Re: Epoxy Paint
Hey scematic, I read your post out of context and thought you were talking about my site at hawaiimaui.com, which aint that great.<br /><br />I love this topic, and have heard many opinions, but I agree with everthing here, mostly taken from a book, Brian Lawson (a fiberclassics member) has compiled a general page on fiberglass, its use, a small history and techniques. Remember, most of it is from a book. It isn't law<br /><br />I've mixed gel coat but I can't remember the formula, itsw best to buy it mixed (except hardner) especially if you ever want to match the color again.<br /><br />What think? <br /><br />Resin types <br />There are two basic resin types:<br />- polyester<br />- epoxy<br /><br />99% of boats built are of polyester resin because they are:<br />- cheaper, and<br />- cure time can be adjusted<br /><br />Polyester <br /><br />Polyester (the one 99% of boats are built with) comes in two types; finishing abd laminating.<br />Finishing is used for most small jobs using a single layer of cloth or for the final layer of glass.<br />Laminating DOES NOT DRY TACK FREE, and so is called air inhibited. It is used to build up success layers in construction and big repair jobs.<br /><br />EPOXY CAN BE USED TO REPAIR POLYESTER......BUT!!!! POLYESTER SHOULD NOT BE USED TO REPAIR EPOXY.<br /><br />Gelcoat <br /><br />Most production boats produced using molds (many boats produced from 1 mold) have been finished (actually started!) using gelcoat. Gelcoat easily lasts 10 years looking great. Most paints or coatings last half as long as gelcoat.<br /><br /><br />Gelcoated boats, if cleaned, waxed and polished will look nearly new after 10 years, and not bad enough to restore after 20. If they're old or really dirty, more heroic techniques are needed.<br /><br />1.) Compounding - is polishing with a paste containing a fine grit. Pastes come in varying size grits. Try the smallest possible, and work to coarser grits until you get the result you want. Make sure you remove any old wax. Use acetone on gelcoat in reasonably good shape to remove wax. Use a toluene based wax removal product if you've used silicone based wax. Use a polisher with a soft pad to apply and polish. Work in patches.<br /><br />If you don't get the results you want, it's wet sanding next.<br /><br />2.) Wet Sanding - uses emory paper kept constantly wet. Emory paper (aka wet/dry paper) comes in 100 to 600 grit; 100 is coarsest, 600 finest. Use the finest possible to get the color back, constantly rinsing and wetting the paper and surface. Then work back up through the papers to fine grit and finish with compounding and polishing.<br /><br />If you still don't get the results you want, it's time to refinish!!<br />Re-Gelcoating vs. Re-Painting <br /><br />When gelcoat is beyond repair you have 4 options:<br />1.) re-gelcoat the boat<br />2.) re-paint the boat with a polyurethane paint (e.g., Awlgrip or Imron)<br /><br />3.) re-paint the boat with conventional marine paint (1 or 2 part epoxy paints, alkyd or modified alkyd enamels<br /><br />4.) too ugly to mention.......yet<br /><br />Option 1 - Gelcoat<br /><br />Builders typically spray gelcoat against a highly polished mold, and then "build" the boat from the outside in. So the finished side of the gelcoat (during contruction) is actually against the mold and never seen until popped from the mold. The smoother the mold the better the finish when removed.<br />There is no better protection for fiberglass than gelcoat...period. It bonds chemically with the underlaying fiberglass. It goes on much thicker than a paint finish. It can look good for 20 years. HOWEVER, no one makes gelcoat that is self smoothing. It is labor intensive to apply and to polish up to a high gloss shine when applied to exterior surfaces. It will not, on its own, dry to a high gloss finish. It takes a lot of labor to sand and polish a gelcoat finish to a high gloss shine. You can thin gelcoat using acetone and spray it on. Start with the hardest to get to areas and work to the easiest. Keep a wet edge, and when done, go back and repeat at a diagonal or perpendicular angle to the first pass. A total of three passes should give you the recommended 15 - 20 mil thickness<br /><br />Option 2 - Polyutethane paint<br />Imron and Awlgrip will last half as long as gelcoat, and because the finish is thin in comparison, is more subject to marring than gelcoat. These paints go on and dry to an incredible shine, almost wet looking. There is no need to polish the finish. HOWEVER, they are very tricky paints to apply well. They need a moisture and dust free environment. They contain materials that are quite hazardous to health so proper ventilation must be used. They are very expensive, probably in excess if $100 per foot to apply. And when applied over fiberglass, an epoxy seal should be laid down before the urethane paint.<br /><br />Option 3 - Marine Paint<br />This third option is often overlooked for refinishing fiberglass. It shouldn't be! Marine paint is a great choice for fiberglass refinishing. These paints are far more durable on glass than on wood. They will look good on glass for years; not as long as urethane, and certainly not as long as gelcoat, but also at a fraction of the cost and labor. These paints are cheap compared to options 1 and 2. These paints also are not difficult to apply. They can be water sanded to a high gloss finish. Do not make your decision without checking out option 3 and giving it some consideration.<br /><br />Option 4 - Navy Target. Barrier reef addition. Salad bar. (You get the idea!)<br /><br />Epoxy resins are better glues than polyester resins. They are stronger, and some can actually cure under water. The problem with epoxy resins are:<br /><br />- 4 to 5 times the cost of polyester resins<br />- harder to handle<br />- mix is exact and can not be adjusted to change cure times. <br /><br />If I might add, we have to paint epoxy resin because it can't handle UV's (sun shine). I've had some luck with tinting it but you have to mix it hot, risky business.
<br /><br />At least the grease is gone. 
