Here's the problem: A Catalina 22 came loose during an overnight blow and fetched up against a bulkhead. As the boat was bashed up against it, the gelcoat was gouged to different depths, some superficial, some to the laminate, and down to the core in a few spots. Gelcoat is white. I've managed to sand many of the superficial scratches out, but the section with some of the deeper gouges covers about 6 to 8 square feet topsides. I'm sorting out different options for repair. I haven't dealt much with this sort of repair above the waterline where it needs to look good, so I'm asking for opinions. I've thought about filling in with epoxy and coating over it with non-glossy gelcoat to match the existing gelcoat or matte paint, or just filling with gelcoat for the whole project and spreading it over the whole area after the fills cure for a uniform appearance (as with I mentioned doing over the epoxy). So I suppose I'm also asking for some feelings toward working with off-the-shelf gelcoat.
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Here is a good link about repairing gelcoat
scratches by Don Casey. http://www.boatus.com/boattech/Casey/02.htm Lots of good how-to articles on the boatus site. I guess the deeper scratches may need to be epoxy filled before applying new gelcoat. BTW, this stuff (gelcoat) stinks to high heaven when using it, worse than Bondo. I have repaired a few dings in our old gelcoat with off the shelf white gelcoat with satisfactory results. Up close you can see the repair but from 20 feet away you cant tell for the most part. The article spells out the procedure better than I could. Your profile makes me think you might have previously owned a Tartan 27. Are you Peter Y. by any chance?
scratches by Don Casey. http://www.boatus.com/boattech/Casey/02.htm Lots of good how-to articles on the boatus site. I guess the deeper scratches may need to be epoxy filled before applying new gelcoat. BTW, this stuff (gelcoat) stinks to high heaven when using it, worse than Bondo. I have repaired a few dings in our old gelcoat with off the shelf white gelcoat with satisfactory results. Up close you can see the repair but from 20 feet away you cant tell for the most part. The article spells out the procedure better than I could. Your profile makes me think you might have previously owned a Tartan 27. Are you Peter Y. by any chance?
You can't put gelcoat back over epoxy
The gelcoat is polyester. Think of the polyester as basketballs and the epoxy as ping pong balls. Epoxy will stick to gel coat, if the wax is removed, but gel coat will not stick to epoxy. If your repsir is not structural (since you're not using glass cloth) use a polyester filler, or microballoons in polyester resin, or unwaxed gelcoat thickened with microballoons. Before we had epoxy, we did this as a regular repair strategy. Hot tub and shower stall builders still use polyester fillers, and they stick pretty well. A lot of folks on this list will remember gypsum putty (polyester resin and gypsum powder) or all kinds of cheap mixtures to hold gunwales and other boat parts together. I've seen lots of sawdust and polyester used as a filler. Even in those ancient times we knew sawdust putty was a sign of a sloppy builder.
The gelcoat is polyester. Think of the polyester as basketballs and the epoxy as ping pong balls. Epoxy will stick to gel coat, if the wax is removed, but gel coat will not stick to epoxy. If your repsir is not structural (since you're not using glass cloth) use a polyester filler, or microballoons in polyester resin, or unwaxed gelcoat thickened with microballoons. Before we had epoxy, we did this as a regular repair strategy. Hot tub and shower stall builders still use polyester fillers, and they stick pretty well. A lot of folks on this list will remember gypsum putty (polyester resin and gypsum powder) or all kinds of cheap mixtures to hold gunwales and other boat parts together. I've seen lots of sawdust and polyester used as a filler. Even in those ancient times we knew sawdust putty was a sign of a sloppy builder.
Fred, I have to disagree
West Products explains how to do it and I have done many repairs with epoxy and the sprayed gel coat over it. r.w.landau
West Products explains how to do it and I have done many repairs with epoxy and the sprayed gel coat over it. r.w.landau
great link Caleb
Don Casey gets right to the point. I would think that you could start out with the small scratches and perfect your technique as you work your way up to the areas with more significant damage. when I am doing a repair and heading into new areas, or any area for that matter, i have found that when i pray and ask God Almighty to guide me and help me make the most of the time and the resources, the work seems to be more effective and enjoyable. The link will send you User Manual and Product Guide and Repair Manuals at no cost. the link is westsystem.info or westsystem.com
Don Casey gets right to the point. I would think that you could start out with the small scratches and perfect your technique as you work your way up to the areas with more significant damage. when I am doing a repair and heading into new areas, or any area for that matter, i have found that when i pray and ask God Almighty to guide me and help me make the most of the time and the resources, the work seems to be more effective and enjoyable. The link will send you User Manual and Product Guide and Repair Manuals at no cost. the link is westsystem.info or westsystem.com
I also agree that WS website has good tips
for using their epoxy product. Particularly under their tab "Using West System there is lots of good advice. There are also other brands of epoxy out there that are cheaper but I have not used them so I cant comment. The gelcoat mixture I used sagged a bit in the scratches it was meant to hide and needed to be sanded down to keep the freeboard looking clean and classicaly arched and smooth.
for using their epoxy product. Particularly under their tab "Using West System there is lots of good advice. There are also other brands of epoxy out there that are cheaper but I have not used them so I cant comment. The gelcoat mixture I used sagged a bit in the scratches it was meant to hide and needed to be sanded down to keep the freeboard looking clean and classicaly arched and smooth.
