Epoxied in place deck mount plate, has anyone done this?

[Bob Quinn]

Just curious as I am chasing leaking screw holes in my deck....
Has anyone tried any kind of epoxied down plate to mount things to?
I have my two front deck boxes that are screwed to the bow deck, and at least one of the small screws has broken off and created a leak. I siliconed the hole for now but I am growing to hate the idea screws in the deck that ultimately will be a leak some day.
So I was thinking about the possibility of some 316 SS pucks with a 1/4-20 tapped hole in the center that could be epoxied in place for holding things down.
a 1/4-20 screw has approximately 2000 lbs of tensile strength and epoxy has a tensile strength of about 5000 lbs per square inch. Theoretically the epoxy could be much stronger than any wood screw screwed into a deck plate.
Your thoughts?


66658

[rob71]

I have the same aversion to screws into the decks.
I mounted benches on the fly bridge with 5200. 4 aluminum stanchions with 3X3 inch base plates glued to the deck. They have held fine for several years.

[Bob Quinn]

I have the same aversion to screws into the decks.
I mounted benches on the fly bridge with 5200. 4 aluminum stanchions with 3X3 inch base plates glued to the deck. They have held fine for several years.

5200 is probably better than epoxy, it would give it the ability to flex a little!

Also, good to know it is feasible :) I think I will give it a try.

[Pascal]

Epoxy doesn’t stick very well to SS and I wouldn’t trust 5200 either. Best option would be to make the pucks out of Coosa which will bond very well with epoxy.

[Bob Quinn]

Epoxy doesn’t stick very well to SS and I wouldn’t trust 5200 either. Best option would be to make the pucks out of Coosa which will bond very well with epoxy.

I like that idea. they could then also be painted to match the deck which would be one less thing to have to try to polish. Maybe use some 316 Stainless thread inserts - if they are available. I have been looking for some, but haven't been able to find any yet. I will keep looking.

[KPTIM]

McMaster-Carr has 316 Stainless thread inserts in stock.
They have true thread inserts that you can use a standard drill and tap to install, no special installation tool needed.
They are not heli-coil inserts.

[brettportzer]

Doesn't West System say you can tap threads into their epoxy?

So maybe coosa blocks with over sized holes drilled out to be tapped?

[Pascal]

Putting insert underneath the Coosa is going to be tricky as epoxy will get in the threads.

West Syatem and 404 filler is tough but I be never tried tapping it. I think coarse screws or even lag bolts with a bit of epoxy or 5200 in the thread is going to be stronger than needed

[OVERBOARD]

I have taked a Dremel, with a 1/4 inch carbide cutter and plunged through the deck, and removed all the balsa core. I hold the vacuum while grinding out the balsa core. I mask the surrounding area and fill the void with west system epoxy. The epoxy soaks into the surround balsa core. Sand the area and then I use a stainless steel wood screw, and a little 4000. No way water is going to get in, and the bottom layer of fiberglass is not damaged, so nothing leaks out causing a mess.

[jim rosenthal]

I used those SS anchors in my aft deck to mount a dunnage box. Drilled the holes, sealed them with West epoxy, and used them to mount the deck box. So far, so good. 5200 would also work and have the advantage of giving a little, too.

[Briankinley2004]

Here is the "official" instructions for epoxy

https://www.westsystem.com/instruction-2/epoxy-basics/bonding-fasteners-hardware/

[cww]

This is a solution looking for a problem. The way Hatteras did it lasted 30 or 40 years before it needed the screws re-bedded. I had to do this on my upper deck, and it had never been done before, so 1981-2022 is a pretty good run indeed. That's objectively some pretty good performance. Just re-do it the way it's supposed to be done and the odds are that most of us will probably be dead before you have to do it again.

[meteor64]

I have used sheets of G10 fiberglass 1/4 inch thick. I cut to the shape I wanted then epoxied to the existing fiberglass With a spatula, I smoothed the epoxy oozing out at the edge then sanded any sharp edges. This actually sealed the old holes. I then drilled and tapped for 1/4-20 screws. I made round pads to fit under the bridge aft railing. This eliminated the bolts going through the aft deck ceiling. Those bolts used to drip bluish drops due to the copper mesh in the fiberglass. I eliminated about 40 bolts through that roof. All nicely painted now. The G10 fiberglass sheet have many layers of cloth tightly compressed with resin. Threading through it works very well. I ordered 12x12" squares from Amazon. It was fairly cheap, not worth making.