Discussion in 'General foundry chat' started by Miles74, Nov 3, 2021.
After or before the divorce?
It looks like I am slowly formulating a plan. I’ll collect 4 of the aluminium cylinder heads and look at processing them into usable pieces.
After that, it’s creating heat by whichever method to turn them into ingots. That will be my simple goal for now. Turn scrap into clean (ish?) aluminium ingots that I can then experiment with.
I’ll stay away from pistons at this point. I do have a few odd aero parts here, but I wouldn’t melt those.
As for using my dear wife’s oven to heat my chunks of head… she WOULD have castrated me, but she’s on the other side of the world and already divorced me
I will however come up with a suitable heater that doesn’t involve my kitchen appliances.
Ian; You may be able to throw them on your outdoor grille and generate enough heat to get the seats to drop out. It would be a cheap and easy enough experiment.
As for the magnesium test; Sand clean a small area on the part you're looking to melt, and place a drop of white vinegar on that spot. If it discolors, or worse, fizzes a bit, there's magnesium in the mix.
Cylinder heads are exactly the type of alloy I look for. I dont think I've ever heard of an automotive one being magnesium, but I dont know much. I broke down a half dozen or so lawnmower decks one afternoon in a stack melter and the last one gave me an unforgettable surprise. Fortunately nothing got destroyed nor did I get unwanted company but I surely don't want it to happen again. A small chip of the metal or some swarf lit up with a plumber's torch is a good indicator.
this is the kind of thing I was thinking of, so I’m glad I’m not crazy for thinking it. I have a grill I can try this with. I don’t mind giving them a little forced assistance if needed. They will come out one way or another.
I’ll clean up a spot on a couple and see what happens, but I think they are likely just cast aluminium. I’m likely being a little over cautious as this is new territory for me.
Hi Pete, thanks for that.
I have no experience here, so it’s a case of ask, learn and try as I gain knowledge. I’m sure I read about the chip test in here last night. Light it up, if it melts, it’s Aluminium, if it burns, it’s Mag? Another good experiment to try.
I’m glad nothing was damaged. I imagine Mag burns at a crazy rate if it’s dumped into a melt.
Not all Piston alloys are hypereutectic.......like forged pistons. I don't care for "Pistonium" because it tends to be more grey and brittle, so it doesn't machine or polish as well. However, it can have higher fluidity which can beneficial for casting more intricate ornamentals or modifying other casting stock.
Wheels (Wheelium ) can also be excellent casting stock, but similarly some are forged not cast, and avoid chrome plating in either case. They have similar challenges in breaking down to crucible size pieces.
This is a staged picture, nobody's floor is that clean. Especially anybody who does as much work as Kelly.
For sure. And whose got that much open space? Lol.
“Headonium” is the only real one on offer at the moment, though there may be pistons there. Now I do have a source of “wheelium” (a set of old Vauxhall alloys), but I’m unsure if they are cast. Is there an easy way to tell cast wheels from forged?
I’m sat here wondering how much the neighbours will gripe if I build a new shop covering the bottom half of the garden… I agree with Andy, you must have polished that floor before the photo. I’m hoping I can keep my shop that clean.
Besides being wise-acres you're all quite insightful. Had to go back and look at the date on that picture. Things have moved on a bit since then in all respects cited....LoL!
The finish on the unmachined surfaces. Backside around the mounting pattern can be a good location to inspect. Forgings typically smoother. Forgings also more malleable. Smack the rim with hammer and casting more likely to fracture.
Thanks once again. Although I’m a little tool limited at present, hitting things I can do. As soon as I collect the scrap parts, I’ll take some pics of the dismantling process.
I have 2 weeks to get a little done before I become a forum reader again for a little while (nooo… I’m not getting locked up). I’m travelling to see my daughter in Brazil
I know it’s not on topic, but I have a nice anvil out there, shame it’s too damn heavy to ship back to the U.K.
I haven’t disappeared I’m currently in the south of Brazil for some time with my little girl. Took my chances with a cheap ticket in the sales. Wow… paperwork nightmare, but I’m here.
