When using aquafortis stain, is the chatoyancy of the curly maple maintained...

[Stophel]

Pigment stains suck.

A.F. is THE historical maple colorant.

some others may have been used, but probably nothing like A.F.   

[Dr. Tim-Boone]

So what is a good source of Tannic Acid to use for experimenting with darkening the stripes etc???   The Science Store has Oxalic Acid which I think is a dirivative from bark, but they do not have "Tannic Acid".....

[Long John]

I remember reading some where, I don't recall where, that acid/iron stains for cloth, leather and wood go back to the middle ages.

In using an acid/iron stain the key is to make sure that your liquid stain, before you apply it to the wood, is clear - not cloudy, mirky, muddy or anything else.  If the stain is clear then the acid/iron salt is in solution.  As a dissolved salt the iron salt goes into the wood as individual molecules.  Adding a little clear dish-washing detergent or isopropanol to the stain will reduce the surface tension and aid in stain penetration into the wood.  When you convert the acid/iron salt to an iron oxide the iron oxide exists in the wood as individual molecules rather than as a grit.  This is what then produces the "depth" of color and the illusion that you are seeing deep into the wood.

Best Regards,

JMC

[DutchGramps]

So what is a good source of Tannic Acid to use for experimenting with darkening the stripes etc???   The Science Store has Oxalic Acid which I think is a dirivative from bark, but they do not have "Tannic Acid".....

No, quite different! The formula is C2O4H2·2H2O, and the stuff is used to remove rust stains; for instance rhubarb contains this acid.
Tannic acid is C76H52O46, and occurs in oak bark, walnut and mahogany.
Hans
who depends on Wikipedia for this show of knowledge

[Rolf]

You can buy tannic acid from most "home brewery stores". It's used in wine making.

Best regards

Rolf

[Mike R]

Under the microscope the structure of the wood looks like a bunch of soda straws glued together.  There are big differences in the structure of the tubes.  The tubes in oak have double thickness double layer walls.  Those in maple are thin walled and single layer.
--Ogre

Very interesting--it is this very alike packing of "tubes" in minerals that give them chatoyancy in light. 

[Ky-Flinter]

Fiber-optics?   

-Ron

[northmn]

I have done cursory research and have seen its use in book bindings, and seperating diamonds from dross, and ivory and bone, but not so much in wood working.  It does go back to about 800 AD but hae not found any historical references to aqua fortis used extensively in wood working.

DP

[Stophel]

Tannic acid is not generally much of a concern in maple, since it usually has relatively small amounts of it, as opposed to other woods.

Boil you a mess of acorns, and you'll have your tannic acid solution.

I need to do this myself so I can do some experimenting with tannic acid and lye.

[northmn]

In a book I have on on tanning hides (Tannic Acid) they use oak bark as a solution for tanning.

DP

[Mad Monk]

So what is a good source of Tannic Acid to use for experimenting with darkening the stripes etc???   The Science Store has Oxalic Acid which I think is a dirivative from bark, but they do not have "Tannic Acid".....

Ok Tim,

In the book on Bedford County Gunsmiths By James Whisker he cites a store record where a gunsmith purchased a "shale" of tanbark.  I suspect that the term used to describe the bundle as "shale" got that because it looked like shale layers in rocks.

So I walked into Dixon's one Sunday.  The place was full of shooters getting their T/C Hawken's ready for the flintlock season.  I set a quart jar on the counter and told Chuck I needed a quart of wood ashes and a bag of oak bark.  You should have seen the strange looks.  But I was looking at the deal the way the original gunsmith would have.

The wood ashes from his wood heater would be the source of the "potash" used on the stock after stain application.  
With the oak bark I simply peeled it off pieces of oak he had in his wood pile.  You scrape the inside of the bark and that dust is rich in tannic acid.  If the bark was just a bit loose from the wood while stored you sometimes see a layer of white dust on the surface where the bark came away from the sap wood.

Bark, such as oak, is very rich in tannic acid.  Some of the fir trees will also give a good supply of tannic acid from that part of the bark but then they also give color you don't want.

If you stain the stock with nitrate of iron, then neutralize it and then follow with a wash of tannic acid you can end up with a stock that looks more like charcoal.

But you can cheat before you stain.  I had given a stock a wash of tannic acid.  Left it dry and then did the final scraping.  That filled the curl with tannic acid while the scraper removed the tannic acid from between the curl.  You can get a very dramatic appearance with this but you must not get too carried away with the pre-treatment with the tannic acid wash.

I have seen originals in Chuck's collection where the curl was jet-black with only very light brown in between the curl.

E. Ogre

[Mad Monk]

I have done cursory research and have seen its use in book bindings, and seperating diamonds from dross, and ivory and bone, but not so much in wood working.  It does go back to about 800 AD but hae not found any historical references to aqua fortis used extensively in wood working.

DP

I suspect that the use of aqua fortis was almost exclusive to working with curly maple.

It appears that its use was confined to things like stringed musical instruments and maple gunstocks.  Things that might be looked upon as individual examples.  If you try it on cabinet work it is nearly impossible to get the colors uniform on all of the pieces of wood that go into the cabinet.  On something like a gunstock this degree of variability makes each one unique.

E. Ogre

[Dphariss]

I have done cursory research and have seen its use in book bindings, and seperating diamonds from dross, and ivory and bone, but not so much in wood working.  It does go back to about 800 AD but hae not found any historical references to aqua fortis used extensively in wood working.

DP

For our purposes its documented.

Dan

[Dr. Tim-Boone]

Thanks Mad Monk....I am off to the wood pile in the am.....gonna try the prewash with the tannic acid and see how it works.