laszlo,
Iread your message from quite a while back about using graphite, 30%, some cab-o-sil, as a base. Then 40% final coat. What would you do to the boat if it were already painted?
About how much graphite and epoxy would you estimate for a CLC17?
thanks RodneyC
Don't know, never used it. But I imagine that as long as you end up with a bare epoxy surface with no contaminents you'd be fine. Maybe a stripper to do the heavy lifting and finsh off with light sanding?
Any of you painter types want to step in here?
Laszlo
Laszlo,
Thanks for the response. Another Question. Would paint stripper be an option to all the sanding? I f so what else would you do to make sure the stripper didn't affect the graphite epoxy step?
Thanks, Rod.
Hi Rodney,
These days I've switched to a 1:1 (50%-50%) by volume graphite/epoxy mix, no cab-o-sil. The cab-o-sil made it harder to mix so I decided to try and see if I could do without. The new mix works pretty well and I haven't noticed any difference in wear yet.
Years back I bought 1 lb of graphite powder. So far I've done a 16LT, a Wood Duck 12 and a 14-ft pirogue (twice) with that amount. I still have enough left to do the sailing dinghy that I'm currently building. The 6-oz can from CLC should be enough for several CH17's (or 1 CH17 refinished a few times).
I would definitely sand the painted area right down to bare epoxy before applying the graphite/epoxy mix. 80 grit is OK (be careful at the seams) because the g/e mixture is very thick and filling. If you roll it on and tip it off with a foam brush you'll never see the sanding marks.
Have fun,
Laszlo
Laszlo, do I understand you to say that you use equal parts graphite powder and mixed epoxy? I tested some West 423 graphite powder with some 105 (50/50 mix), mixed it, and then added 206 hardener for a total product volume of about 2 oz. The result had a consistency of heavy cream that kicked off in 15 minutes. I was using West measuring pumps and while I may have made a mistake I’ve mixed gallons if epoxy over the years and never seen anything like this. Back to my original question. Is the 50/50 mix what you use? Thanks SEEYA Jack
Just for what it is worth.
West Sytems recommends a 10% graphite mix (by volume).
Mike
Jack,
Yes, these days I use 50/50 - that's 1 oz by volume of mixed epoxy/hardener per 1 oz by volume of graphite powder. First I mix the epoxy & hardener in the correct ratio, then add in the graphite. It hardens at the normal rate.
So typically I mix up 1 ox of epoxy plus 1/2 oz of hardener. Once it's thoroughly mixed, I add 1.5 oz of graphite. Once that's throroughly mixed I roll it on and tip it off with a foam brush. This is with System 3.
For what it's worth, I am now seeing a difference in wear between the 1:1 g/e and the 1:2 g/e + cab-o-sil. The richer mixture seems to be handling rocks, oysters and concrete better, while the cab-o-sil mix is handling sand better.
Laszlo
Thanks Laszlo, I must have done something way wrong. I was using those measurements with 423. I'd think graphite powder is graphite power and that the System 3 epoxy and West should work fine together so I'll try again and see what happens. SEEYA Jack