Seal backer board

[breadstick]

I tried to find the original post, but I can't seem to.  Someone here said you should always seal the back of your pieces because unsealed wood would warp and distort the piece.  How much should you seal the back?  I put three coats of poly on the front of the piece I finished last night, but not sure how much to use on the back. Since you can't see it, would one heavy coat on the back suffice?

[hawkeye10]

I would put two coats of clear. If the backer board is ply then you don't have to do it but it might look better if you do. 

[WayneMahler]

Depends on the piece I am working on. If the backer shows I finish the same as the top. If it hidden usually 2 light coats of finish to protect it.

[breadstick]

Thanks.  2 coats of poly isn't too much more effort. Sounds stable to me.

[dgman]

I always apply the same amount of coats to top, bottom and back. Just the woodworker in me.

[NC Scroller]

I have made hundreds of pieces with backers and I have never sealed the back of the backer.  Well I did a couple times because I painted/finished the wrong side but that is another story.  I have NEVER had an issue. But then again I use plywood (mostly 1/8" Baltic Birch) for all my backers.

[Lucky2]

As long as it has one coating of sealer, that's all that's needed. You don't need the back to be as good looking as the front, you just need it sealed so that it can't absorb moisture. 

Len

[amazingkevin]

I tried to find the original post, but I can't seem to.  Someone here said you should always seal the back of your pieces because unsealed wood would warp and distort the piece.  How much should you seal the back?  I put three coats of poly on the front of the piece I finished last night, but not sure how much to use on the back. Since you can't see it, would one heavy coat on the back suffice?

Sounds good to me .Your just keeping the elements from the wood,air water,moisture,