Sand plywood thinner before veneering?

[atgcpaul]

I'm making some slab cabinet doors by gluing shop sawn veneers to a plywood substrate.  I'm using Blumotion face frame inset hinges, and a 3/4" thick door will give a 1mm reveal but thicker doors will need a large reveal so the door clears the face frame as it pivots.

The problem is I can only find plywood that is 3/4" or 1/2".  5/8"+ would be ideal.  I'm thinking I can just sand down 3/4" ply to the proper thickness so I end up with 3/4".  I have a drum sander.  I also have a planer with carbide inserts but I don't think running ply through it would be wise.

Anyway, is it a bad idea to sand down plywood?  Will it lose its stability if I don't take equal amounts off each side?  Is there another way to tackler this?

Thanks,
Paul

[Rob Young]

I'm making some slab cabinet doors by gluing shop sawn veneers to a plywood substrate.  I'm using Blumotion face frame inset hinges, and a 3/4" thick door will give a 1mm reveal but thicker doors will need a large reveal so the door clears the face frame as it pivots.

The problem is I can only find plywood that is 3/4" or 1/2".  5/8"+ would be ideal.  I'm thinking I can just sand down 3/4" ply to the proper thickness so I end up with 3/4".  I have a drum sander.  I also have a planer with carbide inserts but I don't think running ply through it would be wise.

Anyway, is it a bad idea to sand down plywood?  Will it lose its stability if I don't take equal amounts off each side?  Is there another way to tackler this?

Thanks,
Paul

1) Make your own plywood, consider starting with 1/4" or 3/8" MDF.  Then resaw some poplar, also slicing it up so that when you make the skins they are quartersawn.  Then add your veneer.  This however is a lot of work.

2) Put a slight bevel on the edge next to the hinges so that it continues to clear the frame when opened.  If bevel is noticeable (probably not), continue it all the way around the door and make it a feature.

[JGrout]

use 1/2 ply and make thicker veneers or add a layer to each side to get to your core thickness 

or use 5/8" mdf for your core 

it works just fine no need for plywood

[ez-duzit]

"I can only find plywood that is 3/4" or 1/2"."

Baloney.

[Steve N]

I'd opt for the MDF core, absolutely stable, and dead flat, it's a wonderful substrate to build on. 5/8" is available, as it also is in BB ply. You have no indication of where you live. Having that info it's very possible someone can tell you where to go to get 5/8" material. It's certainly out there.

[atgcpaul]

Looks like I'm taking a little drive.  Lumber supplier about 40 minutes away has 5/8" BB.  The other HD about 15 minutes away has 5/8" particle board but I don't want to second guess myself that the screws won't hold.

[JGrout]

Looks like I'm taking a little drive.  Lumber supplier about 40 minutes away has 5/8" BB.  The other HD about 15 minutes away has 5/8" particle board but I don't want to second guess myself that the screws won't hold.

MDF and particle board are not the same thing

[7DWW]

I have been warned numerous times about gluing up on a BB so I stayed away and probably glad I did. Particle board is fine, and 5/8" should be readily available in Maryland. No need to worry about the hinge screws holding if you use the proper screws. Every commercial P-lam cabinet that you have ever seen in offices, hospitals, etc most likely has a PB core.  Be sure to veneer both sides with similar woods.

[Bope]

Do you have a baltic birch ply supplier. I can get 1/8" to 3/4" in 1/8" increments.

I am not sure I would try sanding down ply to veneer. Even the better furniture ply I can get has some small voids.

[atgcpaul]

Do you have a baltic birch ply supplier. I can get 1/8" to 3/4" in 1/8" increments.

I am not sure I would try sanding down ply to veneer. Even the better furniture ply I can get has some small voids.

Already done.  I just didn't want to make the drive, but I did it yesterday morning.  I wasn't feeling motivated to going into work after the long weekend so I did the 1.5 hr round trip for the 5/8" BB and came in late.

Thanks,
Paul