boat it would have been great to have a longer lasting epoxy but that part is now over and i am on the fairing and glassing stage now. even then though, i just simply mixed small amounts and did not have much waste if any. i made sure i had small jobs lying around for the left over epoxy when the main jobs were done.
i have been planning on just using talk for the corner fillets. if i am feeling rich, i might use micro baloons but money has been in short supply lately. i thought about using wood flower but i don't want to be sanding for the next 20 years. i plan on doing a lot of the fairing by hand because it seems like you get more done that way. the sand paper on the orbital and belt sanders clog up too dang fast with epoxy.
Aaron, If you are a member of the BYYB you get a discount at Jamestown distributors. It's usually based on what you buy, but is usually pretty good. We have an account through them, but if you order make sure to have your items sent to to "Your" address, otherwise they show up at mine. :lol: It's one of the perks of membership. I believe we also have a deal with Raka directly.