Fred is correct - gel won't stick to epoxy
Regardless of the advertizing, Fred is correct. Carroll Maine who once built Mumm 30s and 36s built the deck with gel over epoxy and EVERY one has subsequently required complete stripping and repair/painting. On my son's 36, the gel simply pulled off like a sheet of plastic. Suffice it to say that unless you want to be redoing this repair in a year or two, do not try covering an epoxy repair with gel.
Regardless of the advertizing, Fred is correct. Carroll Maine who once built Mumm 30s and 36s built the deck with gel over epoxy and EVERY one has subsequently required complete stripping and repair/painting. On my son's 36, the gel simply pulled off like a sheet of plastic. Suffice it to say that unless you want to be redoing this repair in a year or two, do not try covering an epoxy repair with gel.
Insurance?
Damage amounting to six to eight square feet could be high enough in repair costs to enter a claim. It's possible the insurance could pay for the damage.
Damage amounting to six to eight square feet could be high enough in repair costs to enter a claim. It's possible the insurance could pay for the damage.
incompatibility is my fear
Fred and Don, I'm with you on your reservations about applying gelcoat over epoxy. West System apparently claims they've devised a method that makes the bond works, so I thought to give them the benefit of the doubt and say, maybe, those failures may be attributed to improper preparation for the gelcoat. I hesitate to believe them 100% for two reasons: First, polyester gelcoat sets up a chemical bond, whereas epoxy sets up a mechanical bond. The polyester does not chemically bond to the epoxy, and, whatever mechanical bonding does occur, they may not be adequate to maintain robust adhesion to the epoxy filler. Second, I've heard the horror stories myself. Even if that is the case that West has a good way to prep the eopxy for gelcoating, it's probably fairly impractical, otherwise it would seem more people would follow it and I'd hear less trepidation. For the sake of knowing what that is, I will run to west marine to "browse" through the Gougeon Bros book on fiberglass and gelcoat repair, which I'm pretty sure I saw on the shelf the other day. CalebD, no, I'm not Peter Y. Never even stepped foot on a Tartan 27. However, besides the stink, is there much difference in working gelcoat into the voids or is it about comparable to thickened epoxy. Makes sense that it would be.
Fred and Don, I'm with you on your reservations about applying gelcoat over epoxy. West System apparently claims they've devised a method that makes the bond works, so I thought to give them the benefit of the doubt and say, maybe, those failures may be attributed to improper preparation for the gelcoat. I hesitate to believe them 100% for two reasons: First, polyester gelcoat sets up a chemical bond, whereas epoxy sets up a mechanical bond. The polyester does not chemically bond to the epoxy, and, whatever mechanical bonding does occur, they may not be adequate to maintain robust adhesion to the epoxy filler. Second, I've heard the horror stories myself. Even if that is the case that West has a good way to prep the eopxy for gelcoating, it's probably fairly impractical, otherwise it would seem more people would follow it and I'd hear less trepidation. For the sake of knowing what that is, I will run to west marine to "browse" through the Gougeon Bros book on fiberglass and gelcoat repair, which I'm pretty sure I saw on the shelf the other day. CalebD, no, I'm not Peter Y. Never even stepped foot on a Tartan 27. However, besides the stink, is there much difference in working gelcoat into the voids or is it about comparable to thickened epoxy. Makes sense that it would be.
If you are worried about the stuff peeling off
you might try as Don Casey suggests and get a small bottle of styrene which when wiped on each scratch just prior to filling partially reactivates the old gelcoat, resulting in some chemical bonding between the old gelcoat and the new. I wish I had known this when I messed with this stuff although my repairs are still holding on after 3 years without pre-wiping with styrene. The pot life of the gelcoat I used was < 10 minutes at about 80 degrees ambient temperature and the texture was similar to a slightly thickened epoxy. It should be pretty easy to work into the cracks with a brush. The hard part comes when you try to fair the hull back to smooth perfection after it is cured. Then wax and buff. There must be quite a few sailboat owning Peters in your neck of the woods so it was a long shot at best. Good luck with the gelcoat repairs.
you might try as Don Casey suggests and get a small bottle of styrene which when wiped on each scratch just prior to filling partially reactivates the old gelcoat, resulting in some chemical bonding between the old gelcoat and the new. I wish I had known this when I messed with this stuff although my repairs are still holding on after 3 years without pre-wiping with styrene. The pot life of the gelcoat I used was < 10 minutes at about 80 degrees ambient temperature and the texture was similar to a slightly thickened epoxy. It should be pretty easy to work into the cracks with a brush. The hard part comes when you try to fair the hull back to smooth perfection after it is cured. Then wax and buff. There must be quite a few sailboat owning Peters in your neck of the woods so it was a long shot at best. Good luck with the gelcoat repairs.
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