Backyard metal casting

[akinrog]

I found the following while surfing the net. although I am not sure under which forum topic I should post this (as a new thread or under an already existing thread), I think this fits for the tools, techniques and plans main topic. However, it is very convenient to put this thread under links and literature main topic. So, I would be very grateful if moderator of this forum moves its location if it does not belong here.

Anyway back to what I would like to post. Since many members of this E&W forum is interested in constructing improvised stuff, I thought it is necessary to get a knowledge of metal casting. I came across the following web site during my google search.

http://www.backyardmetalcasting.com/index.html

I search the forum but it did not yield any results regarding the above given link.

The site in addition to metal casting, describes /contains information about how to make a lathe which may be very interesting and somebody better in engineering than me may turn it into a rifling machine.

Anyway enjoy it. :)
Edit : Minor typo corrections.

[j_dmillar]

I think this might have some value connected to the topic on making key duplicates. I've been interested in this for quite some time, I've built two primative charcoal furnaces, and can tell you that both aluminum (assorted scrap, I think my last batch was some old heat sinks) and lead (old wheel weights, free) cast quite easily. Zinc will be my next metal - you have to be careful to avoid the fumes, you'll get metal fume fever. Sand casting seemed strange the first time I heard of it, but it actually works quite well, although I'm planning to experiment with some kind of ceramic for lost-wax castings.

Oh, one other thing... in case you plan to mess with casting lead, two points: 1) its rather toxic, avoid the vapours, wash your hands, etc. 2) Wheel weights are great, but don't waste time removing the steel clips, they will float to the surface.

[paintbatt]

Has anyone here tried this with metals such as titanium. i wonder if it would work?

[aikon]

Download the "Charcoal Faundry - build your own metal working shop from scrap" from the ftp. This little book is an excellent introduction to melting metal and greensand casting. The other titles of the series show you step by step how to build your own lathe, milling machine etc.
Here is the website of a man who build the Gingery lathe: http://ourworld.compuserve.com/homepages/williamk/homepage.htm

[Mephistopheles]

oh man, I love that site; I saw his "organic lipid thermal reactor" thing where you just use old used motor oil as the fuel (which I have a lot of stored around my garage), and gravity for pressure. So I emailed him asking about the dimensions that he used for it, if and once I get my hands on some refractory, I'm going to make one of those. I'll post the dimensions of it once I get back home and find the email. (if you want it) I've been thinking about making a combination oil burner/charcoal furnace, or something like that. oh, and, do you think that I could use a shopvac's output instead of a squirrel cage fan blower? if anyone has any experience with using shopvacs in this situation.

[Bugger]

Has anyone here tried this with metals such as titanium. i wonder if it would work?.

The melting-point of titanium, 1,800ºC, is much too high for the average back-yarder to achieve with amateur furnace equipment. Besides, a container and moulds of materials with even higher melting-points, and not subject to oxidation or nitridation (unless an argon atmosphere could be provided, which would make graphite practical as such a material), would have to be obtained, noting that Ti is liable to nitride embrittlement in the presence of nitrogen.

Even steels are beyond the reach of most amateur metal-casters, for the same reason; the m.pt. of pure Fe is 1,535ºC, although most carbon steels, cast irons, and alloy and stainless steels have somewhat lower melting points, as low as 1,075ºC in the case of white pig iron (which would be about the eutectic composition of the Fe-C binary system). Cementite, Fe3C, the chief constituent of gray cast iron, which has the highest practical carbon content, has an even higher m.pt, 1,837ºC.

However, metals like Zn (419ºC), Sb (631ºC), Bi(271ºC), Pb(328ºC), Sn(232ºC), Cd(321ºC), Al(660ºC), and alloys (especially eutectics) of them like solders and pewters, are well within the reach of amateurs, and, at least when handled in bulk (not finely powdered), are not liable to significant oxidation or nitridation. Mg(651ºC) is somewhat more hazardous from the oxidation point of view. Steel containers and moulds can be used for them.

Bugger.

