Darryl Keil Last Activity 2025-02-12 2:48 PM
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Joel

Posts: 2

Joined: 2007-07-29
Location: Stillwater MN

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Subject : Veneering huge table top
Posted : 2007-07-29 3:43 PM
Post #33975
I'm making a huge conference table (22'4" x 4'6". I'm making the top in 3 sections, two almost 8' long and one almost 7'. I've done a fair amount of veneering but never anything this size. My core is going to be a torsion box made with 1/2" MDF outside and a web of 3/4 mdf on the inside. The veneer will be birdseye maple on both sides. My question is regarding the glue and veneering both sides. Will titebond cold press adhesive work on something this big? Do I have to press both top and bottom veneers at the same time or will I be able to press one side flip the top and do the other side? Any help would be greatly appreciated.


 
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Anton Gerner

Posts: 45

Joined: 2003-09-04
Location: Melbourne, Australia

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Subject : RE: Veneering huge table top
Posted : 2007-07-29 5:15 PM
Post #33978 - In reply to #33975
Joel,

I use PVA all the time on surfaces this large and ALWAYS press one side at a time.
Are you using a bag or fliptop press?
The way I do it is to roll the glue on the face. IF possible have two people and two rollers.
Then lay your veneer on, then put a sheet of thin melemine backing to cover this, then straight into the press and fast as possible. I leave in in for about 2 hours, then do the other side and press for another 2 hours. When you take it out make sure both sides are exposed to the air for a few days.


 
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Jeff Patrick


Joined: 2004-04-15
Location: Bainbridge Island, WA

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Subject : RE: Veneering huge table top
Posted : 2007-07-31 5:24 PM
Post #33997 - In reply to #33978
I also wonder if anyone regularly uses liquid hide glue for veneer panels? I've been wanting to try it out but haven't done so. I do use hot hide glue and hammer veneering on occassion.


 
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Don Stephan

Posts: 825

Joined: 2003-07-18
Location: Cincinnati, Ohio

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Subject : RE: Veneering huge table top
Posted : 2007-07-29 7:26 PM
Post #33980 - In reply to #33975
Curious as to your reasons to use Coldpress over urea formaldehyde. The latter cures rigid rather than semi-rigid, and allows generous working time. If something happens during glueup using PVA's, major disaster. Presonal preference, but I'd gladly trade the shorter pressing time for longer working time, in case roller breaks, veneer splits during handling, et cetera, especially with the added investment in assembling such a large sheet of veneer and torsion box core. My 2 cents.


 
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Enrico Konig

Posts: 74

Joined: 2006-01-06
Location: Vancouver, BC

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Subject : RE: Veneering huge table top
Posted : 2007-07-29 8:16 PM
Post #33983 - In reply to #33975
I'd have to agree with Don. Using the urea resin has a great many benefits, not least of which is no cold creep, and a much longer open time. Also wondering if you've investigated using honeycomb for your core: less work than constructing it with mdf pieces, and also makes for a lighter panel.

Enrico Konig


 
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Joel

Posts: 2

Joined: 2007-07-29
Location: Stillwater MN

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Subject : RE: Veneering huge table top
Posted : 2007-07-29 8:39 PM
Post #33985 - In reply to #33983
If I had to start over I probably would use the honeycomb for the core, But I honestly didn't think of it until I was to far into it. I am considering the urea resin though, I've just never used the stuff before am not sure how it is to work with. Thanks for all your help!!


 
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craig tufankjian

Posts: 308

Joined: 2004-02-01
Location: syracuse ny 13208

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Subject : RE: Veneering huge table top
Posted : 2007-07-29 8:30 PM
Post #33984 - In reply to #33975
ditto with the guys above on the urea resin. your joints may also creep open over time as well. being a conference table, one can only assume what they intend to do on top of it( you know those wild office parties) not to mention coffee, soda, food ect. urea resin in this case is the way to go. i dont entirely agree with the one side at a time but if it works for you , why not!

craig


 
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Bruce Berman

Posts: 20

Joined: 2005-06-01
Location: Pittsburgh, Pa., USA

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Subject : RE: Veneering huge table top
Posted : 2007-07-30 10:23 AM
Post #33989 - In reply to #33975
Joel,
In addition to the reasons mentioned for using for using Urea glue vs. PVA; there is the significant response of maple to moisture especially on large panels. It is one of the worst villains of cold creep on flexible glues like PVA.

Bruce Berman
The Miracle Veneer Trimmer




 
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Anton Gerner

Posts: 45

Joined: 2003-09-04
Location: Melbourne, Australia

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Subject : RE: Veneering huge table top
Posted : 2007-07-30 5:23 PM
Post #33990 - In reply to #33989
Hmm PVA v UREA,
personal choice I guess.
to be honest I think there is a lot of hype around urea.
I press around 25 sq meters of veneer a week using a crosslinking PVA and NEVER have any problems. All the large panel producers here use PVA now and if done right, with the right spread rate it's fine.
Urea is toxic, messy, smells and stains a lot of veneers.
PVA has a shorter clamp time (I press 1 hour per side, then out of the press) and is much easier to use.

As long as you let your panels dry properly and seal the surface correctly your veneer won't creep - it's a fact.




 
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Don Stephan

Posts: 825

Joined: 2003-07-18
Location: Cincinnati, Ohio

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Subject : RE: Veneering huge table top
Posted : 2007-07-31 8:47 AM
Post #33992 - In reply to #33990
Anton raises a good point regarding urea formaldehye glues. With certain woods, sometimes just certain logs of certain woods, staining of the veneer can occur. I've had walnut so spotted yellow I had to scrap and start over, and minor problems with maple and cherry that fortunately were fixable during finishing.

