Quenchcrack

When I worked in a CI foundry, we referred to the worst of the worst castings as "sash weights and sewer lids". And the sewer lids were the better of the two.

Kburd, I have the same forge and it is nicely made. You won't need more that 10 psi to heat it up and about 5 psi to maintain it. It's a real heater.

Philip, do you have a source for HAND CRANKED blowers? We can get electric blowers here but they are a bit cumbersom when taken to a demo site. There are apparently no sources for reasonably priced hand cranked blowers in the US.

This may be peculiar to the Houston area but the commerical metallurgical labs all seem to have a LOT of heavy pieces of steel they have cut up for analysis. I am talking 6"-10" in diameter and just as thick.

Mark B, steel mills that make flat rolled steel strip for the auto industry and the pipe industry make something called a micro alloyed steel and use controlled rolling to produce it. It utilizes very minute amounts of vanadium, niobium and titanium as the alloys. When making these steels the strip is rolled (forged) at a low heat (about 1500F). This crushes the austenite grains but at the low heat, they do not rapidly recrystalize. After the finishing pass at this low heat, the strip is allowed to cool down to below the temperature at which the austenite begins to transform to ferrite. It is then water cooled to form the ferrite within the crushed austenite grains. The result is a very fine grained ferrite with vanadium and niobium carbonitrides precipitated throughout the ferrite grains. It can be as stong as heat treated steel but it is just as-rolled. Does that sound familiar? You can do this at the forge but why bother? It is still simpler to quench and temper small pieces.

While the grains do re-form, the effect of the flow of the metal remains in effect. However, compare forged knives with stock-removal knives. When using commercial stock steel, the material has already been "forged' from an ingot or billet down to finished stock size. This may involve a reduction of 10 or 20 to 1. Does forging another 10-20% really do as much good as we like to think? Don't misunderstand, I prefer a forged blade but I know the vast majority of commercial blades are stamped and ground and appear to be functional for the average user.

Frosty, my meager experience supports your observation on the effect of the waist. My 170# German Pattern from Old World will ring much less if I put a triangular welding support magnet on the waist, just above the pad for the feet. I found it works best if you attach it perpendicular to the side, not flat on the side. You can get these magnets at Harbor Freight for a couple of bucks.

Arftist, I think everyone else answered it.

Orgtwister, you gave me a great idea! I'm gonna make some totally nonsensical hardy tools and tongs and put them on ebay! Imagine the conversations it could start!

Welcome, Federico!

Almost anything you use is going to look like a big ugly patch. I trust you really don't plan to use it to boil tea anymore, though? Cast iron filings in JB weld might hide it some.

I gotta like the shape. Post some photos when you get it finished.

The only thing that was not mentioned previously is that the cast iron has most of it's carbon in flake form. It does not really play as big a roll in contributing to hardness as it's high per centage would suggest. The flakes are really graphite and make a fractured surface appear sooty and grey. Hence, it was called grey iron. It does not ring when struck like steel does because the graphite flakes attenuate the sound.

Bob, good question. I would expect the hot water to be a very slow quench since you already have it to a rolling boil. It would not accept much more heat from a second source. My concern would be that the steam that is evolving in the water, especially around the part being quenched, would cause erratic heat removal. This could lead to distortion and cracking. However, if the part stayed together and you got it as hard as it needs to be, well, it's hard to argue with success.

I'd be careful starting a fire in that general location. Looks like it could spread quickly if it got away from you.

I overheard a spike knife maker making a pitch at the Canton Flea Market in Canton, TX. At first I was going to step in and correct his misrepresentations but thought better of it. The customers needed to learn about snake oil and this was just the guy to teach them.

Our prayers are with him.

There is a type of chemical called a Vapor Corrosion Inhibitor (VCI) that can be sprayed on a metal surface, allowed to dry and the surface will remain rust free for months or longer. One company that makes it is Corr Tech although I think you would probably need to buy industrial quantities from them. This stuff works great, leaves a very slight film, and no odor. It is easily removed with alkyline soap and water and is biodegradeable. I wonder why you can't buy small quantities in the stores.

As has been mentioned, the natural oxidation state of Iron is not Fe. It is FeO, Fe2O3 or Fe3O4. To prevent the oxididation of iron, you need to separate the iron from the oxygen. Wax, oil, varnish, lacquer, paint etc, will do it; the question is which lasts longer before you need to re-apply it. I think that depends on where you are. Here on the Gulf Coast, the iron starts to rust before the coating is dry. If you don't mind re-applying every few weeks, WD40 is OK. I prefer paste wax or black paint. If you really need protection, remove all scale (it is porous and will hold moisture), prime, and apply several coats of exterior paint.

I believe the Boric Acid kills roaches by dehydrating them. Roaches need moisture; the boric acid absorbs it and the roaches just dry up. Other roaches eat them and they dry up too. Of course, now you have the bodies of dessicated roaches all over the place.

Sweany, Happy Anniversary to both of you! My patient wife and I will celebrate #40 this month, too.

I guess this is what they mean by "putting lipstick on a pig".

Harbor Freight Genuine Chairman Mao Brand Cheepo discs. About $.50 each. Second best is the Genuine Vladimir Lenin Brand Grindudown Rusky discs, about the same price.

Every time you anneal a blade, the carbides tend to get bigger. This means the carbon is all tied up in the carbides and is not available to actually harden the steel when you quench it. You can theoretically anneal it as often as needed but normalize it a couple of times before you re-harden it to reduce the size of the carbides. This puts the carbon back into the iron and will harden more effectively. See BP0078 for details.

I live in a very nice neighborhood in the suburbs of Houston, TX. If I lit my coal forge here, I would be avalanched with complaints and possibly an injunction from the local property nazis. Gas is the only way to go in Yuppieville. I run the coal forge when we go to HABA meetings out in the country or at Demos. Coal is clearly more fun.