Veneer and MDF, both sides or not?

[Dan Drager]

I have some beautiful waterfall Bubinga veneer and plan on making a pair of end tables reminiscent of the coffee table done on WoodWorks episode 212. http://www.diynetwork.com/diy/shows_wwk/episode/0,2046,DIY_14350_26923,00.html

I have seen conflicting opinions on this in different threads and would like to ask straight out. When using MDF for a substrate, do I need to veneer both sides? Any and all examples that back up your opinion on this is greatly appreciated.

Thanks.

[Jamie Buxton]

Theory says that a balanced panel is less likely to warp. However, if you're using a 3/4" MDF in this design, the veneer is just not strong enough to bend the substrate. Furthermore, you have the table's aprons to help keep the panel flat. That is, from structural considerations you can certainly get away with veneering only one face. The only argument for veneering the bottom of the panel is that you don't want to look at MDF when you're lying on the floor looking up at the underside of the table. If you or your friends do that often, you could veneer the bottom with something less expensive than waterfall bubinga -- say, maple.

[Jim Becker]

"Best Practice" would be to veneer both sides, but I agree with Jamie...in this case you'll likely be safe with a thin veneer on one side of 3/4" MDF if it's properly supported.

[Rich Person]

I would veneer both sides. You can use some cheap veneer for the back side. MDF is flat, but it is very plyable over time. I tried to make a work bench out of laminated MDF--thinking it would end up flatter than flat. Sure enough, the whole thing warped to one side because I assymetrically glued one side to some plywood. I had to cut up and toss the whole mess.

[Per Swenson]

Dan,

Peace of mind is cheap.

Both sides.

Per

[Steve Wargo]

I agree that you should veneer both sides. Even if the bottom is cheap and ugly, still better to be safe than sorry. I've had 3/4" MDF warp on me before with veneer only on one side. Good luck.

[Danny Hill]

I always do both sides. Both glue and venner on only one side will cause problems.

Post your question on Darryl Keils site http://www.vacupress.com he is the veneer master.

[Mike Henderson]

Waterfall Bubinga can be a problem to glue up - it warps and bubbles a lot when it gets wet. If you've never worked with it before, try some test pieces before you do the whole top. When I've worked with it in the past, I sometimes had it bubble after I took it out of the press, especially if I sprayed water on the veneer tape to remove the tape. One thing I learned is that if it does bubble, it will usually settle down in about two days after the moisture dries out so don't despair if you do get some bubbles.

The bubbles exist, of course, because the glue doesn't grab all of the veneer. You might think that one way to solve the problem is to use more glue but bubinga is porous and the glue will come through. In the worse case, the glue will show up when you finish the top, showing up as blotches.

And as far as veneering the bottom, I would rather be safe than sorry. Get some cheap veneer and put it on the bottom.

Mike

[Jim Tobias]

Dan,
I always veneer both sides. Why? Because everything that I have ever read (which is usually written by experienced craftsmen) say that you should veneer both sides. Some say to keep out moisture, others say to balance the substrate and prevent warping. I have yet to have a panel fail with veneer on both sides, so why risk it for the cost of a veneer skin (lesser quality) and some glue?

Jim

[Neil Lamens]

Dan:

Call up and ask for a "cheap backer" that'll work with your bubinga.

Both sides and put the worry somewhere else.

Neil

[Mike Palmer]

I would definately veneer both sides. It is just a good practice to keep everything balanced. I would also echo what Mike said about Waterfall bubinga. It can be prone to bubbles. Make sure you get the glue spread even and press it as soon as you can. Once you put the veneer on the glued substate the veneer begins to suck the moisture from the glue. I usually glue the backer first and then the face veneer. Below is a lnk to a bubinga project I did some time ago.

http://www.sawmillcreek.org/showthread.php?t=10822

[Dan Drager]

Mikes.....Would using a veneer softener help with the bubbling issue?