Sandblasting

rer_239

rer_239

Senior Member
What's the best abrasive stuff to use on sheet metal. And what pressure should be used?

Tia
Zrer_239
 
I use a product called 'Black Beauty' and as low a pressure that will do the job. Usually anywhere between 50 and 90 lbs depending on if you are removing paint or rust.
Also keep a shallow angle when blasting, Seen a lot of ruined, warped sheet metal from using the blast nozzle at a right angle to the parts. Or staying in one place too long.
Black Beauty is a slag left over from burning coal, or so I've been told.
 
I use sandblast sand. It is the cheapest. It comes in 40 or 50 lb bags. I use 80# of pressure with my TIP USA made pressure blaster. Pressure blasters work many times faster than siphon feed blasters. I have sandblasted 3 model A's - fenders, quarterpanels, frames, pretty much everything. I use a 3" ceramic 1/8" nozzle that after sandblasting for a number of hours enlarges to 3/16", then I toss it. Never blast perpendicular to the surface. Blast at an slight angle. I have never had any metal distortion or warping in the metal, as it is 19 gauge or heavier metal. I blast outside on plywood with a tarp underneath the plywood. I can reuse about half of the sand after blasting several fillings (about 80 to 100 lbs of sand in the pot). Using glass beads, walnut shells or baking soda is expensive and very slow. I wouldn't use any of these. Some people will say a pressure blaster will distort sheetmetal, but unless you really blast with a lot of pressure or stay in one spot a long time there wont be any problems. Sandblasted metal is a excellent base for epoxy primer (or any primer) assuming you clean the dust off well.
Rusty Nelson
 
If possible, I hand strip paint and use heat gun or light propane torch to remove body filler. Then dust with sandblaster for rust and clean off. I just use fine sand from Tractor Supply….not cheap but convenient and dont use all that much.
 
Yes to "OldBlueOval" Strip the paint and old fillers first. Then you'll have less of a chance of damaging the sheet metal. The black grit for sandblastng works well or if you want something finer use glass bead.
 
rer_239 said:
What's the best abrasive stuff to use on sheet metal. And what pressure should be used?

Tia
Zrer_239
Click to expand...

You asked what is best, ...and in my opinion, it is NOT sand or anything silica.

I outsource mediablasting on large sheetmetal items and they use a plastic media to strip the paint and other organic materials. They blast at about 40 psi and it strips the topcoat and substrates layer by layer. You can remove the paint on a Door with the Window Glass still installed and it will not affect/etch/frost the glass whatsoever.

Any rust is stripped with Aluminum Oxide at 35 psi. No warpage or sheetmetal 'texturing'.

FWIW, probably within the next year we will have a Laser Welder that also can double as a Rust Remover. The technology with these units is really moving quickly.
 
Yes stay away from silica…big health hazards. Tractor Supply sand is slag. Wish I had a source as Brent described near me! Would be well worth it to have trustworthy sources.
 
Are there any coal fired power plants in your area? The media refining outfits set up in their complexes.There is one about 25 miles from me that I have been buying from since I started blasting in the 70's.Years ago the place was Reed minerals,and their product was called Black Beauty.Then they sold out,and it was called,Patriot Blast.Same product,different names and different numbers for the grit.It has changed hands a couple more times now,and every time I get a notice that blasting grit will be discontinued.It is all going to go for roofing shingle media.This has been going on for 25 years,and I can still buy blast media there today.Different security now than it used to be,but then again,it is a power plant.For dump trailers,bodies,and equipment I always used fine.For sheet metal I used extra fine.
 
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