Leveling cracks with pillar method

[David Burgess]

1 hour ago, Mark Norfleet said:

That was my first reaction too, but I've been puzzling over this for a while wondering what I'm missing.  Unless I'm mistaken..., it can only help localized curling unless the wedge spans the crack (which it seems to be doing just a little in the photo) or only bears on the opposite side of the top.

I've been having thoughts like that too. Part of me thinks that it might be both pulling up and pushing down on the same side of the crack at the same time.

[David Burgess]

Mark, have you used something like this? (A conventional pillar clamp would be used to squeeze the bottom)

 

 

[violguy]

22 hours ago, David Burgess said:

The wedge under the screw is a nice strategy, Oded.

While we're discussing clamps would you describe your jack-screws? Seems like a good thing to add to my clamp arsenal.

[CSchabbon]

Excellent posts so far.

I hope you might find some additional information here:

https://christianschabbon.com/gluing-cracks-using-the-g-clamp-method/

[CSchabbon]

Also, the type of glue is important too. I think regular hide glue (low bloom, below 200 gram) is the best. High bloom hide glue, technical gel  or rabbit skin will start gelling and tacking too fast and make your life difficult

[Oded Kishony]

a couple of points:

after very carefully lining up the crack (dry, no glue) I glue the cleats in place. This holds the repair in place when I later apply hot glue on the varnished side.

I sometimes loosen the upper screw a bit and ‘pump’ the glue into the crack and then reset the screw, always checking for alignment.

I use 3x5 card stock for the paper at the base of the pillar. To speed things along I put a dab of very thin hide glue on the plate and use ca glue on the pillar to get an instant bond without introducing ca glue to top wood.

I like using the magnets, despite the fact that they can be a bit tricky, because they are light weight and this clamping method does not impose any torque on the plate and allows you to more easily handle the plate.

Oded Kishony 

[David Burgess]

12 hours ago, CSchabbon said:

Excellent posts so far.

I hope you might find some additional information here:

https://christianschabbon.com/gluing-cracks-using-the-g-clamp-method/

Thanks, Christian.

[Mark Norfleet]

On 10/23/2020 at 10:56 AM, David Burgess said:

Mark, have you used something like this? (A conventional pillar clamp would be used to squeeze the bottom)

 

 

Not yet...   
I don't have a photograph of the method I use for keeping adjacent sides of a crack level, but expect to have to utilize it soon while repairing a busted Burgess and will take some photos and post them to this thread then.

What is a "conventional pillar clamp"?

[David Burgess]

46 minutes ago, Mark Norfleet said:

Not yet...   
I don't have a photograph of the method I use for keeping adjacent sides of a crack level, but expect to have to utilize it soon while repairing a busted Burgess and will take some photos and post them to this thread then.

What is a "conventional pillar clamp"?

To me, a conventional pillar clamp is the type pictured in Schabbon's article.

[Mark Norfleet]

37 minutes ago, David Burgess said:

To me, a conventional pillar clamp is the type pictured in Schabbon's article.

Thanks.  Is that the style you use?

[Jeffrey Holmes]

2 hours ago, Mark Norfleet said:

Thanks.  Is that the style you use?

I often use the g clamps... Does that make me conventional? I have two other types I've found work in special cases.

We have to talk to David about those nice instruments he makes that keep getting busted.  

 

[David Burgess]

9 hours ago, Jeffrey Holmes said:

We have to talk to David about those nice instruments he makes that keep getting busted.  

 

Perhaps I should start making them out of steel. Do you have equipment for removing dents from metal panels?

Mark, I have some of Schabbon's pillar clamps, which you are welcome to try/use.

[Jeffrey Holmes]

5 hours ago, David Burgess said:

Perhaps I should start making them out of steel. Do you have equipment for removing dents from metal panels?

Hahahaha! Don't change for me David!  It's those clumsy musicians....

 

[HoGo]

I think I understand Oded's intention. H ementions the hole in the left side is enlarged to allow some movement.

I guess if you insert the wedge between the two bolts you would introduce opposite movement since the upper bolt is threaded into the right side and allows sliding along the left pillar.

[Oded Kishony]

Yes, this wedge is used to level a 'step' in the plate. It's easier to visualize if you think of getting the two sides to first line up, using your fingers, then inserting the wedge, effectively making one leg a little longer than the other. It works, even if it doesn't seem obvious.

The over sized hole is on the lower  thumb screw, on the knurled side, to allow the towers to 'rack' a bit, otherwise they would always be perfectly parallel and you couldn't correct the arch.

Oded