Fixing thru-deck screw leaks

[Civilitas]

So to preface, this is for a friend's sailboat I agreed to help them with.

This is a lovely, well maintained classic Pearson Renegade. The cockpit grab-rails leak through the base, and through the securing screw penetrations. I don't have a website to link pics to, though I have them.

What is the Bristol way to fix this? I am tempted to remove the screws and rails, re-assemble everything with 5200 fast.

 

[Comodave]

I would do them just like what is shown on Compass Marine’s website. Pbase.com has a very through description of how to do it along with photos. It is an involved process but it works.

 

[Lepke]

Squirt epoxy in the hole, then drive the screw. The epoxy holds better to fiberglass, wood, etc., than the screw. And epoxy bonds well to the screw. It also keeps water from weeping down the screw threads. The only drawback is later the screws are difficult to remove. I use a small impact wrench to remove epoxied screws.

I been doing it this way for about 50 years and can't remember a failure on any of my boats or boats I worked on.

 

[kchace]

I definitely would not use 5200. Either epoxy as Lepke mentioned or 4200 or uv4000.

Ken

 

[Civilitas]

Thank you all. I see the issue now. I think this is the link comodave meant, on using tape and countersinking:

https://marinehowto.com/bed-it-tape/

 

[meridian]

I wipe the screw threads with Vaseline before I set them in epoxy. Worst case a soldering iron to the screw head frees it up.

 

[boathealer]

Here's a drawing I made some time ago of what I do:

 

[Comodave]

That is the way to do it.

 

[Civilitas]

I am guessing the “washer” qualified in the drawing refers to butyl tape or...?

 

[boathealer]

I am guessing the “washer” qualified in the drawing refers to butyl tape or...?

Yes - your sealer of choice.

 

[Comodave]

Buytl tape is the way to go if you are through bolting.

 

[TDunn]

Yup butyl tape.

 

[DDW]

A lot of people love butyl tape. I hate it, and use 3M 4000 UV instead.

 

[Bacchus]

+1 for Butyl tape...
I've used the Compass Marine stuff as well as others and do like the one CM sells much better.

 

[kwmeyer13]

Another vote for butyl tape and Compass Marine. It remains soft tacky and flexible and I think that those are great qualities for a bonding/waterproofing agent. Especially on a sailboat where stresses and twisting can come from any and all directions. My brother uses it on his sailboat. He replaced 12 portlights and used butyl tape and has never had any issues. I have resealed my Pilothouse hatches and center windshield panel with it and could not be happier.

 

[dhays]

I’ve been using butyl tape for a while now on several boats. I think it is great to use when you want a sealant in an application where you don’t need/want an adhesive.

My last use was for sealing a holding tank vent fitting a couple months ago. One advantage it has over adhesive sealants such as 3M 4000, 4200, or 5200 is that it is really cheap and you don’t have to worry about the unused portion curing. On the vent, I would have spent 20$ on a 3 oz tube of 3M 4000 and then tossed it. (Yeah, I did read the thread on storing open tubes.) I have a lifetime supply of butyl tape on the boat that never goes back and is always available to use when needed. That lifetime supply cost me less then two 3oz tubes of 3M 4000 years ago. It also isn’t messy like 4000 and its like. Maybe I’m just clumsy but I always make a mess with that stuff.

 

[Comodave]

I just replaced 11 portholes and bedded the new ones with butyl tape. I don’t use caulk on anything that is through bolted. If I am screwing something then I use caulk because I cannot get enough pressure on butyl to get proper squeeze out without stripping the screw threads out in the fiberglass. Especially on something like handrail stanchions where people lean against the rail and the stanchion base wiggles a bit. With caulking you will break the seal, with butyl it just stretches a bit and still seals. I also like Compass Marines butyl.

 

[JDCAVE]

Just to be sure: the grab rails are attached to FRP and not teak? If tank it’s a different process. If FRP, the Compass Marine method is the way to go.

 

[ksanders]

I guess I fall into the 5200 camp.

Rails are through bolted with a washer on the bottom.

I remove the bolts, gob some 5200 fast Cure in the hole, and re-assemble.

Never had one leak afterward.

The 5200 does not “glue” the bolt to twisting motion so you can still remove them.

This is relatively quick, It’s easy, you can do it in the rain, and it works.

I see no downside.

 

[Jeff F]

Interesting discussion. I'm going to try butyl on a replacement stantion I have to install.

To the OP: do you know whether there is coring in that area? Hopefully not but if so be prepared for more work.

 

[DDW]

The problem with butyl tape is it does not harden. You put it under something, tighten the fasteners, and the stuff oozes out from under for the next 10 years. If the fitting is under any shear stress, it slides around on the ooze this way and that way. And the fasteners loosed over time as the stuff oozes out, tighten them more and more oozes out. Something like 3M 4000, after a couple of days it's done doing what it's going to do. It is a bit messier to use for the 20 minutes that it takes to bed the fitting, but less messy for the rest of the decade.

 

[Comodave]

I use butyl tape under through bolted fittings and tighten them 3 times over a period of 3 to 5 days. Yes the butyl does ooze out during that time but I have never had any fittings slide around. I leave the ooze out until the fitting is completely tight and then peel it off. Easy cleanup. It is good that it does not harden up and that it stays flexible. Each one to his or her own, but I love using butyl.

 

[Civilitas]

Interesting discussion. I'm going to try butyl on a replacement stantion I have to install.

To the OP: do you know whether there is coring in that area? Hopefully not but if so be prepared for more work.

I had thought, mostly because of age, it was not. But this made me hunt for an answer and I found an old Practicle Sailor article that said it is balsa cored in the decks and I assume thus there, too (the hull is solid, though). I am goign to remove the rails tomorrow so we shall see...

 

[ksanders]

The problem with butyl tape is it does not harden. You put it under something, tighten the fasteners, and the stuff oozes out from under for the next 10 years. If the fitting is under any shear stress, it slides around on the ooze this way and that way. And the fasteners loosed over time as the stuff oozes out, tighten them more and more oozes out. Something like 3M 4000, after a couple of days it's done doing what it's going to do. It is a bit messier to use for the 20 minutes that it takes to bed the fitting, but less messy for the rest of the decade.

Thats my thought as well.

It might be a bit messy but 5200 and it’s variants work, they work well, and they work pretty much forever.

I buy the stuff in the little micro tubes, and keep a can of acetone around for cleanup.

 

[Seevee]

Good suggestions....

I like what ever works for the situation....

if structural, I like a good backing plate glued on with 5200, bolted with structural washer top and bottom, but like to bevel and seal the top with the CM butyl tape to prevent leaking. Works well.

The tape is only to seal it, not to hold anything, and it does a great job of sealing and easy to use.

 

[Comodave]

I don’t use 5200 on anything except a thru hull because I may need to remove the fitting someday. 5200 is possible to remove but it is very difficult to remove it.