Ultimate Guide to Making a Cheap but Effective Aluminium Forge.

There are many guides and many ideas I've collected and, being that I completed this (the first one... I made a completely new setup just for this instructible... you should feel special.) within two days and most importantly... cheaply.

My cousin /assistant / camera man and I created this instructable so we could share our wonderful smelting smelting experience and win the hearts and minds of the instructable community.

DISCLAIMER

This instructible includes fire and molten metal.
BE CAREFUL and USE SAFETY EQUIPMENT!

Also; If you mortally wound yourself while duplicating this instructible, please delete this from your history internet history before dieing. i don't want to be held liable.

BACK ON TOPIC!

We shall begin.

Step 1: Parts / Tools

In retrospect, the parts / tools list quite long but it should be things that are easily available.

The most expensive thing was the torch. I'm really cheap but it turned out to be a rewarding investment.

The other parts are as follows:

Quick Setting Quickrete (I got a 20 lb bucket for under 10 bucks)
Something to mix the Quickrete in
Something to stir the Quickrete with
Large Coffee Can (6 inch)
Small Coffee Can (4 inch)
Hack Saw (or any metal cutting tool)
Drill (or metal punch or improvised hole making tool)
An empty 14.1 oz propane tank (make sure it's competently empty)
Scrap steel bar like from a printer, about a foot long (you can buy 5/8 steel bar at lowes)
A sharpie (or any marking tool)
Tape
Cardboard
Short (about 2 or 3 inches) iron or steel tube that the torch head fits in. (optional)
A ball peen hammer (any hammer will suffice)
Some propane gas (i buy the ones for camping stoves because their $4.38 for a 2 pack of 16.4 oz tanks.)
An oven (optional)
A vice. ( kinda optional. you could find another way but i find the vice necessary)
A mini muffin tin (optional. you just need something to pour the aluminum into.)
Some cheap thin steel wire (1/8 diameter max. but strong enough to hold some weight)

Comments

[Snidely70448]

Vise, not vice. Vise is for holding things, vice is for having forbidden fun.

[pheenix42]

I'm curious, how durable is the Quikcrete as a furnace refractory?

[jakeuplink]

You need to mix the quikrete with fire clay (8 bucks a bag at home depot, silica sand has a lower tolerance but can be used also) which will up the tolerance of the furnace max temperature. also I would advise vibrating the mixture for a few minutes before you have it set. (air bubbles can be potentially explosive, which is why you wouldnt use traditional concrete)

[pheenix42]

Sounds good, but what ratio of fireclay to Quikrete?

[ClayOgre]

Maybe somebody's already mentioned this, but I kind of wonder about your advice to "have water handy". With the temperatures involved, water tends to turn instantly and rather violently to steam, which can be quite dangerous. If things get out of hand, I would think dumping a bucket of sand (dry) on things might be safer. I've built and operated Dave Gingery's charcoal furnace. The only time I ran into trouble was when I melted a chunk of what I thought was pot metal from an old washing machine. It had some magnesium in it and things got rather exciting there for a bit. Water was not effective, neither was throwing dirt on things. It just had to burn itself out. There were clouds of "zinc smoke". Not good. Fortunately I was outdoors.

[smiley G.I JOE]

for insulation you could use sand or dirt.

[foxworrior]

hello, i really like the instructable and i will try it but i want to know, will a kitchen blowtorch work to heat up he aluminium?

thanks

[shakeval]

if you want a more even distrobution of heat, try making a cone, bout an inch or two high and wide enough you can slip it in and try it, your crucible will rest on the point and the heat will be able to whip around the bottom edge with a lot more exposed metal

[cowscankill]

My ingots were cast in a muffin tin but didn't come out....at all. I had to destroy the tin to rip them out because they were essentially soldered to it. Any idea how I can prevent this?

[{Havoc}.Goliath]

Try coating the tin with soot, like from one of these http://www.instructables.com/id/Easy-and-cheap-Oil-Lantern/
I had the same problem, but with this it popped right out, easy as pie.

[cowscankill]

Thanks! You're the first person to give me a reply!

[{Havoc}.Goliath]

no problem :) just dont try it with copper, I think its too hot so it burns away the soot and sticks anyways, very annoying

[cacci]

Could you melt salt (NaCl) like this?

