How to adjust rail clamp?

[jdmuys]

I purchased a pair of Sea-Dog rail clamps, as described on their web page at:

https://sea-dog.com/groups/3604-remo...l-mount-clamps

Unfortunately it doesn’t fit my rail. I believe this is because my rail’s diameter is 22mm (0.866” or 7/8”).

The clamps are supposed to fit 3/4” (thinner than mine), 1” or 1-1/4” (both thicker than mine). They come with rubber-like fitting shims for 3/4” and 1-1/4”.

Adding either shim is not enough for the clamps to hold tightly enough. Adding both is too much: the clamp cannot be closed.

I am looking for suggestions on how to make it work. I suppose I should use the 3/4” shim and add some material. Should I put the added material outside or inside the shim? What kind of material? Electrical tape? Self-fusing tape?

Any help much welcome.

FWIW, I want to use the clamps to attach a smallish solar panel to my stern rail on my Corsair F-27 trimaran.

[pcmm]

Originally Posted by jdmuys

I purchased a pair of Sea-Dog rail clamps, as described on their web page at:

https://sea-dog.com/groups/3604-remo...l-mount-clamps

Unfortunately it doesn’t fit my rail. I believe this is because my rail’s diameter is 22mm (0.866” or 7/8”).

The clamps are supposed to fit 3/4” (thinner than mine), 1” or 1-1/4” (both thicker than mine). They come with rubber-like fitting shims for 3/4” and 1-1/4”.

Adding either shim is not enough for the clamps to hold tightly enough. Adding both is too much: the clamp cannot be closed.

I am looking for suggestions on how to make it work. I suppose I should use the 3/4” shim and add some material. Should I put the added material outside or inside the shim? What kind of material? Electrical tape? Self-fusing tape?

Any help much welcome.

FWIW, I want to use the clamps to attach a smallish solar panel to my stern rail on my Corsair F-27 trimaran.

A couple of wraps of electrical tape should fix it. Metric tubing is a bit of an odd-ball thing.

[Spot]

My go-to in this situation would be some bicycle inner tube material to help get the thickness up to where the other sleeves and clamps will work. I would image the bushings are 3/4 and 1" ID and 1-1/4" OD within the clamps and the clamps are 1-1/4" ID without the bushing. So make the apparent diameter of the rail from a short 7/8" (22mm) to 1" (25.4mm) with inner tube and then use the 1" bushings.

[jdmuys]

The bicycle inner tube idea is clever! Thanks!

[FabioC]

I went through a similar situation trying to fit a fishing rod holder clamp on my rail. I experimented with electrical tape, duct tape, sailmaker tapes, shims of different nature, but nothing worked.

I think success depends on the use case. If the clamp needs to provide strong holding and not allow the clamp to rotate at all (like in the case of a fishing rod holder, which needs to resist the pull from a fish biting the lure), it may be difficult to achieve. If the clamp simply needs to hold something without wobbling (e.g. holding a rail-mounted flag pole) a combination of electrical tape with some tape with a rougher texture like duct tape or sailmaker tape should work well.

[jdmuys]

Thanks for the testimony. For me, it is to hold a solar panel. It must not rotate [too much] once oriented. The weight is medium (≈ 10kg), and the windage can be significant. I have seen people adding PVC pawer pipes as struts to the solar panel to prevent it from rotating.

[BruceS]

I use a wrap of wet'n'dry for fishing rods. Folded to bite into both surfaces.

[joelhemington]

Originally Posted by jdmuys

I purchased a pair of Sea-Dog rail clamps, as described on their web page at:

https://sea-dog.com/groups/3604-remo...l-mount-clamps

Unfortunately it doesn’t fit my rail. I believe this is because my rail’s diameter is 22mm (0.866” or 7/8”).

The clamps are supposed to fit 3/4” (thinner than mine), 1” or 1-1/4” (both thicker than mine). They come with rubber-like fitting shims for 3/4” and 1-1/4”.

Adding either shim is not enough for the clamps to hold tightly enough. Adding both is too much: the clamp cannot be closed.

I am looking for suggestions on how to make it work. I suppose I should use the 3/4” shim and add some material. Should I put the added material outside or inside the shim? What kind of material? Electrical tape? Self-fusing tape?

Any help much welcome.

FWIW, I want to use the clamps to attach a smallish solar panel to my stern rail on my Corsair F-27 trimaran.

Mantus makes a rail clamp for a 22mm rail https://www.mantusmarine.com/mantus-rail-clamp/

[psk125]

Depending upon the use, a teak or ipé board with U-bolts around the rail might also work, and look better than a clunky chunk of white plastic.

[Smokeys Kitchen]

Originally Posted by Spot

My go-to in this situation would be some bicycle inner tube material to help get the thickness up to where the other sleeves and clamps will work. I would image the bushings are 3/4 and 1" ID and 1-1/4" OD within the clamps and the clamps are 1-1/4" ID without the bushing. So make the apparent diameter of the rail from a short 7/8" (22mm) to 1" (25.4mm) with inner tube and then use the 1" bushings.

+1

I have done this a couple of times with good results. 'Course it requires a few flat bike tubes ...

[jdmuys]

Thank you every one. It turned out using bicycle inner tube worked very well. I used the small diameter insert and two layers to bicycle inner tube. The result looks and feels good to me. I will keep an eye on it to be sure it holds.