Rev plays with metal (casting content inside(picture heavy))

In an effort to stop jacking Rufledts thread, I'm keeping my promise of starting my own casting thread once I had something worth writing about. For my own record keeping purposes, I'm going to start at the beginning, so you may have seen some of these pictures and words before, oh well.

First I made a crappy plaster and sand furnace. Widely regarded by people with any actual clue about melting metals as absolute E36 M3, it's been working alright for me now that I'm able to use it.

I had an interesting problem, I couldn't fit charcoal in around the crucible, at least, not enough to get hot and melt stuff. So I did some dabbling with beer cans and my charcoal chimney This worked well, relatively, and was a good education in air supply and cleaning dross. Seriously, cans are E36 M3. But they made some cute little ingots of pure aluminum that will be good for alloying or adding to a melt.

At this point, I decided charcoal in the chimney was a big waste of time and charcoal. And set my sites on propane. Lots of research. LOTS of research. Brought me to the design I have now, made from a Harbor Freight weed burner, black iron pipe, and the orifice from a Mr. Heater tank top propane heater.

https://www.youtube.com/embed/HzKohEzE-_w It's not supposed to do that.

After much experimentation, I have fixed the burner. It's a 10" length of 1" black iron pipe, with 4 3/8" holes drilled in a corkscrew pattern from the base. The weed burner wand I modified by removing the stock flare, drilling out the end of the wand, tapping in 1/4-28 and installing an orifice. The outside of the wand has 1/8" NPT threads, so I drilled out a 1 inch pipe cap and tapped the inside, then drilled 6 3/16" holes around the cap for air.

It works VERY well now, I don't have any videos online of it in action.

This brings us up to yesterday. I melted down a bunch of cast aluminum into ingots and was trying to decide on something to make that would be actually useful, and settled on a rammer for the flasks and greensand I'll be using down the road. I mocked it up in foam, realized it was way too big, and cut 3 inches out of the middle. From there, I covered in masking tape, and buried it in the sand. The steel can acts as a pressure head, in that it lets the metal hold a higher pressure going into the sand for better fill. is the end result. This end was supposed to be a big flat spot, but I ran out of metal on the pour, so It will be cut off. Thanks to some creative drill press foam milling, the center shaft is hand shaped, so I don't really need that top. Instead, I made another tool.

It's not perfectly flat on either side, but the bottom of it is thick enough I can cut a flat level bottom and smooth it out.

These tools will be used to pack greensand into the flasks for sand casting pours. Making better, more intricate, easily replicatable parts. Most people have both ends on the same tool, but I'm not most people. The excess bits that get cut off will be good starts for my next cast pouring..

looks great!

Nice....

This is fascinating.
How does the temperature for aluminum compare to brass? Aluminum is cool, but I've always been fascinated by trinkets cast from brass.

mazdeuce wrote: This is fascinating. How does the temperature for aluminum compare to brass? Aluminum is cool, but I've always been fascinated by trinkets cast from brass.

500-600 degrees difference in melting point, but the pouring temperature of brass is at or over 2000F, while aluminum pours around 13-1500. Brass should be easier than copper though. When I get my bigger, better furnace built (March ish) I should be able to do brass and bronze as it sits. Adding forced air should put me into copper territory. The issue with casting brass is the zinc content. Zinc tends to vaporize while getting to melting temperatures, and you gotta top it off right before pouring. And zinc fumes aren't the healthiest thing in the world. Brass and bronze also cool faster, making home casting tricky. From what I've been reading, without very proper flow and pressure control, it's very easy to have your brass solidify before it fills the mold.

I have 15 or 20 pounds of old brass fittings sitting around waiting for a project to come along though, so when I have the capability I'm going to try. I could probably do it now, but I honestly think it would destroy my current furnace.

My next furnace will be made from a 20lb propane tank. 2" of ceramic wool topped with a Satanite. That added insulation alone should make brass temperatures easy to achieve. It will look like this.

Picture used without permission from another forum, but it belongs to the person I'm pretty much copying because I really like his setup for simplicity sake.

This interests me. Ive been fantasizing about making custom emblems for my wagon to indicate the motor swap.

awesome! now I can do the threadjacking!

I'm going to be sticking with solid fuel for a little while at least so i'm interested to see how your burner set up works compared to my hair dryer/charcoal set up.

Rufledt wrote: awesome! now I can do the threadjacking! I'm going to be sticking with solid fuel for a little while at least so i'm interested to see how your burner set up works compared to my hair dryer/charcoal set up.

Your charcoal/hair dryer setup is far superior to mine. While I might be able to reach the same temps you do, I have a much harder time directing air into the charcoal chimney. Pretty much have to be pointing straight at the coals, so no lid, and they burn away FAST. Your air adding strategy and the added heat of lump make your setup much better. I honestly expect this setupt with the propane to be equal to yours, maybe a little faster. I'm dying to upgrade to the propane tank furnace though. I'm going to need a bigger crucible.

So far though, I'm still dialing the propane in, and can finally put the lid on my furnace. My plinth has degraded enough that the crucible sits entirely in the hole. I've noticed popcan ingots take twice as long to melt as cast ingots do, part of that is my furnace design part of it is the metal. This is a strange site to see. When you put the ingot that is floating in BEFORE the cast aluminum that it is not only floating in, but that is actively running off of it. For reference, this picture is exactly 20 minutes before the molten one.

I made my furnace from an old kiln. I share my shop with a guy that builds and services them so he has an unending supply of light fire brick that usually cost about $5 ea. Propane burner, crucible that can handle about 12 lbs of aluminum, or 3 Cummins pistons worth

I wish i could get a hold of some automotive cast aluminum! especially pistons. i have a friend who works at an engine rebuilding shop and he said he can get tons of scrap, but we just haven't yet because winter and also because of my recovery and stuff. Soon.. (tm)

I have a friend that works at a Nissan dealership, he's been given lots of junk stuff before, I'm hoping he can score me some pistons or a bellhousing. I will be melting down the aluminum wheels for the Miata that haven't sold in over a year to make some good stock metal in the near future.

But I've been looking for wheels for the challenge car, and found that aluminum wheels are cheap. While none of us really got into this to spend money on metal, a set of 4 aluminum wheels is 40+ pounds of good casting aluminum for $100-150 locally at least. I've been seeing 16 and 17 inch aluminum wheel set for $150, that's 80-90 pounds of good working stock cheaper than any ingots I've seen anywhere.

Since my brand new portaband let the smoke out tonight cutting one of the pieces I cast today, I may be at a stand still till I get better equipment. It may have been I was going to fast for the piece, it may have gotten stuck in the metal, but it definitely smoked and is getting replaced tomorrow.

There was a small scrap operation by my old shop. I used to trade them steel weight for cast aluminum weight. They would let me dig around in their clean cast bin and make a pile. We would figure out the steel value and the aluminum value and give them about 25% more steel value for their trouble. No money changing hands, no sales tax problems.

I probably have about 75 lbs of ingots from pistons alone. Stuff casts like butta'

RevRico wrote:

You're casting with ~dry~ green sand?

It needs to be mixed with water. Enough that you can scoop up a fist-full in your hand, squeeze it into a poo, and then crack it in half and it still holds its shape.

If it's so wet that it all sticks to your hands, it's too wet.

In reply to SkinnyG:

dry play sand for some lost foam experimenting. I haven't actually made any greensand up yet. That's todays project when I get back from Harbor Freight. That sand, in particular, is kept in it's own bucket away from everything else, because it stinks like melted foam and will screw up greensand thanks to the junk left from the tape and foam burning up.

I am a bit surprised at how much fits in a 4 gallon bucket though, almost 75lbs.

Well, after 2 bandsaws, 2 blades, and a lot of patience, I managed to cut all the excess off of my castings from the other day.

This was the rammer that I had to make the base smaller on. Almost a square cut. It's also the only piece I could shine up with the wire wheel I found. A lot of sand burned on, but all the tape lines and everything came off.

I need more wire wheels. And I need to figure out a better way to cut cast aluminum. The portaband works, mostly, but it's really slow and I expect this is destroying the 10/14 TPI blade on it. The 18 I tried was only good for small pieces, not these big ones.

Larger aluminum cross sections cut best at very low speed and with lube to keep the stock cool. It will gall and cause the blade to bind if it gets too hot. Same for drilling.

Yay, more casting material. We have here 5 16x7 wrangler wheels, cast aluminum. Roughly 18lbs each. Puts me over 100lbs of good casting metal.

It's been slow lately since I cut up those tools. I'm going to start foam modeling something a little smaller than does have both tools on one.

I started making greensand last week, and it's still not done. Best recommendation is to stomp on it and smash it together for a week, so that's what I've been doing. It's really difficult mixing this crap by hand, I think the youtube videos cut out a LOT of work.

No real plans, but I'm going to start making a pattern this week of my SCCA regions logo. The hope being I can cast trophy's for the year end event. Bonus points making them out of my miata's old wheels.

Once you get started with green sand find the supplies to make the Kent State green sand mix. Search for "K-Bond". I found the Bentone clay you will need at a place in Ocala, Fl. If you are interested in it I can look for my paperwork. Not cheap but I like the mix better than the kitty litter and water kind. I made a muller out of a Harbor Freight cement mixer and a couple bowling balls.

I've had more luck with Sodium Silicate and plain old sand. You can make more intricate shapes with no risk of bits falling into your casting void. Cool stuff.

Wow-very cool!

Pictures to come later when I get around to uploading them.

But I decided to try to make a better rammer today with lost foam. It didn't turn out.

The foam pattern

First my propane doesn't like 30 degree days it turns out. Runs for maybe 15 minutes, then loses pressure. Nozzle isn't freezing, tank isn't freezing, i don't know what it is. So I switched back over to charcoal, after an hour or so, started to get a puddle in the crucible, then noticed I was dripping aluminum. I burned a pinhole in my crucible. YAY me.

So another hour went by, in a new crucible, and finally I had a whole pot of metal. Poured it into my bucket of sand, and bumped the can I was using to charge the head, breaking off the flat top.

The rest of the piece poured nicely, and there is a very noticable texture difference between taping the foam up and just gluing it together.

The resulting 2 pieces

So on a warmer day I will try again. Maybe the third time will be the charm.

I tried lost foam casting exactly once. I spent all kinds of time shaping the foam, coating it with plaster and packing it nicely in my casting box. The problem I saw right away was as soon as the foam is vaporized you have a puddle of molten aluminum in its place that won't support anything above it. Including sand.

If you are going to cast with regular sand find sodium silicate and make a wooden mold of what you want to make. I used MDF I had laying around and hit it was some urethane to seal it up a bit. Instead of losing all your time creating a foam model that is a one shot deal, take the time to make one you can use over and over if there is a failure.

I bought a gallon from a laboratory supply place I saw small quantities on Amazon. You may skip the green sand once you try the silicate.

That is the plan, overall. Since the first two foam pieces I did came out fairly OK, I figured it was worth it to do it again. If I really wanted to make a fancy rammer, I'd do a split pattern and pour it in a sand mold. '

For the whole 10 minutes it took to cut the foam up though, I'd still be hunting for a chisel or changing the speed on my drillpress to lathe some wood to shape.

I'm picking up some MDF tomorrow to start working on a pattern for my autocross club though, I estimate a month to make the pattern.

If my propane wasn't so finicky, from start to finish would have only been an hour today. For a quick and easy "Don't really care how it turns out, I'm playing with fire" thing that's not bad.

Anyone have any helpful hints for removing the valve from a propane tank?

I'm probably going to make a collar to go over the whole valve and hope it works, seeing as ratcheting the tank to a tree and attacking it with a wrench didn't work.

This project sort of feel onto a back burner between weather and other goings on, so I'm trying to get a push back onto it after the wagon build is complete

I'm 3d printing parts for a member here. He's going to use the parts to cast molds for his foundry. I hope he posts his results. This stuff is all very cool.

Crackers wrote: This interests me. Ive been fantasizing about making custom emblems for my wagon to indicate the motor swap.

What swap? Do you have any sketches?