How are you guys sealing screw holes?

[Cheapie408]

About to drill some holes into the floors for cooler tie downs. Thinking about using some 4200. Do you wait for the 4200 to cure a little before tighting?

 

[pelagic2530]

About to drill some holes into the floors for cooler tie downs. Thinking about using some 4200. Do you wait for the 4200 to cure a little before tighting?

Just posted this for another member. See here for the procedure to fill old holes and seal new ones. It’s written for the pilothouse roof, but will work for the deck. With the deck, it’s especially important not to break through the bottom glass, as there’s no access to plug the hole before filling with epoxy.

https://www.classicparker.com/threads/filling-holes.20729/

 

[Cheapie408]

This is what I'm installing, a tiny screw,

https://www.amazon.com/AIEVE-Cooler...eywords=cooler+tie+down&qid=1619285205&sr=8-5
still do the whole epoxy deal? I have some color coded gel coat here and I can mix with cabosil to thicken but is it really necassary for this project?

 

[pelagic2530]

This is what I'm installing, a tiny screw,

https://www.amazon.com/AIEVE-Cooler...eywords=cooler+tie+down&qid=1619285205&sr=8-5
still do the whole epoxy deal? I have some color coded gel coat here and I can mix with cabosil to thicken but is it really necassary for this project?

Can't get the link to load; I'm working offshore and the bandwidth of the satellite internet is pretty limited.

If you're installing anything that's going to break the top layer of fiberglass (about 1/8" thick) and penetrate into the core, the only proper way to do it is to use the epoxy plug. That's the ONLY way you can ensure that water will not get into the core. Even if you're diligent and re-bed all your sealant every couple years (and almost nobody does), you still run the risk of water intrusion, which will lead to rotten decks, deck replacement, saturated foam... it's not a good time.

If you're installing the hardware, the gelcoat is not necessary. All you'll need is the epoxy, and for something small you don't even really need the thickening. I'm not sure if I'm interpreting your statement the right way, but definitely do NOT use gelcoat mixed with cabosil as a filler for this kind of project. Not only is it prohibitively expensive, but it won't have the structural bond to keep the hardware from pulling out. Gelcoat is for aesthetic finishing of repairs and protecting the epoxy from UV exposure; nothing more.

In this case I would drill the hole, making sure not to go through the deck. You can measure the thickness of the deck near a pie plate, bilge hatch, or other access using a C-clamp or other type of caliper device. The hole should be large enough so that once filled with the epoxy plug, you can re-drill a hole into the epoxy that will fit the screw without exposing the wood around/beneath it. Fill the hole with mixed 2-part epoxy; West System sells small packs of epoxy that will be perfect for this job if you don't want to buy a full can of resin and hardener. Once it cures, drill the correct size hole for your fastener. Make sure that the epoxy is fully cured before drilling (fingernail doesn't make a dent). I top off each installation with a dab of 4200 for good measure and for extra insurance against water intrusion.

Can you probably get away with just a dab of 4200? Maybe, in the short term. But it only takes one compromised deck penetration to allow water ingress and start rot, and this is a quick and easy way to prevent that.

 

[Cheapie408]

So without over thinking it, this is what I did... drill the holes, 4200 squeezed into the hole, bed around the hole and the item to be mounted then screw in, the 4200 squeeze through every opening wipe clean and call it quit?

 

[99Parker2520]

Nice work how do you like the Coho?

 

[Cheapie408]

Nice work how do you like the Coho?

I'd like it to be lighter, the cooler is alone is 33lbs @ 165qt it holds quite a bit of fish. I had it half full the other trip and can barely lift it off the boat, took 2 guys to lower it. But otherwise, for the money, I think it's very well belt. Couldn't justify 3x the cost for a yeti.

 

[sydngoose]

4200 will be perfect for your cooler chocks or tie down system. No, don't let the adhesive sealant kick. Install it completely while wet. clean any excess away immediately.

 

[warthog5]

Following Pelagic 2530....is the proper way and can "Assure" that your core does not get screwed up. I can plainly see you hit into the nice wood core in the deck.

