1974 Sunfish Restoration (in progress) One l

pseudo15prt

New Member
I picked up a 1973 Sunfish on Craigslist last weekend and thought I'd document the restoration on this forum. Partly I want to keep myself committed to taking lots of pictures, partly because I think we all enjoy seeing a half-dead boat come back to life.

The boat is actually in pretty good shape I think. It looks like a previous owner had re-bedded the hardware in some very tough orange/brown epoxy stuff, so I'll leave that alone. The gelcoat is heavily oxidized and I will wet-sand with 800 grit I think, then buff with some marine polishing compound. The keel has a repair just aft of the cockpit that at some point opened back up slightly. When I got home, the trailer was wet under that location. Not sure what the weight is (the Wife won't lend me her scale), but I think it's pretty heavy. I cut an inspection port behind the splashguard and indeed, the inside is damp (but not soaking wet). I plan to restore the top first, then flip and sand away the old repair and re-do it with fresh fiberglass. The daggerboard is horribly warped from sitting in the sun for years - it's cupped to the side that was exposed. One last repair: the port foam block has broken free, so I'll anchor that back in place with some expanding foam through the inspection port.

This is a work in progress and I'll update this thread with changes as they happen.
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Wash it with a bleach solution 10-15% to get all the dirt and mildew out, then get 3M gel coat restorer. Bet it comes out mint. Mine was in worse shape.

If the bottom is about the same, wet sand it with 400 and call it good.

Something about surface tension and bubble adhesion and stuff that is supposed to be worse with a shiny waxed hull. That was the technical version I was given.

Nice boat.
 
Thanks for the cleaning ideas. I've started at the bow and it is turning out well so far. Under the splashguard, the gelcoat untouched by the sun for the past 45+ years looks amazing. What a deep blue!
 
Try just buffing a small patch before going at it with the sandpaper... Might not need to sand the top.
Agree. Try 3M automotive "Rubbing Compound". At $8, it's not THAT very aggressive compound, but should speed up the restoration process—maybe bring back that deep blue color.
 
Sanding the bottom of the hull with 400 or 600 grit paper will make it slide through the water. Hobie cat racers do this to eliminate surface tension. When I buffed my sunfish I sanded it lightly with 1500 grit wet/dry paper with water to get the oxidation off first. Worked great.
 
I'm absolutely going to get the 3M rubbing compound and use that, but to take the devils' advocate position, wet-sanding first at 400 grit or above first and THEN rubbing compound wouldn't hurt, right? Assuming I don't sand through the gelcoat (and in each case I'm just removing a small amount of material anyway), they should achieve the same objective. In neither case will I get rid of the small pits that are present in the surface of the gelcoat. It's my understanding that finishing with a nice polishing compound and some wax will fill those to prevent dirt from becoming trapped in there.
 
The idea is to minimize the thickness of gel coat removed.

If you can polish to original color without sanding, do it. But gel coat is a lot thicker than common paint, so you do have some room to sand before losing the color.

The more you remove, the fewer times you can buff off the oxidized faded gel coat.
 
I would buff a small spot first and see how quick it shines back up. You may not need to sand anything just buff it back to a gloss. If you do need to sand I would use the least aggressive grit first. When I spoke of sanding with 400 I was referring to the bottom only. Sand it dull and leave it that way to eliminate surface tension. That is what the racers would do. If you want to go glossy buff it the same as the top.
 
Try 3M automotive "Rubbing Compound". At $8, it's not THAT very aggressive a compound, but should speed up the restoration process—maybe bring back that deep blue color.
If 3M automotive "Rubbing Compound" isn't aggressive enough, try asking at an automotive paint store for compounds that are more aggressive. 'Course, it will depend on whether or not you are using a power tool to buff...

On another note: Using a dampened clean cloth, 3M automotive "Rubbing Compound" works great to restore the plastic lenses of sunglasses. Even relatively deep scratches will improve...
 
I picked up the rubbing compound and will try it out this week. I plan on taking some progress photos tonight or tomorrow and posting them for you guys. I've given the entire hull an extreme deep-cleaning with all the soap products in my house. That got rid of the mildew and lichen. The deck was the original gelcoat and looks fantastic, but the hull had been painted bright red at some point, then white on top of that. The gelcoat underneath is actually in great shape, but I didn't try too hard to restore that. I sanded with 120-grit to clean off the flaking paint and the final result is 75% gelcoat and 25% paint in patches. You can barely tell the different. Then I wet-sanded up to 800 grit and will leave it at that based on the recommendations above. There were two previous repairs to the keel. One looked great, but the other had opened up again with a hairline crack. I opened that up and put in a cardboard backer, then filled it in with many layers of fiberglass. I put a few layers over the other repair just for good measure. There was the oddest paint/gelcoat/gunk on top of the repairs. It was extremely bumpy and flaky, but couldn't be sanded (it would just spread out and adhere to the sandpaper too). Odd. I had to use a paint scraper to get it off.
 
"There was the oddest paint/gelcoat/gunk on top of the repairs. It was extremely bumpy and flaky, but couldn't be sanded"

Gray/Tan? Sounds a lot like plumber's putty or window glazing. Someone trying to smooth it out but not having a clue.
 
It wasn't plumbers putty. I'm not familiar with window glazing, so can't help there. It was white overall but seemingly very porous on the surface because it had taken up a lot of dirt and stuff so had black spots all over it. I'm familiar with uncured epoxy being sticky and impossible to sand, and it behaved a lot like that. Except it was so flaky! I could just take my scraper and it would explode off the hull. I had to wear safety glasses to keep it out of my eyes. Very odd.
 

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