Thread: Clamp size for GIS blades

Originally Posted by callsign222

I'm on the road for work for almost two weeks. Next week I'll be passing by a cheap-o tool store, which has lots of clamps! (for cheap!) I need sliding clamps for the rudder and daggerboard. Unfortunately I do not have my plans with me.
What size/length metal sliding clamps do I need for laminating the daggerboard and rudder?
Thanks!

"hijacking = not answering the actual question, just inserting useless knowledge for self gratification"

If you're using extended epoxy as the glue there's so little force required that you really don't need clamps at all for that type of job.

Make a simple jig as follows...
* nail/screw one straight-edge to your bench,
* place the pieces to be glued up against the straight edge
* nail/screw a small (2x4x6 inch) block at 25%, 50%, and 75% along the length of the glue up - leaving enough space to insert a set of wedges between the glueup and the jig blocks.

Throw a sheet of plastic over the jig
Do the epoxy thing - not forgetting to pre-wet the individual pieces
Put the sistered wedges in snug - NOT tight.
Check the face surface for flatness.
Go have a libation of choice.

Lots of jobs need clamps but the clamps are pretty much only needed in wood-epoxy building when there needs to be enough force to be exerted to move the underlying timber or ply into position -- it's not at all needed to make a strong joint, to the contrary too much clamping pressure can cause a starved (weakened) joint.

Going away now,

IIRC the CB is a little wider than 12 inches, so 16 or 18 inch clamps for that. The rudder is a couple inches less, so 12 inch clamps MIGHT work but so would your 18 inch ones.

Hi Callsign,

I just made those blanks, centreboard is 34.1 cm max so 14 inch span would do the job. Rudder is smaller with 26.0

I hope this helps

I used 18" bar clamps for both the centerboard:



and the rudder:



Bob

Sweet, thanks.

I'm not going to get started on the blanks until this winter, but I'm passing by the store next week, so I'm going to take advantage of it.

I have improvised clamps too.

Need the pieces to go under the staves to be the 18" 450mm mentioned and big enough to be stiff when there is sizeable tension in them.

put packaging tape on the top surface.

Screw a block at one end with the drywall/plasterboard screws - at least two screws.

put the staves up against the blocks. Put a block on the other side of the staves leaving about an inch 25mm and make two wedges to tap in between the staves and the second block.

It is a lot of load so the long pieces of timber have to be quite stiff or you can screw thinner ones down to the workbench.

MIK