Best way to turn 1/4" ply into 3/4" ply?

[Steve Griffin]

I doing a project which requires just a couple sheets of 3/4" hardwood ply.

The 3/4" is difficult and expensive to get in this species from my supplier.

I ran into this situation before and tried glueing .5" MDF to .25" ply with yellow glue and weights, and ended up with warped product. The moisture in the glue seems to mess it up.

Is there is a better way to do this? Contact cement? Better techniques?

Thanks! -Steve

[Lee Schierer]

Having never done this and based on your comment regarding wet type glues, I would think that contact cement would be the best long term option. Some might suggest construction adhesive or liquid nails, but I've never been happy with the results from those products and you would still need the weights. If you coat both surfaces properly with contact cement and use proper procedure for bonding the two sheets the end product should come out as flat as the product you started with if the bonding is done on a flat surface (like a floor). You shouldn't need any weights, just a roller to make the surfaces bond together. I would use a solvent based contact cement rather than a water based one if you can find it.

[Prashun Patel]

What species are you looking for? Is it an option to seek an alternate supplier? I haven't priced it out, but I'm gonna guess that the price of 2 sheets of 1/4" (in order to give you the hardwood veneer on both sides) might cost about as much as a single 3/4" sheet and will be a lot more work to laminate to the right thickness.

[Josiah Bartlett]

If you use water based glue, glue both top and bottom simultaneously to avoid making a potato chip, and only glue up as much as you need for each piece rather than doing the whole panel at once. Also, it would be better to use a thinner veneer layer and thicker core material if you can, for stiffness. You also probably need a lot more weight than you would think to squeeze out the air, a vacuum press would be ideal.

[Anthony Whitesell]

I would recommend contact cement over a wetter glue like titebond.

[Tim Sproul]

1/4 inch ply - 1/4 inch mdf or 1/4 inch "filler" ply - 1/4 inch ply.

Use a veneer press glue - PVA, plastic resin or epoxy. You'll want a big roller to get that much glue spread quickly. Bag and vacuum it.

Me? Because you only need a couple sheets, 'd rather pay $500/sheet than go to that trouble. Laminating full size sheets of plywood probably isn't a walk in the park.

[John Coloccia]

I'd get 3/4" of whatever species you can get where you live and then veneer over it before making my own plywood.

[Steve Griffin]

Thanks for the replies guys.

Not what I was hoping to hear though. The savings for not needing freight delivery of two sheets is roughly $200. So anything that takes more than a couple hours, or doesn't yield a decent product is not worth doing.

I should have mentioned I only need it to be good on one side, and it doesn't have to be dead flat perfect. (carcass sides which are only 12" deep or so).

I appreciate the replies! -Steve

[Don Alexander]

i have very successfully used contact cement to make 15/16 oak plywood out of 1/4" and 3/4" no reason it shouldn't work just fine to make 3/4" plywood

i needed mine for a builtin bookcase and i had a source for free 1/4" ply that was in 11"- 13" widths (cutoffs from a furniture factory) i ripped the ply to about 1/4" wider than i needed the finished product before gluing it up then trimmed it later to final width worked like a champ

[Chip Lindley]

For consistent laminating, consider using a vacuum press. There are old vacuum pumps available for cheap. and a vacuum bag to hold a 4x8 assembly can be shop-made--or bought new. Use all that atmospheric pressure going to waste for a totally flat sheet of "custom plywood".

[Jim Andrew]

For walnut cabinets, I just make raised panel end panels. Dresses up the kitchen, and if you want plain ends, you could just glue up solid boards.

[johnny means]

Is there any particular reason you are looking for plywood in whatever species as opposed to just ordering a couple of sheets of 4x8 veneer? Then shipping would become a none issue.

[Craig Feuerzeig]

Use curved cauls to make a simple press... Regular old yellow glue. Done all the time.

You likely won't be happy with the results from contact cement. You certainly won't be happy with results of using weights. Vacuum pumps are expensive and mostly a one trick pony. Great if you do a lot. Cauls will have tons of uses in your shop... if you can make them accurately enough. I'm always surprised that this solution gets overlooked.