Help...Birdseye Maple veneer keeps cracking during application

[Derek Hansen]

I am trying to veneer some nice 1/16" birdseye maple veneer to 1/4" plywood for a mitered box top.

I have used the titebond/iron method (http://www.oakwoodveneer.com/tips/ironon.html) many times before with other woods with great results.

However, probably due to the fragility and the wild grain of the birdseye, I can't seem to iron it down without cracking it.

Anyone know another method I could try?

[Mike Henderson]

My experience in attempting to use that technique with "difficult" veneers is that the heat causes the veneer to change size and I then have a mess on my hands. If your top is flat, cold press the veneer. Put down your glue, lay the veneer on top, then a sheet of plastic or waxed paper, then some 3/4" MDF. Clamp the sandwich and wait for the glue to dry.

Mike

[george wilson]

I have soaked veneer very thoroughly in hot water and pressed it between paper in a press for several days,or weeks to flatten it. Especially burly mahogany veneer I used on the side panels of a large harpsichord in 1970. The veneer I used was as brittle as a potato chip,and 1/28" thick (back then.)

I have also heard of using glycerine on it to soften it.I have not tried that myself.

[David DeCristoforo]

Three parts water to one part glycerin. Wet the veneer good and press it George says. But before it's completely dry, use an iron on medium to finish drying the leaves. The heat will "pre shrink" the veneer and if you apply it soon after, there is a much better chance of it staying flat and not cracking. I have found that titebond takes too much heat to bond and highly figured veneers can be a problem. I have always liked "Better Bond Heat Lock" glue for ironing down veneers. Check it out here:

http://www.veneersupplies.com/default.php?cPath=86_40&osCsid=fdf191e7919fe48f280e558e33d7af0b

I have found this stuff to be an amazing glue that is easy to work with, forms a "hard" glue line making it particularly suitable for use with unbacked veneers, and, once stuck it stays stuck.

[David Perata]

I have a vacuum veneer press and use Unibond glue with bird's eye maple veneer and have had no problems. They sell small vacuum presses and I think it's a great investment if you plan to do veneering as a part of your work.

[David DeCristoforo]

"...bird's eye maple veneer and have had no problems..."

It's not the BE maple that's the problem for the OP. It's the heat from the iron. Pressing is always the preferred method for laying up veneers. But, sometimes it's not possible or practical. Laying up veneers with heat activated glue and an iron or veneer hammer is a "tried and true" method.

[Paul Atkins]

1/16" seems pretty thick for ironing to me. The more wood (thicker) the more stress in any movement. Vacuum pressing would seem like the best solution for this. You don't have to get a fancy bag setup for something that small. A piece of polyethylene and a gasket of caulk would suffice with a good vacuum.

[Keith Christopher]

1/16" seems pretty thick for ironing to me. .


I was thinking the same thing. Most of my veneers are ~1/47. I haven't used the ironing technique but I have used the gly/water technique to soften the veneer but I am using much thinner veneer. I would think with 1/16 inch you could simply apply your glue and with a platen and some cauls get good pressure for the glue up. You should also check out joewoodworker.com there is ALOT of articles/tips there.

[george wilson]

In Williamsburg,we often use hand sawn veneers 1/16" finished thickness. They can be laid down using hide glue on both sides of the veneer,and on the carcass,with a veneer hammer. Two of my old journeymen showed this process on "The Woodwright's Shop".

Hide glue doesn't interfere with staining or varnishing either. It is put on both sides of the veneer to prevent it from curling up from one side being wet. After the veneer hammer is used,a damp rag is laid over the veneer to prevent the top side of the veneer from drying too fast,and curling up. Then,it can be scraped clean,stained,or varnished.

[Derek Hansen]

Thanks everyone - Mike's cold-press method worked excellently on these relatively small pieces.

[Thomas Knapp]

In Williamsburg,we often use hand sawn veneers 1/16" finished thickness. They can be laid down using hide glue on both sides of the veneer,and on the carcass,with a veneer hammer. Two of my old journeymen showed this process on "The Woodwright's Shop".

Hide glue doesn't interfere with staining or varnishing either. It is put on both sides of the veneer to prevent it from curling up from one side being wet. After the veneer hammer is used,a damp rag is laid over the veneer to prevent the top side of the veneer from drying too fast,and curling up. Then,it can be scraped clean,stained,or varnished.
George
How large of an area is that technique practical for? I have only used the technique on pieces 1 foot square or smaller and have liked the results. I use whatever techniques I think will work best for a project. I am by no means a purist, but I do think hide glue has been under rated. I have a little crock pot that will keep the glue temperature between 130 and 140 deg. F. I don't find it much bother to heat up a batch.
Thanks
Tom

[David Keller NC]

George can probably answer this question better than I can, but I've successfully used the hide glue and veneer hammer technique on a set of drawers for a Federal-style chest. The largest drawer was 10" high and about 4 feet long, so a little less than 4 square feet. The veneer was shop-sawn highly curly maple, and to say that it was fragile would be an understatement. Nevertheless, it was quite pliable and pretty easy to put down after both sides were brushed with hot hide glue.

One potential advantage of the hot hide glue is that it shrinks very little on cooling, so there's not much danger of the veneer pulling apart as the application dries.

[george wilson]

A lot depends upon the finesse with which you can manipulate the processes. What David has described should be enough for most applications.

In Diderot,they show workers ironing veneer down in large panels at least 2' square. What they did was to apply hide glue-the real cooked glue,because it will gel when cool. They put this onto the carcass and on both sides of the veneer. When the glue had gelled enough to grab,they would run the irons over the veneered surface,melting the glue and making it bond to the veneer.

These processes all take skill development,and should be tried a lot on scrap materials.

I still have my old wooden veneer press. It has a platen about 12" X 30". All made out of 4" oak,with a 2" dia. wooden screw. Was copied from a Diderot illustration.

[Mike Henderson]

Just an additional comment about gluing "difficult" veneers. Some veneer goes crazy when it gets wet. When cold pressing with water based glue, have everything ready and get it in press as fast as you can, before the veneer absorbs much water.

Alternately, you can use a non-water based glue. I've used epoxy in the past, but I think Unibond 800 is non-water based, also. The Unibond people also make a "blocker" that you can add to the glue which will reduce the bleed through of the glue (some veneer with wild grain has grain running up and down - face to face - so the glue comes through easily). The only negative to Unibond 800 is the relatively short shelf life.

If you're applying the veneer to a flat surface, my opinion is that a press is the best way to do it. You can hammer veneer with hide glue but the water in the glue and the heat can cause problems with some veneers, especially if you're new to the process.

Mike