[Mephistopheles]

this is a message that I got from the owner of that page, I emailed him asking him about his Organic Lipid Thermal Energy Reactor. I didn't ask him, but I hope he doesn't mind that I posted this information, it's some answers to some questions that I sent him:

The Organic Lipid Thermal Energy Reactor" (OLTER) works on the same
principal as the "Ursutz derived" burner but is shaped a bit differently to
improve combustion and it has a better air/fuel intake system. The burner is
basically just a sheetmetal box lined with the same type of refractory that
the furnaces are lined with. The refractory is about 1" thick. The inner
chamber of the burner is rectangular about 6" long and 4" wide. The
rectangular shape seems better than a circlur chape because it produces more
air turbulance which speeds the combustion. The air and oil lines are just
as you guesed they are. There is no oil nozzle and the oil is not
pressureized (the system uses gravity to carry the oil). A valve simply
controls the speed at which the oil drizzles into the airstream which blows
the oil into a semi-mist for easier ignition. The burner is started with a
nice hot wood fire (sticks, etc) in the burner's inner chamber. After about
5 minutes the burner is so hot that the oil fire is self sustaining. The
flame exit port is just a sheetmetal tube lined with refractory with a 1 or
1-1/4" diameter tunnel runing through it to carry the flame.

Ways to greatly improve the burner's efficienty:
1) Improve the oil's "atomization
2) warm the oil prior to it entering the burner etc..etc...etc... (this is
the experimentation phase).

[Bert]

Spent what little spare time I had this summer reading "De Re Metallica" and "The Pyrotechnia of Vannoccio Biringuccio", allong with "A Diderot Pictorial Encyclopedia of Trades and Industry" ... Backyard iron and steel aren't out of reach, but your neighbors had better be understanding or far away! Lots and lots of burning charcoal-

[Bugger]

Most of the above metals the melting points of which put them within easy range of backyard amateur founders are also fairly soft, and do not have the mechanical strength of steel and other more refractory metals. This rather limits their use, e.g. ruuling out most mechanical uses.

To the above metals mentioned in my previous post may be added Cu (m.pt. 1083ºC) and Ag (961ºC), which have melting points intermediate between these matals and those of Fe and steels. Some common brasses and bronzes melt around 885ºC.

Bugger.

[Skean Dhu]

I beg to differ, although you could use charcoal for melting steel, you'd go through loads of it. You can however melt small amounts of steel in a propane fired furnace or if your were serious about melting steel you could invest in a cupola furnace and a means to make or buy coke. but this would be a dedicated steel furnace and not much help for anything else. Also bugger what have you got against Al? Sure its a little on the soft side but for most intents and purposes its strong enough

[akinrog]

This is not metal casting in essence, however a little bit related, since it's related to metal machining.

During my google searches I found the following web site (http://easyweb.easynet.co.uk/~chrish/techindx.htm) where a considerable amount of information is provided on lathes, mills, drilling, etc. in short on workshops.
I am now leeching that web site and after completing it, I shall compress the files and upload the forum FTP.
I hope you enjoy it.

[HIM]

where you just use old used motor oil as the fuel (which I have a lot of stored around my garage), and gravity for pressure.....

If you join the Yahoo Waste Watts Group (http://groups.yahoo.com/group/wastewatts/files/Babington/Improved%20Babington%20Burner%20/) is a little quick write up I did on Improving the Babbington Butner design. It makes a nice little burner, but nothing like my new set-up.

Outline:
- obtain (1) empty party Helium tank (aprox the size of a 5 gal propane tank), and (1) small diameter tank.
=Drill a line of .375 inch ~ 3 inches above the bottom of the small diameter tank.
-Cut out the top of the larger diameter tank so that the smaller tank fits tightly into the larger one. Seat the smaller tank so its base is a few inches from the bottom of the larger tank.
-Punch a hole in the larger tank near the base that is large enough to attach a air supply (Exhaust of a shop vac, squirl cage fan ect).
-Fill the inner tank with used motor oil up to the holes.
-Toss in a solvent soaked rag onto the oil. Light another piece of paper and toss onto the solvent/oil.
-After a few minutes turn on the fan and adjust the air flow as nessisary.

