HW veneer on MDF

[James Carmichael]

For a project I'm doing, I wan't to veneer a couple of panels, the largest of which will be about 2'x2' with some walnut crotch-grain veneer. I've read and read about veneering, but can't seem to get any definite answers to:

1. Is it necessary to cross-band and balance an MDF panel? I've read that crotch-grain and burl veneers need backing.

2. I've read about a variety of adhesives/techniques, from vaccum presses to using contact cement just like laminating a countertop, to using plain white or yellow glue and a steam iron. What adhesive/technique has anyone used that worked, short of building a screw or vaccum press?

Thanks

[Stan Smith]

Looks like no one is coming to your rescue. I feel your pain. Not knowing diddly doo ha about veneering myself, I just ordered a book, "Veneering-A Foundation Course", by Mike Burton. I ordered mine online from Barnes and Noble. www.bn.com. I read the customer reviews on amazon.com though.

Stan

[Chris Padilla]

For a project I'm doing, I wan't to veneer a couple of panels, the largest of which will be about 2'x2' with some walnut crotch-grain veneer. I've read and read about veneering, but can't seem to get any definite answers to:

1. Is it necessary to cross-band and balance an MDF panel? I've read that crotch-grain and burl veneers need backing.

2. I've read about a variety of adhesives/techniques, from vaccum presses to using contact cement just like laminating a countertop, to using plain white or yellow glue and a steam iron. What adhesive/technique has anyone used that worked, short of building a screw or vaccum press?

Thanks

I don't understand what "cross-banding and balancing" mean for veneering in regards to MDF. Perhaps you could explain a little bit what you mean? Are you worried about the edges (edge-banding?) or something? I can't even guess what "balancing" means. :confused:

Pick up some cheap veneer (yeah, like that exists) and experiment a bit if you can't get answers. I see myself needing to veneer some future speaker boxes and I happen to have a roll of flat-cut maple with pressure sensitive adhesive (PSA) on it. So, I guess I have my glue needs already answered.

There was an article in either American Woodworker or Wood that had a small ditty on veneering with either contact cement or epoxy I think. It was only an issue or two ago.

Sorry to not be much help...please let us know what you find out.

[Terry Dyck]

First, if you are using an mdf core you don't have to veneer the back, although it is advisable.

Second, don't use contact cement for anything larger then a few inches to a side. The contact cement is too flexible and the veneer will often crack within a few months. White and yellow glues should only be used for small objects because of the fast tack time and it too is slightly flexible.
The size of your panel is a problem. The easiest methods are hard to do when the panel starts getting large. I have never used the iron on yellow glue method but I have been assured it works well. It will also solve the problems in point three

Three, the best clamping method I have found is a vacuum press, which is nothing more than a vacuum pump and a big heavy plastic bag. With this system you can use urea formaldahyde glues which set slowly and cure hard and nonflexible. A big expence for one project but it is the most effective way to clamp a large area.

Another posibility is to 'hammer veneer' using hide glue. I use this mostly to repair damaged or bubbled veneer but it was the way large panels were done in the past. You don't hit the veneer but rather push it into the glue with a steel roller, the tool is available from Lee Valley and others.

I hope this helps. I am out of town for the next week or I would also sent you the titles of some good books. Ah well, I'm sure someone else will be able to help you on this.

[Bob Lasley]

James,

I'm by no means and expert at veneering, but I have veneered panels and drawer fronts for a chest of drawers and I have done a fair amount of studying on processes. The panels I did were about 12 x 40". I used Titebond Cold Press glue, mdf platens, cauls and 3/8" all thread through the cauls for clamping. The substrate was 1/4" Baltic Birch plywood and the veneer was Sapele. I covered the mdf platens with wax paper so the glue wouldn't stick to it. The cauls were made from 2x4's jointed slightly convex on the edge going against the platens. Cauls were placed on top and bottom of the platens. I drilled holes through the ends of the cauls and ran the all thread rod through them with washers and nuts top and bottom. I spread the glue with a notched trowel on one side of the substrate, slapped on the veneer, flipped it, spread glue on the other side, applied the veneer, onto the platen, added top platen, stuck the top cauls on, started the nuts and ran them down with the cordless drill. Snugged up the nuts with a wrench. It worked on two panels and several drawer fronts. The drawer fronts had 3/4" ply substrates. I did use the white glue and iron technique for edging the drawer fronts. All of the above worked, but it was alot of work. I have since purchased a vacuum system.

My recommendation would be to veneer both sides of the mdf. The back side can be a plain low cost veneer. I don't think crossbanding is necessary. Burl veneer sometimes needs to be flattened before glueing though. I think you will find the Cold Press glue will work for the size of panels you are talking about. A urea formaldehyde glue like Unibond 800 might be better. Less chance of creep but more expensive and trouble to use as it has to be mixed. Experiment with small pieces first. You will probably have to play with the glue amounts so you don't get too much bleed through. I would NOT use contact cement.

The book Stan mentioned has some good information as well as "The Veneering Book" by David Shath Square. Check out the Vaccupress website. They have a forum with a ton of good info though it will lean toward vacuum pressing.

Your mileage may vary. PM me if you have more questions.

Good luck,
Bob

[James Carmichael]

Bob,

Thanks for the information, I had visited JoeWoodworker.Com, which has a lot of good info on adhesives and had decided cold press was my best choice, it looks like Unibond is best used with a vaccum press. A lot of stuff you read about veneering assumes you are using paper or wood-backed veneer.

It took me a few reads to understand your clamping technique, but now I'm starting to get it. You tightened down 3/8" bolts through the ends of 2 x 4s convex to the platens since they would bow when tightend down. How many cauls did you use on your 18 x 40 panel?

I had never thought of that, but looks like it should work, an old veneering book I bought at half-price reccomends angle irons for clamping (although it never uses the term "cauls" which gets confusing). I've also got a couple of 4x4s taking up space that might be good for that.

[Chris Padilla]

I would think you could pile a bunch of cheap cinder blocks on top of the platens, too.

I use this method a lot when laminating plywood sheets together.

[Bob Lasley]

James,

It I remember right, I had cauls spaced about 6 inches apart.

Sorry if my description wasn't real clear, but I knew what I was talking about! ;)

4x4's would certainly work as cauls. The reason for jointing the cauls convex is to put as much clamp pressure in the middle as on the edges of the platens.

Bob