Butyl Tape Question

[SMHolmans]

I just purchased a reel of butyl tape to see if it is any good for sealing fittings. I'm not convinced. Any views>?

[dbeck]

We've used butyltape throughout the build. Basically at all drill-fill-drill through the hull, for the acrylic ports in the cabin, for the vents and the inspection ports at bulkhead #1 and the centreboard case and for sealing the lazarettes hatches to the deck. We sail the 2nd season, we did not have a single drop in the cabin yet. The only place were we used marine sealant has been with the installation of the bow eye.

Our butyltape is rather sticky and once installed it will be - unlike a rubber sealing - harder to remove. I recommend a dry fit prior the final installation with butyltape.

We had purchased a roll of 19mm width and 3mm thickness, thinner would be better maybe. Usually I did cut it into smaller strips with scissors and then formed a ring of the required size.

Butyltape is much less messy than using marine sealant and I would always do it again this way. As the only downside, I usually used to much and there was some squeeze out that I had to remove with some small piece of wood.

[slash2]

I used it just as dbeck did. I think it’s an excellent sealer. The only trouble I had with it was when I used it to seal my removable companionway hatch assembly to the cabin. It’s a long joint and was hard to keep everything aligned and under control. But it did the job. It’s used extensively in roofing, so I imagine it must perform well.

I’m curious, did you just not like it, or did experience a failure?

[SMHolmans]

I haven't used it yet. To my mind it looks really thick (2mm) and will cause a lot of squeeze-out and mess. I'm also concerned it will set too hard to allow easy removal of hardware.

[dbeck]

Steve, yes, squeeze out is an issue. But it’s rather easy to remove with a wood piece (I used wood to avoid scratching the finish). But in my opinion the application is much easier than with marine sealant.

For minimizing squeeze out I usually cut/form pieces that are much smaller than the surface to be sealed. As an example, if the contact surface of an inspection port is a ring of 1cm width, I just used/formed a butylring of less than 0.5cm.

Just try,

Dietrich

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I used a lot of white butyl tape on my boat, for example to bed all the deck fittings. I never laid down a flat piece directly from the roll - I tore off a bit,
rolled it into a cylinder, and made a little donut. to put around the bolt(s) that held the fitting. Yes it squeezes out, but I just
used a tongue depressor sharpened like a chisel to remove the excess.

I used "Loctite PL Marine Fast Cure" for sealing the companionway hood to the cabin roof, and I am happy with it. It is very strong, dries fast, and Lowe's (in the USA) carries it.
It's also a lot less expensive than the comparable 3M products. Its only downside is that it can get some mildew.
Loctite is owned by Henkel, so the same stuff is probably available in Europe under a different name.

[dbeck]

just to avoid a misunderstanding: we used thickened epoxy to glue the companionway to the cabin roof; we used butyl only as sealing material elsewhere.

Dietrich