Sandcasting, anyone here done it before?

I've been reading about sandcasting as of late and I find it to be pretty interesting. Seems something that can be done in your backyard and you could make some pretty cool stuff. Anyone here have any experience with it or do it as a hobby?

No experience nor advice to offer, but this is something I'm quite interested in myself. It seems like the metal most people start working with is either lead or aluminum. Aluminum is very easy to come by because it's everywhere. Cans seem to be an excellent source for a beginning hobbyist.

Quite true! I was reading on one of the sand casting forums that old beer cans and pistons are common favorites used for aluminum casting.

I think I'd try casting some ingots first. You pour into muffin tins, so you're not really getting a usable final product, but you're gaining experience. It seems like a small cement forge isn't too difficult to construct, but depending on your fuel, can cost a bit to run.

See you in ten years

http://forums.vwvortex.com/showthread.php?4662626-The-complete-guide-on-casting-parts

I did it in high school, but that was over 30 years ago. I don't think it counts.

Taiden wrote: See you in ten years http://forums.vwvortex.com/showthread.php?4662626-The-complete-guide-on-casting-parts

I love that thread.

We used to cast small cannon parts at work. You need a special kind of sand and can't have any moisture in it, another step in the process. Pouring molten metal is tougher than emptying a deep fryer while the oil's still hot. Wear lots of PPE.

Because of the time, steps of drying, tamping pouring, disassembly etc., we opted for a lost wax process.

Regardless of which one you use, it's only cost effective if you produce quite a few parts.

Dan

I work at an aluminum foundry. Yes, pouring molten metal is pretty cool.

As mentioned above, safety and PPE above all else.

The safety risks are why I never tried it!

The part that made me realize that it's NOT something to take lightly, was when someone pointed out that aluminum at pouring temp runs like water. Not something you want to spill!

And then there was the guy making his own VW parts who pointed out/found out what is kinda obvious in retrospect: Molten aluminum is hot. Just-solidified aluminum is hot. Things shrink when they cool. So you have to design your molds oversized so the part will shrink to the right size... and it's asymmetrical.

And a few more things clicked while talking with cghstang above, about how castings are designed to take the stresses involved into account.

Sounds like a lot more work than I feel like putting in to one-offs, you know? Even disregarding the safety issues (I could cut myself with a bowling ball if I wasn't careful) anything complex would have me worried about problems later on... and anything not complex could be more easily fabricated from stock.

I'm not trying to discourage you from trying it, mind you.

There are TONS of home built foundry 'how to' sites and Youtubes, they're all DIY and GRMer capable. This is on my must do list. Not too much in expenses... fire brick, casting sand and prolly best to buy your first flask. The rest can pretty much be scrounged. Like someone already said, it's recommended to start w/ making muffins.

I wanna work my way up to casting plaques using a 3D router to carve the molds. Eventually bronze.

I work at a steel/stainless steel/white iron job shop foundry as a sales dick/cost estimator/engineer. Ask away.

I did a foundry class in college 20ish years ago. Thick parts are relatively easy, but thin, complex parts are still doable. As I was taught, you tamp the sand, split the molds, remove the original, and start digging trenches. First, there are big resivors to hold a lot of metal to feed the part as it cools/shrinks/ solidifies.from there, multiple small runners go to the part. A good method I found was a horseshoe shaped resivoir, with the part in the middle. The thinner/more complicated the part, the more, and smaller the runners. The resivoir gets a sprue cut going out to the top. metal goes in here. It took me LOTS of practice, but I had fun. Also: +1 on the special sand- different for aluminum and steel, +1 on the warpage/distortion thing- if you're making precise parts, count on machining/drilling/etc as the final step. One more thing-unless doing very small batches, you will need somethig serious to heat the metal. Aluminum cools FAST.

Lot's of sites out there to guide you, lot's of places to find supplies.
I've found this one useful for sand, crucibles, etc. (NFI):

http://budgetcastingsupply.com/

I managed to pick up a used ceramic kiln (Paragon) for $100, runs on 220V. It's big enough inside that I can also do heat treating of parts.
For example changing 6061-T6 aluminum to -T0 (dead soft), so that parts can be easily formed and shaped, and once everything is welded together, then treating back to -T6. (Custom IR intake manifolds).
Or applying DIY engine coatings.
Or powder coating small parts.
You get the idea.

Add a thermocouple from McMaster, and a digital controller, lot's of things become possible.
Search for 'kiln controller*' on eBay, you will find a wide variety available.

Carter

You might see if there's one of the DIY shops nearby. I see TechShop is planning an LA location Real Soon.