Thread: How do you clamp this box for glueing

Does the Pyramid box have just mitres or a locking joint. I would make a base and top piece that fit with paper shims. Tape the ouside joints and wrap with rubber strip from bike inner tubes. The base and top will keep the shape, the paper will compress, the rubber will keep it all tight.

Similar to what Mike says. Lay the sides out inside down. Stretch 2 or 3 pieces of masking tape across each corner, and put pieces in place on the last corner, ready to stick. Flip the sides over and run glue into each corner (no need to spread). Also spread glue on the last two. Then, fold the sides up, not forgetting to put the base in its slot. Stretch the tape across the last corner, and wrap with a strip of inner tube (I use a strip cut from old car inner tube). You don't need to stretch the tube too hard, as each time you wrap around the tension accumulates. Flip the box over and measure the diagonals to check that it is square.

You could make some wedges that match the angles of the pyramid, that end up creating 90 deg corners again, then put a web clamp on it.

M.

First I would connect 3 of the joints on the outside with masking tape (lay them close and join them side by side) . On the fourth joint I would stretch masking tape on either edge. That avoids squeeze out on the difficult to get to inside. Spread all 4 joints wirh glue.
When you fold them up into a pyramid, the joints stay nice and tight.
Then I would use picture framing strap clamps, they keep the corners nice and square..
I'll try and make a picture of it.
Cheers
Wolffie

Spread glue in the joints and close pyramid. Then use either rubberbands or a framing strap clamp.
Have fun
Wolffie

You'll get a tighter clamp if you stretch the tape across the corner, rather than along it. Squeeze out on the outside isn't usually a problem. I usually put a coat of shellac then sand the inside before the glue-up, then smear wax next to the joints, to make any squeeze-out easier to clean up.

Originally Posted by AlexS

You'll get a tighter clamp if you stretch the tape across the corner, rather than along it. Squeeze out on the outside isn't usually a problem. I usually put a coat of shellac then sand the inside before the glue-up, then smear wax next to the joints, to make any squeeze-out easier to clean up.

Thanks AlexS, I like that one, always in a mess with my boxes.

You don't need any clamps or fancy shop bought fixtures or gimmicks. You just need two lengths of good quality string with a high breaking strain and eight pieces of timber about 10mm x 10mm the height of the box. Tie string around the box sides at the bottom about 30 mm up and tie string around the box at the top about 30mm down from the top edge. Get two of the timber pieces per side, lift the string and place them underneath so that they sit full height of the box sides equal distance from each corner. When all eight are in place simply move the timber pieces out towards the corners creating tension and the clamping will take place. If the string is poor quality it will break that is why it must be high breaking nylon or similar. This same method can be used on all boxes and picture frames. You can fold cardboard or plastic from an ice cream container around the corner under the string to stop the string digging or cutting into the corner edge. If the angle of the sides of the pyramid are too steep and the blocks slip just make the timber lengths longer and nail in a brad to form a stop under the bottom edge. As an apprentice I often made dozens of picture frames at a time and used this method to clamp as costs are minimal. I still use this method when making any small boxes as the clamping tension is very high.

Col

I reckon modern glues dont need high clamping pressure, just held in place long enough to set.

Originally Posted by jow104

I reckon modern glues dont need high clamping pressure, just held in place long enough to set.

You are right but if you use the string and block method you only tension the blocks as needed. Pulled along gently to hold in place then pulled tighter if required. Tape is useful in the initial holding together of the components while the string is tied in place and glue application but it is then best removed.
If you use only tape there are some disadvantages. Firstly, once taped there is no movement available to position the pieces as with the string you can release tension reposition and retension. Secondly, glue seepage under the tape cannot be wiped from the surface with a damp cloth whereas with string there is nothing covering the joint so all seepage can be wiped. Thirdly, you cannot see the joint clearly to ensure all gaps have taken up as the corner is hidden or sections are hidden under the tape and with string the joint is visible and in the case of a stuffup you can quickly see what is going on and pull it apart. Some tape adhesives pollute the timber surface and need to be removed fairly quickly especially in hot environments but strings can be left indefinitely. I am sure many of us have experienced the agony of leaving masking tape on a surface too long and the adhesive stays and the paper part just pulls away. The adhesive can be a bugger to remove.
Just my 2 cents worth of course. There are many ways to skin a cat.

Regards
Col....

Thanks to all of you for your helpful hints and suggestions. This thread is one more reason why I spent meanwhile more time in the internet than sitting and watching TV. I posted a question in the forum and before I return from work I have several really helful solutions coming from the other end of the world. (At least from a German viewpoint the "downunders" are the other end of the world)

Today I learned from Col, that I can save my money if I forget to buy fancy clamps and use instead a really simple rope for glueing! Col you have earned a good and cool German beer for this suggestion. If you should happen to be the other day in Germany give me please a call. I would even spend you a second and a third beer.

I love such solutions!

Although the suggestions to use tapes are simple too. When I used the tape in a first trial - I used double sided tape which you use to fix your carpets on the floor - it worked so well and glued so strong that I removed the veneer from the box when I tried to remove just the tape from the edges.

Therefore the suggestion from Wolffie seemed to be a better solution. Specially because the white stripes you can see at the box corners are actually aluminium stripes. Until now they are covered with a protection white foil.So a tape should be easy removable.

This evening (late in the night at 23:00 o'clock) I tried Cols suggestion. Here is a foto:

Attachment 127408

It is an easy solution and as an IT engineer I can say: works as designed! All parts have been produced in about 5 minutes and can even be reused in a next project.

Col a cool solution!

Regards from Germany

Detlef

Detlef

Good on you mate for giving it a try. Very simple and as you say its reusable. I might take you up on that beer one day too.

Regards
Col...

Hope you get the base in

Originally Posted by Col

it must be high breaking nylon or similar. This same method can be used on all boxes and picture frames.
Col

I use cord from curtain tracks - works well.

Was shown this method at a picture framing course a few years ago.