some good advice
– Last Updated: May-19-08 1:02 PM EST –
The mixing ratio between gel coat and hardener (MEPK) is usually 12 drops per oz.
You want this to be between 1% and 2% of the gel coat, so whatever info you have sounds way off, so you may want to check that.
One ounce covers quite a bit of area.
Prep the area. I used a dremel tool, but do whatever works to take down the damaged area to the fiberglass.
Clean it with boat cleaner solvent or acetone, be careful with the acetone not to discolor other good gel coat.
You can use a plastic or paper mixing cup, (plastic to be safe) as this is what is sold at boat shops.
You will use more than one applications and more than one mixing cup.
Use a small throw away brush. Try and clean it and pull free any loose bristles.
Mix first batch, 12 drops per ounce, thoroughly stir. If it is hot, then 10 drops of hardener.
You don’t want too much hardener or the gel coat will be brittle, too little and it will not cure properly.
Apply the first coat with as much gel on the brush as it can hold without dripping off. It is kind of thin but it’s best not to try and touch over it, as the first application is the thickest.
When the first batch is setting up, wait until you can touch it with your finger and it leaves a finger print, but doesn’t pull any gel coat away, and apply the second coat. Then do a third coat is the same way. (you will need to mix another ounce for each coat)
On your final coat, apply a Mold Release gel with a throw away brush. Try not to deform the soft gel coat. You will need to be very delicate, then let the excess mold release drip off. It washes off with water.
The plastic covering is a nightmare and you end up with air pockets and all kinds of problems.
You will be left with a built up area then sand this down. Start with heavy grit with a block, (folded cardboard words well) then work you way down, to 150, 220, 320 wet, 400 wet, 600 wet, 1200 wet.
You don’t need every grade of sandpaper. The 600 and 1200 are more of a polish that shines your boat.
Be careful not to over sand.
Then polish with a compound polish.
Edit: with the gel release, dip thick on the brush then one swipe, redip, as long as it touches the gel you will be fine. Try to apply just before it starts to set up.
If it is hotter then use slightly less NEPK. 10 or 11 drops if it is over 80. Don't spread it out in a pan. (sorry, but it is a chemical reaction) Let it sit in the cup for about a minute or so with mixing. You should have plenty of time for one coat, say 15 minutes, unless it is too hot or you used too much hardener.
You can clean brush and cup with acitone, use latex gloves.