Have you ever had a boat with soft floors? It's typical around pieholes.....The sealent breaks down , leaks and has water intrusion into the core.....Thats where it begins...

A Fostner bit on those marked holes creates a square bottom, round hole that is perfect for back filling with epoxy/Cabisol.

Why do we do all this extra? To keep the boat as strong as it was when now.

The # 1 reason a boat rots is water intrusion from lack of attention to details.

The thing is....You can't really watch it do it....and it doesn't happen overnight....It sneeks up and does it after years.

 

[big_tuna]

Can't get the link to load; I'm working offshore and the bandwidth of the satellite internet is pretty limited.

If you're installing anything that's going to break the top layer of fiberglass (about 1/8" thick) and penetrate into the core, the only proper way to do it is to use the epoxy plug. That's the ONLY way you can ensure that water will not get into the core. Even if you're diligent and re-bed all your sealant every couple years (and almost nobody does), you still run the risk of water intrusion, which will lead to rotten decks, deck replacement, saturated foam... it's not a good time.

If you're installing the hardware, the gelcoat is not necessary. All you'll need is the epoxy, and for something small you don't even really need the thickening. I'm not sure if I'm interpreting your statement the right way, but definitely do NOT use gelcoat mixed with cabosil as a filler for this kind of project. Not only is it prohibitively expensive, but it won't have the structural bond to keep the hardware from pulling out. Gelcoat is for aesthetic finishing of repairs and protecting the epoxy from UV exposure; nothing more.

In this case I would drill the hole, making sure not to go through the deck. You can measure the thickness of the deck near a pie plate, bilge hatch, or other access using a C-clamp or other type of caliper device. The hole should be large enough so that once filled with the epoxy plug, you can re-drill a hole into the epoxy that will fit the screw without exposing the wood around/beneath it. Fill the hole with mixed 2-part epoxy; West System sells small packs of epoxy that will be perfect for this job if you don't want to buy a full can of resin and hardener. Once it cures, drill the correct size hole for your fastener. Make sure that the epoxy is fully cured before drilling (fingernail doesn't make a dent). I top off each installation with a dab of 4200 for good measure and for extra insurance against water intrusion.

Can you probably get away with just a dab of 4200? Maybe, in the short term. But it only takes one compromised deck penetration to allow water ingress and start rot, and this is a quick and easy way to prevent that.

Thanks for this description! Is MarineTex okay to use in the application you described?

 

[WildTails]

Just posted this for another member. See here for the procedure to fill old holes and seal new ones. It’s written for the pilothouse roof, but will work for the deck. With the deck, it’s especially important not to break through the bottom glass, as there’s no access to plug the hole before filling with epoxy.

https://www.classicparker.com/threads/filling-holes.20729/

Would the same process apply to mounting something on transom a few inches below the built in fishbox cooler?

 

[warthog5]

I've never used Marine Tex.

 

[pelagic2530]

Thanks for this description! Is MarineTex okay to use in the application you described?

Personally I'd prefer to use West System. But I don't have any experience with MarineTex; looking at their product data I'd say you'd most likely be fine.

 

[pelagic2530]

Would the same process apply to mounting something on transom a few inches below the built in fishbox cooler?

Not sure exactly where you're referring to, but the process is generally the same whenever you're mounting something into a cored surface. The transom is cored with plywood, so my suggestion would be to do it this way. However, if it's in an enclosed compartment above the normal level of bilge water accumulation with very little chance of water ingress, is UV protected, and the holes are small screw holes, you may be ok with just using sealant.

Be aware that filling holes with epoxy on a vertical or near-vertical surface is more difficult, since the epoxy will want to run out of the hole. In this case you'll definitely need the cabosil filler to make a "peanut butter" consistency to avoid the tendency to drip out. I recommend taping around the hole, and using a small spreader to progressively push more epoxy mix into the hole to ensure you fill the hole completely and don't leave an air void in the back. You will still need to tape over the hole once filled to keep the thickened epoxy inside the hole.