This is the front view of my sandblaster, I bought very little for the project, the jack in front was one piece I did buy though. The frame is an old Carrier 40 ton chiller frame I tore out in the early '80's and cut down in size. The wheels and hubs are off of a John Deere pull type combine. The pipe and unistrut and angle iron are from jobsite trash hoppers. The pto shaft was off the same combine.
The 80 gallon vertical tank was a vacuum tank I tore out from a factory remodel job. It is now the pressure tank and holds just at 600 lbs of silica sand or meramec sand which is much coarser than silica. Use that on cast iron and frames etc not on sheet metal. The front is a 80 gallon tank, different diameter and was a compressed air tank I changed out in a printing company because of a vibration crack. I welded it for my own use, could not do it commercially without ordering a hydrostatic test.
To operate the compressor at less than 1000 rpm, I figured the ratios of the sheaves on the jackshaft with the 540 rpm pto input of a tractor. Unfortunately I didn't have two (4) belt sheaves in the proper diameters so I had to double up two sheaves of each diameter. This is the weakest part of the system and I am actively searching for a 4 speed truck transmission to provide my input power instead of the belts. It will be bulletproof then. I hope.
A close shot of the sheaves and the way I adjust tension. The pillow block bearings, sheaves and belts all scrounged from commercial roof top hvac unit demos.
Side shot of the primary input shaft bearings and their adjustments. I used 5/8" strut nuts welded to 1" flat iron slides inserted inside the unistrut. The 5/8" bolts thru the pillow blocks are tightened after the alignment and tension are achieved. 7/8" nuts welded on the end provide the adjustments.
I run this guage pretty much near pegged because operating pressure is 125 psi. This is just an additional guage laying around from a chilled water pump change out. Its handy to see from the clutch side of the tractor to monitor while starting out and setting throttle. The real guage is a 300 psi glycol filled guage which keeps the needle steady with all the vibration.
Just another cheap guage to plug a fitting... the important part in this picture is one of the pressure relief valves in the circuit. There's a few auxilliary ports for air tools or whatever else you need ...like an air filtering system for your lungs.
Speaking of air filtering, this is a charcoal filter canister specifically for airborne oil mist that you may get in excess when you spin the crankshaft too fast. That is why I maintain 960 rpm on the compressor with 540 rpm on the input. Most of the time I'm running about 800 rpm to minimize this. I have a 50' clean hose that goes to a Clemco helmet with a secondary regulator to maintain proper airflow in the hood. I have sandblasted at 95 degree outdoor temp and not sweat until I take off the hood. You can't do it without the hood for two reasons: the heat and protecting your lungs. Silicosis is a dreaded illness. Oil-logged lungs are deadly also.
Better shot of the charcoal filter.
This will give you an idea of the head size. No idea of the cfm but its a bunch.. I guarantee it.
A back view of the whole compresser. You can see the adjustable unloader controller and piping.
An idea of the width of the three cylinder pump. This compressor also has an aftercooler and adjustable cylinder unloaders.
An idea of the height. My much older brother, (a lifetime Massey guy who just turned into an International lover) gave this compressor to me. He'd had it for a number of years collecting dust and after I blew the original compressor I had on this when I built this rig he decided this big ol boy would be something I couldn't tear up...Is he a great guy or what !!!??
Front view of this old dog. Now guys, PAY NO ATTENTION TO THE JUNK IN THE BACKGROUND !!!!!
The tongue welded on the piece of gas pipe is off of the JD combine or JD haybine, I don't remember but the front portion of the pto is from the combine. Just a little cradle made of flat iron welded to a gas pipe stub for the pto to rest on while disconnected. Did you notice by chance the Massey red and JD yellow ?? I was fresh out of 'Harvest Gold" ( for the rest of us Massey lovers out there ).
This is maybe a 3/16" tip to use with the coarser Meramec sand. They wear up to around 3/8" before they are no longer useable.
An idea of the length. I used to get these at WW Grainger but they quit stocking them.
This is the cross at the bottom of the pressure tank.. the right side is the outlet and the hose and nozzle goes there, the left side is the tank bypass that propels the sand, the top of course is the sand coming into the cross... you use the ball valves to balance the air to sand ratio, the air ball valve is upstream on the left pipe. The bottom is to snap open and closed quickly to purge any blockage in the cross.
This is the glycol filled guage and the tank isolation valve. I leave that shut off until the system reaches unloader setting then slowly crack it open to pressurize the sand tank and down to the closed balance valve to the cross. Every inch of pipe is discarded gas line of various sizes.
Fill the tank through the 2 1/2" nipple welded in the top. I welded a tee handle so a pipe wrench isn't needed.
This little petcock doesn't look like much, but if I keep it barely cracked it blows a tiny mist of water out of the line instead of depositing it into the sand tank on high humidity days. Too much moisture in the tank and the cross will bridge over making you hit the blow down momentarily.
So, there we have it.... another project built from discarded pieces of salvage heading for the junk yard ......
I don't see a reason to spend money unless I have to. I guess I could've held out for a LeRoi Tractair...... :lol: :lol: :lol: