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jjccp · 07-04-2022, 09:15

This is on a San Juan 23. I'm somewhat familiar with butyl and mounting hardware, I redid all the deck hardware on my boat last year and have some understanding of refilling, redrilling, chamfering, etc. with no leak so far.

See pics

The track sits in a recessed well that collects rain water and there is no drain for the well. It was leaking a bit. Note that the track itself is a U shape and the open part of the U goes down on to the fiberglass of the well. Where the holes are for the bolts to go through the fiberglass, nothing will be pushing down on the butyl, at the hole to seal it. Also, there are end caps for the track (not pictured)

I was considering either 2 separate beads of butyl along each side of the bottom of the track or 1 wide sheet along the entire length and width of the bottom of the track. That way there would be some butyl in the middle/open area and when the bolt goes through it, it will at least push some down the hole.

What do you think?

psk125 · 07-04-2022, 09:21

Have not used butyl for installing deck gear. Using a different sealant - 3M 4200? - for the bolts and bolt holes and then butyl for the edges might work. It would be tempting to create a drain into the cockpit for the trough.

Shrew · 07-04-2022, 09:24

I would lay down a thick solid bed of butyl tape, install the track, trim the edges.

Chotu · 07-04-2022, 09:26

Quote:

Originally Posted by Shrew

I would lay down a thick solid bed of butyl tape, install the track, trim the edges.

That’s exactly what I do also. Never leaks.

A nice big strip all along the whole thing. I also put some under each bolt head.

Spot · 07-04-2022, 09:35

What would having some 1/8" 3.2mm G10 washers epoxied at the bolt hole locations look like? Then selectively apply butyl to the tops of them and the bolts. The drain(s) would be my preferred solution but would involve some commitment on drilling and glassing and gel coat touch-up to the visible cockpit and track channel.

Weatherbird · 07-04-2022, 09:44

You could install a strip of aluminum the same dimensions as the track underneath it.

jjccp · 07-04-2022, 10:55

Quote:

Originally Posted by Weatherbird

You could install a strip of aluminum the same dimensions as the track underneath it.

Thank you all for the great ideas. That's why I love this place.

Weatherbird, your idea got me thinking. Instead of a continuous strip, what if I make and install some 1/4" or even 1/8" thick by 1" long solid aluminum spacers at each mounting screw and a couple of longer formed spacers to support the track end stops? This would squish the butyl at the holes and also raise the track and give me some amount of drainage just from the boat rocking.

jjccp · 07-04-2022, 10:57

Quote:

Originally Posted by Chotu

That’s exactly what I do also. Never leaks.

A nice big strip all along the whole thing. I also put some under each bolt head.

Yes, forgot to mention, for sure some under each bolt head too.

Weatherbird · 07-04-2022, 12:46

Quote:

Originally Posted by jjccp

Weatherbird, your idea got me thinking. Instead of a continuous strip, what if I make and install some 1/4" or even 1/8" thick by 1" long solid aluminum spacers at each mounting screw and a couple of longer formed spacers to support the track end stops? This would squish the butyl at the holes and also raise the track and give me some amount of drainage just from the boat rocking.

So basically a strip but cut to leave unsupported spans in between the screws to allow for drainage? Makes sense to me.

I might make each of the spacers take two screws to help keep them straight.

Jerry Woodward · 07-04-2022, 15:46

You might also want to read the article in Marinehowto.com. The butyl tape he endorses and sold in his on line store (the store is no longer open due to health) is called Bed It. That's what I use and it is great stuff. I don't know if you can get it elsewhere.

deblen · 07-04-2022, 19:34

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

Don't forget to bevel the holes per this link. Cheers/Len

PerfectPirate · 07-04-2022, 21:12

Don't overthink this or get too complicated in your approach. In a situation like yours, I would lay a very thin strip of butyl along each bottom flange of the track. This is simply an aid to bedding it against the gelcoat, not for waterproofing. To waterproof the fasteners, I would insert the bolts through the track prior to mounting. Pinch the butyl on the bottom flanges in a bit, to hold each bolt in place. Then, wrap a thin layer of butyl around the threads of each bolt where it will be passing through the fiberglass. This butyl will provide the actual sealing against water penetration.

When everything is prepped, carefully maneuver the track into place, locating each bolt into its proper hole. Then, oh so carefully, try to work the track and bolts down evenly along the length of the track. Once you have enough threads through the fiberglass, then you can pull them down using the nuts, doing a few turns on each nut and then moving on to the next. Repeat until fully tight. If you have gauged things properly, once each bolt is fully seated there should be just a hint of butyl showing on the bolt threads underneath, before the nut is on.

I had a very similar track installation on my C&C 27 and over 16 years it never leaked that I could detect. Also, this is the approach which the builder used for the cleats and stanchions on my current boat. When I pulled those bolts last summer everything was still bone dry after 46 years of sailing. Definitely don't use silicone. 4200 will cure and degrade from UV over a few years, resulting in leaks when the track works under load. I speak from experience on that. Everything that I have ever bedded with butyl has never leaked, but it is important to carry it down into the hole.

Spot · 08-04-2022, 05:06

Because this track is an open channel, putting butyl on the bottom of it does not confine it in such a fashion that it will seal at its best. The spacers under the track would create a nice place for the butyl, esp. if they had the small chamfer recommended by others to create an o-ring effect. I am no longer suggesting epoxying the spacers to the boat now that I have take a better look at the track channel.

Is Ron back in business with the Bed-It product? I thought sales were on hold due to health issues.

A drain is still important otherwise the joints are constantly 'soaking in the bathtub' so to speak.

jjccp · 08-04-2022, 07:10

Quote:

Originally Posted by Jerry Woodward

You might also want to read the article in Marinehowto.com. The butyl tape he endorses and sold in his on line store (the store is no longer open due to health) is called Bed It. That's what I use and it is great stuff. I don't know if you can get it elsewhere.

Yes, thank you for that. I think I've read every word on Marinehowto.com and I have the Bed It tape. Excellent info on that site.