Woody

Frosty, perhaps it would be a good idea to post how to preheat the propane least someone try to apply heat to the propane tank with less than satisfactory results. Just a thought, I know that things can't be made idiot proof. :)

Dodge

I dried my slurry for about a week before I fired the forge, it's cold here so I put a trouble light in the forge and left it on.

http://www.sciencelab.com/xMSDS-Ferric_chloride-9924033

pH (1% soln/water): 2 [Acidic.] With a pH of 2, Ferric Chloride is indeed an acid. Anything with a pH below 2.5 is considered to be corrosive to skin. Also anything with a pH below 2.5 is a Hazardous Waste for disposal purposes.

you can draw any pattern you want on the blade, then coat the pattern with nail polish, I use red because it is easy to see that you have it all cleaned off when you are done. Once the polish is dry, etch in ferric chloride for as long as you want. After etching, wash with hot water and neutralize the ferric chloride with baking soda. Wash again and then remove the nail polish with acetone. If you polish the blade to a mirror finish first, the nail polish covered areas will be bright mirror finish and the uncoated areas a dark gray or black.

There used to be some stuff called Macote that worked as well as ITC 100 but I have been unable to find it lately. I have mixed a 3000 degree refactory cement to a thin slurry and applied that to my new Kowool lining it seems to work well and is holding up good and I can reach welding heat with no problem. I don't know why the Greenpatch wouldn't work just as well.

I came across this website today, it has good information on all kinds of steel. Just type in the steel type like 52100 and click search. Online Materials Information Resource - MatWeb

Remember that all Air Purifying Respirators must be fit tested to your face. Each different manufacturer of Respirators has their own idea of what the "Average" face is like. In one make a medium may fit you perfectly in another it may take a large.

Additionally ALL Air Purifying Respirators have a Protection Factor associated with them. That is the maximum concentration of a contaminant that the perticular stye of Air Purifying Respirator will protect you from. A half face, that is one that covers the nose and mouth, has a protection factor of 10. That is it will protect you from a Maximum concentration of contaminant that is 10 times the permissible exposure limit. If the permissible exposure limit is 1 ppm then that respirator will protect you to a maximum concentration of contaminant in air of 10 ppm. A full face respirator has a protection factor of 50.

If you intend to weld in a confined space without a direct reading air monitoring instrument you are inviting disaster. For welding in a confined space, I would only recommend a Positive Pressure SCBA. I belive that Positive Pressure SCBAs have a protection factor of 10,000 if I am not mistaken.

No one can guess the concentration of the contaminant in the air so it is better to fail on the side of safety and have more protection than you need than less.

Remember that your nose is not a good toxic contaminant. Many contaminants are harmful to the body at below their odor threshold. That means that before you can smell them your are poisoned. With extremely toxic substances your nose will only work once, you get a good whiff and then you are DEAD.

Sam I am impressed by your compassion for your assailant. You have taught us all a lesson. God bless you and thank you.

Woody

People make knives out of railroad spikes which are mild steel unless they are the HC ones then they have .30% carbon and the tout their edge holding ability. 4340 has .10% more carbon than a HC rr spike and some additional alloy metals chrome and moly I think but I am not sure and I am on the road right now without access to my reference material. 4340 will make a knife it may not hold an edge as well as some of the high carbon steels. I have made a Katana out of 4140 and although I havent done a lot of cutting with it, it is very sharp and I clamped the tip in the vise, grabbed the handle and bent it to a 45 degree angle and it sprung back to it's original shape.

Make a knife out of it, see what it does and learn from the experience.

prayers on the way, also file charges, assult is a felony, then sue him and his parents for damages. God bless you and return you to health.

Woody

my guess is they were used in some sort of crushing mill to pulverize rock, or perhaps in a grain milling operation.

