Bed a fitting to non-skid or fiberglass?

[zachduckworth]

Hi,
I’m installing a 4” round access port on the floor of my cockpit. I’ve faired the fiberglass down. Should I caulk the fitting directly to the fiberglass, then re-do the non-skid or re-do the non-skid and caulk to it?
For the record I’m doing this to plug the hole the pedestal left when I pulled it out to convert to a tiller. The pedestal was in place for 37 years, did not leak, and was caulked to a layer of non-skid.

[Midday Gun]

Caulking directly to the fiberglass is better.

If you're worried about getting non skid on your new access port you can mask off the area it sits & paint first.

[Rumrace]

You can get matching moulds for most non-skid patterns. Does your access hole have inner and outer parts with a 1/4 turn lock centre. They usually need a 3/8 smooth lip.

[ItDepends]

My suggestion is to do whatever looks best.

You can certainly get a good waterproof seal to non-skid if that's what you prefer (witness your old steering pillar...)

[flee27]

bedding to non skid is not a problem IMO. I also would suggest looking into Bed It butyl tape and not caulk. Especially if there is any flex in your cockpit sole. Bed It does not ever harden so the seal will not be broken by flex. I personally have never had anything the I bedded with Bed It leak. I use it for everything that I am not looking for any bonding properties from "sealant".

Foster

[PerfectPirate]

I second flee27's recommendation of Bed-it butyl tape. Anything which I have bedded with butyl tape has never leaked. Any time I tried any of the many recommended sealants, they always started leaking after a year or two.

When I started working on deck fittings on my recently acquired 47-year old boat, the ones which the builder had put down with butyl were still bone dry. All of the fittings which previous owners had put down with sealants had allowed moisture to penetrate the deck core.

[michaeld]

I dug out a roll of butyl tape that was stored away sealed in a plastic bag. It was very stiff. I decided to discard it. We have two deck prisms that have redeveloped drips/leaks during heavy rain. I just order a roll of Bed-It from Hamilton Marine. I'll report on it when I get this project done.

[CarlF]

Another vote for Bedit butyl in this application. Part of the instructions for Bedit from Rod is to go back later (next day or later) and tighten the fasteners a bit more. Do this again another day later. This helps the butyl to flow into the tiniest crevices.

I expect it would be fine over the nonskid but it would be easy to trowel on some polyester fairing compound and sand smooth before mounting. You could leave about 1/4 of unfilled nonskid at the edge to be sure the filler doesn’t show.