Supplies needed

[GobblerForge]

Hi folks. I'm in the middle of a knife and need some help. I am not able to find rub on letters for a raised letter etch. I'm looking for a script about 1/4 in to 3/8 in. high in some nice old English or something. And I can't find any ferric-cloride to etch with. I like this for it realy attacks the high carbon well. Radio shack used to sell it for etching circut boards but no longer. Any suggestions? Thanks. Brad

[ThomasPowers]

For the lettering we used to find it at art supply stores in college towns; sometimes in office supply stores.

.

Thomas

[sandpile]

GOBBLEFORGE--I had a hard time finding the etchant at RADIO SHACK. I finally found one store that had it in Dumas Tx.

All of the others could have ordered it for me. Just did not want to, not enough demand and they have to buy a case or so at a time.

Can not help on the letters, sorry.

Chuck

[HWooldridge]

Hobby Lobby or something similar sells the letters. You can use other etches besides ferric chloride if you can't find it - diluted nitric is a good substitute.

[GobblerForge]

I've never used nitric acid before. Where do I find it? How does it come? How much do I dilute it and why? Any other tips on its use? This is interesting. Thanks. Brad

[Mills]

Chemical supply houses would be the first place I would call. If there are any environmental labs in your area they use copious quantities of all kinds of nasty stuff like nitric.

[Woody]

Be very careful with Nitric Acid. It is extremely corrosive to carbon steel and also very corrosive to skin. When you dilute it add the acid to the water never water to the acid. Wear rubber gloves, goggles, a full face shield and a rubber or plastic full apron. Why do I say a rubber apron, because a lap full of nitric acid will have you singing a new verse of the old Jerry Lee Lewis hit. Also remember that acid reacting with metals evolves hydrogen gas. Very flammable stuff. Also the nitric acid when it is no longer usable will have to be neutralized before you can dispose of it. You cannot just pour it down the drain.

Woody

[GobblerForge]

Thanks for the tips. Neutralized with what?Keep them coming. I'll try to post some pics if I can. Brad

[Mills]

most common neutralizer would be Sodium Hydroxide. Can be found in concrete cleaners.

[Glenn]

You can neutralize acid with baking soda from the kitchen.

Sodium Hydroxide is lye and a strong base in solution, which can be just as bad as acid only in the other direction of ph. When sodium hydroxide is added to water it creates an exothermic reaction meaning it gets REAL HOT sometimes to the point of boiling. And there is the problem of how much to use to neutralize the acid. Too much and you still have a dangerous chemical on your hands, only now instead of an acid, it is a base solution.

Baking soda is the way to go on this one in my opinion. It is used in cooking, in food, and can be handled without a hazmat suit.

[Woody]

Never put sodium hydroxide into acid solutions, you think the heat reaction you get by adding it to water is strong, just wait till you toss it into acid. You will have it and acid flying all over the place. Baking soda is a good neutralizing agent. If you want something that works a little faster, you can use soda ash (get it from a chemical supply store) or lime. Soda ash neutralizes acid on a 1:1 ratio. That is NOT a one cup to one cup ratio. It is one pound of soda ash will neutralize one pound of pure acid. Lime, available at any lumber yard, neutralized on a 2:1 ratio, that is one pound of lime will neutralize 2 lbs of pure acid. Pure nitric is if my memory serves me correctly about 13 lbs per gallon, so you would need 13 lbs of soda ash to neutralize one gallon of pure acid. If you have one gallon of 40% solution you would need only 40% of 13 lbs or 5.2 lbs that is assuming that my estimate of the weight of a gallon of pure acid is correct. You will need to check that. The hazards of using stronger alkalis like soda ash or especillay lime and sodium hydroxide is that you can easily add too much. Then you end up with an alkaline solution that is also a hazardous waste. Anything with a pH of less than 2.5 or more than 11 is a Hazardous Waste. If you generate a Hazardous Waste, you must register with the EPA as a Hazardous Waste Generator. In addition to the corrosive hazards of nitric acid, it is also a VERY strong oxidizer, stronger in fact than pure oxygen. If you look at the formul of it HNO3 and of pure oxygen O2 you can see this. If nitirc acid comes in contact with organic materials, it can cause them to decompose and ignite. Additionally, when mixed with other chemicals it can form explosive compounds. When nitric acid, over 40% in concentration is shipped, it is placarded and labeled as an Oxidizer not a Corrosive because the oxidizing potential is the greater of the hazards. I think you would be better served to continue your search for ferric chloride than to mess with nitric acid.

Woody

[GobblerForge]

The nitric sounds very caustic. What other etch acids do folks use? I'm no chemist. Thats for sure. Brad

[sandpile]

GOBBLER--You can etch with Lemon Juice or Vinegar, just takes longer.. Some people use a citric acid. BBUUUTT Half and half FERRIC is the prefered. Keep trying the different RADIO SHACKS, you will finally find it. I did Grin.

One part water to one part FERRIC ACID. The Lemon juice will take an hour to three hours( longer if you want it really dark) to get the contrast. Not quite so long for Vinegar. I have not used Citric.



Chuck

[GobblerForge]

Half and half ferric and what? I've always used it strait. Seamed very effective. Have I been doing something wrong? Is there something I should know? How long is longer with vinegar or citric acid? Hours? Days? Does it surface etch or does it penitrate? Vinegar is easy to come up with. Honey? Can I use............? Thanks. Brad

[Ralph]

Gobbler,
half and half is half acid to water.
As to how much longer.... Well it is why you make a test piece first and experiment first. Changing the concentration will aftect how long as will the bath temperature.
A lot of this smithing stuff is trial and error. We can often get you close to what you need or want but some experimentaion is required to fine tune it for your application.

Ralph

8)

Edit
Always - slowly add the acid to the water with constant stirring, never the other way around.

[GobblerForge]

Thanks to all for their replies. Brad

[julian]

Someone correct me if it is bad to use, but pool acid would work? I tried it, and it does etch some. It's not as powerful as other acids, but it will still badly burn skin; so all acid precautions should be taken. Soda ash will neutralize it (why we put it in pools )