I'm on my way to doing this. OK, I did step one today and bought a sheet of MDF. Well, something similar anyway.
A 2 x 4 sheet of MDF is $6 with tax. I can get about 18 inserts from it or a cost of 33¢ each. Since that is kind of pricey, I bought a full sheet of sheetrock instead. Cost per insert sill be about 8¢ each. Great idea huh!!!
My question is, what type of paint should I put on the sheetrock? Is gloss latex better than the flat? I would think the wood being cut would slide better that way. I'd be interested in knowing your experiences of using sheetrock to make zero clearance inserts. I think I'm really onto something here and maybe you and I can sell them as an economical alternative to those expensive MDF ones.
I'll go back tomorrow for the screws.
Ed