Warping of carving

[BoilermakerAndy]

Hi everyone.

I purchased a 3D model of a Byzantine cross for carving a while ago, and I've carved it once before, out of Mahogany. It came out great.

This time, I carved it out of cherry. I glued up three strips of cherry wood that were approximately 8" x 36", giving me a blank of 24" x 36" x 1.1" thick. I ended up carving the cross against the grain, length-wise (spanning all three boards).

Though I did not plane the blank prior to carving, it was pretty darned flat. After carving, and removal from the material (it was tabbed), the cross was really warped. I'm guessing that this is from "stress relief" within the wood itself causing this once the majority of the material was removed. Is this possible? Anyway, it is what it is.

I CAN push the two ends flat, and was considering cutting out a plywood cross that is offset 1/2" in from the carving, and gluing it. I'm worried that the stress on the cross could cause it to break at the glued seams.

Does anyone have a way to try to un-warp something like this without breaking the glue seams?

Thanks.

Andy

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[noahlorang]

This is something I've spent a lot of time fiddling with, as deep 3d carvings is most of what I do.

You can probably get it to flatten back out by adding moisture back to the carved surface. Often what I'll do is take a bath towel, dampen it, and then lay the piece face down on the towel. As moisture is absorbed, it will flatten back out (overnight will probably do it). This isn't a permanent fix, because once you flip it back over it will dry back out again, but I find that a few cycles of this does a pretty good job.

In the future, cutting a few reliefs in the back of the carving will help to alleviate this. I typically do a 3/16" deep, 2" wide relief across 75% of the width of the carving, every 4-6 inches as the shape allows, and that solves most of the warping. You can also use those slots to install steel bars if you still need to pull things flatter.

[garyb]

A little hard to tell from the photo, but looks like you didn't alternate your grain in your glue up, then I would run the grain in the long length
Gary

[BoilermakerAndy]

Thanks for the replies. I don't have a planer or jointer, so I had to try to clean the edges up with my table saw, and I picked the best edges I could find. Plus there was some drastic color veins I was trying to avoid. But, yes, the grain issue is correct. Also, I didn't have the right strategy. My "Blank" is large enough for 2 more crosses. In hindsight, I should have just made one blank with the grain the right way. I cut out of Mahogany about a year ago, and I did cut it lengthwise as opposed to against the grain. It did not have this issue.

Here's a different question: Can you take lumber (cherry, mahogany, etc..), cut them into, say, 2" strips, plane the faces and glue up a blank that is 2" thick? I'd like to try this on a thicker piece of material, since so much of the material is cut away. Plus, I could make the model "deeper" so that the detail stands out more.

[dlcw]

Since you live in GA, you could try what I do. Put the board out on the grass, crown up. This lets the board get sunlight on the top (dry it) and moisture on the bottom. I've done this with many boards, in the summer. Right now there's snow on the ground here so can't use this method.

[BoilermakerAndy]

That's awesome! I'm going to try it!

[chiloquinruss]

"In the future, cutting a few reliefs in the back of the carving" that's what I do when doing mantle pieces. Had an eight footer that I left overnight on the Bot, went out next morning and released the clamps - ouch about an inch riser on both ends of the mantle (after 7 hours on the bot)! NOT HAPPY. But doing a relief carve in the backside before the front side will help. Russ

[bobmoore]

your 2 inch edge grain will work fine and also be more stable than the flat grain.

[barrowj]

Andy,

You are within a reasonable driving distance from me (Cleveland, TN) and if you need anything (including rough cut lumber) don't hesitate to reach out. I have all of the tools you are missing and would enjoy some company from time to time.

Joe