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I Forge Iron

Forges & Foundries


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Hi All,

I have been slowly going through your threads and trying to find out what the most efficient ways of building a production shops. I am a plumber/pipefitter/gasfitter. I have knowledge with natural gas, and propane. I have access to all the tools necessary as well as scrap metal.

I have questions that need some help with.

I am looking to get in to bladesmithing and random metal fabrication with steel, copper and so on.

What would be the recommended forge? Gas or coal, if gas, propane or Natural?

What size of a forge would a guy need?

Gas or coal

Melting down metals can I guy melt down aluminum motor blocks, copper pipe, brass fittings, railroad track, iron pipe etc? I have access to all this stuff.

I would like to also know about getting rid of impurities about the various metals. How does one go about cleaning your metal you recycle?

Hardening knives, is the a thread here that explains how to make one?

Sorry for the questions, I am just very curious. If there is good reading material like books that can explain all this i would appreciate it.

My great grandfather taught me how make basic knives when i was 14, then he passed away. Now the time has come to rebirth what has been taught and take it to the next level.

Thanks very much.


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Jaret; size and fuel depends on WHAT you are making; describing a knife forge won't be any help if you are working 1" sq stock into gates. Don't expect to have 1 forge to do everything. Forges are cheap compared to fuel usage so having a range of size can save a lot of money in the long run. So can you narrow down what "random" entails?

Foundry work: yes you can melt and pour your own metals. Most folks work with brass and Al as being easier to melt and work with. For cast iron look into a cupola furnace for a simple method. Melting steel is a whole nother kettle of fish and you would probably be better off just buying it in the basic shape you want (induction heated vacuum melters work good for steel to preserve the original properties but the cost is extreme!)

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Thanks thus far. Again I am a newbie. I am mostly curious about making knives and swords. I know I have to start with the rudimentary basics, but when I build something, I like to build it to last for sometime. What I am curious in then is what kind of forges say for making a katana style sword to your basic knife.

Thanks again.


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Jaret; when making a sword you do not want to heat more than you can work before it cools; so the major difference between a sword forge and a knife forge is thatn the sword forge has a port in the back to stick the metal you are not working on through and get the part you are working on in the hot spot (both solid fuel and propane forges).

Now if you had a powerhammer you might want a longer trough style forge as you will be able to work a longer area when it's hot. Digging a simple trough forge in the back yard will work for heat treating which is the only time you need the entire blade above critical temperature.

Probably 90+% of the forging done on a traditionally made katana is done during the processing of the tamahagane and so it's basically billet welding and so a forge optimized for that would work best. If you are working with modern alloys no welding is needed and so a well designed large knife forge with rear port will work.

You may well like to build for the ages; but isn't it rather a waste if you build stuff *before* you know what you like and want in a forge? Like building a 5 bedroom house before you decide to be a no child family? Relax and tell yourself that you expect to re-build your forge every 6 months to a year until you get it just right for you! Forges are rather consumables as well needing to be re-lined or re built on a regular basis. I just relined one of my gas forges and the other needs a new shell to go over the lining.

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There are a lot of things to be said against junkyard steel but, yes, it's certainly possible to make knives from recycled steel. Old files and automotive springs (leaf or coil) typically will make satisfactory blades. So will plow discs, sawmill blades, some smaller circular saw blades, some industrial bandsaw blades, old hand saws and bed frames. But with junkyard steel there are no hard and fast rules except that you won't know for sure if it's usable until you've done a little testing.

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Look up spark testing of steel and practice it with some "known values" like a good brand of file and some known mild or A36 steel.

One thing about junkyard steel is that you should always forge out a sample to test it for heat treating---so about the thickness of your avg knife blank at heat treat. Then looking at the spark make a guess if it would do best quenched in Air, Oil, Water or Brine and then try it and check the hardness with a file. If too soft (once you go through any decarb) move to the next more aggressive quench and try again. You want the one where it will quench hard but not crack. Once you figure out the proper quenchant to youse then you can draw temper on the piece slowly from end to end and check the hardness at each colour band and decide which is the appropriate one to temper to.

If you have a nice big piece like a coil or leaf spring one test should be good for all the blades you make from it.

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