I'm pretty new to metal working and just got the gingery book on making my own furnace. I've browsed through dozens of web pages on the subject and read every post I can and I have never seen anything mentioned about the legality of home shop foundrys. When I told my friend who works at a machine shop that makes aluminum horshoes he told me that it is illegal to melt aluminum. He talked to some other machinists he knows and was told that you have to have a proper license from the EPA and that if you were found doing it that the fines are quite extreme.
Am I getting smoke blown up my rear orifice? Or is there some truth in what hes telling me? I'd really like to build myself a home foundry but I do not want to do so if I need to get a permit to melt anything. I should also mention that I am in Pennsylvania outside of Philly, just in case these type of regulations vary from state to state.
Is melting aluminum illegal?
Moderator: Harold_V
Is melting aluminum illegal?
Been you to have any spliff man?
Re: Is melting aluminum illegal?
I may be wrong, but I think your "friend" is smoking something illegal. To my knowledge, there are no controls on melting aluminum on a private, hobby basis. Should you get involved in a commercial operation and melt dirty stuff, painted, oily, like that, you would likely have more than your share of trouble with EPA with emissions, however. You'd want to avoid that situation anyway, because that introduces hydrogen to your metal, which manifests itself as little tiny voids (bubbles) in the castings. Keep dirty metal out of your operation as much as possible.
Build your furnace and enjoy! When you do, keep in mind that you may want to melt brass in the future, so be sure to build a furnace that is capable. Not too large, not too small, and able to melt metals up to 2,000° F.
Melting gray iron presents its own problems in a crucible furnace, so I'd likely try to discourage you from that endeavor. You could build a small cupola to handle that issue when you feel the need.
Good luck!
Harold
Build your furnace and enjoy! When you do, keep in mind that you may want to melt brass in the future, so be sure to build a furnace that is capable. Not too large, not too small, and able to melt metals up to 2,000° F.
Melting gray iron presents its own problems in a crucible furnace, so I'd likely try to discourage you from that endeavor. You could build a small cupola to handle that issue when you feel the need.
Good luck!
Harold
Wise people talk because they have something to say. Fools talk because they have to say something.
Re:melting aluminum-
Hey Harold-
As I stockpile various scrap aluminum for the future,I have wondered if there is a problem with aluminum that has spent several years bathed in oil. I'm talking about cylinder head parts , etc. One guy recommended used transmission cases. If these parts are cleaned first (hot tanked, glassbeaded, etc) are they suitable, or does the oil have the ability to penetrate the aluminum. Just wondering...
As I stockpile various scrap aluminum for the future,I have wondered if there is a problem with aluminum that has spent several years bathed in oil. I'm talking about cylinder head parts , etc. One guy recommended used transmission cases. If these parts are cleaned first (hot tanked, glassbeaded, etc) are they suitable, or does the oil have the ability to penetrate the aluminum. Just wondering...
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Re:melting aluminum-
Hanz,
One way to get away from hydrogen problems with oily cast aluminum is to "burn out" the aluminum before the actual melting. We used to accomplish this by setting aluminum on top of the furnace next to the top exhaust to preheat the metal. Once up to about 700 degrees, the oil evaporates or burns off.
Finally, there are chlorine tablets available from foundry supplies that go in a stirring rod with a small cage on the end. The tablet generates chlorine gas that scavenges hydrogen from the aluminum.
One way to get away from hydrogen problems with oily cast aluminum is to "burn out" the aluminum before the actual melting. We used to accomplish this by setting aluminum on top of the furnace next to the top exhaust to preheat the metal. Once up to about 700 degrees, the oil evaporates or burns off.
Finally, there are chlorine tablets available from foundry supplies that go in a stirring rod with a small cage on the end. The tablet generates chlorine gas that scavenges hydrogen from the aluminum.
Re:melting aluminum-
Another question- As I machine different aluminum pieces, it is quite obvious the different qualities in them, I believe mainly due to different silicon (sp?) content. Now, I don't even know what I plan to cast in the future, I would guess maybe self designed (large model) engine components, but is alloy or silicon content something to worry and/or think about in collecting this scrap, or is this being too nit-picky? Thanks
[url=http://www.hanzenginehouse.com]www.hanzenginehouse.com[/url]
Re:melting aluminum-
In addition to the method Jim mentioned to remove hydrogen from aluminum, one can bubble nitrogen through molten aluminum, which accomplishes the same thing. A lance is placed to the bottom of the crucible after it has been superheated and removed from the furnace, and nitrogen is bubbled through the heat until it has dropped to pouring temperature. This was the system used by one of the foundries that I used to frequent as a boy.
Harold
Harold
Wise people talk because they have something to say. Fools talk because they have to say something.
Re:melting aluminum-
Everything I've read indicates that one should use scrap that is similar to what is being cast. Sort of makes sense considering aluminum is alloyed for particular properties for the application. I think I'd follow the rule as much as possible, but can't imagine the aluminum cops would show up if you used pistons to cast a head. [img]/ubb/images/graemlins/grin.gif"%20alt="[/img]
Harold
Harold
Wise people talk because they have something to say. Fools talk because they have to say something.
Re:melting aluminum-
There are a lot of alloying elements used in aluminum to give specific properties. Mixing them can produce some surprising results, some of them rather unpleasant. The silicon you mention needs to be kept in a fairly narrow range. Silicon allows precipitation hardening of the alloy. Too little and it won't harden, too much and it forms abrasive sand grains in the material. This feature was what shot down the cast aluminum cylinders in the Vega back in the 70's.
