MattBower

Not sure I understand your question. Steel generally needs to be clean and free of finishes before it is forge welded. After welding and patterning, it is acid etched in order to improve the visibility of the pattern. In order to show a good, bold pattern, the steels used in piece have to be chosen for their etching characteristics. Steels high in manganese tend to etch black. Steels high in chromium tend to etch bright. Steels that aren't particlarly high in either one tend to fall somewhere in between.

My favorite piece of music, of all time, bar none, is the final movement of Beethoven's 9th. Many people are probably more familiar with the translated version that you may find in your hymnal at church: Ode to Joy. I enjoy a lot of music from a wide variety of styles, but nothing gets to me like that piece. When it's on, I can close my eyes and hear the angels singing along.

Interesting. I'm not sure what to make of that.

No, it was based on the fact that Hago's gph ratings for its nozzles are rated at 3 psig of air: http://hago.danfoss....33_VDDZE222.pdf The same seems to go for Delavan nozzles: http://www.delavanin...catalog_New.pdf But if you look at the data for standard nozzles that use pressurized oil, they seem to be rated at around 100 psi of oil pressure: http://hago.danfoss....DF/VFDZB122.pdf So when BigCotton mentioned 3-7.5 psi to run an oil burner, I assumed it must have been oil air pressure through a siphon nozzle, not a traditional pressurized oil nozzle. Did you try your burner at really low (5 or less psi) pressures?

One thing about those siphon nozzles is I believe that their GPH rating is for a given air pressure. I don't know what happens if you turn up the air beyond that pressure. I would expect that at least up to a point you'd get more fuel flow, although I don't know if it might start to cause some problem at a certain point.

Are you sure he wasn't using a siphon nozzle? 3-7.5 psi of air pressure to run a siphon nozzle sounds about right. But you need a compressor for that.

Say you have an oil tank with a diameter of about 12" (an old propane or freon tank). The surface of the oil will be 113 square inches. Atomizer nozzles are designed to work on something like 100 psi. To pressurize your oil to 100 psi you'll need to supply 100*113 = 11,300 pounds of force to your piston, a tank that can handle it, and seals on your piston that can handle it as well. Not to mention a precise piston/cylinder fit, that sort of thing. If you reduce the surface area you need less force, but your fuel tank starts to get funny dimensions -- really tall and skinny. Some folks here might know how to build what you want to build. To me, it sounds hard. Mechanical atomization has been tried a number of different ways. None I've seen have worked very well, but that's not to say you can't come up with something. Other possibilities people have considered to pressurize oil for atomization have included scrap auto parts -- power steering pumps, fuel injector pumps, that sort of thing. Again, all discussed ad nauseum at the other site.

Glad to help. Oil burners interest me. I've been reading about them -- and following attempts to build a good, reliable, simple, cheap waste oil burner for foundry use (which should also work fine for a forge, of course) -- for several years now. I built a Brute style burner five or six years ago. I wasn't very satisfied with it, but I did learn that it's possible to produce genuinely scary amounts of heat by burning oil. Someday I'm going to make some crucible steel, and that can get very expensive if you're burning propane. When that day comes, I expect I'll use an oil burner based on a siphon nozzle like the Hago referenced further back in this thread, or a homemade version of it -- unless, in the meantime, someone comes up with an oil burner that's cheaper/simpler and just as effective.

Here's an article on piercing the corporate veil. Good reading for any small business owner. http://www.nolo.com/legal-encyclopedia/personal-liability-piercing-corporate-veil-33006.html

The Brute requires a preheat. You will not get atomization with just a blower, using any design I have seen. That'd be the Holy Grail of oil burners. Hasn't happened yet. If you want easy atomization, get a used household oil furnace burner. Depending where you live, it may be free. Otherwise, look into the evaporator burners at AlloyAvenue. That blower is probably more than enough.

Sure. Hope it's helpful. How you can do what, exactly?

Ceramic suppliers sell SiC by the pound, although you may have trouble finding some of those grits. I would bet the stuff for ceramics is more pure than blast media, too. (I wouldn't bet a lot. I could be wrong about that.)

