Lesson learned veneer (sort of) need advice

[John TenEyck]

John, what happened to your table glued with Better Bond? Open seams, or worse?

I suspect the glue used on this project is less problematic than the crossgrain rail glued to the underside of the solid wood top.

Kevin, here's the RS WO veneer panel before I vacuum bagged it onto Baltic birch plywood, which I think was two layers of 1/2" that I had glued together several days earlier. I don't recall exactly how long I had it in the vacuum bag, but I know it was several hours. I specifically tried it because it is supposed to bond in only a couple hours, IIRC. Prior to that I had mostly used Plastic Resin Glue and was leaving it in the bag for about 13 hours.




and the table w/o the drawer handle installed.



All was well for a few weeks, then I got a call from the customer that there were "cracks" in the top. Those cracks turned out to be where the veneer opened at all four seams and curled up a good 1/8". No fixing that. I made a new top using Plastic Resin Glue. Ten years later it still looks like new. That table was my first work for that customer. I thought it would be my last, but it turns out she became one of my best customers for many years.

That was my one and only experience with Better Bond. Since I pretty much only use shop sawn veneer, it'll never grace my shop again.

An interesting side note. I had glued the veneer seams with TB II before gluing it to the substrate. Despite that, they opened up. Flash forward several years to my friend who had the same problem on one of his projects. My conclusion is edge gluing offers no real benefit because you can't apply any pressure to the joints as the glue dries, and unclamped TB II, etc. does not result in much strength. I remember that when I remade the top, I did not edge glue the seams.

John

[Kevin Jenness]

Thanks, John. That really is a "lesson learned"- the hard way. I did a couple of projects long ago using 1/16" sliced doug fir and ash with Titebond and as far as I know they held together (and I would have heard) but I wouldn't do it now. All my shopsawn veneer has been laid with epoxy but plastic resin (UF) glue would also be a good choice. I just don't keep it in stock because of the short shelf life and it's no longer available locally.

[Tom Levy]

Can you post a pic of the final result? Guessing I’m not the only one here interested in seeing how this looks after gluing all those end grain cutoffs on the sides.

[Thomas McCurnin]

I learned that Titebond has a cold press glue fit for veneering. Never heard of it.

[Mel Fulks]

I would not have used solvent based contact cement. I would have used hide glue or liquid Old Brown Glue.

I agree. Contact is made to make to be quick…not to stick !

[Mike King]

FYI, Better Bond is NOT recommended for shop sawn veneer, only commercially sliced stuff. I found that out the hard way on a small table I used Better Bond on with shop sawn veneer about 0.080" thick. There was nothing about it in Joe Woodworker's website, so I called him. He told me it wasn't recommended for shop sawn veneer. Later, he added it to the info. on his website. Guess I was the first to bring it to his attention.

Intuition suggests Cold Press Veneer Glue would be in the same category.

I have had good results with shop sawn veneer up to 1/8" thickness with TB I and II, Unibond 800, epoxy, and the no longer available Plastic Resin Glue. I would not use TB III because of it's low creep resistance, but many do.

John

No idea if Titebond Cold Press Veneer has problems with shop sawn veneer, but the manufacturer's data doesn't recommend against it.

http://www.titebond.com/product/glue...9-5794cc3ae102

[John TenEyck]

No idea if Titebond Cold Press Veneer has problems with shop sawn veneer, but the manufacturer's data doesn't recommend against it.

http://www.titebond.com/product/glue...9-5794cc3ae102

True, but if you look at the strength data, you'll see that the wood failure % (which is the percent of the glued area that pulled away wood when it failed in their testing) it's 6% for Cold Press Veneer Glue vs. > 70% for TB Original and TB II. That alone makes me very suspect of how well it maintains a bond. I'm sure it's fine with commercially sliced veneer. It's thin and has low strength after the slicing process. But for shop sawn veneer, which typically is at least 1/6' thick and done in a way that does not compromise the inherent strength of the wood, I'm not convinced it's a good choice.

John


Cold Press Veneer Glue:

BOND STRENGTH ASTM D-905 (ON HARD MAPLE)

Temperature	Strength	Wood Failure
Room Temperature	2,508 psi	6%
150°F. Overnight	656 psi	0%

TB Original:
BOND STRENGTH ASTM D-905 (ON HARD MAPLE)

Temperature	Strength	Wood Failure
Room Temperature	3,600 psi	77%
150°F. Overnight	1,600 psi	10%

TB II:

BOND STRENGTH ASTM D-905 (ON HARD MAPLE)

Temperature	Strength	Wood Failure
Room Temperature	3,750 psi	72%
150°F. Overnight	1,750 psi	6%

STRENGTH ASTM D-905 (ON HARD MAPLE)

50°F. Overnight	1,750 psi	6%

[Mike King]

Perhaps, but the strength is over 2500 psi. I suspect that the issue with the pull away is the pecan shells. Or is it that the shop sawn veneer was rough sawn so the glue is not strong in filling the gaps?

