…because, boy, what I did sure didn’t work! 8->
I’m working on an end table, and decided it was a good project to try using some quilted maple veneer I’d picked up cheap. Never, ever done this before, but I decided to make sure I couldn’t be accused of lacking ambition. I made bookmatched quarters, jointed them, and pulled them together nice and tight with veneer tape. Looked good to that point. Today, I picked up a manual pump vacuum bag kit at my local Woodcraft, did a dry run, and all still looked good. So I mixed up some urea glue from Pro-Glue, and went at it. My balance veneer (birch off a roll) went fine, but as soon as the glue hit the quilted maple, the veneer began fighting the tape, buckling against it and becoming so ripply there was no way it could have been laid flat.
It’s abundantly clear that I didn’t do enough beforehand to prevent this. When I first got the veneer I did moisten it and press it between two piececs of MDF weighed down by multiple forty-pound bags of salt. Seemed pretty flat after that. I didn’t try it with moisture again, though.
Should I have opted for a different glue — hide glue and hammer, perhaps? Should I have used a chemical to make the veneer more manageable? Did I stretch things too hard when I applied the paper tape?
All in all, an interesting and not really disheartening experience. I’m just hoping you folks can help make it educational as well.
— John
Replies
I get the feeling from reading your account that you spread the glue onto the veneer. Is this so? The glue should only be spread (use a roller) onto the substrate. A caul is then placed on top of the veneer to hold it in place. Then the assembly is placed into the veneer press bag.
So how did it all turn out? Or, did you abandon the glue-up and wash the glue off?
IMHO when veneering you should definitely apply adhesive to both sides. The veneer and the substrate. If you only apply it to the veneer, that's not enough adhesive. Also, the "pro glue" from Woodcraft, if I remember correctly, you have to mix with water. Stay away from water in your adhesive when you veneer.
Get on the web and order some "Unibond 800". This is a urea formaldehyde glue that I use for veneering in my press and have never had any problems. Go to your local craft center and buy some "ink rollers". These are perfect for spreading the glue. Once you use Unibond 800, you'll never use anything else again.
Jeff
Thanks! It did seem like it was the water content in the glue that sent things off-kilter in a hurry. With two of you recommending Unibond, getting some will be my next step.
I would second the comments that you probably applied the glue to the veneer. That is not recommended practice in spite of comments that favor that. You can get away with applying glue to the veneer on small panels, but it is risky) My experience is extensive with both Unibond and a PVA adhesive from Joe Woodworker (about 100 panels total). I apply adhesive only to the core, not to the veneer. The key is to get a uniformly wet coat of adhesive on the core. A 3" long foam roller works well. Roll out the glue in both directions, and pay particular attention to the edges.
I have used the glue from JWW (which is water soluble) on a lot of panels, and have not had problems. But you do need to get the clamping caul in place within a few minutes. Rehearse the process before applying the glue.
Good luck, Tom.
Nope, I put glue only on the substrate. It seems likely that a different glue would have helped a lot here.
jkl. Keep a spray bottle of water ready. Some veneers will curl and buckle when glue hits their undersurface no matter how flat they have been prior to gluing. It's standard practice when using hot hide glue to wet the veneer before gluing. The maple would have settled down if you had lightly sprayed it as it began to react to the glue. Rich
A spray bottle certainly makes sense -- I'll remember that for next time.
JKL, I do quite a lot of veneering. A vacuum bag is the way to go although hammer veneering is good don well. I use liquid hide glue for nearly all my work for a couple of reasons. Firstly, it's repairable down the road. In practice it will repair the same way hot hide glue does. Secondly, it has a long open time with lower moisture than PVA. This means it's not a terrible rush to get it into the bag before the glue flashes.Small tops are done this way. The veneer is laid on the caul upside down, the substrate is coated with glue using a 9" foam roller. Then the substrate is laid on the veneer and it's slid into the bag.Larger tops are done with the caul on top. The substrate is coated with glue, the veneer is laid on that, then the caul.Burls and other figured woods will go wild once the moisture hits it. Marquetry patterns do it too. I just laid up a walnut burl top and the key is to get the caul on top of it immediately. It some cases, like the burl top I just did, I'll tape the veneer to the caul to speed the process.Always use a caul, well, almost always. The only time a caul is not necessary is when thicker veneers are laid up on curves. I use plastic laminate as caul material on curves if it can take the bend.Check this out, it's an 84" diameter starburst. http://www.furniturecarver.com/Turek4.html The previous page has a pic you may find useful, it's a pic of the top in the bag getting the balancing veneer.Leehttp://www.furniturecarver.com
Great stuff, Lee! Rich
Thanks Rich.Lee
Liquid hide glue for vacuum bag work. Why haven't I thought of that? (slaps myself upside the head) I've been trying to think of a good viable alternative to Unibond...... I like the way it works, but am not all that keen on the formaldahyde aspects. I've used pva but it's open time is way too short for all but the smallest panels.I haven't used the liquid hide glue for some time, but I'll be getting a bottle right away. Once dry, are the characteristics the same as for hot hide glue? Do you thin it at for rolling out or do you use it as is from the bottle? Are all brands similar?
