Clamping a live edge glue up.

Nebraska · February 09, 2021, 07:17:58 AM

My wife requested a night stand for up at the cabin. I had a little piece of live edge fir about the right size, she thought it would do. It had some cup and a little twist. I split with my saw guide and used somewedges and screwed it to a board to get it flattened with my little planer. Then lightly jointed the kerf to true it for glue up. Does anyone have any tips for bar clamping a live edge glue up?

Old Greenhorn · February 09, 2021, 07:31:31 AM

I clamp boards on the top and bottom to maintain the alignment (leave one side a little loose until final tightening) then beam clamps perpendicular to the joint. I use heavy terry towels for padding on the clamp faces. You don't need a lot of pressure if the joint is true, just enough to squeeze some of the glue out.
Another trick I have used is to glue it upside down using the top and bottom straps again, but screw a block to the bottom on each side of the joint and put you clamps on those joints. The screw holes are very minor and disappear pretty much after the blocks are removed, or you can just press in a little wood putty if it bothers you. You could also put screw blocks on the top and bottom, but I have never tried that....yet.
Let us see how it comes out!

Nebraska · February 09, 2021, 09:47:39 AM

Ok my first attempt wasn't good and I quick pulled it apart an backed out to fight another day. The kerf line was really good just laying side by side. I added some biscuits to the joint and pulled it together and couldn't get it to go decent. Could not get a good bite with the clamps and said "forget it I'm gonna ask". I thought about ratchet straps with C clamped boards to hold it flat after I had posted my question they seem like a reasonable way around the uneven live edges.

samandothers · February 13, 2021, 05:15:54 PM

Were the biscuits causing the alignment issue or just the uneven clamping? OGH's approach of adding clamping aids screwed to the bottom and cauls clamped on the top and bottom may help keep the halves from kicking up at the joint.

Old Greenhorn · February 13, 2021, 06:50:06 PM

A cabinet maker I put a lot of stock in told me "biscuits are for alignment only, they add no strength". I take him at his word because he has always been right, so far.
With that said, and no photos to understand your issue, could you describe it better? Is your main problem getting the clamps to hold properly against those live edges, or is there something else?
With blocking top and bottom for alignment, I think your ratchet strap idea might work.
Here is one I did the other day, I don't know if it helps at all and it's not live edge.

Old Greenhorn · February 13, 2021, 07:41:17 PM

I just went out to the shop and mocked this up real quick, would something like this help?

doc henderson · February 13, 2021, 08:45:51 PM

I agree, a bar clamp is rigid and can wreck a chunk of bark. remember live edge can be with or without the bark, and bark is soft. I like the idea of custom wedges to soften the clamp edges on the slab.

21incher · February 13, 2021, 09:47:59 PM

I use some 3/4 thick fairly high density vibration pads I got on Amazon that are used under machines that I put on the clamp pads when gluing up natural edge panels with bark on that work good. You have to carefully prepare the edges for a perfect fit and I use biscuits so you don't have to worry about alignment.

kantuckid · February 14, 2021, 08:30:49 AM

I did a bunch of live edge walnut 8/4 shelves for a son's kitchen redo in TN couple years back. They were sized for holding dishware and contractor installed after I made them up to the finished point. The contractor knew his work and ask for a specific angle on the back straight edge to assist with them remaining level under the load of heavy dishware. They were mounted on some sort of stud. I used old terry cloth towels wrapped around the live edges to avoid clamp damage during glue-up.
I also made the two columns that hold their new counter bar area from striped maple, 6" sq..
I've never had a slab that held the bark to the point of use as the critters inside there loosened them by the time the wood was ready to use. I do have a bunch of ERC slabs with bark but as you know it's loose and stringy and not much purpose esthetically.
My LR coffee table and end tables are live edge walnut, done long before the slabbing frenzy we see now days. I was copying George Nakashima's work as seen in Fine Woodworking magazine years ago.

Dan_Shade · February 14, 2021, 08:37:33 AM

Have you considered trying a rub joint?

Basically, you slide the two boards back and forth with glue until they "stick", then let the glue dry....

doc henderson · February 14, 2021, 08:50:47 AM

you make a good point, that the joint does not need a million pounds per sq inch. even masking tape works for small stuff, or miters on a frame. If the end product does not call for the bark, you can clamp the bark and take it off later. I have also left ERC bark on, and occasionally glue it back on.

Don P · February 14, 2021, 09:03:08 AM

Use your cauls to keep it flat then wrap a few inner tubes around it and pump them up?

low_48 · February 15, 2021, 12:49:01 AM

I make an L shaped hook pad out of plywood. At least 1 1/2" tall stock hooks under the natural edge slab, and a bit of profile cut is made on the vertical leg with a bandsaw to match the edge if it has a dramatic angle. Add a top horizontal piece to make it a U shape if you want more control over the pads. This lets you center the clamp pressure in the middle of the slab.

doc henderson · February 15, 2021, 01:03:52 AM

wrap it in surgical tubing. like and ace wrap.

low_48 · February 15, 2021, 11:55:15 AM

The problem with anything wrapped is that it is too easy to have more stretch or pull on one side than the other. Too easy to have a cupped glue up then. I've used rubber bands for laminated woodturning. That's where I learned about that issue.

