How would you fix this ?

[RQF4]

Picture should explain it. Looks like this was the second attempt by the PO. This is the suport arm for the fore deck hatch. All four holes are stripped leaving the screws constantly falling out. The mounting hardware already has the biggest screws they will take. There is no access into this rim, it's a Hunter, there is no access anywhere. I've tried injecting epoxy in the holes but with no backing can not get it to set up right. Epoxy putty wont stick either.

I'm thinking to grind each hole to a dish and lay a couple of pieces of glass mat on, feathered. Then just re-drill 'em. I've never done glass work but figured this would be a good start.

FWIW this is in a live-aboard toddler's room, so keeping him from messing with it is not an option, meaning I dont want any exposed glass. I'm hoping that can be remedied by sanding and painting.

Thanks for any tips or advice!

[sy_gilana]

Well now, have you thought of the following.
1 Butterfly nuts, as for drywalls, they go in through a small hole and then pop open.
2 Move the support to a new location.
3 Add a piece of PVC board to the front 5200 and screws to fix it, then fix the bracket to that with drilled and tapped threads
4 Move it vertically to that ?aluminum? strip and fill the holes with gelcoat.

[bobconnie]

If it was I, I would cut a square out where the holes are at, install a square of hardwood with steel inserts on the centers of the Arm hardware. Then epoxy in place, glass over the wood ,fill and fair and paint, install with proper sainless BOLTS and your done. just a thought ! Bob and Connie

[Blue Stocking]

Rivnut fasteners. Available in stainless or aluminum. Used to place secure female threaded inserts into thin material.

[Boracay]

The grey trim looks like it might be removable. If so remove it and see what access can be found.

Otherwise I'd be tempted to go with the "Butterfly" fasteners. Replace the central carbon steel machine screw with a stainless one.

The big worry would be that the fibreglass there could be wafer thin, and that support strut puts a fair bit of a load on it. Once that toddler starts swinging from it then it's not going to last long.

What about using a small hole saw (2"?) to cut a hole in the headliner. You could then glue an epoxy plug to the underside of the deck and use long bolts into the epoxy plug. Come to think of it you could reinforce the entire back of the hatch surround with epoxy once you can get behind it. Drill and tap into the epoxy.

[minaret]

Sometimes pop rivets will work as quick fix for that sort of thing.

[Nicholson58]

All band-aids. Use a die grinder or Dremmel to open the holes big enough to see what you are doing. Drive and/or pack in whatever seems appropriate to whatever you find inside. I am partial to gray Marine Tex if you cna find proper bedding and back-up. Otherwise, perhaps resin soaked glass mat. You hope to find material to bond to on the other side even if you have to fill the cavity solid.

[delmarrey]

From a Machinist point of view, I would take a 1/4" thick SS flat bar about 6" long and as wide as the FG area. Then bend about 2" of it to go around the corner. Drill about 8 small holes around the edges for #8 screws for mounting, then transfer the screw holes to the FG and drill and tap the FG for #8 machine screws as deep as you can.

Then drill and tap the flat bar for the support arm bracket for what ever size it takes. Then smooth of all sharp corners and polish it up to what ever suits you.

With 3M-5200 mount the SS plate using the (8) #8 screws and fair in the 5200 around the edges.
Then mount the support bracket. You may have to drill into the FG and re-tap it for the support bracket screws.

And that'll be stronger then anything you could do to the existing FG and still be cosmetically nice.

[roverhi]

If there is nothing behind the fiberglass, fill the holes with that foam you buy in cans for sealing pukas in houses. Don't use the stuff that says it doesn't expand because it never really hardens. With the stuff that does expand, don't put too much in because it really does expand with considerable force and can distort the fascia. Use a #199 dremel bit and rout out the foam around the pukas. The foam that's left will contain the thickened epoxy that you squirt in the pukas with a syringe. When the epoxy has kicked, drill out the hardened epoxy and reattach the hardware with self tapping screws.

The foam trick works when you have to fill pukas with epoxy anywhere you can't get at the back to contain the epoxy like with a liner.

[RQF4]

Wow, those are great ideas. Now I feel kind of dumb for not having come up with some of those, like just move the mounting location! I could just move it down tight to the trim and fill the old holes, I never even thought of that. Although I would then probably be looking at the same problem soon enough again. By the way the trim is just rubber like and hides nothing useful from what I remember, just a cosmetic thing.

Funny comment about the boy swinging from the arms as we have just reached that stage, hence the rise on the priority list.

I had thought of butterfly nuts but avoided them for concern that (perhaps if I ever removed one) I would lose the nut in the rim. Rivnuts look awesome, never seen them before. Great tip on using expanding foam for epoxy backing. I like the ideas of adding a plate too.

