I do CNC work. I did several pieces that the panels were 32x16x1 before carving. Removing up to .4 in on one side caused many of the panels to cup/warp inward.
I bought an inexpensive wallpaper remover steamer and a plastic concrete mixing tub 36x24x9. I drilled a hole for the steamer hose in one end. Used short pieces of 4x4 to suspend the panel over a piece of polystyrene insulation board. Steamed it for 15 minutes and gently clamped the board between pieces of marble sink countertop leftovers. Left it clamped for 4 hours.
Worked great.
Go to your local marble company they will have stacks of free counter top sink cut outs they usually have to pay to have removed.
Buy a steamer. As you can see in the photo I bought a simple wallpaper steamer off Amazon ~$50. Bought a concrete mixer tub at Lowe’s ~$20. You can use any storage tub you think can take the heat and is big enough for what you are working on. I was working on 30x15x1 mahogany. Drilled a hole in the tub that fit the hose snuggly. Took about 15 minutes to start to steam. Steamed it for 15 minutes. Then I used my press. This is an inlay press I bought the design on cicworkshop.com. I added the 32” marble slab because I really wanted it flat. I also placed a 30” pine panel on top to distribute the pressure evenly.
I used the 4x4 to raise the pieces higher in the tub. Placed them on the edges so as much heat and steam could flow. Be careful removing the tub. You will get a face full of steam and the piece is also HOT.
