I am fabricating a 132" painted Bench Top for a window unit. The top will be 1 1/2" thick and I was planing on using 3/4" CFC Maple Plywood with a 3/4" CFC Maple Plywood build up underneath. A solid Maple wood front edge will be applied and the whole unit painted white Pre-cat Laq. My concern is the joint that needs to be made and the possible shrinkage at the end joint where the two pieces will join and opening a crack in the finish. I was planing on using a half lap joint to eliminate this problem, followed by securing a built up scab board underneath as part of the build-up. I would appreciate any feed back on this.
From contributor Gr
Your method sounds good. Be sure to clamp the joint together very tight and closely inspect the joint after its dry and use bondo if any needed to fill any possible defects. Finally, consider a pigmented coversion varnish instead of pre-cat laquer. Use a heavy primer first.
Just my 2 bits......
From contributor Ad
Use epoxy resin to glue the sheets together. Even with the half lap joint, it is still alot of end grain glueing.
From contributor Br
Your end joint is going to open no matter what you do. It's what happens with paint and wood movement.
From contributor Ke
Why not use solid poplar and be done with it?
From contributor Ji
Do I dare mention it-
Order a sheet of 4x12 MDF or 4x12 maple veneer core and be done with it.
From contributor Ri
Thanks to all the response. I actually found a supplier that carries 3/4x5x12 MDF and we placed the order. I was sure of and very concerned that no matter what I did, the joint would eventually open. While this is being done as a bench seat top, it is not actually a used seat by the client, but as a simple top covering for the lower cabinet run under a window. I do get a lot of advise from this forum, simply by just reading it every morning. Thanks again for all of your replies.