Saturday 13 June 2020

Carlins & Sheerclamps | Installation

Satisfied that everything fitted properly I prepared to glue the carlins and sheerclamps permanently in place.

It didn't take long to realise that applying glue to the sheerclamp before fitting it was not going to work. It is just not practical.

The sensible way to apply the thickened epoxy would be to do it with the sheerclamp already in place.

A friction fit secures the sheerclamp when it is sprung into the slot in bulkhead 2. This holds the length in the cabin firmly against the topsides, and leaves a wide gap between the piece and the topsides in the bow section.

So it would be easy to glue the length in the bow section, but the length in the cabin would have to be prised away from the side a little to allow the joint be glued.

Before starting the glue up, I decided to use temporary screws to hold the sheerclamp in place in the cabin section. I found previously when gluing the cockpit deck support cleats to the hull sides that friction held the frames in place during the dry fit, but they slipped all over the place when buttered up with thickened epoxy and I had to hurriedly fit a lot of temporary screws.

So I drilled for three temporary screws in the cabin, and started the glue up on the port sheerclamp.

First an old screwdriver was used to open a gap in the cabin section, as here.

I gathered up all the clamps I possessed, and the drill driver.

Then thickened epoxy resin was squeezed into the joint from a pastry bag dispenser. The screwdriver was removed, and clamps applied working forwards from the rear cabin wall.

This is what the port sheerclamp looked like after installation.

You need a lot of clamps to do this effectively!

Here is a temporary screw, stopping the sheerclamp from springing or sliding out of place.

I didn't have enough clamps to install both sides at once, so I left the port side to cure for 24 hours before using the same clamps to fit the starboard sheerclamp.

Here is a view of the starboard side.

Proving the truth of the adage 'you can never have too many clamps', I used twelve G cramps and 30 spring clamps. They did a great job!

I agonised about how much the sheerclamps should protrude above the topside panels.

About half an inch is needed in the cabin to allow the sheerclamp to be planed down to accept the curve of the cabin roof, and the same again forward of bulkhead 2 for a foot or so to accept the tops of the Dorade boxes. The notches in bulkhead 2 make this obvious and easy in the cabin, but what do we do at the bow?

Should the sheerclamp finish flush with the top edge of the topsides, or should the 1/2" protrusion continue all the way to the stem?

The photos in the build manual offer no help - their quality is too poor, as is often the case. And the text makes no recommendation.

Looking at other builders' blogs I seemed to find both approaches being taken, although it is hard to tell from photos alone.

In the end I decided to fit the sheerclamps to finish flush with the topsides at the stem, as here.

The curve from the bulkhead to the stem is very slight, so it should provide enough material to round over for the Dorade boxes while still looking graceful towards the bow.

The only thing I was a little worried about was whether there would be enough room below the sheerclamp to fit the bowsprit, where some of the topside has to be cut away at the stem.

Naturally, I didn't think about this until after the event when it was too late to do anything about it. However a quick look at the drawings showed the depth of the bowsprit at the stem is 2 1/2". A check with a rule showed that this would be a perfect fit!

So all was well. Here is a view from the bow of both sheerclamps installed.

The blue tape is covering a stout wire stitch which is preventing the join between the topside panels from cracking further, and you can see the gap at the front of the port sheerclamp which I will fill with an offcut.

Finally I glued in the carlins, as here.

That's it - job done!

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