Sunfish fiberglass repair on a "new" 1990 boat

todd1988

New Member
I bought a "new" 1990 Sunfish off eBay, when the winner backed out. The boat was in a garage for 30 years, never sailed, and had all hardware and rigging in the original packages. The sail was a promotional sail and has Miller Genuine Draft across it. The one flaw was it had a saw blade injury towards the aft. See photo.

I am now going to repair it. I have done some fiberglass work before. I have some West Systems Epoxy and have 403, 406 and 407 fillers. I have rewatched various you tube videos on repairing the damage. Grinding out on a 1:12 ratio, putting in a backing board with thickened epoxy, layering it up, fairing it, and then re gelcoat.

But before I start I wanted to solicit any specific advice that anyone might have.

Thanks for any and all help.

Todd
IMG_2345.jpeg
 
Great find.
Post more pics.
Watch this video:

Thanks for the video. Will definitely post the pics.

BTW thanks for your blog / website. It really inspired me and gave me the confidence to repair a Sunfish for my daughter (14 yrs old). This boat is for me to sail on the lake with her. I have a Hobie 18, which I love, but I really have enjoyed being back on a Sunfish.

Todd
 
I guess you are going to put an inspection port above that section on the deck?

TheGoldenDuck,
Do you think I need to? I really hate to cut into the top if I don't have to. I cut into a 1978, with some cringing, but want to keep the top of this one pristine. I think i can slide a piece of cured fiberglass tape (with string through it) into the slot and then inject some thickened epoxy for the backing. If it does not look sturdy enough, I might have too.

Todd
 
NO inspection port.

You will be doing a blind hole patch. It will be sturdier than original because you will have at least double hull thickness in that area. We use cardboard and woven roving for the patch, all wet out with thickened epoxy. It cures inside the hull. Now you might go your route and make a cured patch first using the hull as a form, it seems like an extra step.

RM 4 Blind Hole Patch.jpg


Blind patch 5 ray.jpg
 
Thanks everyone for the input so far. Have been out out for a few days.

My plan was to try the blind hole patch. Thank you for the videos and sheet. Before I started sanding down for my patch I made a fiberglass backer, in case i wanted to use it instead of cardboard. (picture 1) I then marked off 20mm circle around the cut and sanded it beveled. The left side of the sanding gave way more right at the edge of the hull, so there is a larger hole there.

There is a lot of foam behind my hole. (I was expecting some) I am trying to clean it from around the hole. It is going to make my backer plate hard to slide into it. I am debating on how much to try to cut out.

Thanks again for the input.

Todd
 

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The 2 part expanding foam is yellow, it holds in the white structural extruded polystyrene (XPS) flotation block. You can trim out just about all of the yellow foam, leave a small bit where it secures the white block.

Your internal patch only need to be big enough to catch an inch or even a little less around the hole, so trim the backer patch as needed. Fiberglass backers are a good way to go also, we've done a couple. Made a pattern from wax paper.

RAY patch mold.jpg


Then made the patch from a layer of fiberglass cloth and epoxy. I had to trim this patch down quite a bit.

BUD Deck backer patch.jpg


This was during our Coat Hanger Phase of methods to hold the patch in place until the epoxy has a soft cure, i had little hooks inside. It was tough to pull the hanger out, I though the metal would be softer and easy to pull.

merci chine patch installed.jpg


We are currently in our Paint Stir Stick phase. I bet you come up with something creative.

IMG_2594.JPG
 
Congratulations! I put a bid in on that boat in the last 45sec. of the auction. I was the last bid before the winning bid. If I had won it, I was going to use this method to repair it:

Good luck!
 

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