I gotta sandblast six bumpers + six sliders, then paint them (1 Viewer)

[alia176]

I wanted to pick your brains on this topic so that I can figure out the best way to spend my money. Long time ago, I got a quote for $300 for blasting four bumpers and now I have six of everything. I have a 5hp/80g/dual stage IR comp so I've got plenty of air at home, and wanted to know if I should get one of those HF sand blasting pot.

My work has a paint booth that I'm going to use to paint all these things, so I don't mind spending a little coin on the prep stage. Paint booth is not real fancy like a body shop and it's open one side but it does have a helluva air handler with lights. It also has no heating capacity so I might have to buy couple of those halogen work lights on stands as a heat source.

Thanks for your inputs.

 

[Malleus]

I'd look at a "dustless" system before I invested in a 30-gal pot for one job. You'll wind up with your own beach when you're done, but for a large job that's a one time affair, I'd go this way. It's probably a wash financially over a dedicated blast booth such as a blasting shop would have, and it's for sure a bigger mess for them, which is why it's not a commercial success, like this guy hoped it would be.

There are lots of YouTube experts with demo videos on the wet systems.

versus

 

[alia176]

interesting concept. Use water to remove paint, then get flash rust? Of course I'd need to rent a pressure washer.

 

[Malleus]

I don't know what the average humidity in your corner of the world is, but here I get flash rust out of the blast cabinet. I'd be glad to loan you my PW, but you'll have to pick it up.

 

[BILT4ME]

I wanted to pick your brains on this topic so that I can figure out the best way to spend my money. Long time ago, I got a quote for $300 for blasting four bumpers and now I have six of everything. I have a 5hp/80g/dual stage IR comp so I've got plenty of air at home, and wanted to know if I should get one of those HF sand blasting pot.

My work has a paint booth that I'm going to use to paint all these things, so I don't mind spending a little coin on the prep stage. Paint booth is not real fancy like a body shop and it's open one side but it does have a helluva air handler with lights. It also has no heating capacity so I might have to buy couple of those halogen work lights on stands as a heat source.

Thanks for your inputs.

View attachment 3337648

That's the route I would go with a HF blast pot. A couple large tarps, maybe a 12x12 car cover and plastic sheeting to "enclose" it and would allow you to recover your sand. Also look at your blasting media. Black Beauty will give a faster clean but a deeper cut requiring more paint. Sand will give an even blast with medium paint. Glass bead will give a great looking finish, much smoother, and will require less paint, but may have slight adhesion issues if not cleaned well enough after blasting. Also, disposal of the blast media afterwards could be an issue.
Glass beads is not going to "go away" and could build up in your driveway, lawn, or wherever. Also a slight silica risk.
Sand will "blend in" but poses a silica risk.
Black beauty will fracture, but remain and will discolor your work area and will always be noticeable.

You could also consider walnut shells which will take a LOT more product, but is "biodegradable" and may work itself into your lawn over time, but you will have piles of it. It will also take longer but will give a very nice smooth finish, but will not create a surface profile for the paint to "bite' into.

 

[alia176]

That's the route I would go with a HF blast pot. A couple large tarps, maybe a 12x12 car cover and plastic sheeting to "enclose" it and would allow you to recover your sand. Also look at your blasting media. Black Beauty will give a faster clean but a deeper cut requiring more paint. Sand will give an even blast with medium paint. Glass bead will give a great looking finish, much smoother, and will require less paint, but may have slight adhesion issues if not cleaned well enough after blasting. Also, disposal of the blast media afterwards could be an issue.
Glass beads is not going to "go away" and could build up in your driveway, lawn, or wherever. Also a slight silica risk.
Sand will "blend in" but poses a silica risk.
Black beauty will fracture, but remain and will discolor your work area and will always be noticeable.

You could also consider walnut shells which will take a LOT more product, but is "biodegradable" and may work itself into your lawn over time, but you will have piles of it. It will also take longer but will give a very nice smooth finish, but will not create a surface profile for the paint to "bite' into.

This is GREAT feedback, thank you typing all that in. I live out in the boonies, got no neighbors so I got some leeway there. I needed the education on the blast media and this was uber helpful.

 

[BILT4ME]

This is GREAT feedback, thank you typing all that in. I live out in the boonies, got no neighbors so I got some leeway there. I needed the education on the blast media and this was uber helpful.

I recommend looking at "surface profile" information so you can get familiar with what different blasting profiles are and do.

The deeper the profile, the better the bite for paint.
The deeper the profile, the thicker paint must be to fill the peaks and valleys.
Definitely solvent wipe EVERYTHING before you blast. This way if you miss an area with blast, the paint will still stick.
The "whiter" the steel is after the blast, the better the adhesion, but you will use a LOT of media to get there. it may also stretch and deform the flat sheet areas of the bumper, depending on the thickness.
Get a "Wet Film Gauge" from the paint supplier to measure how thick the paint is that you're spraying. Then you can calculate how thick the dry film thickness will be by subtracting the solvents. (A 67% solids paint will dry down to about 67% of what your wet thickness is.) You want to end up with 4-8 mils Total Dry Film Thickness (TDFT) Part of that is primer and part of that is top coat. Primer is what attaches the paint to the steel. Top coat is what make it look nice. The primer is the most important to keep it from rusting or having the paint delaminate.

WEAR A REPSIRATOR WHEN BLASTING!!!
(Preferably a forced air type, but a HF twin silica pack will do OK as long as you are clean shaven at least where the mask contacts your face.)

I deal with welding, fabrication, blasting and coatings all the time for my livelihood from an application, specification, and inspection standpoint.

 

[PIP]

I will happily pay way too little money for pro sandblasting so I never have to do it again.

I bought a Ingersoll diesel compressor (185cfm i think?) and built my own pressure pot rig about 25 years ago. I was a firefighter in the military at the time and I got one of our old masks with tear offs and built my own filtered supplied air system. I bought a couple tons of good blasting sand and I blasted two 70's pickup bodies, w/chassis and a trailer. It worked pretty good, but man was it miserable, monotonous work.

I sold that setup off quickly after a few uses and have just had a small industrial blast cabinet for the last decade. I often use a metal cleaning company that uses hot lye and electrolysis to strip old steel like new. They charge around 30 cents a lb for this and do amazing work. I use them for everything that is too delicate for sandblasting which is almost anything old that I deal with. For sandblasting I use a large local ag implement manufacturer. In fact, just this morning I dropped off a 800 lb lot of 150 steel weldments for one of our products for sandblasting and powdercoating. I was quoted $300 total for the lot blasted, powdercoated and protective wrapped.

And I highly recommend shopping around. The price of blasting and painting services varies wildly. A powdercoater that I used in volume religiously for over a decade began jacking blasting and coating prices through the roof during the pandemic. Parts that used to be $2 were suddenly $8 in large quantities and the owner looked me square in the eyes and tried explaining that the cost increases were because of increased powder cost- LOL. Yeah, right. The cost of his powder made my bills change for $500 to $2000. So I shopped around. Tried supporting a couple other smaller powdercoating shops, but only one of them was decent and reasonable and he didn't have blasting capabilities which made using him a pain.

 

[Malleus]

Also, remember that blasting leaves a charge on the surface, so you HAVE TO deionize it, or you'll get flash rust under the primer (even if you prep in a 0% humidity environment, because the paint has water in it). ZirconiumPhosphate is the stuff to use to prevent this.