Glue Choice and Open Time for Veneer Glue-Up
Veneering sometimes calls for glue that can give the woodworker a little extra time. Here's a discussion of glue choice and veneer gluing technique. November 24, 2007
Question
I have had it with this product, Titebond 1, 11 and 111. Not one of them has the open time claimed on the container. I have tried all (repeatedly, believing I had gotten old stock), and they all dry within a few minutes and become completely unusable and cause a lot of rework (the best case about 18 minutes). I just cannot work that fast gluing up a door with veneers. I am sure they will claim that it is because I am in a humid, hot country (Australia), but I think that if you are going to sell to this market, maybe you should modify your product to suit local conditions.
Forum Responses
(Adhesive Forum)
From contributor H:
Let me introduce you to 4 letters... HVAC. There is also a Titebond made with a longer open time. Have you tried that one? And you may well have gotten some old stock.
From contributor J:
You should check out the Titebond website! I don't believe any of the products you mention is supposed to have an open time that long! You may want to look into Titebond Extend or, if you're veneering, get a glue for veneering. I have used the different Titebonds for about a decade now and can't say I have ever had any significant problems with them.
From contributor D:
Why are (were) you committed to Titebond? It is far from the best for veneer in most cases, and there are factories working three shifts producing some of the best veneer glues in the world, just waiting for you to order. I can't think of a situation where I would use yellow glues for veneer. Try Unibond 800. Just because you are on the other side of the world doesn't mean you have to suffer.
From contributor T:
You need to check the specs on the product you use. Out of the three, TB III has the best open time, 10 min. I'm using it as we speak. I'm veneering 4 - 24 X 31 doors at a time and getting them in my vacuum bag with time to spare. I roll it on with a 4" roller, press for 30-45 minutes, pull them out and glue up more.
From Professor Gene Wengert, Sawing and Drying Forum technical advisor:
The adhesive open assembly time *does not* include the absorption of the wood. If you have very dry veneer, the assembly time is much shorter. It does not mean that the adhesive is poor. It is common to find that veneer is very adsorptive. You can extend the open time by using a slightly damp cloth on the veneer before you spread the adhesive. The veneer will absorb this water and then the adhesive's water will not be absorbed.
From contributor R:
Titebond actually makes a veneer glue with a 15 minute open time. So they agree with you that Titebond original, II and III are pretty fast for veneering. That is one of the selling points of these products - they set up quickly so you can get your work off clamps faster. But there are other great veneer glues out there, so stop spinning your wheels and use a glue meant for veneers.
From contributor C:
Thanks Gene, but what about the veneer cupping from the damp cloth?
The Titebond polyurethane I have says 30 minutes on the side. I find it foams so fast and aggressively it tends to lift the veneer up and clamping becomes an interesting problem. The MC level of the veneers is around 13% measured by a very accurate MC meter. My workshop is fully insulated and air conditioned (cold - 24C - and dry due to the high temperatures and humidity here in Brisbane), so this possibly does not assist the drying.
I generally apply with an old credit card, with a decent amount of adhesive. 1 side of an external door, 2100mm X 820mm, generally uses a complete (looks like about 500ml) tube of Titebond. A roller, I imagine, is a lot faster and more economical.
From contributor D:
Well, daggummit, I'll just ask you straight out - why don't you use a veneer glue like Unibond? It has a rigid glue line, is waterproof, easy to mix, spread, clean up and sand, and economical. Or the other side is, why are you so tight with Titebond, if it is neither? (tight or bonded)?
From Jeff Pitcher, forum technical advisor:
Many people all over the world have used Titebond and other PVAs for years to veneer. You've got an application problem, not a glue problem. I noticed a lot of folks suggested using Unibond 800. This will work fine, but I think you'd be happier with a powdered UF resin rather than a liquid. You'll have a longer shelf life and a much lower price. In addition, you can adjust your open time by the amount of water you use in the mix.
From contributor I:
To the original questioner: you mentioned taking an accurate moisture measurement of veneer. How? My meter and all the ones I've researched need at least a 1/2" thickness to get a decent reading. I usually end up microwave drying samples of 5/16 stock that I'm trying to accurately measure moisture on (and that's a pain).
Jeff, I've used Unibond many times, but am not familiar with the UF resin you mention, unless it's the powdered plastic resin glue that you mix in water. What manufacturers in non-industrial quantities are you aware of?
From the original questioner:
I have a Merlin moisture meter that starts at 2mm thickness and goes up to 40mm, but can be used from both sides for, say, 80mm. It is a fully adjustable, for wood, density, etc. Cost a heap, but it is a brilliant piece of equipment. The veneers I am placing are 6mm and 20mm thick.