I’m told there is a local workshop that recycles aluminium into ingots. I’ll see if I can have a quick visit. Doesn’t hurt to ask.
Engine parts, including engine heads are my alloy of choice. I've melted VW, GM, Audi and maybe more that I remember. I never test for magnesium as it probably won't be a good alloy to be made into engines I guess. I build a dedicated furnace for scrapping heads and other bulky parts. Clean alloy runs from the bottom, non meltable stuff stay inside and get scrapped off when cold. I also melt pistons separately and use them as silicon additives cause they seem to have more of it than other engine parts. I think alloys with more silicon shrink more.
Thanks for the info. What type of furnace do you use to melt the heads? I only have a few heads and some wheels at present. I’ll give those a go first. Creating clean aluminium ingots will be a good start.
I have been using heads and pistons for years without any problems.
To destroy a head I set it in my power-hacksaw and cut it into slices. In the early days I noticed that the blade would cut through valve seats, but now I run a weld bead with a stick welder around the seat and they shrink and fall out. My woodwork bandsaw on slow-speed is useful for cutting thin wall castings.
For the modern multi-valve heads that are too big for the hacksaw, I think I will have to make a reverbatory furnace.
If you have a press, that can be useful like a sledge hammer, but be very careful, I had a piece fly past my face once.
For steel that can't be removed, I lift it out of the melt with a skimmer and then de-gas. Foseco recommend de-gassing twice in their hand book.
Thanks Charlie, good information there. I haven’t been offered any pistons yet, but I have half a dozen cylinder heads that need breaking down, plus a 3 set of alloy wheels. It’s a start.
I’ll try the weld bead trick on the seats.
Cutting the heads into usable pieces is likely my first hurdle. I have some ideas from here, plus a home own rolled experiments to try. I’ll look up the furnace too, but I’m guessing anything big enough to take a cylinder head intact won’t be small.
What do you use for ingot moulds? Do people buy them or make their own?
Like many others I have 4 ingot molds made of 6" lengths of 2 inch angle iron with steel ends welded on at a bias. 1/8inch should be sufficient but mine are 3/16 I think. It seems to be in conflict with the idea of iron contamination which has been touched on above, but that's what I generally do. In fact I use the same molds for bronze. That's probably not kosher for some, and for good reasons, but I'm not casting anything structural or industrial so I dont think it matters too much. Others might chime in.
When making molds like I described, I made every attempt to have smooth fillets with no undercuts on the inside (easier said than done for me. I'm not a welder, I'm a grinder/painter so I've been told lol), and allowed them to get rusty.
I suppose I should have just ground the mill scale off to begin with, but heating them up to red and then leaving them outside did the trick eventually. They worked for aluminum immediately but not so for bronze. Those stuck bad and I had a helluva time getting them out. I think they stuck to the mill scale. They work fine now.
I just use open sand molds for cast iron. I dont know if iron would stick to my steel molds or not.
On another note, a horizontal bandsaw with a good bi-metal blade is a great addition to any hobby workshop and can be had cheap on the used market. I wouldn't want to be without mine.
I just use a sharp chisel. A couple good smacks with a hammer imbedding it behind the seat and then they pry right out. -Fast.
The heavy oxide (and often pickled) coatings on hot rolled steel profiles like angle is actually good barrier for preventing metal contamination, but it won't taking crucible duty. Aluminum skins and chills almost instantly and once it's solid, there's no longer any chance of solubility of iron. I fit mine up tightly and applied all the weld to the construction backside.
Bronzes are a different story. I suspect if you had a very thermally massive steel mold with the oxide coating, even bronzes may skin like aluminum, but they very aggressively wet clean steel.
Even aluminum will stick tenaciously to bare clean steel. When I used steel tubing for lost foam kush/pouring cups, aluminum would tightly bond to the interior if it was bare and clean. If I heated them before use so they developed an oxide layer and I could slide them off the slugs after casting and once they were reused became even better seasoned. I tried making a sheet metal pouring sprue for aluminum......it was an unrewarding experience. It served it's purpose once but I had to peel it off.
As mentioned, for iron, sand mold.
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