Everything Man

Random projects from an alchemist's workshop.

Wednesday, 19th October, 2016

I’ve been playing around with the Gingery Foundry and I’ve discovered that lost foam casting is dramatically easier than trying to make split forms in sand. With green sand cope-and-drag casting you have to make the pattern in wood, ram up half the mold, flip it over without spilling sand everywhere, ram up the other half the mold, lift off the cope - again without spilling sand everywhere, gingerly take out the pattern, line your cope and drag up properly, and then pour your melt.

With lost foam casting you basically just have to make the pattern in foam and bury it in sand. It doesn’t even need to be special sand. Regular old play sand works pretty well. If you want a better surface finish, you can coat the pattern in something like drywall mud before you bury it. Plus you can cast a much wider variety of shapes and not have to worry about parting plane geometry. It’s just all around easier.

Sunday, 3rd July, 2016

This post is part of a series on making and using the Gingery Foundry.

Over the previous posts, I’ve made all the parts and accessories required to run a Gingery Foundry but had yet to actually cast any metal. Time for a test run!

My first test with the new foundry was a categoric failure. Even running at full blast, the furnace simply wasn’t getting hot enough to melt aluminum. It seemed like it was getting plenty of air, and containing the heat well (the outside of the furnace body stayed relatively cool), so I figured it was a problem with my fuel. I was trying to use “long burning” charcoal briquettes, which presumably had some additive in them to try to keep your grill from getting too hot. I picked up some lump hardwood charcoal at the store and tried again a couple weeks later.

Wednesday, 4th May, 2016

This post is part of a series on making and using the Gingery Foundry.

I’ve made several posts so far about putting together a Gingery foundry setup: flasks, molding sand, and air blast control. The next thing I needed to have a working foundry was the actual foundry furnace.

The furnace is contained in a 5 gallon steel bucket. Two 8” plywood disks were cut out, and wrapped in sheet metal to create a form for the interior of the furnace. I drilled a couple holes in the bucket for drainage and tuere outlets.

The bucket and furnace form
Wednesday, 13th April, 2016

This post is part of a series on making and using the Gingery Foundry.

One of the most critical elements of the solid fuel foundry is the air supply. A constant blast of air is what lets the furnace get hot enough to melt metal. Gingery recommends using a bonnet hair dryer to feed the furnace blast, but since I don’t have one I’ll be using the the blower output from a shop vac.

Unfortunately, using a shop vac for a furnace this size is tremendously overpowered. Running the air at full blast for any length of time would melt my furnace down into slag and glass. I need some way to control how much air is actually being directed into the furnace.

Tuesday, 12th April, 2016

This post is part of a series on making and using the Gingery Foundry.

The principle behind metal casting is simple: heat up metal until it’s a liquid, and then pour the molten metal into a mold. The mold itself is usually prepared in one of several ways:

Green sand casting involves using a wooden pattern blank. Molding sand is packed into a frame around this pattern, and then the pattern is removed to leave a pattern-shaped void in the sand. Molten metal is poured into this void to create the cast part. The shape of the part being cast is constrained in some ways, since you need to be able to remove it from the sand without destroying the mold.