Gluing up a large box

[benwheeler]

I'm building a sandpit for my son. The main part of it consists of Tasmanian Oak laminated together to roughly 230x45mm, with bevelled corners and Dominos. Completely unnecessary, but good practise.

I was very pleased with myself when I remembered an item in Fine Woodworking about gluing corners, using the type of arrangement below.  However, it completely failed to work at the crucial moment, as the MDF clamping blocks slid along the sanded surface of the hardwood.

Has anyone experienced this or come up with a solution for it? The problem is definitely not the clamps - I was using Bessey K-Bodys.

 

[rljatl]

Looks to me like the triangular blocks are glued/nailed/screwed to the long strips of wood and the long strips are held in place by one set of clamps and the corner is held together by the second set of clamps on the triangular blocks?  The first set of clamps should prevent anything from sliding around, shouldn't they?

If not, you maybe expecting too much for that type of clamping jig...you can only tighten it up so much without slipping...So try a different type of clamp.

 

[Bohdan]

I used to build loudspeakers which are basically large mitred boxes and we would clamp them using steel packaging bands and aluminium corner pieces. The bands were reused many times on progressively smaller boxes.

To prevent the aluminium from sticking due to excess glue squeeze out they were waxed.

There is a clamp on the market which uses a steel band but it also needs aluminium corners to prevent misalignment.

http://www.carbatec.com.au/heavy-duty-pro-framerrsquos-clamp_c8270

 

[nclemmons]

Try using adhesive sandpaper on the clamping cauls to prevent them from slipping.

 

[benwheeler]

RLJ-Atl: you are correct, and one would think they wouldn't slide around, hence my confusion.

I think the method is sound, since plenty of people use it - I think neilc has my solution.

Thanks for the replies!

PS Bodhan - being a former music producer and now carpenter, I'm very keen to make at least one set of the DIY speaker boxes that are around on the net. Thanks for the tip!