Epoxy questions

[HinduKush]

I am putting water right bulkheads in Pearson Triton. Bought the plywood and will begin cut card templates for plywood cuts. I wanted to get a recommendation of epoxy to use. Weights of glass tape, fabric, if I need any glass strand matt what weight. Never worked with epoxy yet. I live in the deep south so it is hot and humid in summer. Also what type of filler to add to make it thickened. What type of fairing compound for the interior to use before paint. Thank you for any advice you may have.

[markwesti]

Learn all you can about West system epoxy , the people at West system put out a book and it will tell you everything you need to know . https://www.westsystem.com/the-gougeon- ... struction/

Also the book Sailors Sketchbook is good to have , one thing in the book you will be interested in is a tic board it will help you lay out the bulk heads . Good luck and keep us posted .
https://www.thriftbooks.com/w/the-sailo ... q=12276573

[atomvoyager]

Those are good resources. I also use West System epoxy and fillers but I've also used cheaper MAS epoxy or those from US Composites in the past with with no issues. With West I use the slow hardener in 75-80 degree temps and extra slow above 80 or when using thicker amounts because it generates heat soon after mixing that rapidly speeds up the hardening. You'll know if you need a slower hardener or mix smaller amounts when it cures in the mixing cup or before you can get it all applied. I use West 406 or other colloidal silica for thickening and 407 for more easily sandable fairing. On the interior non-structural fairing I sometimes use a polyester 3m marine filler or similar cheaper automotive Bondo type pre-mixed fairing compound. I sometimes use 1.5 oz fiberglass mat that works best around compound curves but I find it messy and most often use a 9-12 oz cloth in 2, 4, and 6" tape rolls or 48" rolls or less often a 6 oz for thin smooth finish such as on a stitch and glue pram dinghy and 1208 and 1708 biaxial (17 oz cloth backed by 3/4 oz mat) for high strength and thicker buildup.

http://uscomposites.com/epoxy.html

http://www.uscomposites.com/specialty.html

[HinduKush]

Thank you again for the advice. I think I will go with the West System 105 and the 206 hardner. And use the 407 filler for smoothing out the uneven surfaces. I pulled all the Formica off the interior and sanded down the green glue. Got one cockpit locker sanded down and inside both cockpit lockers doors. I used 60 grit and will follow up with 120.

[HinduKush]

Hello Atom Voyager, I did look into and called the US Composites office. I am considering using USC product because it is half the cost of Wet System. I read on their web page the 635 is for laminating and fiberglass cloth/matt layup and the 105 is for adding filler and fillets to bond two pieces together. So was thinking 5 gallons 635 thin epoxy for plywood covering and fabric wet out and maybe 2 gallons of the 105 thick epoxy for fillet joints?

Question on Osprey and Triton 503 the transition from the bulkheads on the head and hanging locker to the cabin top. Did you use Matt or tape or just make a fillet? On mine they had a manila rope for a molding to cover from a 1/4 inch to half inch gap. I wanted mine to look like the Osprey and a nice smooth transition from the bulkheads to the cabin top.

[atomvoyager]

It gets complicated and expensive to use two resins so I'd only buy the standard thinner resin since you can thicken it as well. How much you need depends on your job list. I normally use 9oz cloth on upper bulkheads but you might try mat there and see what you prefer. On the Triton there is a glassed joint on one side and rope or rubber filler strip on the other so you only need to cut out the rope, fill with silica thickened epoxy and apply one layer of cloth to prevent cracks from slight movement. By the way, it is easiest to apply the cloth quickly over the fillet otherwise it's hard to sand the fillet flat to apply the cloth over it later. In other cases you may want cloth over mat. Experiment. The 1708 is sometimes too thick and stiff for high visibility areas that don't require its added strength. But I do use it a lot in locker and bilge areas and cut the 48" wide rolls into 6" wide strips or whatever width needed.