Lightening stag?

[muskrat man]

I was wondering if any of you have ever tried to lighten the color of stag chemically? I recently was asked to restore some case knives that had been exposed to some kind of chemical or something and the stag is a hideous chocolate brown all over and looks very dry underneath the flaking (what appears to be varnish or clearcoat, I've witnessed this on many vintage case knives in stag). I'm not sure where to start on these. Was thinking about a good scrub with acetone to remove the remaining varnish, and maybe that would lighten the color a bit? then a good soak in mineral oil? I'm lost on this one. Whatever the chemical was is badly rusted the blades and ate pits into the backspring like what you witness on knives that are outgassing. Any thoughts would be helpful

[tjmurphy]

If it is varnish or lacquer, both of those finishes will oxidize over time and turn dark. Sounds like you are on the right track. Good luck.

[coffeecup]

For what it is worth, after cleaning and restoring a lot of old game trophies I've almost got a standard routine. First you have to figure out what the clear coat is.

Hit it first with denatured alcohol on a cotton swab--if it comes off, the finish is probably shellac. That's an easy one to remove, just scrub it off with a scotchbrite dripping with alcohol.

If that doesn't work, try lacquer thinner on a swab. If that softens it, it gets a bit more tricky: sometimes removing the finish will drive some of it into the surface of the stag. Best bet is to work a small spot at a time.

Sometimes you'll run across a handle that was treated with oil; linseed and tung oil are the common ones. These will both darken over time and with UV exposure, and are a pain to remove. Try different solvents until you find one that softens it, and use that in a small spot at a time. The problem with these is that often people will use various proprietary mixes, that are apt to contain anything from various lacquers to polyurethane.

If it is a poly finish, of a finish containing polyurethane, you're on the right track with acetone.

If you get lucky, someone just waxed it with an older auto wax; those will usually come off with lacquer thinner.

Worst case, once the finish is off you can bleach it out and then restore the colors and fake the patina. But the best way to do that may be affected by contamination from the current topcoat.

Jim

[FRJ]

You may want to try methyl ethyl ketone aka MEK. It's powerful stuff but I always have a can around.

[coffeecup]

OK, found my notes. This procedure is what we used to restore an old chair made of elk and deer antler, probably about 1900 or so (?). Anyhow, I've used it over the years on various pieces of stag, deer antler, and bone. Experiment with it on some stuff that doesn't matter (scrap, etc), so you can see how your chemicals work (different strengths of the chemicals and different mixtures will work faster or slower, etc).

MM, can you take the knives apart to work on the stag? Some of the chemicals involved are fairly potent oxidizers, and others are just plain nasty.

First step is to remove whatever topcoat was used.

After that, scrub the stag with strong ammonia and a toothbrush. You don't want an ammonia with added soap, just ammonia and water. The stronger the concentration, the faster it will work. USE PRECAUTIONS. Work outside or under a fume hood, wear a vapor mask and goggles, etc. That should get clean surfaces to work with.

To bleach, get some hydrogen peroxide (as used to bleach hair) and powdered white chalk (magnesium carbonate). Mix them into a paste and apply to the surface of the stag. All the chalk does is hold the peroxide in place longer. After a while, scrub it off with a toothbrush and wipe the surface clean with water on a piece of old T-shirt. The peroxide (more likely, the water in the peroxide mix) will slightly soften the surface of the stag, so be careful. You can repeat this procedure if needed.

Clean it up with water and maybe yet another toothbrush to get the chalk out. From there it is just a matter of staining/dying the stag--everyone has their own voodoo for that.

Jim

[orvet]

You may want to try methyl ethyl ketone aka MEK. It's powerful stuff but I always have a can around.

MEK will remove a lot of different finishes including automotive finishes. I used to use it to clean dried lacquer and enamel from old spray guns when I repaired them.

CAUTION: When using MEK always wear rubber gloves, the chemical resistant kind. MEK is one of a handful of solvents that can penetrate the skin, travel through the blood and cause liver damage! Always use it out of doors with LOTS of fresh air and with a respirator! It is HIGHLY FLAMMABLE!

But it sure works good to remove dried finishes.

If the stag is still too dark, you might experiment with wood bleach rather than laundry bleach. Laundry bleach can yellow some materials.

Be sure to let us know how the project comes out.

[muskrat man]

thanks fellas. I've seem to have found a regiment that works. I thought of using peroxide but underneath all the black you can just see that sweet yellow mellowed out stag everyone loves so much, so I hate to do much to it in the way of WHITENING it. Just need to pull some of the darkness out is all, after removing the top coat. They have been soaked in transmission fluid which is what has caused all this. I use peroxide in whitening animal skulls a lot. Laundry bleach like clorox you don't want to use on ANY bone type material, in years to come it will cause it to practically disentigrate, making it very soft, porous and flaky, it's too harsh even in diluted form. skull people nearly pass out when you tell them you whitened your skull with actual bleach, LOL

Besides, the stag on these seems porous, and brittle even though it's practically oozing with oil. I think it was something in the transmission fluid that is causing them to break down.

[orvet]

Thanks Kaleb for the info on bleach.
I have not encountered this problem before so have not had occasion to use bleach on stag or bone.
I will be sure to keep it avoid using it.

[muskrat man]

Here are some of the knives after some work. They had been soaked in transmission fluid and had some kind of thick topcoat on the stag. The stag was completely black and/or chocolate colored on all of them, they tuned up pretty nice.

[orvet]

Those look pretty good.
What kind of transmission fluid did you use?
Does the stag smell like oil?

[trutemper]

Whatever you end up doing DON`T allow bleach and ammonia to mix because it becomes HIGHLY toxic!

Bob

[muskrat man]

they had been soaked in trans fluid prior to my getting a hold of them, that is what the problem was

[gringo]

brake fluid will remove the tranny fluid...and will wash out with soap an water.