Stripped out threaded holes in deck

[kip]

The uprights for the lifelines on my boat are screwed to the deck with 1/4-20 SS bolts.

Over the years, some of these holes have stripped out. I have repeatedly filled the holes with different compounds and retapped them, but the repair never holds very long.

Any expert advice out there?

Kip

PS: We are in the Dominican Republic - so no West Marine on the corner.

[CharlieCobra]

Use epoxy, longer screws and a backing plate where possible.

[sailingdog]

I am guessing that through bolting is out of the question.

Is the deck cored? If so, I would do the following:

1. Drill a hole about 3/4" in diameter using a forstner bit. Try not to drill through the inner laminate.
2. Dig out the core around the hole for about 1/2" or so.
3. Take a bolt, coat it heavily with release wax and screw it into a t-nut like the one pictured below until it was flush with the bottom of the t-nut.
4. Put the t-nut in the hole and fill the hole with thickened epoxy. Because you've dug out the core in the area surrounding the bolt, it will create a larger "plug" of thickened epoxy that the bolt and t-nut are part of... so it will be very unlikely to pull out.
5. Unscrew the bolt after the epoxy cures. The screw hole will have cast threads in the epoxy as well as the stainless steel t-nut threads at the bottom
6. Countersink the top of each bolt hole slightly. Use a countersink bit while the drill is in reverse.
7. Screw the stanchion down. You'll want screws that are cut to just slightly shorter than the thickness of the epoxy "plug" and stanchion base.

[toewsrus]

This has happened to me on two seperate occasions. I've used a Helicoil kit and so far so good.

I drill out the hole, fill with epoxy, redrill with the proper drill, put in some thickened west epoxy and thread in the repair insert. 5200 the whole thing when putting back together. It's held so far.

I would have rather through drilled and put a backing plate, but it's not possible to do with the outboard screws.

the kits are expensive, but they work so i guess it was cheaper than a new boat. You can get the kits at Fastenal or a cheaper kit I've gotten at Advance Auto Parts.

[sailingdog]

helicoils are far more likely to strip out IMHO than t-nuts embedded in the bottom of the epoxy plug.