This burner is extremly impressive and I have to use Oxy/Acetalyne Welding goggles when looking anywhere near this burner as it burns extremly hot. (My Digital Thermometer maxed out at 1300 C)

[doom4?!]

Here are a few links that I have compiled when I first found out how easy it is to melt metal and do what you will with it.

http://www.visi.com/~darus/foundry/ details the construction of a charcoal furnace made from 2 coffe cans and a simple fan, capable of melting aluminuim.

http://www.backyardmetalcasting.com/crucibles2.html shows a homemade crucible made from a steel pipe

http://www.visi.com/~darus/foundry2/ is the improved version of the cofee can foundary in the first link.

http://www.backyardmetalcasting.com/greensand.html how to mix greensand, a type of sand used in molds for casting

hope these links help someone in some small way.

[redbull]

Im suprised no one mentioned it yet... why not make firearm recievers? Anyone
know how difficult it would be to make cast .45 caliber 1911 pistol recievers?
Im sure it would need some cleaning up after casting but thats no big deal...
how do you take a working store bought reciever and make a metal mold? Im
not that familiar with metal working.. I just wanted to propose the idea.. Im
looking at finishing 80% by finishing the slide rails. Anyone done this before? :)

EDIT : Oh yeah... you can buy sten reciever tubes (and other tube based
firearms) with reciever templated bonded on... you just use a drill press and
make the simple holes to finish your reciever. I suppose thats THE easiest
way to build a firearm reciever but its no pistol... :D

[Skean Dhu]

Well this started off as a thread about rifling barrels, and FYI I mentioned it(www.Backyardmetalcasting.com) in one of the improvised weapons threads that Anthony started.

I'm sure it wouldn't be too hard, if you had some prior mold and casting experience. Also if you know what your doing the only after-cast work would be drilling and threading holes, along with hacking off the sprue and vents.

[Anthony]

I was under the impression that firearm recievers were not cast due to strength issues? Rather, they're either machine from solid billets, or folded/welded from plate steel.

[FrankRizzo]

I was under the impression that firearm recievers were not cast due to strength issues? Rather, they're either machine from solid billets, or folded/welded from plate steel.


You're right, they're either forged, or machined from a block of solid metal.

[festergrump]

Just a note on something I found very interesting following THIS (http://www.unitednuclear.com/chem.htm) link from a thread in the pyrotechnic section.

At the very bottom of the page is a compound metal sold in bars called "Woods Metal" that melts at a mere 158 degrees F. ($12 for just under a 1/4 oz. bar. They say it's a 1/4 pound, but this must be a typo. Found it HERE (http://shop2.chemassociates.com/shopsite/Chemassoc2/PAS-woodsmetal.html?OVRAW=Wood's%20metal&OVKEY=metal%20wood&OVMTC=standard) for a comparable price for a 25g bar). I thought an interesting use for this would be to test out your forms before casting the real deal to prevent wasted time in the event your mould needs modification. This might be great for testing trigger parts and smaller castings, especially. You should be able to cast your parts with this and check them for fit and action, perhaps, before firing up the furnace and wasting time with a failing part.

It's a bit costly, but time is money, and for $12 a bar, you really can't go wrong if you do alot of small castings. And the second link will do you right on quantities, also.

A search of the forum revealed two earlier mentions of this compound. Once in the Water Cooler for it's use in a hot bath and it's heat conductive properties, and another in a patent for FOX-7, but nothing else. I have never used this myself, so it's simply a thought...

[tomu]

Most receivers today are steel or alu precision castings. Even bolts are being made by precsison steel casting.

In some hunting rifles and in high grade, high priced hand made arms is the receiver and other parts milled from solid stock.

Have look at the Ruger Companies web site http://www.ruger.com/

[Pb1]

Different companies jack up their prices different amounts. A bit OT, but why is it that wood's metal is so safe even though it has a high cadmium content?