[Ant1885]

Hi I'm new to this site but have a question;
I have recently bought some beautiful walnut burl veneer ( 0.6mm thick) and am using cold press method and "Tightbond professional strength veneer adhesive" The problem I am having when doing test runs is after the adhesive has cured and I take clamps etc off the burl is wavy and has bubbles between the burl and sub strata - any idea why this is happening? I am putting plenty of glue down and have also tried with less glue but no joy..!

Secondly the burl in its natural state is quite wavy..when it is glued down will the dimensions increase or stay the same ( length and breadth not thickness) ?
Cheers
Ant

 

[cabinetman]

Wavy curly veneer needs to have a veneer softener applied. It may solve your problem.

.

 

[Steve Neul]

I agree you need to get some veneer softener. Burl walnut is pretty stiff and wavy so it resists gluing and it doesn't take very much of a void to create bubbles. You would also have better luck if you would get a vacuum press to do you veneer work. The size will increase but I think it will be so slight I don't think you could measure it. I normally make veneer oversized and trim off the excess after it is applied so the size doesn't make any difference.

 

[Ant1885]

I agree you need to get some veneer softener. Burl walnut is pretty stiff and wavy so it resists gluing and it doesn't take very much of a void to create bubbles. You would also have better luck if you would get a vacuum press to do you veneer work. The size will increase but I think it will be so slight I don't think you could measure it. I normally make veneer oversized and trim off the excess after it is applied so the size doesn't make any difference.

Ah cool thanks I'll buy some and look at buying a vacuum press...you say veneer oversize and then trim off excess but what if I'm doing a design with various elements ie coffee table with 8 - 10 different veneer components?? :icon_confused:

 

[cabinetman]

Ah cool thanks I'll buy some and look at buying a vacuum press...you say veneer oversize and then trim off excess but what if I'm doing a design with various elements ie coffee table with 8 - 10 different veneer components?? :icon_confused:

If that's the case, you cut your patterns to fit.

.

 

[Steve Neul]

Ah cool thanks I'll buy some and look at buying a vacuum press...you say veneer oversize and then trim off excess but what if I'm doing a design with various elements ie coffee table with 8 - 10 different veneer components?? :icon_confused:

When I veneer something has designs with multiple pieces I cut and fit the veneer and lay it out face up and bind them together with masking tape so all the pieces make up a single sheet. The outer part that makes the border though I leave it oversized in case it scoots slightly when glued. Then after it's dry I trim off what is left over.

 

[cabinetman]

When I veneer something has designs with multiple pieces I cut and fit the veneer and lay it out face up and bind them together with masking tape so all the pieces make up a single sheet. The outer part that makes the border though I leave it oversized in case it scoots slightly when glued. Then after it's dry I trim off what is left over.

If you use a vacuum bag, there is the possibility of the overhanging edges getting bent, split, or cracked. The fitted pieces could shift.

.

 

[Ant1885]

OK thanks to everyone for your advice....I'm from London UK and am finding the veneer softener difficult to source. I've found a formula online which is as follows;

1 gallon of water
8 Oz of glycerin
8 Oz of Methalated spirits (denatured alcohol)

Will there be any side effects using this formula..? Walnut burr is really expensive haha

 

[Steve Neul]

If you use a vacuum bag, there is the possibility of the overhanging edges getting bent, split, or cracked. The fitted pieces could shift.

.

I don't leave enough of a overhang that that is an issue. I leave less than 1/8". It's better than have it shift and have the veneer 1/16" short on the edge.

 

[Rick Mosher]

Burl veneers are very unstable. All of the commercial veneer shops I have worked for make a 3 ply veneer with the burl on the outer face and each layer at 90 degrees to the previous one. That stabilizes the veneer much more preventing buckling and checking in the future. After pressing the 3 ply then they press it to the substrate. The vacuum press will eliminate any wrinkling you are having.

 

[Ant1885]

Burl veneers are very unstable. All of the commercial veneer shops I have worked for make a 3 ply veneer with the burl on the outer face and each layer at 90 degrees to the previous one. That stabilizes the veneer much more preventing buckling and checking in the future. After pressing the 3 ply then they press it to the substrate. The vacuum press will eliminate any wrinkling you are having.

ah cool..that sounds like a good idea - thanks :smile:

 

[Rick Mosher]

Make sure you balance with the same thickness on the backside of the panels as well.

 

[Bill White 2]

The glycerin solution is ages old, and works.
Bill