MDF question

[Ivan Vegvary]

Trimming out an enclosed stairwell (to be carpeted) with 1x12x18ft mdf slipped between the stringers and drywall. At both the bottom and top of the staircase I would like to end the diagonal trim with a vertical block, say 1x6x12", very slight chamfer on visible edges. Problem, cannot find small chunk of mdf that is a full 1" thick. I've seen builders use a thicker horizontal board above doorways for accent. This is Portland, OR and the best I can do is 5/4 lumber 8" wide, 16ft long and that would be a special order. Expensive! Suggestions? Work-arounds? Thanks!

[dadiOH]

Glue up two thinner pieces.

[J. Clarke]

It's MDF--it's already glue and sawdust with nice flat surfaces. What's the objection to just gluing two thinner pieces together to get the thickness you want?

If it _has_ to be one piece and you can't find it anywhere else, Boulter Plywood will sell you a quarter-sheet of 1" MDF for 33 bucks and shipping. They can go as thick as 1-1/2" but you noromally have to buy a full sheet for anything thicker than 1".

For something that's going to expose a vertical edge near the floor at the top or bottom of a staircase though I'd go with something more tolerant of abuse.