Tannins in bamboo?

I saw a video on finewoodworking.com about ebonizing wood.  You take some steel wool, soak it in DNA, for a few weeks, filter it, and then wipe it on the project piece.  Apparently, the mixture reacts with the Tannins in the wood to produce a deep dark color.  I thought that this might look nice on a board with a bamboo veneer.  Does anyone know if bamboo has much tannin?  Has anyone ever tried doing this?

Edit:  You are supposed to soak the steel wool in vinegar -- not DNA.  Sorry.

just about all plants have tannins in them to one degree or another. Judging by the taste of bamboo chopsticks I would bet that they have enough tannins for that to work.

Back in the lait 1980s and early 1990s I used the steal wool in vinegar a lot . Will work on most woods but the color can be anywhere from gray-black-brown or green depending on the kind of wood. Can make darker by multipul aplications. After you get the shade you want wipe down with bakeing soda and water. Do not put a lid on your vinegar and steel wool jar- it will explode. The first time I made it I did it in a mason jar and screwed a lid on put it in a locked cabinet in the shop  where I was working . It explode over the weekend . The weekend crew called the fire department and the hazmat guys showed up . I was called in to explane what it was that had exploded.!!

Hey Swied,  I just tried it a few days ago on some raw bamboo pole and there must be very little if any reactable tannins in the wood.  I scraped and sanded past the wax layer to get to the wood when I gave it a try.  No reaction.  The ebonizing solution I made was very strong though and blackened most woods in the shop within seconds. 

About that ebonizing solution, I used a couple fine steel wool pads and a few rusty nails in about 1/2 cup of apple cider vinegar.  I only let it soak for about 6 hours before giving it a try, and it worked like crazy - almost instant blackening of walnut, mahogany, oak, magnolia, poplar . . .turns maple and cedar a greyish green.  I was surprised because I read that it would take at least 24-48 hours to get a good solution.  Maybe it was the heat here that made it work so quickly???   Wood Ogre is certainly right about the pressure build up in there though, so be careful about sealing the jar too tight. 

If you want to get that bamboo to ebonize you’ll need to make a tannic acid tea to prep it with before attempting to ebonize.  I’ve heard that collecting some tree bark and steeping it in water will make an excellent solution.  I just ground up some oak leaves in my coffee grinder and made a prepping solution tea that seems to work quite well too.  Kind of seems like a cheat though as you’re really not ebonizing the wood’s tannins, but the tannins in the prepping solution you made.  At that point, why not just stain with India Ink?

Oh yeah,  this is why I was attempting to ebonize bamboo . . .

[img_assist|nid=1053386|title=bamboo frame|desc=|link=none|align=left|width=640|height=480]

that is awsome!

it looks cool as is just a good clear coat works for me

is there metal inside the bamboo?

I think so too Ken.  That heat treated bamboo looks great as is.  I’ve built two frames already with that finish (second one in the pic) and wanted to try some thing different on the third - make it look like natural black bamboo. . .

The only metal in the bamboo is the parts you see - steerer tube, bottom bracket, seat tube, and dropouts - just at the joints to fit standard components into.  The heat-treated pole is ridiculously strong and stiff - supposedly a higher yield strength than light weight steel tubes used in road bike mfg.  The ride quality is unbelievably smooth too.

Why not use a torch to put some color in the bamboo? I'm sure a few passes wont make any damage and will "toast" the surface to a nice brownish color.

 

In Swied’s case a little torching on the veneer may cause problems with the glue in the bamboo veneer, unless it is rotary cut vener - no glue lines.  The darker areas on the bike frame are from a over zealous torching on my part, so yeah - it darkens easily, but to make it black is to burn it. . .

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

nice work, mike!

btw is this frame for a racer bike or a mountain bike? curious to see the finished assembly, additional pics would be great!

cheers,

that’s cool I didn’t know about this ebonizing trick. I know a little about ‘fuming’, though, so I thought I’d add something about that, even though the guys who already posted on here probably know it already. Maybe not for bamboo, also needs tannins to work. Oak chestnut hickory, maybe other woods…well hardwood is too heavy to have much use in board construction, which is what it works best on, but for what it’s worth knowing for general woodworking projects…basically you put your wood in as small of an enclosed area as possible with a pan of ammonia, and the wood darkens over several hours or days, darker the longer you leave it. Pretty neat. First time me and my brother fumed a big stack of hardwood flooring for this guy and this guy got some high strength ammonia from a blueprint shop. Made a rack, stacked all the boards with space between them all and made a tent over it with access spots to funnel ammonia into the pans. I took a whiff from a foot away and it felt like I burned my nasal passage even from that distance. Gotta hold your breath or wear a mask! Second time, shorter lengths of flooring for a bathroom, made a tent, stood up a bale of fence wire in the tent, halfway unrolled but still in conical form. Slid all the flooring into the spaces in the fence wire. Looked like a porcupine. Oh yeah and first we put a kiddie pool in the tent with the bale of wire sitting in that. Used one of those sticker zippers that you slap onto the poly and cut a slit on the tent. That time we used regular ammonia from the hardware store. Pour it all in the kiddie pool, dont breathe, zip up the tent, check on it the next day. Works good, was chocolate brown when it was done. Just another trick, I reckon.

Thanks for all the great info everyone!

So, based upon Camplus's test it appears that this trick will not work with bamboo.

 

WoodOgre:  I'm glad you told me about the explosion risk.  I must have missed that warning in the video.

Camplus:  I continue to be a amazed by all of your creations.  Nice work on the boo-bike.