Thread: Where to find sash clamps for laminating top

Eastern suburbs is a big area.

Happy for you to borrow mine, can't remember exactly how many I have but it is definitely more than ten.

Also have workhorses that you could use. You could bring your timber here and assemble.

Also have a Domino that you could use to align the boards.

Eddie,
If you don't take up DJ's offer,

You could possibly drill them and have some lengths of threaded rod with washers pulling them all together, then glue two lengths over the front and back to cover the holes. That's if you intend on glueing the 90mm faces to each other, it would still work with the 45mm as well But a 90 mm thick top sounds good.
Or leave the back cover off for later adjustment if it shrinks a bit, Radiata Pine likes to move a bit with time.

And it may save on all that jointing with a plane for a full glue up, if that's what you were thinking of doing.

Just a thought.

Rob

Hi DJ's Timber,

Is this Domino joiner - Wikipedia, the free encyclopedia a type of Domino that you have mentioned, please?

( I am still not familiar with a lot of the terms. )

Regards,

...behai.

Originally Posted by DJ's Timber

Also have a Domino that you could use to align the boards.

Originally Posted by behai

Hi DJ's Timber,

Is this Domino joiner - Wikipedia, the free encyclopedia a type of Domino that you have mentioned, please?

( I am still not familiar with a lot of the terms. )

Regards,

...behai.

Yes

Eddie

for a once off glue up you can use timber battens and wedges to hold everything together while the glue dries

Hi Eddie,
I was planning on building a top similar to your own. I am going to go down the threaded rod path (as Auscab) mentions. In terms of sash clamps, make your own. I have been looking around, and have come across a few good examples of different styles....
shop made sashclamp - by reggle @ LumberJocks.com ~ woodworking community
https://www.woodworkforums.com/f11/panel-clamps-44508/
I will be very interested to watch how you go....

Once I start getting timber etc and start putting mine together, I will update my thread.

Greg

Originally Posted by ian

Eddie

for a once off glue up you can use timber battens and wedges to hold everything together while the glue dries

Originally Posted by Greg_stewy

Hi Eddie,
In terms of sash clamps, make your own. I have been looking around, and have come across a few good examples of different styles....
shop made sashclamp - by reggle @ LumberJocks.com ~ woodworking community

what I was trying to describe, thanks Greg

Hello again guys,

I'll most certainly be taking up DJ on his very generous offer. That's why I love this forum. (PM sent).

As for the other options, I'd be reluctant.

-I've tried making my own wooden clamps, using epoxy and threaded rod. It's a lot of work, but they are pretty functional with a thick 90x45 beam. The problem is that in order to make them work well one would need to use a drill press - I only have a brace and bit which, although accurate, isn't accurate to the tolerances required for this (even with various jigs etc). Plus, making ten of them would be an extremely time consuming and trying to get them all clamping up at the same time would be a misery.

-Similar problems occur with using posts and wedges. I did try this, but found it miserable in practice. I've also read a number of things about glue and lamination that suggests that the pressure supplied in this manner simply isn't enough to ensure a really high-quality join. I understand that my workbench top might not survive more than a few years, so this might not be a problem. But then again, it might, and I want to always build the absolute best thing I can.

-The threaded rod idea does sound really interesting. Can someone tell me more about this? How many threaded rods are used? How would one ensure that all the holes are lined up, assuming that the drilling takes place before lamination? Would it be possible to get sufficiently accurate holes using a brace and bit rather than a drill press? Would the compression from the rods interfere with the contraction and expansion of the benchtop? And finally: would it still be possible to fit an HNT inset vice without interference from the rods?

Originally Posted by snafuspyramid

I'll most certainly be taking up DJ on his very generous offer. That's why I love this forum. (PM sent).

No PM in my box Eddie

Originally Posted by snafuspyramid

-Similar problems occur with using posts and wedges. I did try this, but found it miserable in practice. I've also read a number of things about glue and lamination that suggests that the pressure supplied in this manner simply isn't enough to ensure a really high-quality join. I understand that my workbench top might not survive more than a few years, so this might not be a problem. But then again, it might, and I want to always build the absolute best thing I can.

strange

periodically there's a discussion on Woodcentral about what tools were in common usage in 19th century commercial shops. During these discussions, a few of the "grey beards" refer to shop inventories from the era. Universally, those inventories are missing sash clamps (cramps), or any other screw device for glueing up panels. The conclusion drawn was that the post and wedge method was the norm for what you need to do.

I know that even today, it's the most practical method for gluing up thin panels.

Sorry DJ, I last tried to send a PM via iPhone. No bananas, evidently. PM sent... again.

Interesting point Ian, I've been wondering about this a lot myself. I have seen a decent number of vintage wooden clamps (usually at the HTPAA tool sales) but they aren't usually larger than about 20". I need to look into this more to find out whether super-strong sash clamps are actually important. I have read several articles over the years stressing the importance of using top-quality clamps, and lots and lots of them, but I can't find where. I have also seen quite a few Roubo builds on the interwebs where the glue line has failed, apparently because of inadequate clamping.

Another quick question, though - when laminating all those 90x45s, need I first flatten all the glue faces with a jointer plane? (Don't own any machines.) Most Roubo builds I've seen don't seem to mention this step, they just stick together the lumber and hope for the best (I guess that provided they are of even thickness the clamps will force them back into shape and the lamination hold them there).

Now I don't mind jointing 100 metres of radiata pine with my trusty #6 or #8. For me, this is all about acquiring new skills, and you can't deny that by the end of it I will be very good at using a jointer. But I don't want to waste my time with it if it's unnecessary.

I'll be using construction lumber, left to acclimatise and dry out a bit for a few months in my shed.

Hi Eddie

if you go down the threaded rod route -- i.e. the top of your bench is held together with threaded rod, I don't think you really need to worry about glueing the 4 x 2s together. The threaded rod will apply all the long term force you need.

Where I'm unsure is if the quantity of threaded rod you will need is cost effective. Rather than borrowing DJs Domino, you might be better off arranging access to his jointer/thicknesser


In terms of 19th century glueing practice, I think back then, if a joint wasn't sprung it was a poor quality joint & sprung joints don't need a lot of clamping

Originally Posted by ian

Hi Eddie

if you go down the threaded rod route -- i.e. the top of your bench is held together with threaded rod, I don't think you really need to worry about glueing the 4 x 2s together. The threaded rod will apply all the long term force you need.

Where I'm unsure is if the quantity of threaded rod you will need is cost effective. Rather than borrowing DJs Domino, you might be better off arranging access to his jointer/thicknesser


In terms of 19th century glueing practice, I think back then, if a joint wasn't sprung it was a poor quality joint & sprung joints don't need a lot of clamping

Interesting. I did do a little more reading on the topic, and it turns out that:

A) Sash clamps have in fact been made for hundreds of years, both with threaded screws and simple wedges;

B) Hot hide glue doesn't need clamping owing to its very short open time, and the fact that it draws the joint tighter as it dries.

C) As you point out Ian, sprung joints don't require as much clamping force.

The problem with the threaded rod solution (aside from expense) is that it would interfere with the placement of the end vice, although there might be a way around that. I'll give it some thought, because it otherwise seems like a great idea.

Thanks guys!