The only difference between hot hide glue and liquid hide glue is an additive that lowers the gel temp to a bit below 60f in the liquid hide glue. Other than that they are the same animal.Watch the expiration dates. A test to see if older glue is good is to put a dab between thumb and index finger and keep separating them as it dries. Good hide glue will form many, many strings as you separate your fingers, this is the protein chain that gives hide glue it's adhesive properties. If these strings form it's good glue no matter what the date on the bottle is.I've thinned it for easier rolling and have left it whole. It's easier to roll thinned but the added moisture makes a thinner film and affects the veneer so it's a bit of a trade off. If I do thin it, I will for large areas, I'll roll it until it's about the same consistency as the unthinned.Another big plus is that hide glue is transparent to most stains.As far as I know there are only two brands and they are comparable. I may have heard of Patrick Edwards making room temp formulation but I'm not sure.Lee
Hi, I work in a custom woodworking shop and we do tons of vennering. Everything from full sheets of plywood, to custom figured panels and curved parts. We used to use Unibond but have switched to using National Casin's Venner Glue. It's a PVA glue but the neat thing about it is they add really fine ground up walnut husks to make it a thicker consistancy. The biggest benift is that it woun't weep through the grain of thin venners and is safe and non-toxic. Its also much less expensive and doesn't have a short shelf like unibond.
Aha! Caul on top -- that would have made things easier. I spread glue only on the MDF substrate, but the veneer started buckling and rippling within seconds of being laid on top. Made for quite a wrestling match getting it into the bag.I did what I could to wash the glue off, but I'm not sure yet if I'll be able to salvage things. Taking advice from other replies, I think I'll switch my adhesive, too.Edited 2/25/2007 8:45 am ET by jkl
Edited 2/25/2007 8:53 am ET by jkl
I second what Jeff said. The Unibond 800 is excellent for this process. And the glue should be applied to both parts. Just don't waste any time before you sandwich everything and then tape together. With the size of an end table, you should have plenty of open time, no matter what.
good luck
Jerry
Hello: What do you all think about "cold press glue"? I bought some to use on a cabinet top to be veneered with home cut white oak veneer on a white oak substrate. I don't have a vacuum system and intend to do it with clamps and cauls and weight plates, full propane cans (5 gal size). I'm also cleaning up and flattening my work bench top so it will all have a flat surface to sit on. It will be my first veneer job of any real size. Also I will be cutting through mortises after the top is ready, are there any special concerns cutting though a veneered panel?
Thanks, Duke
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Duke
I have several thoughts about your question and description.
Firstly, cold press glue, whatever it is, is fine. There are many different types.
Next: I would be very careful about simply putting weight on cauls. The weight of a propane tank, albeit full, is much less than the pressure exerted by a cold press.
What we have done in our shop when we had 5' x 12' panels to glue up and the presses were full, was the following. We Built a dead level and well supported base using hardwood and particleboard. We glued up our panels and stacked them and then covered them with about 15 sheets of 1 1/8" particle board. The glue up was perfect.
I would suggest putting your veneer and cover board and cauls on the cabinet, and using car jacks to exert the pressure you need, using the floor joists of your shop (if you work in a basement shop) Be careful not to break the house or crush the cabinet below.
My last thought is that you should be cross banding the veneer that you are gluing to the solid wood substrate, to insure stability of the glue up and reduce the possibility of the veneer tearing when the solid reacts to humidity changes. JL
Her's anither from left field. After talking to very accomplished acquaintance, I follwed his advice and used contact adhesive. It is called Ados F3 here in New Zealand. I was veneering straight grained rimu around a flexiply curved vanity door and adjacent flat door and drawers. I waited until
roughasguts
Only part of your message posted.