I think I have some ideas to work with, thanks everyone!

[atoll]

could just get rid of the bar and use the bungy cord and line system,that way you dont even have to get up from the bed to close it!

[s/v Jedi]

Much depends on how thick the fiberglass laminate is. If it is thick enough for screws, and the area behind it is hollow without access, the following is the preferred fiberglass repair:

Cut a hole with a holesaw 1" diameter or more, in the center of where the bracket attaches. This gives you access to clean and prep the void behind. Also bevel the edge of the hole using a Dremel drum sander or file.

Now you need to add a layer of fiberglass to the back, where you have no access. Use this trick for that: cut a circle 3" diameter from fiberglass cloth. Using a flat surface, put down a sheet of waxed paper (like used for baking) and the cloth circle on top. Mix some epoxy resin with hardener and pour on the center of the circle. Carefully use a brush to spread it. Let cure 24 hours.

Now remove from the paper and clean up a bit. Scrub with scotchbrite under running water and dry.

Use sailmakers needle and waxed thread to attach a length of thread to the center of this wafer. Punch through and 1/4" away back and tie a loop, leaving a foot or more of thread.

Now mix some epoxy resin with hardener. Add colloidal silica (=cabosil) to make it syrup consistency. Through the hole, wet the backside around the hole. Also wet out the wafer on the side of the string. Now roll up the wafer and push through the hole. Do NOT let go of the other end of the string! It will spring back to wafer shape once through the hole. Manouver it so that the string attachment comes to the center of the hole. By putting tension on the string, the wafer will form even around a corner on the inside if needed. Tie the string off to something and let cure.

Cut the loop of the string and pull it out the wafer. Now it's just a regular repair using circles of cloth and epoxy and fairing it out. For inside, I add white pigment to the fairing epoxy which makes it like marinetex to match color. When ready new holes for fasteners can be drilled. Tap this and use machine screws instead of self tapping screws.

This method is based on the Gougeon Brothers book "on boat construction".

ciao!
Nick.

[SailFastTri]

Originally Posted by delmarrey

From a Machinist point of view, I would take a 1/4" thick SS flat bar about 6" long and as wide as the FG area. Then bend about 2" of it to go around the corner. Drill about 8 small holes around the edges for #8 screws for mounting, then transfer the screw holes to the FG and drill and tap the FG for #8 machine screws as deep as you can.

Then drill and tap the flat bar for the support arm bracket for what ever size it takes. Then smooth of all sharp corners and polish it up to what ever suits you.

With 3M-5200 mount the SS plate using the (8) #8 screws and fair in the 5200 around the edges.
Then mount the support bracket. You may have to drill into the FG and re-tap it for the support bracket screws.

And that'll be stronger then anything you could do to the existing FG and still be cosmetically nice.

delmarrey you gave the best solution, IMHO. Good on ya! Best strength for minimal modification to structure, and it does not need special skills to make it look nice. I would add that the OP should take care to smooth all the metal edges.

I would emphatically advise against using expanding foam. It has no structural strength and no use as a backing or deck filler. (It has no use on a boat, IMHO, unless perhaps as an insulator -- but it's not even ideal for that because it can trap/hold condensation/moisture).

[minaret]

I'm surprised at all of the people suggesting drilling and tapping into solid fiberglass or even epoxy filler. I would never ever do this in a pro setting, it is gauranteed to fail. Glass and filler are just too brittle to hold a fastener for long, it's just not done. You need to tap into something more substantial if that's the route you prefer. Otherwise you'll be back to square one very quickly. A lot of the methods mentioned here are surprisingly time consuming as well. I would fix this in five minutes or less with a rivet gun, and it would be stronger than the screws ever were. Actually looks good too.

[s/v Jedi]

Put the math to tapping fiberglass/epoxy lay-up... I did once and lay up thickness of 1.5x diameter of fastener with 70% thread depth matches the regular nut for the screw.

Will not work in just epoxy with filler without going for more thread length. But that can be done too if using the high density filler. This is often done to fasten genoa tracks on cored decks, eliminating through-bolting it. (Using 1/2" holesaw through outer laminate + core and filling it with the epoxy + high density filler) You need much more thread length of course, but these decks often have 1" balsa core so more than enough room to work with.

These epoxy plugs have a risk of being pulled out (never saw that happen though). I always sand away some of the core under the top layer laminate with Dremel drum sander. This locks the plug in.

p.s. for this repair I agree with using rivets... how strong does it have to be?!

ciao!
Nick.