Yeah, it'll work -- with a couple caveats. First, you'll need to preheat the forge to a nice orange with something that burns much more easily than oil; propane is a very common choice. You can just inject it right into the tuyere and make a blown burner. Once the forge is hot you can turn on the oil and shut off the propane. (If you want to be able to ignite oil without preheating the forge, it needs to be extremely finely atomized or heated to the point of vaporization. Either of those requires a burner much more complex than what you propose.) Second, in my experience gravity-fed oil is hard to meter consistently. You're forever adjusting the fuel valve. I suggest you pop over to AlloyAvenue.com and check out the Burner Engineering forum. That's the highest concentration of oil burner devotees that I know of.

Acids are good at rusting steel. HCl (hydrochloric acid) and HNO3 (nitric acid) are both traditional for this. (Nitric acid is hard to get in the U.S. these days, because it's so useful in making explosives. But maybe things are more relaxed in Slovakia.) You can just seal your part up in a warm cabinet with a water source and open containers of nitric and hydrochloric acids. Leave it overnight and it'll have a layer of rust on it the next day.) A tent made of a plastic tarp would probably do. Obviously, you want to be very careful handling the acids, and avoid breathing the fumes. And I suggest you do this outside. If the fumes get loose in your shop, you're going to have rust everywhere.

Final addition: my instructions for rust bluing are crude at best. If you really want to get into this, Google "rust bluing" and start reading. You can spend a lifetime on the subject if you feel so inclined. :) There are lots of old books out there with in-depth info on this subject, and probably hundreds of formulas for the rust solution. (Some of them involve chemicals you're not likely to be able to get anymore, and wouldn't want to play with even if you could.)

Have seen that before, maybe here, but it's been a couple years. Thanks for re-posting it.

By the way, although a wax coat on top of rust bluing isn't a bad idea, non-stainless steel needs regular oiling, especially after it's been handled. That's unavoidable.

I am a big fan of rust bluing -- which, by the way, I believe to be a very old technique. It it's done well, it looks beautiful. It's also very durable -- vastly more so than heat colors or baked-on carbon (which is what you described). Essentially you cause the piece to rust lightly, then card off the loose rust with steel wool or some other very light abrasive. Repeat the process until you have a good, solid coating of tightly bound rust over the entire piece, then you boil it until it turns black. What you end up with is essentially the same as the "black oxide" coating you find on a lot of drill bits, etc. There are many ways to cause the rust. Probably the simplest is to get a rust browning solution. Rust browning is basically rust bluing without the final step. For example, Laurel Mountain Forge sells a browning solution: http://laurelmountainforge.com/ Birchwood Casey Plum Brown is another example: http://www.brownells.com/.aspx/pid=24772/Product/PLUM-BROWN This process is time consuming, but it works very well. The key to any kind of bluing is that the piece must be absolutely clean before you start, and througout the process. Any sort of oil on the surface -- even if it's just from your fingers -- will screw up the bluing.

That book is out of copyright: http://books.google....epage&q&f=false I love Google Books.

Thanks, Phil. I guess I need to do more networking on the empty drums; when I've needed them I've found them on craigslist, but far from free! (Although to be fair, they're a lot cheaper than buying the equivalent amount of sheet metal new.)

Thanks for the tip, Fe-Wood. I signed up over there and have already gotten a line on some DVDs that look like they could be very helpful.

Here's an English language page that goes into the same subject, although the method in the original link, above, seems to be more advanced and successful. This page hasn't been updated in years, so I assume he more or less abandoned the project. http://home.c2i.net/metaphor/mvpage.html

I've never done any significant sheet metal work, but I think I'd like to try playing around with it a little. For example, I had the idea of trying to raise a helmet for my seven-year old for next Halloween. My first question is whether anyone has any suggestions for cheap or free sources of sheet metal to practice on. My second question is whether anyone can recommend any good books on the subject -- sinking, raising, etc., generally, or armorsmithing specifically. I've already found some good videos on YouTube.

Well now Jerry, which is worse for files: taking a freshly forged blade, grinding off the scale, then filing, or taking a freshly forged blade and filing off the scale? :) Of course I know all about vinegar and the other chemical methods of removing scale, but there are times when waiting for the chemicals to do the job just isn't in the cards. Personally, I grind then file. (Sometimes I use a wire wheel to remove the scale, which is probably the best non-chemical solution as far as the files are concerned.)

Very impressive work! Thanks for posting those.