[ElFantastic0]

yes, you can; however, depending on your objective, you may achieve poor results. Melting salt in a steel crucible will contaminate the salt to some degree (and it tends to eat up the crucible). Also, like the prior response suggested, avoid melting wet salt. The issue isn't so much that the salt will explode. It might bubble a bit as it melts, but the majority of the water will be lost before the salt is even able to melt. The problem is if you're trying to melt a mixture of salts in correct proportions by mass (e.g. to make fluxes). Seemingly dry salt stored in permeable containers will contain a remarkably large amount of water. This will offset any attempts to weigh out the salt charges. The only way to fix this is to dry the salt by heating it. Last method i used was to alternately roast and grind the salt, though a prolonged roasting would work too.

I know these are old comments, but i reply for the sake of anyone who ever hits this via google (like i did)

[lasermaster3531]

sure. you could melt salt in this thing, but make sure that there's no i repeat NO water in the salt. if there is, it might explode. maybe use something else other than the steel crucible or use one only for salt, because it might do something weird if you try to melt something else like aluminum in it, because aluminum's melting point is higher than salt's boiling point. also, don't heat it red hot. use an IR thermometer and get it to 900 deg Fahrenheit, but not lower than 800 and not higher than 1000.

[curvy77]

when i melted my aluminum cans (all i had and quite a bit =) ) there was lots of slag at the bottom and it fused with my crucible. pushed it down with stick adn squeezed out enough aluminum for 1' by 4' of aluminum ingot. slag at bottom normal?

[mmrakozy]

This crucible doesn't seen far fetched, but what about the holes in the bottom?

[coocooachoo568]

Truthfully, i dont like this ible. sorry. i thought it was REALLY cool, but it turned out to be not. i made this thing EXACTLY like this ible said, but in the end, it failed epically. i even had the same crucible as him.  nothing melts! I tryed aluminum cans to a small aluminum pipe. all that happens is the aluminum cans and pipe turn a goldish brown and never melt. is there any possible way to fix this? i have a top and everything. i dont see how this works. HELP!

[Twitcheth]

How hot is your torch burning and what material (steel) is your crucible? Heat passes differently through different metals. Also a good way to tell if your torch is hot enough is simply if you see lots of flames theres not enough oxygen and not enough oxygen means it isnt burning as hot as it could be.

[curvy77]

i dont know about using gas to melt it but wood and charcoal work great for melting it. mostly wood. i used the last of my embers from a steel knife craft and i melted 3 aluminum cans in a soup can before the flame went out. (i had a blow dryer to help fan the flames)

[dcarr1]

what gas you using?

[coocooachoo568]

propane

[Firestorm_101]

I am just now getting into this sort of stuff but what may help is, in order to do larger pieces of metal like pipe, you must first already have a pool started. Cans are good but they must be denser otherwise they will oxidize and never burn. Cut off the ends, smash the tube flat, and fold it up into little square strips we'll call feedstock. It will be thick enough to melt effectively but not too big as to radiate all of its heat away. Good luck, hope this helped.

[Data643]

You could spend all of your time saving up for a lathe. Or... you could just cast your own using David Gingery's Books. I have his metal lathe book & it's awesome.

[r_harris2]

I know this is long time later to reply, but I thought I would post the counter-point to this. I think the Gingery lathe is a good project in itself, if that's what you want to do, but if you want a lathe, probably quicker to buy it. Think about it, a decent 7x12 lathe plus some tools is about $400. That's only six weeks of working part-time at a minimum wage second job. Not as enjoyable perhaps, but much faster than starting from scratch, casting metal and hand scraping the ways on the lathe, etc.

I considered the build-my-own approach, but I wanted to make some stuff, besides the lathe itself, and I am glad I bought the lathe. Once I had the lathe, I did a lot of little things that were really fun and easy. I doubt I would have finished the Gingery lathe. It is a pretty big project in itself, and I notice that you can find lots of web pages showing the start of a Gingery lathe, but last time I looked, I could not find ANY of a finished Gingery lathe and something made with it.

[Data643]

I do see your point in that it would take less time and require less work, but a Gingery Lathe would cost far less. Where have you seen any 7 x 12 metal lathes for under $400? The cheapest I can find them for is about $550 for a 7 x 10. Here is a link to a near - completed Gingery lathe machining its own tailstock ram.

[r_harris2]

Yikes! I am in shock. I didn't realize they had gone up so much since I bought mine. I am becoming one of those old guys who say "Back in my day sonny, you could buy..."

