# Lost foam/wax casting



## pomputin (Dec 8, 2011)

Have anyone of you heard about lost foam/wax casting? If not you should check it out. I am going to try 
it on the bullseye ringshot model by bullseyeben and hopefully I will have a aluminium cast pocket slingshot. Thank you bullseyeben from this great model







.


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## Dayhiker (Mar 13, 2010)

I have never heard of this but I will be interested. Keep us posted.


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## Blue Danube (Sep 24, 2011)

Used for centuries for jewelry and weapons, Peter Hogan could elaborate far better than me.......


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## brainleak (Nov 9, 2011)

In high school, we had an art teacher that would make jewelry with lost wax casting. Cool process. As long as you have access to the right tools, oxyacetylene torch (for silver, never messed with alum) and a centrifuge, its a rather easy process. just take your time with the foam/wax. All imperfections are going to show in the casting.


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## ZDP-189 (Mar 14, 2010)

I do lost wax casting of pewter, silver aand bismuth alloys.

Lost foam suits larger, less detailed forms, but is simpler because you don't do a burn out.


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## Catfish (Dec 26, 2011)

It's overall a pain in the arse to work with aluminum when smelting and casting. I did it for a little while on an amateur level with armature results.
Do try to find aluminum objects to melt down other than soda cans because they are covered in a vinyl layer that will produce waaayyyy to much slag in the melting process.
I bought my starting sand casting kit from here:
Foundry 101
You can melt pewter and lead on a stove, but when working with Al you'll be needing to make a furnace. I would suggest starting with a forced intake and a charcoal set up. Even if it is just a pit in the ground, you will get some results.


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## Pro-Shot (UK) Catapults (Apr 21, 2010)

Hi Lost wax/form casting for a catapults /slingshots in aluminium is a bit over the top ? but good luck and just keep safe when your casting,
Moltent metal has a very nasty habit of letting you know who is the boss.if i can help you just give me a PM will try to point you in thr right direction
just one last thing soda cans? for casting .To remelt this metal with any grate result you real need to melt with a induction furnace(Electric)??
the cans are that thin? they just tern to dross unless you have the right tools for the job


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## Catfish (Dec 26, 2011)

Hogancastings said:


> just one last thing soda cans? for casting .To remelt this metal with any grate result you real need to melt with a induction furnace(Electric)??
> the cans are that thin? they just tern to dross unless you have the right tools for the job


Not exactly. The dross is a result of the vinyl and thin walls of the can's side walls. I've had great results using just the tops and bottoms of the cans. Usually I used a "silver dollar" ingot to make a puddle and then began adding the can parts. I have about 13lb of ingot metal sitting at the house (from my "survival-barter" days"), and all of that came from soda cans. The reason I used cans is because that is the material I had laying around, and lots of it! I'd say almost 80lb of cans at one point or another from gathering for my scrappers.

Oops! for got this tid-bit: My largest furnace was a forced air (blow dryer) connected to a motor/veggi oil drip pipe to give me a decent blast furnace inside of a brick and clay 1/2pit-mound. I do repeat though, I took a novice level approach to smelting Al and then decided to stick with pewter and lead due to it's ease of usage and greater level of products I could make.


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## Pro-Shot (UK) Catapults (Apr 21, 2010)

Catfish said:


> just one last thing soda cans? for casting .To remelt this metal with any grate result you real need to melt with a induction furnace(Electric)??
> the cans are that thin? they just tern to dross unless you have the right tools for the job


Not exactly. The dross is a result of the vinyl and thin walls of the can's side walls. I've had great results using just the tops and bottoms of the cans. Usually I used a "silver dollar" ingot to make a puddle and then began adding the can parts. I have about 13lb of ingot metal sitting at the house (from my "survival-barter" days"), and all of that came from soda cans. The reason I used cans is because that is the material I had laying around, and lots of it! I'd say almost 80lb of cans at one point or another from gathering for my scrappers.

Oops! for got this tid-bit: My largest furnace was a forced air (blow dryer) connected to a motor/veggi oil drip pipe to give me a decent blast furnace inside of a brick and clay 1/2pit-mound. I do repeat though, I took a novice level approach to smelting Al and then decided to stick with pewter and lead due to it's ease of usage and greater level of products I could make. I Bow to your superior knowledge thanks for putting me correct
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## pomputin (Dec 8, 2011)

After some research I decided to use zinc and aluminium alloy maybe ZA27 or ZA8.


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## Pro-Shot (UK) Catapults (Apr 21, 2010)

pomputin said:


> After some research I decided to use zinc and aluminium alloy maybe ZA27 or ZA8.


Hi try ZA12 12% ali we had a go with it and got some good casting from the ZA12 only thing with ZA Alloys the go dull very fast unless you clean them after every use .work well in you P U dip after? or better still powder coating? good luck


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## pomputin (Dec 8, 2011)

Sorry it's taking so long but I have no access to a large enough propane torch. Meanwhile I was thinking about the coating and started searching for polyurethane varnish but I only managed to find two part varnish, is it OK and also if I would mix in some titanium dioxide with the varnish to give it a nice colour/color?


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## jskeen (Feb 7, 2011)

Propane burners for forge/furnace applications can fairly easily be cobbled together from standard plumbing and outdoor cooking parts. I've easily achieved smelting/forge welding temps and clean reducing atmosphere conditions in fire brick pile forges with burners I cobbled together from a few bucks worth of plumbing parts. The simplest can be made with no tools other than a hand drill and a specific size bit. Google forge burner rather than casting, as most of the work seems to be posted by blacksmiths.


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## Pro-Shot (UK) Catapults (Apr 21, 2010)

POMPUTIN good luck in your endevers Im out of this one


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## pomputin (Dec 8, 2011)

I tried casting the slingshot but the mold was cracked and the alloy just leaked out.


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## Pro-Shot (UK) Catapults (Apr 21, 2010)

pomputin said:


> I tried casting the slingshot but the mold was cracked and the alloy just leaked out.


OK im back in??? what ya make the mould out off?


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## pomputin (Dec 8, 2011)

The mould was made out of plaster that I had bought from a hobby store. I'll make another cast with casting sand (that I bought from the same hobby store).


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## Pro-Shot (UK) Catapults (Apr 21, 2010)

pomputin said:


> The mould was made out of plaster that I had bought from a hobby store. I'll make another cast with casting sand (that I bought from the same hobby store).


was the plaster,, casting plaster and did you use a steel flaskto put it in????
Peter


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## pomputin (Dec 8, 2011)

I am not sure what type of plaster it was and no, I didn't use a flask (fasepalm).


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## Pro-Shot (UK) Catapults (Apr 21, 2010)

ok first of everyday plaster of paris is no good for casting aluminium in to? its just not up to it?
if you have a modelling shop you can get casting plaster that is made for metal casting? did you make a wax? or split mould plaster?
if its the split mould plaster you can put the mould together and then put the mould in a frame and ram sand round it this will help stop the metal running out


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## pomputin (Dec 8, 2011)

Hogancastings said:


> ok first of everyday plaster of paris is no good for casting aluminium in to? its just not up to it?
> if you have a modelling shop you can get casting plaster that is made for metal casting? did you make a wax? or split mould plaster?
> if its the split mould plaster you can put the mould together and then put the mould in a frame and ram sand round it this will help stop the metal running out


It was a wax cast and the plaster will withstand the heat of molten zinc alloy, but the mold cracked when I was melting the wax out of the cast.


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## Pro-Shot (UK) Catapults (Apr 21, 2010)

pomputin said:


> ok first of everyday plaster of paris is no good for casting aluminium in to? its just not up to it?
> if you have a modelling shop you can get casting plaster that is made for metal casting? did you make a wax? or split mould plaster?
> if its the split mould plaster you can put the mould together and then put the mould in a frame and ram sand round it this will help stop the metal running out


It was a wax cast and the plaster will withstand the heat of molten zinc alloy, but the mold cracked when I was melting the wax out of the cast.
to much heat to fast slow heat in oven with a bowl of water to help keep the are moist remove wax?
then dry mould???
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