Even that I used graphite finish quite successful on my boat Isa FS13 I want to ask this question. On the FS13 I sort of guessed 200 grams of mixed epoxy and 70 grams of graphite powder will be fine for one coat of the bottom. I did 3 coats like this. For my AD14 I do not want to guess I would like to make it 100 percent right.
I must say beforehand that I worked exactly to CL graphite finish instructions like at the quote a bit further on under rule 2 and that is were my question arises. I do not know for which boat he wrote it for where he says 9 ounces of epoxy and 3 ounces graphite powder for one coat.
Larry if you should read this I am sure you can remember for what boat you said 9 ounces epoxy and 3 ounces graphite for one coat ( post from tcason ) and if it is comparable to the bottom of AD14 ( 14 foot long and about 6 foot 6 inches wide from frame C to T ) I want to epoxy graphite it to the waterline so also a bit on the sides roughly 3 inches above the bottom at the bow and also at the transom. In the middle of the boat that will be about 12 inches up the sides.Rule number 1. Work when it is as hot as possible. I'm not kidding. When I put the first coats of graphite on this boat it was still cool weather and no matter what I did, I got lumps, clumps and bubbles. Have you ever tried to stir powdered coffee creamer into cold coffee? It doesn't hardly dissolve. Stir it into warm coffee and it instantly dissolves. Same for the graphite powder. The last coats were done in the middle of the day, outside temp was about 104, the epoxy temp was near 100. The powder mixes completely and it flows out like water. In the heat of the day the epoxy obviously cures fast, so you have to work fast. This is a big advantage because the faster it cures, the less time it has to accumulate bugs, dust, dog hair and other trash.
Rule 2. Sift the graphite twice, but don't turn the crank or squeeze the handle on the sifter mechanism, just shake the sifter lightly and collect what passes through easily. Discard the rest. This boat needs 9 ounces of mixed epoxy for a full coat, to that I add 3 ounces (volume) of sifted powder.
Rule 3. Mix the resin and hardener completely before adding the graphite, stir it very good, then let it sit a minute before using. This will let any chunks settle to the bottom of the cup. Pour it out slowly and evenly over the entire bottom of the boat, but don't pour out the last 1/2 ounce or so in the bottom of the cup. This is where the uglies live, and they are best left in the cup
Rule 4. Do not use a foam roller, it induces bubbles and usually foam fragments too. I got the best results using a 3/8 nap roller made for glossy acrylic latex kitchen and bath paint. Premium grade, from Lowes. Use a full size roller, the smaller ones leave a lot of roller marks, the wide ones not so much. Roll it out completely in every direction with a lot of pressure, then roll it lightly in one direction only to remove the roller edge lines and smooth it all out.
Rule 5. Roll it out very thin and use multiple coats. I wet sanded with 120 grit between each coat, then before the last coat I scrubbed with a Scotchbrite pad and water. You do not want
Greetings from Karl