For cleaning: Big fan. Start with a putty knife and a wire brush and get all the gunk that can be vacuumed out, out. Then start with a
parts cleaning brush and Acetone. Wipe down rag it, anything that can be dissolved... Will change the color of the rag. Spread your rags to dry on something that won't be harmed before disposing. Wet rags covered in acetone dissolve
paint, harm
varnish, etc.
Don't pile up wet rags... Clean 1 foot by 1 foot areas until a white lint free rag comes up clean, then move lower. If you have any stubborn looking sticky grease spots,
Interlux 202 solvent with a
paint brush. Put the rag over the spot, and keep the rag wet. It should dissolve it.
Most nasty looking bilges are bare laminated resin, and laminating resin is sticky. You can't water wash the uncured sticky resin that has the junk in it, but you can dissolve the uncured resin and junk off with Solvent.
For the most bilges... So long as they are dry, you can skip the water wash down as you are dealing with dirt, which can be vacuumed... Or oily grease, which solvent cuts. If you start with soap and water, you really shouldn't be pumping it
overboard, and if you are
on the hard it ought to go in buckets to a waste disposal site.
Epoxy:
Look into Composite Polymer Designs Super Slow hardener if you are going to do this...
Depending on where you are, it's 80 degrees here at night, and even with west systems 209 tropical hardener you'd be hard pressed to do an inch at a time without things foaming up and getting messy. You can do 50/50 milled glass fiber and glass microballoons fairly easily to a 1/2 inch pour even in the summer time if you care about weight, but if you want to go thicker then you need something like talc
You can chill off the resin down to 60 degrees or so in a cooler full of ice, right about to the temp where things start getting difficult to mix you can buy a little more time.
Screed the top of the last batch. Take a pair of 1x1
cleats and hot glue them to the side of the
hull as a guide runner. Cover them in packing tape, and pack any cracks full of modeling clay.
You'll need a load of different length sticks to pull level across the top, so you can either keep a long one that just does fit and use a jig saw to cut it to size as you go, or have a stack of sticks ready to go.
Over fill the middle, and make the last batch a little bit juicy compared to the rest, but not so loose that it runs with gravity. Wiggle the stick back and forth as you very slowly
work down the length of the fill. If you take off excess, pick the stick up and take a putty knife and clean the stick moving the excess to a low spot or back to the mixing pot.
When you have a clean run of it, you want to wait until it goes green and run some screws into the cleat and pull your guide rails out before it kicks off fully.
Mix up a slurry of milled glass fiber, and brush it into the surface filling any low holes while everything is green, but keep it out of the guide rail grooves.
If you use something smaller than 1x1, it is difficult to get a grinding bur down inside the groove, and you don't have much room to wiggle back and forth. If you aren't doing a big space, you can just tip a mini grinder into the groove until its scratched up... Though the nicer you can keep the 2-3 inches beside the groove, the easier it is to use a putty knife and just fill the groove by eye to the
hull.
What you end up with should give you a flat surface. Grind lightly any of the high spots, and put an even scratch on everything. When you go to glass it in trowel a layer of cabosil a 1/8th or so thick over the filler using a drywall knife, let it tack up, and then lay in a few layers of 1708. Use a 6 inch wide air roller for the flat surface and roll it in lightly enough to float it into the troweled cabosil, but not so hard that you push little waves of it around. You are glassing over bog, a little more bog to float out flat without grinding saves grinding the bottom of the bilge... Which you will have done enough of by this point.
If you use a 3 inch air roller, you'll
work the glass down into all the imperfections that your 5 inch grinder cut in. So use a 6 inch air roller everywhere it will fit.
Add another coat of resin to fill the weave, then peel ply it...
If you are going to use
Interlux bilge coat paint, you need to wait a few weeks for the epoxy to fully cure and amine wash/acetone wipe it or it will stay wet for weeks...
Cheers,
Zach