Heavy Duty Clamps for Glueing tabletop?

[sitefive]

Cheers Keith, much appreciated. Final question, what diameter are the 'pegs', they look about 20mm?

Edited to add: I have to make some of these bad boys!

https://www.youtube.com/watch?v=qfZMGJRVKsw

Honestly these look even much better than the expensive sash clamps for glueing tabletops, and you can make them yourself at almost no cost. Alright off to make some myself from some scrap timber.

 

[MusicMan]

Yes I think about 20 mm, but am out today and will check tomorrow.

Keith

 

[JSW]

Thanks again Keith, looking forward to seeing the pics of the stretchers you used.

@ sitefive: if you go ahead with a mock-up, could you post a link to the metalwork you used? Just got home from work and searching for something suitable, and easy to work with, and bend to my own means ATM, ta!

 

[marcros]

if i was making some, I would use pairs of wedges rather than a piece of threaded rod.

 

[Ian down london way]

I've used the same kind of dogs that Axminster are selling, as above (I think mine were from veritas). The benefit is that you use two lengths of timber, one above and one below, so that it stops the worksurface you are clamping from bowing as it applies pressure above and below, as well as the side to side claming pressure.

Mine are now stacked up on my mobile clamp stand, with two sets of wooden 'bars' - long and short. Whilst rarely used, they are invaluable.
I think you need four sets.

 

[JSW]

Well, following on from earlier, I just got done making a quickie mock-up of Jack Houwelings panel clamps, using some 3/4 x 2 & 1/4" Birch Ply, 28" long (all I had to hand, need longer to get a better overall impression) a knackered old garden rake had some good usable 1" dowel as a handle, and luckily I just picked up on the way home from work a set of forstner bits Lidl have on offer for £2.99 (!?!) and there so happens to be a 25mm one in there, which worked out perfect.

10mm threaded rod I had already, pair of captive nuts ground down as in the video, then another pair at the opposite end trapping a hardwood 'handle', machined it all, glued up, drilled the holes and put it all together, and I have to say, the amount of pressure you can apply with NO bowing of the work material (the upper and lower cramp battens take care of that) is frankly pretty staggering, very very impressed indeed!

 

[MusicMan]

As promised here are pics of my stretchers. The peg diameter is 18.5 mm approx (they are cast, so are not perfectly round) so they fit in a 19 mm bench dog hole, which can be handy.

As you see, they are very similar in concept to the Jack H clamps though can provide even more clamping force with its steel Acme thread screws. I probably needed this for my yew, as I used biscuit joints as well to align the bowed segments and it did need a lot of oomph. But Jack's do look very practical, if you have the time to spare in making them. As JSW says, the freedom from racking/bowing is brilliant.

Keith