So, you face a choice: use a veneer glue with fiber to restrict bleed through, or go with a glue that may very well do so. Perhaps the issue is the substrate. If you use MDF, there isn't as much movement in the substrate to create a potential problem. Go with a solid wood substrate or plywood and you may have problems?

[lou Brava]

Can you post a pic of the final result? Guessing I’m not the only one here interested in seeing how this looks after gluing all those end grain cutoffs on the sides.

Yes, & hopefully it will be something I'm proud of.

[John TenEyck]

Perhaps, but the strength is over 2500 psi. I suspect that the issue with the pull away is the pecan shells. Or is it that the shop sawn veneer was rough sawn so the glue is not strong in filling the gaps?

So, you face a choice: use a veneer glue with fiber to restrict bleed through, or go with a glue that may very well do so. Perhaps the issue is the substrate. If you use MDF, there isn't as much movement in the substrate to create a potential problem. Go with a solid wood substrate or plywood and you may have problems?

Strength means nothing if it doesn't stay stuck. I drum sand my veneer to 80 to 100 grit. In the hundreds and hundreds of square feet of veneer I've glued down the only failure I've ever had was with Better Bond.

Veneer on solid wood will best accommodate seasonal movement, since they both move at about the same rate. It's when you use shop sawn veneer on stable substrates like MDF and plywood that problems are more likely to occur unless the glue has very high creep strength to prevent the veneer from moving. So why do I use MDF and/or plywood with shop sawn veneer? Because I can make wider panels that aren't prone to warping like solid wood panels often do, I can run the veneer in any direction, and I can assemble cabinets w/o concern for cross grain movement between panels.


The OP's situation is unique in trying to glue end grain veneer. End grain has inherently high seasonal movement, especially white oak. The best option I can see is to make it thin, maybe 1/16". Just doing that is going to be hard to keep it from breaking apart. What glue and/or prep method to use is not obvious. I might try spraying the face with several coats of dewaxed shellac before gluing it down, hoping that would prevent bleed through.

OK, so here's how I might do it. Start with whatever thickness you can glue into a sheet of veneer, say 1/4". Spray the finish side with several coats of shellac. Bond that face to a piece of 1/4 MDF with double stick tape. Drum sand the veneer down to 1/16" and glue it to the substrate. After the glue has cured, drum sand off the MDF.

John

[Warren Lake]

is the veneer on the panel with the blue tape 90 degree to the ply, is the same veneer on the other side?

[lou Brava]

Strength means nothing if it doesn't stay stuck. I drum sand my veneer to 80 to 100 grit. In the hundreds and hundreds of square feet of veneer I've glued down the only failure I've ever had was with Better Bond.

Veneer on solid wood will best accommodate seasonal movement, since they both move at about the same rate. It's when you use shop sawn veneer on stable substrates like MDF and plywood that problems are more likely to occur unless the glue has very high creep strength to prevent the veneer from moving. So why do I use MDF and/or plywood with shop sawn veneer? Because I can make wider panels that aren't prone to warping like solid wood panels often do, I can run the veneer in any direction, and I can assemble cabinets w/o concern for cross grain movement between panels.


The OP's situation is unique in trying to glue end grain veneer. End grain has inherently high seasonal movement, especially white oak. The best option I can see is to make it thin, maybe 1/16". Just doing that is going to be hard to keep it from breaking apart. What glue and/or prep method to use is not obvious. I might try spraying the face with several coats of dewaxed shellac before gluing it down, hoping that would prevent bleed through.

OK, so here's how I might do it. Start with whatever thickness you can glue into a sheet of veneer, say 1/4". Spray the finish side with several coats of shellac. Bond that face to a piece of 1/4 MDF with double stick tape. Drum sand the veneer down to 1/16" and glue it to the substrate. After the glue has cured, drum sand off the MDF.

John

John that is one hell of a good approach, but a day late for me I read your post this morning prior to un-clamping what I glued up yesterday ! So far good results with the WO end grain veneer & Tite bond 1, very little glue bleed. I could of actually used your method and used the MDF as a backer gluing it to the top as there is a rabbit on the top, the veneer rabbits into the edges & sides. I could have just made the rabbit deeper. At this point I'm hoping the seasonal movement isn't going to be a problem with 1/8" thick & fully glued, I don't want to tear out everything I just glued up. If this was for a paying customer I'd probably tear it apart & go with your suggestion.
Thanks for the help

[John TenEyck]

Glad to read your approach worked, Lou. I look forward to seeing photos when it's done.

John

[lou Brava]

I was asked to post up finial result of this "un-natural & unique" edge grain debacle, so here it is. Just want to say thanks every one for your input it really helped me out & if I would have posted up prior to the build some of the advice could have been used & outcome would have been better. It really didn't come out exactly how I wanted, but what's done is done !
I had a heck of time with finish, I'm posting up in the finish section for feedback.
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