Forging With A Kiln?

[mik32176]

Hello, im new and had a couple of questions about forging. first im only going to be melting aluminum. so I was wondering if a kiln would work or if I would have to get a small forge. Im leaning torwards the kiln also because I hear you can heat treat steel with it?(comments) last I was wondering if there was a special way to forge aluminum. I hear people saying if you forge it right, you almost cant tell it was cast. Is this true? any info will help, where to get a forge, kiln, supplies etc, I would very thankful.

[debogus]

HERE
Some moreHere

Dave

[scottsss]

Just to ask, the kilm electonic or gas? Front or top loading?

I bought a electronic kilm to experiment with making Mokume. (You can google it.) Plus other projects. The problem I found with using it as a forge is being top loading you have to make another top for it with an opening. Since the time it takes to lift the top off, nove it to the fire bricks and grabe your piece for hammering is a pain and alot of motion.

A propain fired forge with a front opening, puts out a lot of heat, you can easily see the piece your working on and if it is just a quick reheat so you can finish forming it you can leave the tongs on it and just pop it i the forge for a second.

I've not trid aluminume. I've only done copper, brass, nickle silver, mild steel. I've also played with a charcoal forge. But it is something that you should think about.

Somehting else you can sort of play with is if you can get a decent blower, I dug a trench in the back yard and put charcoal in it. Kingsford if I remember correct. I was able to forge string steel. Even managed to melt a bit of it with this setup if you just want something to play with.

Oh if you do decide on the electric route, if you have 220v you'll not take as big a hit on your power bill. I went 120v and when I run the kilm for an extended period of time I can see the difference vs months when I do not run it. So if I had to do over again I would go 220v.

As for the forge, their are plans floating arounf the net to make one. Fire briks and liner can be bought from a number of different places. I've even seen one made out of an old propane bottle. With some fiber liner inside. So it is all do able.

[mik32176]

debogus that was an awsome link, thank you. scottsss I was thinking electric, only because I didnt want to deal with refilling the propane. good advise on the 220 i didnt think of that. I do have 220 and was going to buy the 120 model not even thinking. all good info guys thanks alot if you think of anything else just let me know. mike

[Mcgyver]

sounds like what he wants is a furnace or oven...nothing wrong with being a newbie but the nomenclature is a little confusing.

forge: something you heat metal up in before forging, as Dave described
forging: beating away on said metal, i.e. blacksmithing
furnace: something you place a container of metal in to melt it prior to casting, usually using some kind of gas for fuel
casting: pouring molten metal in to a mold then letting it cool
oven: a little finer temp control than a furnace, nice ones have controllers that ramp up, soak and ramp down controls allowing a variety of heat treating processes, can be used for melting smaller quantities of non ferrous
kiln: something pottery peeps use, definitely not part of a he-man metal working type's lexicon.

Well ok, not sure about the last one.

PS, having an oven would be a real luxury, but most of us home shop types regularly heat treat home made tooling with nothing more than a pair of pliers, propane torch and a tin of old oil.

[murphy625]

Gas and Propane will most likely be much cheaper than electricity... Electricity is a horrible way to heat things.. Very expensive..
Disclaimer would be that electricity does have certain advantages.. Its clean, does not require venting, and quiet as no blower fans are running. But its expensive..

And then there's the fact that its expensive.. Did I say that already? LOL

Murphy

[TinkerDJ]

You can very easily and cheaply build yourself a setup to use as a forge and a fournace. I built my aluminum melting fournace to have two bricks come out right in the middle so i would have a through way for forging steel. I've only used it a few times and use the fournace for casting aluminum alot more. If your set on getting a kiln make sure it is 220 for sure, and get the appropriate cabling for it. A way to cheat and not have to buy another breaker is to get a cord end for a dryer and then unplug the dryer and plug in your kiln. Here is a sight for a homemade electric fournace.

http://www.dansworkshop.com/The%20New%20and%20Improved%20Lil'%20Bertha.shtml

I use propane and a 30lb cylinder will last me for more then 5 or 6 melts. Some times less sometimes more, when i'm using the burner to break or smelt aluminum parts i've had it running at 10lbs pressure for 5 or 6 hours straight. In total it only cost me around a hundred dollars to build my fournace, and i have been very pleased with the results. Another idea is Ron Reils forges.

