Furnace for Metal Casting

This is the waste oil part of the rig. The battery charger is just used as a 12 Volt power supply. The pump draws around an Amp, so most common 12 Volt supplies should work.

The Delco EP12S fuel pump was something I had on hand which happened to work. The oil is pretty thick so other similar pumps may or may not work. Lionel at www.backyardmetalcasting.com uses gravity as a pump for his setups, which can save money. Cruising the web for the EP12S shows them going for around $60, which for how it is made, seems way too expensive.

Here is the air supply. The fan is from a Jacuzzi. It supplies way too much air, so I have a KBIC-120 speed controller on it to slow it down. I tried other speed controllers, but the more common controllers used for power tools don't seem to work well. One would not work at all at low speed, another would not regulate the speed well. The KBIC uses back EMF from the motor as speed feedback, so it can regulate the motor speed even if the load varies.

This picture shows the copper oil tube sticking out beyond the burner housing. I thought the oil tube might melt if it stuck out beyond the housing, but I planned on trimming it back once I got an idea of how much of a problem it was. It turns out the oil tube has no problem with this length and stays much cleaner for some reason.

This is the whole system. I have a fitting on the burner for propane, but it is not hooked up. The plan is to warm the furnace up with waste wood to save on the cost of propane.

Here is another burner I tried. The top fitting is for compressed air. I liked the control, but I would prefer not to run my compressor if I don't need to. The middle fitting is for propane. The bottom fitting had a valve on it, and is for oil. I also had the Jacuzzi fan on this setup which allowed me to play with using the fan and compressed air in varying amounts. Either air supply seemed to work well.

This burner is made up from 1/4 inch copper tubing. The tubes are held together with hose clamps, which also space the tubes to the center of the housing (1" pipe). The oil tube is the longest, with the air tube an inch back, then the propane tube another inch back. I blew into the propane tube while I crimped the end to make a jet. The propane regulator needs a small jet so that there is enough back pressure to allow the regulator to work. The jet needs to be small enough for good regulation and big enough to get enough flow.

Here is a propane burner that doesn't need a powered air supply. The propane jet pulls in air as well as a jet effect from the nozzle on the end. I have easily melted aluminum with this one, but it may not have enough power to do much more.

The fitting on the top is the propane fitting. This view shows the jet. I used a piece of brass bar stock with a small (around .030") hole in one end and turned the outer diameter of the other end to a press fit into the flare fitting. The green tube is from the oil pump, then in succession: flare female, flare male, valve, 1/4" pipe nipple, 1/4" pipe female to 1/8" pipe female, 1/8" x 1.5" nipple, 1" male pipe cap, 1/8" female to 1/4" compression, 1/4" copper tube. The 1/8" x 1.5" nipple press fits into the 1" cap. I drilled the cap with a letter Y drill for the press fit. Other than the propane jet, which is not really needed, drilling the cap is the only "machining" needed.

I have a cover for the furnace, but it turns out the hole in it is too small for oil burning. I'll make a new cover with a hole a little smaller than the vent area shown here.

It's hard to see, but the burner is at the upper left of the vent area. The oil tube points down and has a stream of oil that flows down the picture and hits the wall of the furnace.

The upper right of the vent area shows the furnace wall were drops of oil hit then vaporize and burn.

I turned up the air a little which seemed to clear a lot of the flame out of the furnace, which allowed me to get a better shot of the oil stream.

Pages Created by Kirk Wallace

Copyright © 2010 WALLACE COMPANY
Rev. Date: 2010/01/17 21:43 PST KW