Check here for Hazard Information on Borax. Sodium borate decahydrate Once again if you don't have a MSDS for every chemical in your shop, GET ONE and read it instead of using it to start the fire in your forge the life you save may be your own. I think I did a blueprint story on Toxicology or Respiratory Protection or something like that you might want to check the archives and if you find it there look here Toxicology part 1 and part 2

Mixing alcohol, a flammable liquid, with nitric acid, a powerful oxidizer, is not recommended. They could ignite. Nitric acid in concentrations over 40% when shipped is not placarded corrosive, it is placarded an oxidizer. Although it is extremely corrosive, the oxidizing potential is considered to be the greater hazard. Remember you need 3 things for a fire, something to burn, in this case alcohol. Oxygen, in this case, Nitric Acid, HNO3. A source of ignition, the heat that can be produced by the reaction of the acid and the alcohol.

The IDLH concentration, that is the concentration of vapors that is Immediately Dangerous to Life and Health, is 25 ppm, the odor threshold is 27 ppm, that means by the time you can smell it you are over the IDLH limit. The permissible exposure limit, PEL is 2 ppm that means by the time you can smell it you are 10 times over that limit. The LC50, or lethal concentration that killed 50% of the test animals, in this case rats, is 67 ppm.

In the photo's that show the two edges of the break together, I notice a dark part that starts at the cutting edge and goes a ways into the blade, then the break is clean bright metal for the rest of the way. I think that perhaps the blade was cracked on the edge at the time it was heat treated and it broke the rest of the way when it was subjected to the mild shock of tapping on the handles. The original crack could have been from several sources, hammering it when it was too cold, not getting all the file teeth ground off, bad karma etc.

God Bless and Keep you all may he heal your daughter compeltely.

What type of steel did your start with, was it a medium or high carbon steel? Heating to bright orange is too hot for heatreating most steels, you want to heat to just above the point where they go non magnetic and then quench. If you started with mild steel, you probably won't be able to get it hard enough to function as a center punch. Perhaps start with a piece of coil spring from a car.

"*One method of solving this, is to wash the weld in water with a bit of baking soda. If you have ever used a blacking agent, then you've done this or something similar."

Borax is on the alkaline side of the pH scale, so is baking soda. One alkali will not neutralize another, it takes an acid to neutralize an alkali. As far as the steel "absorbing" the borax, I think that is highly unlikely.

jarrett I posted the new link a couple weeks ago, Glenn incorporated it into the old thread. The new link is on page 5 of the Thread here it is http://www.feine-klingen.de/PDFs/verhoeven.pdf

Get someone else to do the arc welding. Why take a chance. On the other hand A/O Welding is pretty easy and does a nice job.

I have a coffee can with damascus pieces that were cut off from blades that were never etched, some have been around for over a year, none are leaching white stuff. If your weld is leaching white stuff the problem is more than likely not in the flux but more likely in the smith .

I have welded up many damascus billets using only borax, I have yet to have one develop white residue. 20 mule team borax melts into a black glass like substance at a red heat, in fact borax is a major ingredient in glass. I have never experienced a problem with borax, perhaps some poeple are confussing Boraxo, a hand soap containing some borax, with 20 mule team borax.

To my way of thinking, any weld that leaches white stuff is not completely fused. If the weld is completely fused, the flux along with any disloved goop in it are forced out by the initial hammering allowing the clean hot unoxidized surfaces of the metal to meet and be fused together under the hammer.

Be careful with Grade 8 bolts, if they have a gold color they might be cadmium coated, others may be zinc coated. Several years ago there were a multitude of "counterfit grade 8 bolts on the market" They were sold as grade 8 but did not meet the specs. The Tank Truck Magazine "Modern Bulk Transporter" ran an article on them identifying all the different counterfit bolts by their manufacture and markings about 1992 or so.

Woody

If you use Boric Acid for flux, buy it in the drug store, they sell it very cheap as opposed to Roach Powder which is more expensive.

I have never had a problem with white stuff leaching out of my welds, if it does I am thinking that the weld was not completely joined.