Thoughts on Making Deck Clamps

[BradNSW]

I'm faced with making the Deck Clamps to support the beams for the main deck.

The plans show (and I love the look of) angled mortise/tenon for the beams to fit into.

I feel making the angled mortise joint will be extremely difficult after the beam is glued in place. Has anyone had success doing this way and have any advice?

Making them before installation of the beam seems straightforward for the parallel midbody BUT the curved stern/bow has me stumped. Has anyone done them before installation and have any advice?

Finally, has anyone tried doing them this way:
1. Installing the bottom 3/4s of the deck beam (no notches).
2. Then cutting the mortise on a separate piece (the top 1/4 of the beam) to make the notch.
3. It would look something like the below photo:


Any feedback appreciated!

 

[AllanKP69]

The plans show (and I love the look of) angled mortise/tenon for the beams to fit into.

Hi Brad,

What ship/nation/year? At least for British warships in the age of sail the mortise in the upper strake of the deck clamp was typically 1 inch (about 0.25mm at 1:96, and 0.5mm at 1:48) This can be done even after the clamp strakes are in place with a small sharp chisel, hobby knife or file. It is so small, you can mortise the end of the beam, and it will appear the same as if the clamp was mortised as was actually done. At 1:96, maybe not worth the trouble to try to make a 0.25 mm mortise in either the clamp or the beam. As the upper strake of the clamps (there were usually two or three strakes for the clamps) were about 14" to 18" broad, the depth would be 1/14th to 1/18 deep, not 1/4 deep. Looking at various sources I cannot find any mortise being 1/4 the breadth deep. Are the plans you mention from a kit or otherwise modern drawings or are they contemporary plans?

I would not try to cut the mortises before installing the clamps. The chances for perfect alignment of every beam are possible but not likely and not easy to do.

Allan

 

[BradNSW]

Hi Brad,

What ship/nation/year? At least for British warships in the age of sail the mortise in the upper strake of the deck clamp was typically 1 inch (about 0.25mm at 1:96, and 0.5mm at 1:48) This can be done even after the clamp strakes are in place with a small sharp chisel, hobby knife or file. It is so small, you can mortise the end of the beam, and it will appear the same as if the clamp was mortised as was actually done. At 1:96, maybe not worth the trouble to try to make a 0.25 mm mortise in either the clamp or the beam. As the upper strake of the clamps (there were usually two or three strakes for the clamps) were about 14" to 18" broad, the depth would be 1/14th to 1/18 deep, not 1/4 deep. Looking at various sources I cannot find any mortise being 1/4 the breadth deep. Are the plans you mention from a kit or otherwise modern drawings or are they contemporary plans?

I would not try to cut the mortises before installing the clamps. The chances for perfect alignment of every beam are possible but not likely and not easy to do.

Allan

Allan,
French mortar ship Salamandre. 1:48 scale, plans by Boudroit.

Looking at main beam 8 (circled). It measures 13"x13". It is cut into the deck clamp 4" and the deck clamp is 13" (about 25-30%).

I agree, cutting the mortises BEFORE would be extremely difficult to get perfectly perpendicular beams. I've got some good sharp micro chisels to cut the in place but the tumblehome of the hull and tight working space at bow stern make it seem like it will be difficult.

BUT cutting those angles (on a scale strip 4" thick or 25% of the deck clamp), OFF the model would allow for extreme accuracy of both the joint and keeping the beams perpendicular.

Appreciate any more thoughts you might have after seeing Boudroit's drawing.

 

[AllanKP69]

I have no experience with his work but would trust that Jean Boudroit did a ton of research on something like this. Never having had to cut such deep mortises on such small clamps I am not sure what route I would take, cut in place or off the ship. Sometime in the past I remember learning a good rule of thumb was that the depth of the mortise should never be more than two thirds the thickness of the piece.
Sorry this is no help in answering your question.
Allan