Again experimenting would be recommended with both the bird's eye and plain maple veneers. I'd suggest trying Unibond with its Blocker (to eliminate bleedthru), or Pro-Glue, both of which are very good urea formaldehyde glues. Eliminating bleed-thru might prevent any staining that I've had occasionally with Unibond; I've not experienced staining with Pro-Glue but it recently may have been reformulated, not sure.


 
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Enrico Konig

Posts: 74

Joined: 2006-01-06
Location: Vancouver, BC

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Subject : RE: Veneering huge table top
Posted : 2007-07-31 10:29 AM
Post #33993 - In reply to #33990
I find this glue debate interesting. Must be nice to NEVER have problems though ...

Personally, I've had a few problems with PVA bleedthrough showing in pores in open-grained woods when I'm using dyes, and I like the urea resins because they can be easily tinted beforehand and are easily dyed afterwards too. Also, I'm doing lots of multi-layer curved forms, and I need all the extra open time I can get. PVAs set up way too fast to do such panels. I also have zero springback with urea resins, when allowed to cure properly, whereas with PVAs it's much harder to control.

More interesting though, is this: At the most recent Furniture Society conference, Richard Oedel, in a presentation on double tapered laminations, related that a furniture restoration guy told him how happy he was that PVAs are in such wide use. According to this fellow, PVAs crystallize over time - reportedly in the 50 year range - and ultimately fail, providing a booming business for furniture restorers in the future. Makes me think back to some repair work I used to do, when it indeed seemed like all there was in a pulled-apart joint was some dried up crystally stuff. So for all of us who think we're building heirloom quality furniture ...




 
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Jeff Patrick


Joined: 2004-04-15
Location: Bainbridge Island, WA

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Subject : RE: Veneering huge table top
Posted : 2007-07-31 1:26 PM
Post #33994 - In reply to #33993
I've several thoughts regarding glues:

Enrico: about that reported 50 year life span.... Does that apply to modern day pva's? I'll assume that the 50 year life span is for glues that are at least 50 years old now. Otherwise how would they know? The manufacturers are constantly tweaking and enhancing their formulas. So does the 50 year life still apply to them?

Does anyone have experience using Titebond II, Extend wood glue? I recently used it on a few largish panels (2'x6') and got numerous failure bubbles. The veneer was American Sycamore, flitch cut. I'm very apprehensive about using this again. I'm fairly certain that I laid out plenty of glue and didn't miss any spots.

I would really like to keep away from the urea glues because of the health aspects, but is this really realistic? Anton's experience, however, seems to offer hope. Anton, are you using the pva with flitch veneer, or is it two-ply, or backed veneer? And which brand of pva are you using exactly?


 
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Enrico Konig

Posts: 74

Joined: 2006-01-06
Location: Vancouver, BC

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Subject : RE: Veneering huge table top
Posted : 2007-07-31 2:29 PM
Post #33995 - In reply to #33994
I suppose Richard Oedel's point was that whatever we are using, be it PVAs or urea resins, is really untested for long-time durability. That's my question: how do they (or we) know, even now, with "enhanced" formulas? I have continued using PVAs when appropriate ... hope for the best?? But I have been wondering if anyone else has heard anything about longevity issues with any type of glue.

I too wish there was something to use for what I'm trying that didn't have a bunch of health and environmental issues. Just like I wish that water-based finishes performed favorably in comparison to solvent based ones. Because urea resins do have a lot of downside, in terms of health & environmental issues, and in the amount of glue that one ends up tossing because of having to catalyze it and because of its limited shelf life (especially when it's warm!)


 
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Anton Gerner

Posts: 45

Joined: 2003-09-04
Location: Melbourne, Australia

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Subject : RE: Veneering huge table top
Posted : 2007-07-31 4:57 PM
Post #33996 - In reply to #33995
The PVA I am using here in Australia is called AVXL plus. It's a high quality cross linking PVA.
You won't find it in the USA, but you may have similar products.

In my experience bubbles in veneering are generally not caused by the type glue used.
Variations in veneer thickness and the way it is pressed are the main causes.

I would suggest to all those who would like to get away from Urea to do some tests.
Why not press up some panels, say one with Urea and one with a high quality PVA, with the same veneer and same substrate. Let them dry, sand them, finish them, take them home to your living room and watch them and see what happens.

You will be convinced.

I am using flitch veneer and pressing onto plywood or solid core lumber (blockboard).

I am only talking about flat panels and agree for laminations where spring back can happen, a more rigid glue line might be required.



 
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Darryl Keil

Posts: 1454

Joined: 2003-05-22
Location: Maine

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Subject : RE: Veneering huge table top
Posted : 2007-07-31 9:05 PM
Post #33998 - In reply to #33995
Enrico,

A little information about our work with Urea Resins. I too am conscious of the environmental and health concerns around Urea Resin glues. We tried hard to offer a urea glue that had as low a formaldehyde content as possible. Unfortunately the less we put in the worse it worked especially at room temperatures. As you increase the temperature, above 150 degrees you can start to decrease the formaldehyde.

In our case, we are working with folks that are room temperature pressing mostly using vacuum presses. To get the kind of performance I want to see out of a urea glue we have to leave in the more standard amount of formaldehyde for this type of glue. I am a firm believer in the benefits of full catalytic glues but whenever I feel its not required I'm happy to grab a good PVA.

Sincerely
Darryl Keil
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