Tuesday, January 16, 2007

The Grease Gauntlet

After trying the old fashioned method of removing the cosmoline from the SKS by repeatedly spraying each piece with degreaser and/or WD-40 and wiping dry with a shop rag, I decided I'm going to give the "low-heat method" a try, and build my own version of the "Easy Bake Garbage Can", as illustrated there at www.surplusrifle.com.

The basic concept is pretty simple - put a lightbulb in the bottom of a galvanized trash can, lay the thing on its side, and put your gun parts on a rack inside, over a drip pan of aluminum foil.

Close the lid, hit the power, and just wait for the cosmoline to melt away.

This design seems to have a couple basic design flaws. First, there's a lot of wasted volume inside, requiring a higher wattage bulb than might be necessary. Second, and this was the big one for me, you're limited as to the length of the piece you can fit inside with the lid closed.

The barrel/receiver would have to be flipped around to get both ends heated up, and you wouldn't be able to close the lid to maximize the efficiency of the unit.

The length issue was addressed, somewhat, in this addendum to the original design posted at surplusrifle.com. But, face it, while it might work perfectly as intended, the stacked garbage can method won't win any beauty contests.

That is where "The Grease Gauntlet" (for lack of a better name) comes in.

I went shopping at Home Depot during my lunch hour today, where I was most successful in designing the Grease Gauntlet, completely on the fly, and purchasing most of the parts I'll need to get the working prototype up and running tonight.

It will be a horizontal oven, constructed from a 5-foot long section of 8" round sheet metal duct with end caps ($18 at Home Depot). The fixed end will have the electrical box and ceramic light socket on the inside.

The main selling point of this design lies in the "parts sled", a removable, 4-foot long, mesh sled on runners. The cross section of the sled is curved to match the shape of the tube. The parts to be degreased are simply laid out on the sled, which slides into the tube. The end cap is secured, the unit is plugged in, and you're in business.

At least on paper, anyway.

Like I said, I should have a prototype completed tonight, and will try to update this post with step-by-step pics, as well. Here's what we're talking about...

The Grease Gauntlet


(1) 5-foot section of 8" round sheet metal duct
(2) 8" round sheet metal end caps for duct
(1) ceramic light fixture
(1) ceiling electrical box
(2) 3' lengths of metal mesh "gutter guard"
(2) 10' lengths of L-shaped metal drywall trim (1" leg with holes x 1/2" leg without)
(26) #8 x 1/2" round-head, slotted machine screws with nuts and washers
(21) self-tapping sheet metal screws (1/2")
(1) 8' tool replacement cord with two-pronged plug.
(1) 3/8" cable clamp
(1) barbecue grill thermometer


Power drill
Phillips-head screwdriver
Flat head screwdriver
3/4" spade bit or tin snips
1/8" drill bit

1. The Tube

Crimp the seam closed on the 8" round duct to form tube, if not already closed. Secure with five sheet metal screws along the length of the seam (if desired). Note, once the screws have drilled through both layers, tighten by hand.

Drill a small hole near the seam, and insert the barbecue-style thermometer.

On the end cap, which is NOT going to hold the light fixture, drill (4) 1/4" holes, spaced about 1/8" apart, along the edge. These will serve as the drain holes for the liquid cosmoline to run out of.

2. Electrical Work at End Cap

Remove one 3/4" knock-out on the electrical box to feed the cord through to the light socket. Center the box on the inside of the lid, trace the outline of the knock-out onto the lid, as well as the small mounting holes. Remove box, cut out the hole you just traced, and drill 1/8" holes where marked.

Attach the electrical box to the inside of lid with the #8 machine screws, using a washer and nut on the outside face of the lid.

Feed the cord through the cable clamp and through the lid from the outside, into the electrical box. push cable clamp through the hole in the box. Slide cable clamp nut over the cord and secure cable clamp to electrical box. Do not tighten clamp onto cable just yet.

Attach wires from the power cord to light fixture by looping around the screws and tightening. be sure there's no excess bare wiring exposed that could come into contact with any other metal parts.

Mount light fixture to electrical box using the two mounting screws on box. Pull the excess cord out the backside of box. Tighten mounting screws and the cable clamp.

Screw in a 60-watt bulb, and set this assembly aside.

3. The Parts Sled

Cut four (4) 4-foot lengths of drywall trim (get a hole to line up 1/2" from the cut end). These pieces will be the runners for the sled.

Cut one of the 3-foot lengths of gutter guard in half, making a section approximately 18" long.

Attach one runner to the edge of one of the gutter guard sections using the #8 screws and nuts and washers. Start at the end, and put a screw in every 12 inches. After the third screw is in, line up the cut section of gutter guard (cut edge underlaps the uncut section by about 6" or so) so that the end lines up with the end of the runner.

Continue fastening with the #8 screws every 12". Note: the fourth screw will be right at the end of the uncut section of gutter guard. Now, add another screw to line up with the cut end of gutter guard. There will be six screws per runner.

Attach the runner on the other side of the sled in the similar fashion.

For the inside runners, the pieces will be flipped so the "leg" with the holes will be pointing toward the outside runners. Space them so the runners are evenly spaced across the bottom of the sled.

Carefully bend the sled assembly to fit the curve of the tube, allowing all four runners to support the sled when placed inside.

4. Dry Fitting

Place the end caps on the tube and plug in the power. Check the temperature to see how hot the tube gets inside. If the inside temperature exceeds 150 degrees, decrease the wattage of the bulb and/or drill a row of vent holes along the top of the tube.

If the temperature is too low, increase the wattage or type of bulb used.

5. Assembly

Once you determine the adequate bulb wattage, secure the end cap with the light fixture using four of the self-tapping sheet metal screws. Again, once the screw has drilled through both layers of metal, tighten by hand.

Well, you should be good to go now.

Place your parts to be degreased on the sled, slide it into the oven. Place the end cap on (DRAIN HOLES DOWN). Prop up the closed end to create a gradual slope down toward the drain, place drip pan under drain holes, and turn on the power. All I need to work out now, is a set of legs to support the tube and hold it at the proper angle.

We'll see how this works out. If anyone jumps on this and makes one before I get mine done tonight, let me know how it works.