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A question for anyone who has experience dying veneers or other woods.

I'm hoping to find a suitable substitute for ebony to create a thin, decorative layer between two other, lighter layers. The final thickness of the decorative layer will vary between .05" and .1" but prior to processing I need it roughly .2". I could use ebony to create the layer but the process can potentially waste up to 3/4 of it.

So...any black dying technique that would work for me would require a deep, even penetration....and have to be a fairly deep black.

I've seen interesting dyed laminates that indicate dying to depths approximating my needs is certainly possible....but I can't find out how it's done.

Any insights?

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

The color tone stuff from stew Mac does not go very deep. So I'd look elsewhere. I have heard that pressure cooking the veneer with the dye will cause deep penetration, but who has a pressure cooker that big?!?!

You won't get it to penetrate much more than 0.2 mm's even after soaking a veneer for weeks on end. I can just about do 0.5 mm Maple. Pressure cooker will change things though. For thin veneers I coil the stuff in the cooker. You probably can get a head veneer in a catering size pressure cooker. Cookers that size aren't cheap though. The other method that you might look into is vacuum dyeing but I've absolutely zero experience of it. I don't know if it will work.
Ferrous Sulphate and Walnut gives a decent and pretty permanent Black.

You said .2". How wide? If it's long and narrow, you could easily make your own custom pressure cooker out of a length of pipe. For many colors you'd want stainless steel, but for black, galvy should be fine. Cap both ends, and put a pressure cooker release valve somewhere, and you're set. I think pressure cookers go to about 15psi. The pipe will take 100 safely, so you could bump up the pressure. Do have a relief valve. I blew a brazed cap off a steel tube under steam pressure. Very exciting.

Rockler just introduced a DIY wood dyeing pressure cooker thingy that might be worth looking at....

Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

How about some of that black fish paper from Shane Neifer?

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Audiences and dispensations on Thursdays ~ by appointment only.


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Sorry Eric but that's really terrible advice and potentially very dangerous. Pressure cookers are designed with all sorts of back ups if things start to go wrong. You even admitted yourself that a cap blew off. If someone happens to be in the way of it the consequences might not be that funny. This is bomb making but without the intent. Leave steam, pressure and relief valves to the experts. Forget it, it's just not worth it for a bit of dyed wood.

I tried to do something similar a while back. I thought I might be able to get a decent ebony substitute by using tannin and iron acetate (typical ebonizing process used in woodworking) on cherry, walnut and osage orange. I built a vacuum/pressure chamber with sch 80 PVC. I began by infusing the hardwoods with tannin in the chamber using an alternating sequence of vacuum (29 in Hg) for 30min and then pressure (120 psi) for 30min. I then replaced the tannin in the chamber with iron acetate and repeated the vacuum/pressure sequence.

It was an interesting experiment with lousy results. The surface of the hardwood samples looked great, but minimal sanding with 180G paper exposed the natural color interior. I never really measured the actual penetration, but I'm guessing not more than about .005". If you could figure out a way to use the ebonized wood without a need to sand before finishing, this wood probably work.

Dean

You could try and find some Holly that's dyed black. Sometimes looks more like ebony than ebony does.

Brent

I wonder if you treated your wood with tannin, and then fumed it with ammonia. Oak fumed for Arts and Crafts style furniture in this manner could have the colour very deep into the wood. While it might work, ammonia fumes are very dangerous, and proper precautions should be taken, and it would likely take several applications.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

I'd agree in principle with that. Some of the stuff I saw on the internet was pretty scary. But I've built a number of large, high pressure molds. A small pressure vessel capable of containing two plates measuring 20" x 8" x .2" and pressuring to 150 psi. would be a simple project by comparison....and the pressure pots I saw on the internet only ask for about 15 psi. I'm not certain pressure is the solution though....or that I really want to go to that much trouble for this.

I've found Maple to highly permeable compared to Walnut....both water and air...which suggests dye might easily penetrate to the depths I need....with some help. I don't know about Cherry or Osage Orange. Before I go to the trouble of making a full scale pressure pot or vacuum chamber, I can test the idea with some stuff I already have.

I'm guessing high vacuum would be more effective to infuse the Maple since it's vacuum, not pressure that is used to saturate compacted fibers in various composite molding processes (VARTM). In those processes they use very low viscosity resins and often use additives (surfactants) to reduce surface tension. I'll be doing an experiment today with that. I'll put a 1/2" thick piece of Maple under a vacuum with denatured alcohol and some Transtint black dye. The alcohol is a natural surfactant so that's probably the best bet as a dye carrier. We'll see.

If it works I'll snap some pics and post them.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

The dye would need to be highly soluble so I think the Transtint dyes will go as far as one can toward that end.. I saw that iron acetate / vinegar thing on the internet. That's a chemical process but it sounds like the chemistry didn't get in there too far.

My observations about Maple come from many comparisons to Maple vs. other woods of the same thickness on a vacuum plate. The Maple invariably results in less sustained vacuum on the gauge... indicating permeability. Permeability has little to do with whether or not the wood has pores. Purple Heart...for instance...has large pores but holds fast to a vacuum plate at full vacuum at very thin thicknesses...indicating zero permeability. I need something hard so it machines well...but is permeable so it dyes. I think Maple is the best bet. We'll see.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

If it's pressure that causes the dye to penetrate the wood, you could add a pressure gauge on one screw-on cap and install an air nozzle on the other screw-on cap and easily and with control maintain a low pressure like 15psi or so. You could connect it through an air line to the pressure regulator on your compressor and let the pressure regulator maintain the pressure in the pipe. Save messing with steam.

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Formerly known as Adaboy.......

Pressure certainly works in getting the dye to penetrate deeper. I've done 1.2 mm's in a pressure cooker.
What method do they use for treating outdoor timber? I know that that is usually softwood but the treatment is supposed to go pretty deep.

I stand by my suggestion. It's not much use for Stuart, but he knows how to make a pressure vessel if he needs to. If someone wants to dye binding strips, the pipe will work just fine. I don't know what pressure cookers look like in the UK, but over here, they're really pretty simple. If you want to play it safer, you can also mount the blow out plug from the pressure cooker in your pipe cap. If you do that, stick with the standard 15psi.

Steam pressure is plenty dangerous. I'm not disagreeing there. An exploding pressure cooker could kill you. I'm sure it has happened. But it doesn't make any difference whether the pressure cooker is shaped like a pot, or a pipe. A pressure cooker is a pressure cooker. I like to whistle "Wreck Of The Old 97" when I'm working with steam.

When I blew the cap off a steel tube, it was during a welding operation. There should have been a vent hole in that tube, and there wasn't. There shouldn't have been water in that tube, and there was. It had nothing to do with pressure cookers.

I think that the temperature is an important part of the equation when pressure dyeing. For one thing, dyes are more permanent when used at high temp. Importantly too, the viscosity of water drops dramatically as it heats up. Water at 250 F (the temp inside a pressure cooker) has a viscosity that is 1/3 that of room temp water. Lower viscosity means better penetration. The high temperature also causes the air, and liquids in the wood to expand, and be forced out of the wood. As the wood cools, a partial vacuum is formed that pulls the dye into the wood.

Gurian offers back veneer in dyed Pearwood that is very nice. If Maple doesn't work out, maybe try Pear?

Fine. Just remember that this is a public forum. Anyone can read and decide to take on your ideas - including the young, the inexperienced and the naive. Messing around with this sort of thing is potentially very dangerous and I'm pretty sure that domestic pressure cookers go through some rigorous and approved testing before they are allowed on to the market.

I have made veneers (3/32) black using steel wool and vinegar and was able to get 100% penetration. I used red oak veneer which is pretty darned porous. I needed long strips so I stuffed a bunch in a 1 1/2 inch pvc pipe (capped at both ends) and filled with the iron acetate solution. I wasn't in a hurry so I let them set in there for a few weeks. When I took them out and rinsed them they were pretty ripply but ironed out just fine. I glued them up into b/oak/b purfling strips and when I cut them to thickness the black went all the way through. Those strips have been glued in next to Oak, mahogany and WRC for about 3 years and there is no evidence that the iron acetate reaction has effected the color of the other woods. I should note that I soaked the strips in a baking soda solution for a few days after the vinegar solution. I'm not sure if that accomplished anything or not but my reasoning was that it may stop the reaction from continuing on adjacent woods.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Do you have any requirements for the type of wood? Pulling a hard vacuum followed by pressurization can easily destroy wood from internal stresses. I used to do it on a regular basis as part of a rapid water saturation method for testing wood and adhesive properties, and the wood audibly starts cracking within a minute of going to 70 PSI from a hard vacuum. Anyways, if you can qualify your needs I might have some ideas.

check this out

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Mike McNerney

Why does this need to be so complicated. Get a vacuum bag, and laminate up enough black veneer for your purposes. It's just a laminating layer, and if done properly, no one is going to see the joint.