Reinstalling Hollow Half Round

[angus99]

I removed all of the steel half round on our boat to paint the teak rubrail beneath it. Looking for the proper way to reinstall it. It looks like it had been originally packed with Dolfinite or some other bedding compound, which would really complicate the job.

Thinking I might wrap a bit of butyl tape around each screw to waterproof the wood penetrations and declare victory. Is there a better/preferred way?

Thanks in advance.

 

[rslifkin]

On my boat the similar stuff used for a rub rail is only sealed at the screw holes. The only benefit to sealing up the whole thing would be to keep dirt from getting behind it.

 

[Larry M]

I filled, predrilled and caulked. When I removed ours, a few of the screws were stripped so I filled with a polyester resin, predrilled the holes and then some caulk on the screw threads before reinstalling. If I had too much caulk, it cleaned up easily with mineral spirits. YMMV

 

[rslifkin]

Thinking back to when I removed some of mine, I caulked the screws with 4200. Nice and easy for the install. Just a little glob into the hole, a bit on the screw threads, and pop the screw in. Stop every few screws to wipe off any excess.

 

[angus99]

Thank you both!

 

[Comodave]

I have used Sika 291.

 

[twistedtree]

I think if there is any sort of a cavity behind the rail that can get water into it, you will get rust bleeding out from the rail. This is why stainless is typically fully bedded, and why your rail was originally filled with sealer.

 

[rslifkin]

I think if there is any sort of a cavity behind the rail that can get water into it, you will get rust bleeding out from the rail. This is why stainless is typically fully bedded, and why your rail was originally filled with sealer.

Interestingly, my boat has never had this issue. It seems that it's not a tight enough space to actually hold water (and they used good stainless), so even after 38 years the rub-rail doesn't show any rust (or rust drips from behind).

 

[Snapdragon III]

I would bed the whole back of it in Butyl tape. You can order it in all kinds of sizes. Find a size that would fill up the back in a single pass. Not bedding it will lead to rust seeping out of it, and a loss of your sanity.

 

[angus99]

Thanks, all.

I use butyl everywhere I can on our boat for bedding. I used it to wrap the screws only—not the voids in between—securing the half-round on our hand and toe rails. Really a tedious, cumbersome process for a few hundred screws, but three years later, I’m not seeing any rust.

I thought about filling the entire voids on the rubrails with butyl but have two concerns. It doesn’t compress readily and will actually cause anything that’s even slightly overfilled to stand off. Also, if you try to fill the entire void and then penetrate it with a screw, it will sometimes wrap around the threads and pull apart, leaving voids.

I’m thinking this may be a job for a caulk that will fill and spread out; just not anything too tenacious for the next poor sap that has to remove the half-round. And, for RT’s benefit, definitely not silicone.

 

[Bmarler]

Dolphinite is good for that application. Cheap, easy to use.

 

[Still Boating]

Does anyone have a source for the 1/2 round stainless in Ontario? I get blank looks no matter where i ask for it.

I see Steveston Hardware in BC has it, but the shipping costs as much as the material.

 

[Comodave]

Check Taco Marine and see if they have any Canadian distributors.

 

[angus99]

Defender has it and ships to Canada.

 

[Ron Stevenson]

I am sure you have resolved this by now, be it known that on our Chris-Craft varnished mahogany boats that feature this trim, we never bed the trim. It comes off every 5 years or so for new varnish. We don't bed the ss screws either, they are going into wood. I would bed the screws with your choice of goop on a FG cruiser,but not if it is on a wood rub rail.

 

[angus99]

I am sure you have resolved this by now, be it known that on our Chris-Craft varnished mahogany boats that feature this trim, we never bed the trim. It comes off every 5 years or so for new varnish. We don't bed the ss screws either, they are going into wood. I would bed the screws with your choice of goop on a FG cruiser,but not if it is on a wood rub rail.

Thanks, Ron. I’m assuming rust streaks aren’t an issue? Is that due to the frequency of refinishing the varnish? Since mine will be reinstalled over a painted rub rail, I’m hoping they’ll stay attached longer than five years.

 

[Ron Stevenson]

Rust issue

I have been around these mahogany roundabouts with half round for 40 years. All of us renew our varnish at different times, the only time I’ve noticed any rust is with low quality stainless steel screws. However, there maybe another factor since we are raw water cooled we don’t run in the salt water. I am also involved with the classic yacht association, and participated for 10 years at the Chris Craft Rendezvous in Port Orchard, with my 35 foot Chris Craft Commander. I believe the record was set at 110 Chris Craft cruisers sitting on the saltwater. Most of these boats are very show-worthy, Yet again, I can’t recall stainless steel trim ever being an issue for rust.

 

[Comodave]

Use 316 S/S screws, not the ones from Ace Hardware. I have had excellent support from McMaster Carr. Look for 316 half round too.