Sure, contact adhesives will glue most anything to anything. I have used it in some situations to make repairs when there was no other choice at the time, but it is not the best solution for gluing up veneers because the veneer is "floating" on a layer of flexible glue (rubber) all the time. The glue adheres to the substrate and the the glue adheres to the veneer, and then when the pieces are mated together, the glue adheres to the glue, but the veneer never adheres to the substrate. JL
Jeanlou,I have a couple of items veneered with contact cement 40 years ago. Both suffered damage, not deterioration, in that time. One was so badly damaged that I stripped the veneer to re-cover the whole piece. Stripping it was quite a task! Contact cement gets great respect from me now though I had always felt that I had taken an amateur's shortcut by using it. The glue line was very thin. I had to remove the veneer in very small pieces.Finishing pieces veneered with contact cement may be the biggest problem. I used linseed oil with no problems. Thinning the first application probably is not a good idea. Lacquer may not be a good idea as lacquer thinner seems to dissolve contact cement. Other finishes may be problematic also.It takes some practice to learn how to spread contact cement also. As I remember it, I used lacquer thinner to make it spread more evenly by brushing. Thick zones in the glue can be sanded through or telegraph through as hills and valleys in the veneer.Finally: NEVER, NEVER, EVER use water-based contact cement with veneer! The veneer absorbs the water. Need I explain further?Cadiddlehopper
caddid
When I had less experience I also used contact cement much more than now. I have found out over time, as you, that there are other adhesives that do the job better, but, I will agree that when correctly applied, it is an amazing adhesive / tool. I always have some in my repair kit.
The finishing limitations that you touched on are important, especially these days, with the thickness of commercial veneers approaching the see-through state.
Correct application requires a sealer coat of glue on each surface, followed by a final coat on each surface. If the first coat is too thin (thinner added), then there is definite danger of the glue soaking through the veneer into the surface grain, affecting the finishes applied.
I agree that it can be used in many applications, but I would avoid using it with wood veneer whenever possible. I limit myself to repairs, and some plastic laminate work. Even PL work, if I can press the parts using PVA or urea glue, I will do that before opting for contact cement.
Many smaller woodshops use contact cement for their work because it is quick. They set up mobile spray "booths" next to the assembly station and the worker /cabinet maker applies his contact cement with a spray gun, and 40 minutes later, two coats have been applied and dried with the parts glued up and being trimmed, The fact that it works doesn't make it good. Most of these same shops build the carcass of the cabinetry with all butt joints, nailed through the face or even stapled, with limited joinery, and the final laminate covers all the less-than-professional workmanship.
Contact cement definitely has its place, but in my opinion it has made its way into areas where it never belonged and still doesn't belong. JL
I built a veneer press so that other glues are what I now use, too. I never had space for a press in the past. I used PVA to replace the veneer on the table I repaired.Are contact cements different in Canada? I never used a sealer coat. The 40-year-old stuff that I had such a struggle removing was attached with no sealer coat. Of course, veneer was 1/28-inch thick back then. Is thin veneer the reason that a sealer coat is needed? It seems to me that so many coats would be too thick and perhaps uneven also.I am sorry that you mention nails. My own feeling is that if a brad, staple, or nail is used, it is not fine woodworking. One exception to that is for attaching upholstery with staples in an invisible location. I am undecided about decorative upholstery tacks. It seems that there should be a less tedious way to do something. As I said about contact cement, I felt perhaps using it was not fine woodworking -- until I tried to get it off. I don't use it now, but I feel that I may.Cadiddlehopper
Edited 3/10/2007 8:10 pm ET by cadiddlehopper
Caddid
There is a place for contact cement, without a doubt, but I would not use it to build fine furniture. Call it my prejudice.
When I say a sealer coat, I mean that when gluing porous material, like wood, the first coat of contact cement seals the wood and the second coat is the true bonding coat of glue. I even use two coats on non-porous materials, to insure a proper bond.
Contact cements in Canada and the USA are the same. JL
J.L.: Sorry for waiting so long to reply. Since the original post I have decided to go the vacuum route purchasing a small vacuum pump from EBay and a bag sized for this project (42"x14"). I have thought of using the hydraulic floor jack to apply pressure but my shop building is very old and rickety and on top of that I can't lift very much weight, so the vacuum approach seemed the way to go. I am going to pick out the best looking face grain from the 8/4 stock I bought for this project and keep slicing to get enough to veneer the bottom as well. I might even try something other then just straight across piecing of the veneer such as "framing" the very best slice of veneer with a straight grained surround. This is my first serious veneering so I don't want to stretch to far. Should the bottom veneer have the grain going the same direction as the top and substrate? Other then the top the rest will be solid wood. Boy is this thing getting heavy! I'm going to start to take pictures as the cabinet takes shape; it might help document any trouble that shows up later. Hoping to post this one if it looks good.
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Duke,
The face veneer, be it on the top or on the bottom should always be oriented at 90 degrees to the substrate, it the substrate has a grain. This is one of the reasons why particle board or other similar products work so well as a substrate, because there is no grain, ergo no grain direction. When using particle board as a substrate, I always run both the top and bottom pieces in the same direction.
Enjoy your new vacuum press. I am sure that you will have a great time using it, and that the results will be up to your expectations. JL
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