Technique for repairing hull/wing sockets, etc.

I don't know if this is common practice, but it worked so well, I thought I'd share it. Had to cut access into the side of my H21SE to repair a shattered wing socket. So, got a compass, drew an 8 inch circle (in case I opted to go back with a screw in port), took a deep breath and drilled a hole on the line big enough to get a scroll saw blade in there.

Cut out circle and, wow! seeing the cut-out in cross section and handling the piece of the hull, I can honestly say the thing is made TOUGH! Cool. Repaired wing socket and then when it was time to close the hole up again, I took some carbon fiber tape, about 12 inches long and laid it out on some mylar (epoxy won't stick to mylar). Wet it out, pressed it flat and let it kick. Have 2 12 inch, tough strips for backing to hold the circle in place when I epoxy it back.

Next, I took a rifling file; any round rasp would likely work, and filed out just a bit of the foam from the cut-out and from the edge of the hole in the hull, all the way around. I glued the carbon strips in place on the inside, holding them with C-clamps. Let that set up. Test fit cut-out and ensure I can hold on there flat, with some pressure. Then, I thickened up some epoxy with milled fiberglass and colloidal silica to about peanut butter consistency, A bead all the way around the cut out and all the way around the hole and on the carbon. Stick cut-out back in place, exactly, use REAL aluminum tape (not duct tape), and tape angle across hole to ensure it's dead flat to hull. I practiced this before attempting with epoxy. Worked AWESOME! VERY strong; no hint of flex, etc. when you pound on hull, etc.

My theory goes: I wanted to secure the circle cut-out back, using rounded edges, filling the saw kerf and getting at least a fiberglass layer's worth of epoxy between the hull and the cut-out inside the foam area. Basically, when set the epoxy forms a circular bead like an O-ring around the cut-out and between it and the hull. Not only was it strong, but I had very little fairing work to do. Basically, sand and will epoxy prime this afternoon. No filler really needed at all (e.g. like Bondo).

Will attach image showing in just a bit what I mean. Love it when something goes right.

Edited by charlescarlis on May 15, 2019 - 11:49 AM.
Great work..... Thanks for sharing.

Mirage Tandem Island -sold
Hobie Bravo -sold
1979 Prindle 18 Sold
2019 Hobie Getaway
Polk City, Florida
Got more coming. Kind of in a hurry to get it seaworthy before labor day, so im just epoxy priming the patches for now. Big, white slanted stripes. Man, once sprayed you can sure see where you need to go back and fill/sand, etc. That Interlux epoxy primer is THICK out of the can! Once reduced, it sprayed really nicely though.

The guy i got the boat from "repaired" the starboard front wing. I went to sand it flush, etc. before priming it and boy, was i disappointed. It was an 8x11ish rectangular patch with what appeared to be a rather thick layer of gel coat. The problem was all the silicone caulk around the perimeter of the patch... SO, i had to dig all that out, recess back a bit and then fill the perimeter with chopped carbon/epoxy/silica. Worked great, but i don't know what the guy was thinking using silicone. Sometime at the end of summer, ill strip the whole boat and do a proper paint job. Right now, its time to get it on the water and see what else needs to be done.
Is your boat a Stars and Stripes edition with gunsmoke blue hulls and a very light gray deck?

Bill 404 21SE
Nope. White deck, original. The hulls were sanded down to glass, primed gray and painted that blue. The paint is very thin, but very impressive. I mean TOUGH. The rest of the boat was wet sanded and then buffed with Mcguires swirl remover and Makita buffer. Looks really good for as old and hard of a life it's had. Where the giant, tacky stickers were left light stains that won't come out, but i can't worry about a re-paint as its time to maiden. Looking to try this weekend. It's going back together nicely. Will post pics tomorrow, time permitting.
So, added pics. Cleaning up way better than I thought it would. The thing was REALLY rough when I bought it, but solid, no soft spots and no blisters. What I don't like - a lot - is that the previous owner painted the bottom with ablative bottom paint. I think it looks ugly and was likely done for 1 or 2 (or both) reasons: hiding a rough bottom job and/or because he kept it moored in a fresh water lake.

Also bought some replacement end-caps for the wings, designed for "exercise equipment". Worked great. Thought that was ironically fitting. Those are in the album.

Hey Bill404/anyone - do you trailer the mast with the comptip facing forward or back? Seems like back would be more convenient for raising mast, but also more likely to get permanently damaged by accident. Don't know...
Hey Chuck,
I trailer my mast with the comtip riding just on the rear mast caddy to bear it's weight. This way the comtip is supported but doesn't carry the weight of the lower section. You don't want the comtip unsupported potentially bouncing about on the highway. My rear mast caddy is 7' off the ground, just as high as my hands can reach. And well above most tailgaters.

My trailer is the definition of over built. I order the trailer without crossbars or a rear mast caddy and with capable of carrying the weight of 2nd 21 if I wanted too. Still looking for that 2nd boat.
Way way over built..... denk

As a young man in the sheet metal trade and looked at the trailer as a way to define my abilities....the cross bars telescope in and out to match the boat which also telescopes.The rear mast caddy is removable and carries the mast level to the road. I use a 10' tall aluminum ladder to support my mast before stepping it. This give me the opportunity comb out the standing rigging and to have the mast at shoulder height instead low. We use a crane style mechanism on the forward mast caddy that raises that 33' long beast with a winch. I can do this solo but prefer help.

Most of my sailing is solo so being able to setup my boat without crew was paramount. I did trailer my boat wide for 20 plus years without issue.....except once at a toll booth. doh That where the trailers side guides knocked the toll booths basket to the ground....alway use the outside lane at a toll booth. icon_lol

Bill 404 21SE