Old Greenhorn · February 15, 2021, 01:36:22 PM

I will say this, there are lots of interesting ideas here. I didn't even ask the question, but I sure picked up some good stuff. Hope I can remember it all then I need it next!

Nebraska · February 16, 2021, 05:57:13 PM

Sorry folks for leaving this hanging a little, thank you so much for all the ideas. I apparently failed to come back here over the weekend must've been the cold air :

. The biscuits were to help with aligning, I used the bigger size 20. Before I tried gluing the first time the joint was almost invisible with the two sides sitting side by side on the flat surface. After my failed first attempt I pried it apart, cleaned up the glue, left it dry. I sanded the joints and recut the slots for the biscuits. Used the smaller ones the second time.
I went and found two pieces of good flat board wrapped packing tape on them to keep the glue from sticking. I used two big C clamps to pinch it flat and then wrapped ratchet tie downs around it to draw it together. I put the ratchets to the bottom side of the piece and slipped a couple pieces of cardboard box under the metal edges, it worked fairly well. I was the able to use a couple bar clamps on either end to snug it some more. The joint wasn't as nice as I wanted it but I am contemplating working a little dust from the sander into some thinned epoxy and working into the joint with a syringe to camoflauge it a little. I didn't take any pictures of my glue up, my work bench at the moment is a sexy particle board stair tread on a couple saw horses in the garage. It's too cold out there now to do anything. So the project is sitting for a bit. The end product will be bark off. I do have a cattle bander that uses heavy surgical tubing I will have to try some time. Thanks for that idea Doc, I tried a couple pieces of shim I had around, but they failed. I have some kneeling pads and that thick foam may have been the right answer the first time as well as the wedge trick. The clock was running and I was failing so better than have a big gap, I went to plan B, forum consult.

doc henderson · February 16, 2021, 06:05:51 PM

I have a DeWalt biscuit jointer, and finally adjusted it a bit deeper so I did not run the risk of bottoming out a biscuit and being unable to close the gap, kinda the same as using a smaller biscuit. I also have a gage to measure the slot to see what biscuit will fit. i put a line across the joint to align the biscuit cuts. if they are offset at all, it can make the biscuit too big (wide) to pull the joint closed.

Nebraska · February 16, 2021, 09:11:57 PM

I probably should find one of those gauges sounds like a nice simple thing to check. I would hate to screw up a really nice piece of wood.

21incher · February 16, 2021, 09:19:42 PM

I have had issues with old biscuits getting fat from expanding over time and fitting tightly. Just hitting them on some 80 grit sandpaper on your bench can make them slide in easier. The glue will still expand them for a tight fit.

btulloh · February 16, 2021, 09:38:46 PM

I stopped putting glue on the biscuits for that reason. They swell. Can also cause a surface swell. If you sand the surface before all the moisture is gone, there will be a slight depression after a couple weeks when the swell shrinks down as the wood in that area reaches emc. Since it's a long grain to long grain joint, there's plenty of strength anyway and the biscuits are only needed to keep the joint aligned when clamps are applied. BTW, this swelling occurs along the glue line as well. It pays to wait before leveling the surface or you will probably get a depression along the glue line.

doc henderson · February 16, 2021, 09:45:56 PM

you can also put a desiccant pack in the container and keep it closed, or put them in a dehydrator and then store them if the gain moisture. just like the ones for a gun safe, they can be recharged in the oven. I get ones from like shoe boxes ect. and other packaging.

DonW · February 18, 2021, 08:14:14 PM

My suggestion depends on your dimensions to a degree. I think you can rule out bar clamps. The one time I've glued up live-edge stuff I clamped one side firmly to the workbench top small face down laid up the mating plank and place a sufficient caul loosely parallel and clamp that down tight. In between the caul and free plank you can set a series of opposing wedges spaced so you get glue squeezing out along the whole joint.

Nebraska · February 18, 2021, 11:47:10 PM

I like the wedge suggestion good way to do that.. I hope to have a wood shop with a work bench for nice projects, My small shop has two, neither fit for wood projects. Plus I have to keep the work truck in there heated, it is bad if it freezes so no room this time of year.

alan gage · February 19, 2021, 03:04:32 PM

Quote from: Nebraska on February 16, 2021, 05:57:13 PMThe joint wasn't as nice as I wanted it but I am contemplating working a little dust from the sander into some thinned epoxy and working into the joint with a syringe to camoflauge it a little.

I think thinning the epoxy will be unnecessary because when you add the sawdust for coloring it will thicken the epoxy to stiffer than when you started. But that's not a bad thing. For filling holes and cracks I much prefer thickened epoxy about the consistency of peanut butter. It's much easier to apply and it doesn't find a crack to run out on the bottom side. Just work it in with a piece of wood or plastic squeegee and leave it slightly proud for sanding once cured. If you catch the epoxy while it's still green you can shave most of the excess off with a sharp chisel to save yourself a little sanding.

Alan