Desert Gold! Desert Drywash OK Enterprises P.O. Box 2908 Lake Havasu City, AZ 86405 www.lookout2000.com/desertgold email: desertgold@lookout2000.com 866-496-3197 ext 702
DESERT DRYWASHER MATERIAL REQUIREMENTS -Used squirrel cage blower -Sheet metal, minimum 20 gauge, 60 x 36 Available at major hardware stores or steel fabricating shops Cost: approx. $30.00 -Expanded steel, 3/16 (thickness) x 1/2 or 3/4"(openings), 12 w x 30 long Available at major hardware stores or steel fabricating shops Cost: approx. $8.00 -Perforated steel, 24 ga. with 1/8 holes 3 x7 sheet Available at major hardware stores or steel fabricating shops Cost: approx. $8.00 -Angle Iron, 1 x 1 x 1/8, 30 Available at major hardware stores or steel fabricating shops Cost: approx. $10.00 -EMT conduit, 3/4, 10 length, 5 ea. Available at major hardware stores Cost: approx. $10.00 -Unistrut, 1, 10 pc. (1/2 or 3/4 thick) Cost: approx. $3.00 -Coarse Muslin Material, 1 yd Available at yard goods stores Cost: approx. $5.00 -Foam rubber weather-stripping 3 /4 x 1 /4, approx 15 Available at major hardware stores Cost: approx. $4.00 -Hardware, 20 Ea 1/4-20 x 1-1/4 bolts 4 Ea 1/4-20 x 1-1/2 bolts 20 Ea 1/4-20 nylon locknuts 4 Ea 3/8 unistrut nuts 4 Ea 3/8 x 1-1/4 hex head bolts 4 Ea 1/4-20 wing nuts 8 Ea 10-24 x 1 pan head machine screws w/nylon lock nuts 1 Box 1/8 pop rivets 10 Ea 1/4-20 pan head screws Available at major hardware stores Cost: approx. $8.00 -Briggs & Stratton Motor, Horizontal shaft, 3 1/2 HP -Pulley, aluminum, 5/8 shaft, 6 dia. -Pulley, aluminum, 5/8 shaft, 3 dia. -Drive belt, (size to suite)
DESERT DRYWASHER FABRICATION INSTRUCTIONS 1. Obtain a squirrel cage type blower assembly like you would find in an evaporative cooler. The width of the housing should be between 12 and 18. This width is important because it determines the measurement of the frame, grizzly (hopper), plenum box and other frame parts. 2. Bend all EMT pieces to make frame. (Refer to drawing #6) Lay one piece of 3/4" EMT on flat level surface. Measure 24 from end and place mark. Refer to instructions on 3/4 bender for 90 stub up. Make second mark. Put bender on EMT with arrow on second mark and lift until 90 bend. Lay EMT in its side with 24 section against a vertical surface. Measure from vertical surface down conduit to 40. Place mark. Refer to instructions on bender for back-to-back bend. Make second mark. Place arrow on bender on second mark, turn 24 stub up vertical and lift until 90 bend. Cut off at 48. You should now have a frame piece exactly as that labeled Bottom Frame on drawing #6. Repeat this process for second Bottom Frame piece and twice each for all other frame pieces. Cut two straight pieces of EMT to join the two lower sections of the bottom frame. The length of these two pieces will be determined by the finished width of your machine, which depends on the width of your blower. My machine, as illustrated, has a 12 blower. Therefore, the grizzly and plenum box will be 12, and then the two EMT frame pieces would be 13 1/2" long. 3. Cut and bend the plenum box as illustrated in drawing #7. You should be able to purchase all sheet metal (16 ga. is really sturdy), buy the perforated steel and have the plenum box bend at a steel yard, all for a total of around $50.00. That is what I did. That was the single largest expense that I incurred, other than the motor. I cut and bent the other sheet metal myself. Cut the opening in bottom of plenum box to fit your blower. Attach blower by bending up the sides and securing with self-tapping screws and/or weld. Install a 60 piece of angle iron on each side of plenum box 1 1/2 below the top edge of plenum box as shown in drawing #4. Install end plates. Either weld or overlap and secure with screws or rivets. The upper end plate should be flush with the sides, while the lower end plate should be 1 1/2 lower to allow the dirt to flow out. Install plenum box with blower attached to bottom frame assembly with 1/4 x 1 1/4 bolts as shown in drawing #2. 4. Attach motor frame EMT to lower frame (with 1/4 x 1 1/2 bolts) and to plenum box (with 1/4 x 1 1/4 bolts), as shown in drawing #2. 5. Cut two pieces of unistrut, to bridge across the motor frame, at a place as shown in drawing #1. Secure with 1/4 x 1 1/4 bolts. Cut two pieces of unistrut to bridge across the previous two pieces of unistrut at a 90 angle. Secure loosely with unistrut nuts. 6. Set the Briggs and Stratton motor on the last two unistrut pieces and secure loosely with 3/8
bolts. 7. Fabricate the grizzly as shown in drawing #3. Two pieces of angle iron must be installed along the inside, 4 from the bottom, to hold the expanded steel in place. This angle should be drilled and tapped 1/4-20 at several places to allow the grizzly to be attached to the top frame and the expanded steel to the grizzly. Install the top frame assemblies to the plenum box with 4 ea. 1/4-20 x 1 1/4 bolts, as shown in drawing #2. Install the grizzly to the top frame assembly with 4 ea 1/4-20 x 1 1/2 bolts, as shown in drawing #2. 8. Fabricate the riffle rack, as shown in drawing #8. The riffle rack is a 60 x 12 rectangular frame of 1 x 1 angle iron with 1 x 1 angle iron riffles running down the rack. Install the 3/4 foam tape to bottom of riffles. Cut the perforated steel to match the rack and then muslin a little larger and stretch over the back of the new riffle rack and secure with masking tape. Then secure the perforated steel over the muslin and secure with rivets around the outside and the 10-24 bolts down the center. Install the riffle rack to the plenum box with 4 ea. 1/4-20 x 1 1/2 bolts and wing nuts. These dimensions can be altered and should still work just fine, but mine is made with a 9 landing spot and then riffles every 4 down to the end. My belief is that it is not very important how the riffles are constructed on a good drywasher. The important thing is that you have plenty of space for dirt to land and the right angle for it to fall down the riffle rack, and plenty of hot dry air and space to blow the lighter elements out into the air and away from the machine. Install the pulleys to the blower motor; align the motor to the blower by sliding the unistrut bolts into position and tightening. Size the belt by wrapping a 3/8 piece of rope around both pulleys and cutting the rope where they meet. Make sure you leave travel on the unistrut to tighten the belt. Measure the rope in inches, and go to the auto parts store and tell them you want a B belt that long. Most will be able to match it. Install V-belt and tighten motor. Drill out blower bushings, tap, and install grease fittings and grease.
Platform Material List 1-20 foot piece of 1"x1"x1/8" angle iron 3' of 1"x3"x1/8" steel tubing 48" x 16", 3/4" expanded steel 22" of 2" receiving tubing 1-3/8" eye bolt Instructions Cut steel and weld together as indicated on the drawing. Hint: Make sure you ask for 2" receiving tubing at the steel yard. It is sized exactly to slide into a standard 2" receiving tube hitch installed on most vehicles. Most steel comes in 20 foot pieces. When buying short pieces, quite often the steel yard will charge you for the whole 20' piece and then charge a cutting fee on top of that. I therefore highly recommend purchasing the whole 20' piece and cut it at home. If that is not practical, after asking to check in the scrap bin, buy the 20' piece and pay to have it cut up into a size you can carry home.