Vacuum dyed poplar veneer

[Charles Perelman]

I plan to make dyed poplar veneer using Transtint Dyes, vacuum infused. Using water to mix dye, what is the best method to dry the veneer (1/16" and less) after vacuum infusing, to prevent warping? Should I use denatured alcohol instead of water in spite of its volatility? Any help appreciated!

[John Keeton]

Seems like a lot of effort when one can buy dyed veneer very reasonably. http://www.dyed-veneer.com/dyed_veneers.aspx

You would have uniform color and flat veneer. I have purchased from these folks multiple times.

[Charles Perelman]

Thanks John, I checked out the prices and they are quite good.

[Mike Mason]

I'd like to dye 1/16" thick wood veneer I resaw myself for use in marquetry. I just started experimenting a bit with Procion MX (fiber reactive) dyes and various light colored wood species (poplar, sycamore, maple) in a heated bath, but haven't been able to get the dye to penetrate throughout the thickness of the veneer. I am wondering if vacuum might be the answer, but before I invest in a vacuum pump, I would like to know if that's likely to help much. I thought I should go to the experts to get their opinions, as I have found a few contradictory posts online.

Do you have any advice that you can give me regarding how well this might work? Any thoughts as to the time required under vacuum (I don't want to wear out a pump if it needs to run for days); whether a heated bath is necessary and if so, what temp is needed; what might be added to the water/dye solution that is safe and the vapors won't harm the pump,but might reduce surface tension and improve penetration; the amount of vacuum needed (i.e., will a less expensive pump work); etc.?

Any advice you can provide will be much appreciated!

[Charles Perelman]

Mike, First of all, as of now, I have not dyed any micro thin wood. From all the You tubes that I have watched and literature that I have read the vacuum pump is the way to go and as I understand it you do not have to heat the dye solution. Also, the pump does not run that long anyway -- just maybe an hour or two till the liquid stops bubbling. At that time the pump is shut off. I hope this helps you.
Charlie

[Mike Mason]

Thanks, Charles. I have done some experiments with dyeing in a heated bath, using two different brands of dye and 1/16" thick samples of poplar, sycamore and maple. I have heated them up to 185 degrees F for three days, and have had no real penetration at all in any test. I think there's some misinformation out there as to dye penetration in wood using only a heated bath at atmospheric pressure - it's hard to believe that others have been successful while none of my testing has been. Applying vacuum (maybe following with pressure, if needed) is my next step. I'm not sure that I can simply immerse the wood in a dye bath before applying vacuum, or if I need to apply vacuum to the wood alone, before allowing the dye solution into the evacuated chamber. I've seen the infusion videos with thick pen blanks being immersed in "cactus juice" ( brand name) before applying the vacuum, but I don't know what the chemical kinetics are with a water-based dye bath; in other words, will the vapor pressure of the water be such that, during the time the vacuum is applied, much of the water in the dye bath will turn to vapor and be sucked through the vacuum pump? If so, then I will need to first evacuate the chamber with just the wood, then introduce the dye solution to the chamber, and shortly after that release the vacuum. At that point, it wouldn't be too difficult to apply pressure as well.

[Brice Rogers]

Mike, you raise an interesting point. I was curious about the boiling point of water under a vacuum, so I googled it: http://www.engineersedge.com/h2o_boil_pressure.htm

If you keep the vacuum below 26" of Hg, the water won't boil unless it is hotter than 122 F. So you may suck some water moisture through your vacuum pump but it will not be dye.

[Ron McCormack]

mike, im curious if you've tried the vacum method? I have been trying to dye standard thickness 1/42" veneer, and have had no success. I tried soaking for days as well as hot water baths. I just set up a vacum chamber and tried that but i'm not getting positive results from this either. Ive only run it for 1/2 an hour so far but this has not worked. Id like to hear if youve gotten any positive results yet.

[Bill ThompsonNM]

Christopher Schwartz had a blog entry on dying wood: https://www.google.com/amp/s/blog.lo...thickness/amp/

This sounds like just what you need

[Paul Gilbert]

the pressure treated wood that you buy for outdoor use is produced by first placing it in a vacuum chamber and pulling a high vacuum. The chamber is then flooded with the chemical preservative and then pressure is applied. They get around an inch of penetration using this method. I would think it would work for dye.