They also add zinc, magnesium, copper and iron for various properties. The alloys range from gummy to glass-like and the precipitation hardening grades come out of the mold gummy and become glass-like after heat treat. If you are going to make something critical, cast a test coupon in the same mold to allow you to test for strength, ductility hardness and heat treatability.
They also add zinc, magnesium, copper and iron for various properties. The alloys range from gummy to glass-like and the precipitation hardening grades come out of the mold gummy and become glass-like after heat treat. If you are going to make something critical, cast a test coupon in the same mold to allow you to test for strength, ductility hardness and heat treatability.
Re:melting aluminum-
Sooo...to cut down on R&D time...is there a short list of 'desirable scrap,' as well as undesirable?
[url=http://www.hanzenginehouse.com]www.hanzenginehouse.com[/url]
Re:melting aluminum-
Anymore it is difficult to separate out the types. I do two things to get past alloying issues.
Break the scrap casting and see how it deforms and what the break surface looks like. Put similar scrap together, and I usually won't turn down anything meltable.
Second, design for the worst case and assume you got the worst possible material. That's where the test coupon comes in. If the part is important, break the test coupon and look at the deformation, toughness and fracture surface. This is just insurance that you won't drop something on yourself if the casting breaks or hurt someone. The part will be heavier than probably necessary, but it's safer.
Among favorites of people I know:
Aluminum car wheels
Aluminum pulleys
Just about any aluminum extrusion.
I use mostly aluminum die cast material containing 12%zinc from scrap parts from a known source. There is a lot of skim off the surface, but it has known strength properties, machines well and flows very well. I'm having to watch this one as some of the parts are being converted to magnesium with 6% aluminum, which doesn't work with my equipment.
Break the scrap casting and see how it deforms and what the break surface looks like. Put similar scrap together, and I usually won't turn down anything meltable.
Second, design for the worst case and assume you got the worst possible material. That's where the test coupon comes in. If the part is important, break the test coupon and look at the deformation, toughness and fracture surface. This is just insurance that you won't drop something on yourself if the casting breaks or hurt someone. The part will be heavier than probably necessary, but it's safer.
Among favorites of people I know:
Aluminum car wheels
Aluminum pulleys
Just about any aluminum extrusion.
I use mostly aluminum die cast material containing 12%zinc from scrap parts from a known source. There is a lot of skim off the surface, but it has known strength properties, machines well and flows very well. I'm having to watch this one as some of the parts are being converted to magnesium with 6% aluminum, which doesn't work with my equipment.
Re:melting aluminum-
That's interesting that you list extrusions, I know I read somewhere that that person felt they were no good, but I trust your experience with this. Hanz
[url=http://www.hanzenginehouse.com]www.hanzenginehouse.com[/url]
Re:melting aluminum-
The person is correct in that extrusions are basically a soft, low alloy aluminum. Machinability on the castings is not particularly stellar and the strength is relatively low. Ductility, however, is good.
As long as you design for the material, you will usually come out well.
By way of explanation, I used to do engineering for nuclear reactors and one of the hard and fast rules was that core lifting hardware had to be designed to use soft low carbon steel. The reason came from a situation where the core lifting rig for a refueling many many years ago was designed such that it used a hardened high strength pin for the crane attachment. Some QA guys doing a survey of the supplier just happened across a piece of steel sitting in a tray in QA storage and decided to trace the pedigree as part of the survey (not related to the lifting gear).
After chasing it down, they found it was for the high strength pin, but it hadn't been used on the job. They started asking questions and finally tracked the job for the pin down to the point that it had been installed for soon upcoming work at a shipyard.
The pin got pulled at the yard and they found out that somehow the pin that was installed had been made from cold rolled steel and would have sheared if it had ever been used. The final fix: design for cold rolled and if you get something better it adds to the safety factor.
My reason for liking the extrusions is that they are cheap, baseline strength, relatively ductile (not brittle) and tolerable for machining with WD40 as the cutting oil.
I'm of the opinion that if you intend to make something critical to safety, buy raw material to a spec and avoid contaminating it or else bite the bullet and test samples from the melt.
As long as you design for the material, you will usually come out well.
By way of explanation, I used to do engineering for nuclear reactors and one of the hard and fast rules was that core lifting hardware had to be designed to use soft low carbon steel. The reason came from a situation where the core lifting rig for a refueling many many years ago was designed such that it used a hardened high strength pin for the crane attachment. Some QA guys doing a survey of the supplier just happened across a piece of steel sitting in a tray in QA storage and decided to trace the pedigree as part of the survey (not related to the lifting gear).
After chasing it down, they found it was for the high strength pin, but it hadn't been used on the job. They started asking questions and finally tracked the job for the pin down to the point that it had been installed for soon upcoming work at a shipyard.
The pin got pulled at the yard and they found out that somehow the pin that was installed had been made from cold rolled steel and would have sheared if it had ever been used. The final fix: design for cold rolled and if you get something better it adds to the safety factor.
My reason for liking the extrusions is that they are cheap, baseline strength, relatively ductile (not brittle) and tolerable for machining with WD40 as the cutting oil.
I'm of the opinion that if you intend to make something critical to safety, buy raw material to a spec and avoid contaminating it or else bite the bullet and test samples from the melt.