Repairing Cracks in Furniture: How to Clamp Awkward or Curved Surfaces

[Matthew Hutchinson477]

Howdy folks,
I've got a few of these repair projects waiting to be done but have yet to figure out how to clamp the joints while the glue is drying. Here are some pics of two of the pieces needing some repair. Both of them have splits that did not break into pieces so when realigned the cracks close up very well and, I think, should not need a dowel or screw or anything like that. The desk can certainly just be glued. The muffin stand...that's a tougher one. It is actually warped significantly so repairing the broken piece on it would mean putting permanent tension on the wood.
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I don't think there is a way to place bar clamps that will squeeze the split back together as well as necessary. I've heard of folks using strips of rubber from a bike tire tube and basically wrapping the crack while the glue is drying. My concern here is that I wouldn't be able to wipe off the squeeze-out and both of these pieces have good finishes that I don't want to sand/scrape and subsequently repair. I suppose I could do that if necessary but hopefully there's a good way to avoid it.

Thoughts? How would you guys tackle repairs like these?

Thanks

[Sam Murdoch]

Tough ones :(. I think I would use heavy duty strapping tape - the stuff with the threads in it. This you can pull very taut and can come right back around and stick to itself. A spanish windlass with cord could work too but you need room to spin the tensioner. As for the glue ooze out My choice would be to apply a painters tape very carefully and ever so close to the edge of the cracks OR apply a controlled film of wax that you can later remove. The wax might compromise the effectiveness of the strapping tape. Clear epoxy would be my glue choice because it will dry mostly invisible should you get some where you don't want it.

Will be interesting to see what other strategies will be suggested.

Good luck.

[Adam Herman]

i like to use a ratchet strap around a whole piece if possible, sometimes a thick rubber band can be helpful.

[Mike Wilkins]

In the course of making repairs to furniture over the years, I have come up against similar challenges. I find that I need to make a one-off clamping block with one flat face for the clamp to grab, and the other face with the outline of the curved part. Attach some sticky-back sandpaper around the curve area to give it some bite.

[Andy Giddings]

+1 on the ratchet strap or strap clamp. You need something that you can tighten and pull the crack closed. Squeeze out can be controlled by covering the area with masking tape

[mike holden]

google "patrick edwards vector clamping" for some ideas on how to do this.

Mike

[Sam Murdoch]

If you choose to use a ratchet strap sometimes it helps to use one strap to secure your piece to a solid and not so precious panel or cauls or old door or bench etc. (padded on the furniture side). Now as you tighten the strap on the joint you are not misshaping your furniture. Those clamps can pull too hard. Then use the other strap or two as you need to close the joint (also going around the added panel/cauls/solid object of your choice). And yes, shaped clamping blocks or strategically placed wedges can help immensely.

[Matthew Hutchinson477]

Thanks for the replies everyone. I do have a strap clamp as well as a bunch of ratchet straps so I'll see how those do for closing the crack. As for taping off around the crack...what is the precise method? Do I tape along the crack so that the tape sticks out over the edge and then trim the excess with a razor blade? Or would that still leave a visible glue line?

[Sam Murdoch]

A glue line might be the least of your worries - you might still see the crack. You don't want to hide the crack during the glue up. Best to tape as close to the edge without obscuring how well the joint closes and to allow you to clean off the residual glue while it is still wet.

[Rick Moyer]

surgical tubing

[glenn bradley]

Based on the pressure required to close the joint I can offer a couple of possibilities. Vector clamping with some custom made cauls will probably offer the most controllable pressure. If a strap will do it, that would be easiest. I use surgical tubing for some of these things but, the joint must close easily. A right angle head (http://www.homedepot.com/p/Milescraft-Drive-90-13020703/202241668?gclid=Cj0KEQiAh4fEBRCZhriIjLfArrQBEiQArz zDAc4hwxOePTiDzo661f5WXrNE904DGKGfNVBCSybypccaAsNu 8P8HAQ&gclsrc=aw.ds) with a hex drive bit (http://www.homedepot.com/p/Ryobi-8-Piece-SpeedLoad-Hex-Shank-Drilling-and-Driving-Set-AR2073/100634392) could allow you to drill a through hole from behind up to the opening. Then a pilot hole for a long screw to be used as both a clamp during the repair and as a mechanical assistant afterward.

[Grant Wilkinson]

You've already received lots of clamping options. As for the squeeze out, I use a product called Waxilit. I think it's not much more than a fancy wax. You can spread it very thinly on the face of the piece, on either side of the crack. Squeeze out will not stick to it. I've used epoxy, titebond and elmers. They all simply wipe off the surface.

Here's link about it

http://web.hypersurf.com/~charlie2/EntryHall/Waxilit.html

[Matthew Hutchinson477]

Well, I believe I have a solution for the clamping, at least. But I've never done this before so I want to see what the herd thinks. Referencing the pictures, the two bar clamps can get the joint pretty well-closed but not quite enough. So my innovation is the line wrapped around the leg and then secured to a heavy object with an adjustable hitch so that I can apply just the correct amount of tension to close the crack. By the way, the large visible crack in the pictures is not the actual split. That's a joint between two different pieces of wood. The split I'm repairing is to the left and not visible in the pictures as the clamps are all tensioned.
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After looking at my options, I'm leaning towards using hide glue since this is a pretty old (probably antique but I'm not sure the exact age) piece of furniture that already has some cracks and imperfections in it. I have a bottle of Titebond liquid hide glue but it's at least a couple years old so I'm testing it on some scraps to make sure it cures correctly.

Thoughts on all this?

Oh, and as for the squeeze-out issue...are there any easy-to-find-locally waxes that would possibly work? I've actually used regular Johnson's paste wax to cover metal when bedding rifle stocks and served the purpose well but that was using a thick bedding compound like acraglass or JB weld, and the wax was applied to metal.

[Andy Giddings]

Looks like a creative solution to me - if it does the job go for it. Hide glue is always a good option for heirlooms. Paste wax will be ok as long as you can get a film to stay on the finish. Might be worth testing the approach on a part that isn't usually visible. Will you be re-finishing the repaired area? Just that wax may interfere with a finish if you are

[Matthew Hutchinson477]

Looks like a creative solution to me - if it does the job go for it. Hide glue is always a good option for heirlooms. Paste wax will be ok as long as you can get a film to stay on the finish. Might be worth testing the approach on a part that isn't usually visible. Will you be re-finishing the repaired area? Just that wax may interfere with a finish if you are I don't plan on refinishing, and I'm pretty sure I'll be able to get away with it. There are enough marks and imperfections in the piece already that I don't think a visible hairline crack will detract from it much.

[Matthew Hutchinson477]

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All in all I'd say it turned out well. The crack is certainly visible, as you can see, but structurally it feels like a strong repair and everything fits back together correctly.

A thick coat of paste wax was sufficient for keeping squeeze-out from sticking and my improvised clamping system worked well.

Thanks for the advice everyone.

[Andy Giddings]

Looks good, Matthew. If you're bothered by the crack visibility, you might try a touch up marker, wax filler stick or something similar to disguise it

[Matthew Hutchinson477]

Thanks for the suggestion, Andy. I think I may try one of those. If for nothing else, an opportunity to learn a new skill.