http://www.frontiernet.net/~gnreil/design1.shtml

[mik32176]

but anything about casting aluminum back to origanal? am I mistaken about what I heard? specific kind of aluminum maybe? and what aluminum should I use to cast with for practice? thanks, mike

[murphy625]

I'll jump in again.. (but remember I know very little about this stuff)

As for the quality of the finished product, I would think that is going to almost completely depend on the quality of the mold.
Also, your comment about heat treating steel in an electric setup is correct.. But it can be done with a gas setup also.. It's all up to how stable you can get your temperature and how well you can control it. "Heat Treating" is a very wide term.. Kinda like saying your getting into the Painting business.. It doesnt denote what your treating, or for what purpose your teating it..
Heat treating anything means bringing the temp up to a specific point within a specific amount of time, holding it there so long, and then lowering to a specific point within a specific amount of time and sometimes repeating the process. (sounds complex but just about any common programmable temperature controller can do this. (Sometimes called process controllers). Your working temperatures and accuracies needed will dictate to you the type of thermocouple you will need.. (IE Type K, Type J, RTD, etc etc).

As for building a furnace or kiln, I can help you out to a point with design work.. I have build several ovens that could swallow a pickup truck with temps ranging from cure (300-600 degF) to temps ranging in the burn-out areas (600-1400).. The burn ovens are built with a fireboxs that are much like any furnace I suppose.. The temps I designed for are around 2800 deg F as there was direct flame impingment in these areas. I used a ceramic fire-brick and ceramic cloth that was backed by a "Fiber wool" type material called FBX2900.

As for what kind of aluminium grade, I would start off with whatever scrap I could find.. Of course, if you think about it, perhaps it doesnt matter.. Its not like you cant melt it back down and use it again if you mess up..

Murphy

[mik32176]

as far as the heat treating goes, truth is I dont even know yet. what I dont want is to buy or make the wrong thing. I want one multi purpose machine. maybe even something that I could use for curing powder coating?.( i know not gas!! I have some cnc equipment in my garage and I want to make-------- stuff. maybe gears, as you can tell Im not sure about that either. Im trying to find my nitch. but my space is limited. My shop is in a two car garage, so at least I got plenty ventalation. and the garage has its own 100amp service. I have a 50 amp welder outlet that is avalible for power.has to be single phase. im not to worried about the electric bill. if it goes up a hundred bucks a month so be it. After talking with you guys Im pretty set on a electric furnace. I know some of you advise against, but im just to lazy to deal with the propane tank thing. so if I were to buy? does anyone know where the best spot is that I can get a front load furnace and how much apprx.? also Murphy how much do you think it would cost to build one? a very thankful mike

[Mcgyver]

check jewelry supply houses

[murphy625]

Give me some specs..

How much space do you want inside? How hot do you want to get?
I WOULD NOT GO ELECTRIC...
You can cure powder coat with gas heat.. Where did you hear you can't from?

Gas is also much easier to hook up than electric is when you start getting into high KilloWatt / BTU requirements. And.... you will have much fewer problems with gas than electric.. Any boiler burner with standard controls can be used and purchased for a hundred bucks or so.. ok.. enough with that..

*a few tips on oven building.
Size and temperature is everything as far as the costs go..
Be ready to do alot of sheetmetal work..
Dont buy cheap refractories or insulations...
Make sure you have VERY GOOD fire protection (automated sprinklers are highly recomended)

Do you have the ability to machine and shape hard foam? If you do, you can machine your own ceramic insulation parts which will go along way in making doors or access points...

You can also cast your own ceramic shapes.. I've never tried it but I read somewhere they sell a castable formula or something.. Im also not sure what the temperature is rated for but the stuff you will need should go to your required temperature + 30% over that...

Be very carefull with high temperature ovens.. When you open a door, an invisible cloud of very hot gas can light a low ceiling on fire quite easy...

Murphy