Best media for sandblasting paint

We spent yesterday afternoon at IDS Blast in Indy. We tried a lot of different media and cabinet types trying to find out the best and fastest way to strip the sheet metal on these 300 up series that are so difficult.

We determined the Wheel horse parts are not painted with a conventional spray method. It is a coating directly bonded to the metal with no primer. The exact method is still not known, but we do know it is an electrolysis plating type of method. The coating was between 3 and 3.7 mils thick on all of our shiny, perfect test parts we took with us.


The best media for stripping - mid grade plastic. The fastest method - a pressure system with a long venturi nozzle. This puts the media hitting the metal at over 200mph. The plastic in a pressure system should strip all of the sheet metal, hood, fender, steps, and guards, in less than 20 minutes. The outside of a belt guard was completely done in 1 minute. The only problem is there is no profiling of the metal so either it has to be blasted with something a little more aggressive, or an etching primer used.

Just for info, the plastic was over 10 times faster than aluminum oxide in the same exact cabinet, nozzle, and pressure. Aluminum oxide also eats up guns, nozzles, hoses, and fittings like crazy.

We determined the most economical way to etch it quickly and lightly is the use of a Hybrid Garnet based media at lower pressure with a suction type gun. This media would also be used on rust, as the plastic may not do well if there is very much of it, or a lot of pitting to clean. It is close to the coal slag on the hardness scale, performance is about the same, it lasts longer, and without all of the dust.


The plastic benefits are incredible speed, and are enormous as far as consumables also. It doesn't wear any parts within the cabinet, and has almost no dust. The only way it can be bought is in drums. Likewise, the Hybrid Garnet (The Garnet gem, with other rock particles) would be a dual purpose media. It could profile the metal slightly at low pressures, also saving consumables and the air compressor run times, or the pressure can be increased to blast cast iron or other parts where profiling is not a concern.


We learned there is sure a lot to sandblasting yesterday. What you are doing will greatly change the media and equipment someone should use. There is even sponge material for asbestos paint situations, corn cob is best for shells to be reloaded, and the list goes on and on. We did these tests in a professional environment, with the same conditions on each type of media. This is a real test of what is best and fastest to strip the newer Wheel Horse paint with, and the equipment needed for that, not just my opinion.

Thanks Gene:
Your technical information is really helpful, going to have to stop using oxide now and find plastic.

FYI: The main reason that AMC purchased Wheel Horse in the late 80's was for the painting patents and the engineers.
Jeep & Wheel Horse had worked together in the 70's on the "Wheel Horse - Jeep - Golf Cart" and "Jeep-Trac mower" projects, they made of few of them then the projects stopped. Also, the 2000 Jeep Liberty had some major influences from the former Wheel Horse engineers that AMC wanted and used, and even now, all the Jeeps utilize the 'secret Painting techniques' that AMC got in the deal, also, that's why there were no real changes in the Wheel Horses for 4-5 years after AMC took over.
That's the reason the paint is so hard to get off, great bonding . . . I also heard that the heated drying line where the pieces hung/moved was a 1/2 mile round trip that took hours, so the painted pieces could cool down very slowly after being baked.

Glen

Thanks for the info Glen. I had also heard that AMC bought Wheel Horse for the paint "secrets". The thing a little confusing about that is AMC bought Wheel Horse on 5-23-74 and sold to Munn Investment group on 1-14-1982. Toro bought it in 1986. The paint is get much harder to get off starting with the Blackhoods in 1979, so something changed there. The super hard to get off paint is mostly on the 300 up series which began in 1985. Has anyone ever had an explanation for that? Did AMC improve upon the "secrets" they found and Munn used their paint? Lots of questions with the story there.


If you switch to plastic it may not work well with a suction cabinet. We didn't try that yesterday but can when we get it in. It was used in a pressure cabinet, with a $200.00+ venturi nozzle. The nozzle itself makes a huge difference. What type of blaster do you have?

never used a blast cabinet did the old way out side using silica sand bout 2 100 pound bags can do a tractor cost me 20 bucks but gota wear protective gear though