Aluminum casting experience???

My next foray is into this. Got the book a while ago and just realized most of my aluminum work would have been easier to do if I had just cast the things to begin with.
It seems simple enough to make the furnace and the molds.
Aluminum is real cheap when your using free pistons and such.


This will be another page (or more) on my site, the casting thing.

Anyone else already doing this? Got any suggestions? Trying to make it small and light. Although both are relative terms to what others already have built. Thinking of using propane rather than charcoal, most of what I've read is people hooked on this eventually go propane.

I would like to cast my jack plate parts but probably never will since I would have no idea just how strong they would be. Limited to glitzy things and low stress items.

I never messed with casting Al. but have been working around it. The biggest thing is going to be degassing so you don't end up with swiss cheese. The propane will be a lot easier to control. If ya look around you should be able to come up with a used furnace. The $ part will be the crucibles. Sounds like fun:cool:

Just finished making a Baja logo, hours of cutting, grinding, fileing, finishing. Cast would have been sweet. Gotta be careful with the sand..to dry=mold falls apart, to wet=mold EXPLODES! should be able to form a ball and break cleanly in half. Ya probably know this...I'll shut up now.

It's not all that simple. most of the parts we make are for the marine industries. Mercury Marine is our largest Customer. Most castings are of an alloy which not just aluminun. There are up to 16 different components that make up alloys, at different percentages to get different mechanical properties and strengths. Different alloys are used for transom brackets than pistons. it depends on what you are going to cast. Parts have to be corrosion resistent and free of prositiy for good strenght in a marine enviroment. It can be done at home but getting good casting with out the right equipment and know how can also be dangerous. Molten aluninum can and will explode. If not careful. If you need any infomation e-mail me. I've been in the foundry industry for over twenty years.

HydroV, any idea how I could get several champ type mids sand cast? Apparently the T4's are non existant and I've got enough stuff to build 2 more motors, except for the mid housing itself. I'd like to make some kind of plug off mine that somebody could make a mold off of. I'm not real fired up about shipping the only one I know of, off somewhere to get it lost or damaged. I've been unable to find a foundry within reasonable driving distance so I could take it and let em build a mold.

Doing this at home is pretty simple and idiot free except as Hydrovector mentioned about molten metal. It's just the safety stuff to be concerned about. The deagassers, if needed, are availble. No rammed sand needed if not wanted. Use dry sand and foam. The molten aluminum burns the foam away and is pretty simple to me.
If you screw the pour up then just remelt it and try again.
You lost fuel only.

The furnace is a can filled up with an insulating mud stuff with a hole in the center and a hole in the side for an air blower. This uses charcoal. The propane uses the hole for the air fuel torch. They both use an insulated lid.

One simpler is a hole dug in the ground and insulated!

I think the one big warning is this seems to be addictive once you start.

Here is a site with links and stuff if your interested.http://www.backyardmetalcasting.com/

techno,As you cast items for experimentn the porosity is the hardest thing to control.Machining castings is around 80% of our buisness.I was very suprized that many foundrys still use potatoes to control poprosity.i believe it is the moisture content of the potatoes that controls the rate of "out gassing".ISO 9000 is a joke at foundries,its too much of an art to make it easy to control.See ya Dave

it's difficult to do a housing because of the inside would have to be made with a core. a core would have to be made to make inside passages. The housing could be used to make the mold but it's going to to get some kind of damage done to it to make the mold. I do have a friend that has a small sand foundry if your interested.

LaveyT and Techno
foundry use potatos to control shrinkage in the castings as the metal solidifies. they are adding gass to the furnace by doing this. (making prositiy). this helps control shrink in thin sections. In thick sections of the casting the gas will expand and create larger pockets of holes or prositiy (The stuff you see machining). If you are to make casting free of prositiy you need to degas the melt but the means of Nitrogen or argon bubbled in the molten with a lance. Pills are availble to do this but they are clorine and are a health hazzard. the explosion hazzard is moisture that forms on tools and the metal ingot. everything needs to be preheated. foam castings or lost-Foam as is called is not just a piece of foam in sand it is also coated with a slurry ceramic coating. Mercury uses this process now for the new 3.0liter blocks. It takes 1 million btu's of energy to melt one pound of aluminum so the cost can add up real quick.

Hydro, I'm very interested. The beauty of doing a champ style housing is that there are NO inside passages as there are in a conventional mid. Just a simple inside plug and outside mold are all that's required. I'm just unsure on the inside plug part.

As an alternative, I've even thought of trying to do one in carbon fiber.

Hydrovector, the lost foam I've seen uses dry sand or green sand. It can also be coated or nekked. There is a bit of lattitude when your doing this in your back yard as apposed to a business. You can break all the rules except the ones about not getting burnt.
One site even shows doing this with vacuum but it's for tiny stuff and with wax.

Now this potatoe. You don't put a tater into the aluminum do you?
The pills should I use my supplied air hood when I'm doing this? Haven't seen much mentioned about the porosity but that might be that they aren't machining on them.
To degass you bubble 1 of those gasses? or does the powder/pill thing work?

Raceman you can cast your mid, just don't use a core. Cast it solid and then machine it out! Yeah right!
I always thought the way to go was a fabricated mid. Move the engine down and make the (bottom of the) cowl water tight to compensate. This would also provide a bit of floatation.

Hydrovector,back in 1974 I ran the casting machines at I.B. Goodman manufacturing co.Goodman is a large Jewlery manufacture plant.I only did this for a few months but as I recall
we would set the gold in the crucible,pull a lost wax investment
"mold" from the oven(melted out the wax) and place it in the centrifuge arm.then we would pull a vacume and pump in nitrogen
(still a vacume).We would heat the gold untill melted the drop in the thermocouple.At the desired temp for that peticular alloy
we would drop the heating coil and raise the thermocouple and turn on the centrifuge.After the gold had traveled into the "investment" we would rmove it from the machine and blast away the "investment"(like plaster) and be left with a "tree" of 14kt rings to be processed.The second half of the day was spent searching for gold scraps.The total weight of product cast and scraps had to be within a certain percentage of gold recieved from gold control or you were indeep ****.
That was my tenth grade summer job,sorry for running on:rolleyes: