aqua fortis color/ rubbing back?

[StevenV]

 the above picture is of some samples from three different batches of nitrate of iron stain I just recently finished making , two questions:
1.) after reading a good amount of the archives on the staining with aqua fortis I come to the conclusion most want darker, to the point of staining again and blushing again, are your samples coming thru lighter than these ,the 3 batches were at 4:1, 6:1and 8:1 ratio's
2.) how are you "rubbing back" your stain to make it lighter, steel wool , sandpaper, scraping,  and when are you "rubbing back" after the heating and application of linseed oil then do you rub the color back? I like the colors just would like to get them a bit lighter, I thought 8:1 would produce a lighter color I guess I will have to dilute some of the batch a whole lot more to produce lighter results
Thank you very much for your input          Steve

[Mad Monk]

Going back to the 1980s when I did a lot of test blocks with AF (nitrate of iron) I tried "rubbing it back" as you call it.

I used degreased steel wool.  Steel wool comes through with an oil on it so that it does not rust.  You don't want the oil on the stock.

Rubbing it back with steel wool will light the color on the area where the grain runs parallel to the surface.  The light areas between the black curl.  After rubbing it back you look closely at the wood to look for any little bits of broken off steel wool fibers.

You might also try to buffing it with a wad of stiff cloth.  A heavy cotton muslin.

Some of the threads have discussed how you treat the stock after applying the AF stain.  I had first started my work with baking soda solution in water.  That results in some foaming on the wood.  The foam lifts some of the iron off the surface.  Mainly where the grain runs parallel to the surface.  As I wiped with the cloth wet with the baking soda solution some iron that was lifted off worked into the cloth.  Some was also pushed down into the open end grain that makes up the curl.

Stain penetration "across grain" is very shallow.  When you apply the stain solution it goes deep down into the end grain curl but only sits on the surface of the wood between the curl.  There is very little stain penetration cross grain in wood no matter what type of stain you use.  Be it water or alcohol based.

I put a lot of time over a high-power binocular microscope looking at how stains and finished penetrate into wood.  Different types of wood, sanding versus scraping and types of stains.  That gave me a bit of guidance in wood prep and post stain approaches.


Mad Monk

[smart dog]

Hi Steven,
I shifted from using steel wool or cloth to Scotch-Bright pads. I usually use a grey or maroon pad to rub back stains before applying finish.  If I am using a tinted oil/varnish for the finish, I may rub that back with rottenstone and oil.

dave

[smallpatch]

Scotch-brite is the way to go. Started using them 10 years ago in place of steel wool on wood . Leave very little residue, and it just wipes off,like dust.
Steel wool is for metal, not wood!!

[P.W.Berkuta]

StevenV what did you use for your heat source? I have used a few different heat sources and got from a light chesnut color to a almost black color all with a 6:1 solution. One heat source was a electric oven coil that was not regulated and was HOT - this is the one that produced the almost black stock finish. the light chestnut color came from a heat gun that produced about 650 to 750 degrees.

[P.W.Berkuta]

Stevenv - I sent you a PM with pictures of my heat source's and some info - hope this helps you - good luck.

[smallpatch]

Steven,
The black is probably scorched wood.
The hair dryer type heat gun is the most controllable.  They are pretty low wattage, so you just need to keep it moving, and as the wood "blushes", (changes from that nasty gray-green color, to a nice amber-red), move on to the next section.
It's really pretty easy. Don't overthink it.

[WadePatton]

Also know that each piece of wood (tree) will take the iron solutions/blushing slightly differently according to the micro-chemistry of the wood.  Those samples don't look like any of my plank scraps, but then i don't have a bandsaw in my shop.  Point is, get your color/process dialed like you want it on actual wood from the stock blank, or you could be in for some surprises.

[P.W.Berkuta]

StevenV, here are two pictures that were taken this weekend - one shows the aqua-fortis applied to the stock and the other shows what it looks like after it was blushed with the Wagner 1000 heat gun. The screws on the patch box are only "working" screws not the end product. The stock was neutralized with an ammonia / water solution.

[StevenV]

Thanks for the reply P.W. I appreciate the others input also. I have no doubt the type of heat source does effect the final color. This is something I will play with. I am also going to dilute some of my stain to 10:1 and see what I get. I will post pics when I get to that. I am just tickled pink to have made 3 batches with the help of numerous peoples experience and they turned out really really nice. I have all but exclusively used aqua fortis to stain my guns in the past with very good results. I am just playing around with the stuff I made to see what range of colors I can obtain. Thanks    Steve