A winter fun project

[Jerry Crawford]

Finished this pair of saws today. It has been a fun scrap wood project to while away part of a winter. Curly maple, ebony, brass and waxed hemp string. Hand cut M/T & DT's. Bow saw is 12" X 19", Frame saw is 14 1/2" X 23 1/2". Finished with aqua fortis and potassium permanganate, rubbed out with steel wool and boiled linseed oil. As soon as I can find a good piece of blade I'm going to make a DT & coping saw to complete the set. More details on my web site.

http://home.comcast.net/~boondocker1/finished%20pair.jpg

[Ted Shrader]

Jerry -

Those look pretty slick! What did you use for blades in them?

Regards,
Ted

[Jerry Crawford]

I ordered a couple of blades from Highland Hardware then cut them down to fit my saws

[Marc Hills]

Jerry:

That is a beautiful pair of saws. A frame saw is next on my tool making list, because I want to try my hand at resawing. I really like your "antique" finish, it gives your pieces a wonderful patina. Can you elaborate a bit on your finish? I'm quoting from your website:

"The finish is very appropriate for the era this saw represents; a combination of Aqua Fortis (made from nitric acid), potassium permanganate and boiled linseed oil. Properly applied it give up a beautiful finish aged and very much appearing like 18th century gunstocks."

Can you give us an idea of where we can obtain these compounds? I'd also be interested in the exact formula and tips on how to properly apply it.

[Jerry Crawford]

Sure Marc, be happy to elaborate on that.

Aqua fortis is a very old formula going back to when alchemists were trying to make gold. It's a solution of varying proportions nitric acid to water. Among my gun making friends the most popular ratio is a 10% solution: 1 part nitric acid to 10 parts water. Add the nitric acid to the water, not the other way around. I mix up about 1 1/2 cups in an old jelly jar in the back yard. Then I add several rusty 1" finishing nails and let it set for a week. Some guy's use steel wool and I've heard that works faster than nails but I had lots of nails and not much wool on hand when I made mine. Pretty soon the liqued will begin to turn black and after several days it's ready to use. There aren't any cast-in-stone rules here.

When you're ready to begin finishing just paint the AQF onto the clean bare wood. I use a throw away 1" brush for my small projects. You'll notice the AQF will go on the wood not quite clear but with a noticable greenish tinge, not the black you'd expect looking at the jar. Let it soak into the work piece and set it aside to dry. It will darken as it dry's.

Next step is to heat the AQF. To do this you need a heat gun like a hair dryer or real heat gun. Being careful not to scorch the wood play the heat over the surface and pretty quickly the AQF will turn a fuzzy looking brown - keep the heat moving because you're pretty close to the scorch temperature of the wood.

Now - if you have or are going to be inlaying or inleting metal into the wood piece you need to neutralize the acid you just saturated into the wood or the metal and acid will act on each other in a nasty way you won't like. Mix a solution of baking soda and water and scrub the wood down. Wash off the soda solution with plane water and let the project dry.

The next step is a "WEAR RUBBER GLOVES" operation only because PP stains skin and won't wash out. Mix a cup of water with a teaspoon of potassium permanganate crystals. It turns a really ugly shade of purple. Using another brush paint this this onto the wood. You can apply a couple of wash coats and the wood will turn really black - this is OK. Set it aside and let dry.

When you come back to the project (I wear rubber gloved for this too) you are going to scrub the project down with steel wool and boiled linseed oil. I scrubbed down small sections, a corner, half a stile or rail, at a time and wiped it down often with paper towels when the oil got nasty. This step is pretty much a judgement call by the operator. I had carving on the corners and numerous tool marks on the wood that I didn't want to erase so I left some finish in cracks and wrinkles. It's giving the tool an aged appearace which is what I was working for.

Depending on how much you scrub and the kind of wood you are going to get different lights and darks showing through the finish.

As for obtaining the nitric acid and potassium permanganate crystals; you'll have to source them elsewere. I found Nitric in Denver at a chemical supply outlet. A 17 oz bottle cost me about $21 - and that's a lifetime supply for me. A friend gave me the PP crystals but I understand it's used in water purification systems somehow.

I hope this has been helpful. I realize it's not as simple at wiping on Formby's but IMHO I get a better looking finish for what I want.

[Aaron Kline]

Jerry,
Very nice! Do you make flintlocks or percussion rifles? If you could please, post some pictures of the completed rifles. I'm sure everyone would enjoy them.

[Jerry Crawford]

Aaron, I work at building flintlocks and so far I've completed two. One a kit from Jim Chambers (http://www.flintlocks.com/) and the other a scratch built 54 cal in the style of Issac Haines. I have three others in my shop in various stages of being built; smooth rifles in the style of Fredrick Sell (ca 1800). I'm certainly a rookie at this activity compared to most of my friends who are real masters, skilled in style and embellishments. I know a few who make museum grade guns in the 5 figure range.

I happen to have my son's Haines on the bench repairing a sight so I'll take some pictures of it for my web page. At the moment I'm trying to get my tool chest put together for the gun making demo I take part in ever summer in Indiana at the National Muzzleloading Rifle Association's (http://www.nmlra.org/) semi annual shoot. Anyone living within a hundred miles of Southern Indiana and want to see some real works of the gun makers art come by in June or September. This event draws competitors from all over the world.

These two saws were a learning activity for me in design and engineering as well as to practice using a new (to me) finishing process. I had some scrap laying around and hated to throw it out. There was also a design challenge inherent in making them in the manner of the 17th/18th century specifict to gun making as opposed to carpentry or cabinet making.

[Dave Anderson NH]

You have made two absolutely beautifal saws. Well done.

[Bob Hawley]

Jerry,,Beutifful. A tip for those less advanced than you, follpw the imstructions carefully, the rusty iron neutralizes the nitric acid. Nitric acid and wood equals nitrocellose, useful for lacquer base, early film base {said to be clearer than modern plastics], and nodern smokeless gunpowder. Descriptions of early smokeless powder plants generally went somthing like this "They made gumpowder for a short time, then the plant blew up with a large loss of life." Then someone figured out that they could use equipment used in papermaking to wash out the nitric acid and today smokeless making is less risky than black powder. In the reasonable quanitys, the two risks I would see are one, nitric acid will stain you so persitently that the skin must wear away to get rid of it, and two, if you spill any on wood or cotton {guncotton}, neutralise with baking soda, flush lavishly, and dispose of it like you would spilled gunpowder. Sorry to be so longwinded, I read when I can't sleep.

[Jerry Crawford]

Thanks for the follow-up Bob, Like anything else there are inherent dangers and problems in working with a strange chemical or process and due safety needs to be observed. My knowledge about this is mostly rote rather than in depth study and education although I can understand the linkage you refer to. I depend on my friends who have been at this for years to guide me and keep me from killing myself, so your comments are well founded and appreciated.