I would like to cut a Cottonwood stump to use in a deer mount. Do I have to do something to it to keep the bark from falling off? Or will it stay on?

Thanks ! I will watch that

time of year has a big impact on if the bark will stay on. Spring is typically the hardest to keep on because the cambium layer is more full of water. Fall/winter is best to keep bark on. But that being said, it can still be done. You need to cut it and get it in a dry environment so the cambium will dry out before it starts breaking down and the bark falling off.

Are you doing a cross-section cut (end grain) or a plank style? If the cross-section, you will want to seal the end grain so it doesn't dry out too fast and crack a lot. Looking up radial/tangential shrink rates, cottonwood is moderately high at about 2.4:1, so you will have some more warping and cracking if you dont seal it.

What I would try to do is cut it across the grain, cut the stump to use as a table.

to secure/strengthen the bark, i use an ultrathin superglue to let it soak in.

For cutting a table from end grain, it takes time. Cut it thicker than you want the final product (say 3" thick if you want a 2-2.5" thick finished table). then seal, let it dry for a while, then you will need to flatten off the surface and finish it up. Typical air drying is 1 year per inch of thickness, but end grain is faster. The hotter the location, the better (even put it in the attic if you want).

Thanks for the info. Is there any chance I will be able to use a fallen dead tree or will that bark fall straight off ?

I'm interested in your take on the best flattening setup. Especially for long slabs.

if its laid on the ground for more than a week or two and there was any moisture between the tree and the ground, then you are going to be pressing your luck on if the bark stays on. keeping if off moist ground is the biggest factor i can think of.