Re-Bedding Fixtures and an Apology

[thataway]

I have used a number of Bimini tops on boats for over 60 years. I never had to remove the deck fittings (SS). There should be pins or bolts holding the frame to the deck fittings. Those should be unloosed if you need to take the frame off. The Bimini should have zippers on the part you use on the bows--they zip on and off.

My experience with Butyl take is mostly on RV's and I had yet to see one instance where there was not some dirt and water trapped under the fitting and the fiberglass or metal that it is attached to. That experience is also over a period of 60 years. I would use 4000 or 4200.

[Donald Tyson]

Well there ya have it...60yrs is a long time as I'm only 66. I like 5200 and 4200 but I'm going to use (amazon just dropped it off) 4000 Fast cure UV. I had some experience on my Skiff that casued me to remove the mounts, I forget what and why, It was so easy as there was no bedding used on the outside open gunnels.

[olsurfdog]

I first came across over drilling and creating a epoxy plug around bolt holes through a balsa cored deck and cabin tops while helping a friend commission a new boat about 35 years ago. The rigger who showed us how to do this also had us countersink the new bolt holes to form a small v-groove around the bolt when the fitting was replaced. This v-groove filled with caulk when the fitting was rebedded— sort of an additional o-ring of caulk. We redid all of then deck fittings including the lifeline stanchions. All these years latter non of the fittings have ever leaked and are still our original job. The balsa core is dry unlike her sister ships that were not redone. I don’t remember what caulk was used, probably 4200 or similar.

[Donald Tyson]

I take it you did not overdrill, fill with epoxy and redial before you bedded?

30and again 35 years ago I used Lifecaulk, a polysulfide. It had idiosyncrasies and I was poor at accommodating them. Took forever to cure. I always made a mess of it though thankfully it was effective in waterproofing.

[Donald Tyson]

The Bimini product I'm using did not come with backing plates and only roundhead wood screws came with it. Furthermore when I drilled the holes guess what? Yup, wood fiber came out. I thought for sure that this area had no core. But it did.
Now I will over drill and fill with epoxy and then redial tomorrow. Bummer. nice to have a long weekend to do this unexpected extra work.
For backing plates I am thinking to use fiberglass. I recently cut up a 15' 1972 tri-hull ski boat. I have lots of pieces of it to use however I need and I think that with large washers these trimmed pieces of 3/8" fiberglass will make nice backing plates for the few pieces of Bimini hardware.

[olsurfdog]

Donald, sorry, I guess I wasn’t very clear. We did over drill the holes (using a small Allen wrench chucked up in a drill), filled the cavity with thickened epoxy and then re-drilled the bolt hole and lastly added the counter sink. Thickened the epoxy with fiberglass saw dust. We also added quite a few stainless backing plates. Too bad the manufacturer didn’t do all this in the first place. I guess understandable from a cost point of view but it still needed to be done! Cost a lot more to repair rotten spongy decks.

[thataway]

[Donald Tyson]

Drill and fill, drill and fill, drill and fill...

[thataway]

Drill, undercut, fill, drill pilot hole.

[Donald Tyson]

Yes.

[olsurfdog]

As per my original post I would add to Dr Bob:

drill, undercut, fill, drill pilot hole, countersink

Not 200% sure the countersink adds much but it makes me feel better!