Bonding Veneer to MDF

Advice on laminating "wood on wood" veneer to water-resistant medium density fiberboard. January 8, 2010

I am building a cabinet style cigar humidor and need to laminate Spanish Cedar WOW (wood on wood) to Medex. WOW is a real wood veneer that is about .0625# thick and Medex is water resistant MDF. I need a type of adhesive that is water resistant and has little or no odor. Any ideas? We will be laying up full (48"X96") sheets. I was concerned about the odor in contact cement.

Forum Responses
(Veneer Forum)
From contributor U:
Assuming the same definition of water resistant (WR), here are some ideas: the best is UF (urea formaldahyde), water proof but if has trace amts of out-gassing. Crosslinked PVA is very good emission wise (green) but is not a WR as the above. You would need to hot press the UF, though you could find a version that would cold set. Not sure what equipment you have so without a press of some sort the above may be moot.

From contributor C:
Try Unibond-800 or Pro-Glue. They are both urea glues that are highly water-resistant. Google those brand names, and you will find more info. They can be pressed cold. I use a vacuum press with both of these products.

From contributor J:
File under "Unsolicited Advice": why buy backed sheets and lay up with contact cement in 4' x 8' sheets? You will end up spending more money for an inferior product than if you had these panels laid up from flitch stock by a veneer pressing house.

From contributor U:
I'd second what contributor J mentioned. I'm not sure what the face material is, but you can save money having a panel specialist lay them up. I've seen many shops wing a few panel only to have them go bad after delivery. Think about it!

From the original questioner:
Thanks for all your ideas. After doing a little more research, it looks like Unibond 800 will be a good choice. I have contacted a couple of the sites that sell this stuff and can't seem to get a straight answer. My question is: can I do this without a press or vacuum bag? Can I lay this up and then stack about a unit of material on top and let it sit? I have Medex in stock and have already bought the Spanish Cedar WOW.

From contributor C:
I believe Unibond 800 is their product. So, you are thinking of stacking stuff on top of your panels to press them. Ok, let's see...I have a vacuum press. It can pull about 25" of Hg (mercury). That translates to 12.28 pounds of pressure per square inch. You stated that you will be laying up 48"x96" sheets. That is 4,608 square inches. My press would apply 12.28 x 4,608 pounds of pressure. That is 56,586 pounds, or over 28 tons of pressure on that 4x8 sheet. I doubt you could stack that much material on top of it. Also, and this is very important, the vacuum press will apply even pressure over the entire surface.

For working with 4x8 sheets I would suggest looking at a flip-top table. I have a 5x10 table which makes laminating large pieces very easy. No sliding in and out of a large bag. Glue up everything in place, then close the lid and turn on the pump. Vacupress also sells vacuum bags, flip-top tables, pumps, etc. No, I don't work for them. I am just a very happy customer.

From contributor V:
You can also use powdered plastic resin glue which is also urea resin based. The advantages of this product are you are not paying freight for the water (which you add to powder when mixing glue), more economical and a 12 month shelf life. There is also a tinting agent available for making the glue a lighter color.