But I will STILL stand by the basic idea. Only go in for a Gingery Lathe project if you really want to build the lathe. If you want to turn metal, a few months of part-time work, say $750, will get you a better lathe, with a 3 jaw and a 4 jaw chuck and a selection of cutters, boring bars, a dial indicator set and a few other starter items.

Oh yeah, with a little effort and talking to your favorite garage saler / flea market fanatic and you might get a call on a saturday morning...

[panzuman]

also take a nail and hammer and smash it through top to release gas then if you have it use an air tank (bike pump would probablly work to) and pump air for at least a min then you can use all the power tools you like :)

[sbeck3]

Perhaps puncturing a propane tank with a nail is not a good idea? Just attach a torch and burn the remainder until it uses the last of the gas on its own.

[mcivor]

NOTE: Be VERY careful when cutting a propane tank open, and for the love of God do NOT use power tools! Some guy in my area was cutting one once, and didn't realize it wasn't completely empty. Propane had flowed out of the tank and pooled around his ankles. Didn't help that he was using a circular saw to cut it. I'm sure you can picture the ending here.

[lburrow]

@mcivor

Reading your post makes me thing that having a fan blowing on the floor is a good idea too to disperse any remaining propane that does come out before it's concentrated enough to ignite.

[lostowl05661]

I just used my forge for the first time and it worked GREAT!!! I couldn't find the right torch that the author had used, so I got a benzomatic grass burner and bent the shaft to fit. See below. I have a question, though. There seemed to constantly be a skin of aluminum on the top during the melt. Is this normal surface tension or was it not hot enough?

[k7classicrockfan]

This might be slag (impurities (paint, non metal material) from what you are melting, if you are melting pop cans, this is sure to happen. don't worry though, you can simply take it off using a small metal "rake", to skim it off. Hope this answered you question.

[lostowl05661]

Also, what is a good space between the crucible and the refractory? Mine seemed like a lot of space, I may pack it in a little with fireclay.

[lostowl05661]

How hot a torch? I found that if the blue flame from the propane torch wasn't directly on the crucible, it wasn't hot enough, even with a forge lid. When I made the handle the crucible, it suspended the crucible about an inch above the inlet for the torch. Even after 15 minutes the crucible didn't heat to red hot. I put the crucible down on the base refractory and it heated right up. Also, I was able to put the can lid back on to keep some of the heat in. I think I'll have to do it that way and pour with channel lock plier. It must be that even the grass burner torch doesn't produce enough heat. Still, doing this project really helped me feel like I could do this. Next weekend's project: The Gingery Charcoal Forge!!!

[didgitalpunk]

you could use an oxygen-acetylen torch but don't. why? simple: it can make holes in 5mm tmpered steel sheets. OC2H2 torch VS crucible, well say bye to your crucible.

[hintss]

will a bunsen burner work?

also, ceramic and graphite crucibles

[John Smith]

That "skin" is dross, or slag. It's a layer of floating oxides and impurities on top of the real metal. You should skim it off after adding metal and before pouring. From my experience, I'd go right to propane, skipping charcoal. It's more expensive to begin with, but it's more rewarding in the end.

[lostowl05661]

Well, I'd need a better burner. i've seen some sites on the web to explain how to make a good propane burner. The bean can has been a problem, and I am out of propane bottle crucibles. The steel crucible I had doesn't get hot enough with the propane torch I have (which has now deteriorated beyond the point of safe use) So, anyway, I have my charcoal forge now, and I'll use that until I can make a decent burner for it, then I'll convert it to gas.

[John Smith]

Well, if you do make one, I can tell you what burner i made. It works great, very VERY sturdy. Charcoal is great, but I have to say, the second you use a good propane burner, you'll think you were dumb to even try charcoal. No comparison. BTW, I really think that this instructable needs to be renamed. ITS NOT A FORGE! Forges are used to shape metal, this would be considered a furnace. The whole setup; a foundry. Of course it could be used for minor forging (maybe, i probably doesnt get hot enough), but the name is Al Forge. So either way, its a furnace. The name should be "Ultimate Guide to Making a Cheap but Effective Aluminum Furnace" I disagree with 'ultimate', because it misses out on critical, key points of casting aluminum, and other non-ferrous metals. IM me, (AIM), at Alt Ctrller. Or Email at [e-mail]. Or comment back here. hope that helped