The Stovebolt Site Forums The Shop Area Paint and Body Shop Dustless blasting?

My cab is empty except for the pedals and the insulation glued in way up under the dash. I have found a place that has a 2 hr min. Better that I am not wasting too much time with the 4hr and 8hr min guys.

I have replaced all the metal I think I need to but I do expect the blasting will show something else to attend to.

Who else has done the dustless? Good bad ugly?

When I got my cab blasted, the guy was at it a full 8 hours. Of course mine might have been in worse shape than yours. It was mounted on a rotisserie that allowed him to rotate it to get to everything. My blaster could have done dustless blasting, but he didn't recommend it. When you add water to the blast stream, it increases the force applied to the metal and would increase the possibility of warping the sheet metal.

If you're having the whole cab blasted, I'll bet it would take at least 4 hours to do a reasonable job.

It is strange that your guy would say dustless blasting increases the chance of warping the metal (the pressure can be adjusted). The argument you hear most of the time is that dustless blasting is cooler and there is less chance for warping. I have no experience with either. I just follow all of the post because at some point I am going to need to have at least some of my truck blasted. I wonder if he was just saying that because he had a "dusty" blaster? I am curious to see what others experience has been with both methods.

Agreed. Dustless is supposed to reduce warpage, but a experienced blaster will not warp either from what I have seen.

I think the dustless will get into all the seems on the cab better than a regular grit set up. Plus they have a rust inhibiter so it wont flash.

My guy had the capability to do either dry or dustless blasting. He was the expert and I let him chose which to use. Maybe I was wrong about the warpage, but the addition of water would increase the mass of stuff hitting the metal. I don't believe that it's heat that causes the warpage, but the peening of the metal. MPandC has a video where he demonstrates the issues with blasting just on one side of a hood where the back side was made inaccessible because of reinforcements.

And what media was used?

He used a fine glass media, I don't recall what the grit size was though.
[on edit] grit size was 80.

Plenty of Dustless Blasting videos on YouTube. Here’s a ‘63 Impala done in 1 hour.

www.youtube.com/watch?v=bCehkkTTeMk

Wondering if there's going to be anything left of that rust bucket afterwards.
The front of the hood looks pretty swiss cheesy.

The "water is cooler so it won't warp" is marketing hype. Media hitting the panel is basically many tiny hammer heads hitting the panel. Too coarse of media is basically using larger hammers. Too high a pressure, whether that be using air or water pressure, is just swinging those hammers harder. Warping occurs when the hammers are too big or swung too hard.. has nothing to do with heat. If the panel gets hot it is from the peening action. Take a hammer and pound on a piece of sheet metal on an anvil and it also gets warm. But just like media blasting, the panel stretches long before the heat shows up.

The biggest detractor for using the dustless blasting is that the slurry that it makes winds up in nooks and crannies and is difficult at best to remove. So now it becomes the next moisture trap for starting more rust.

I love how the videeo says that blasting that rust bucket Impala in the guy's driveway is "eco-friendly".

Oh ya, everybody knows that ground up glass particles mixed with 60 year old automotive paint is good for the lawn!

Ground up glass is simply sand. The paint can be swept up and thrown away. In my case it will end up in the grass.

How about dry ice dustless blasting?

My brother in law’s cousin does this for oilfield refurbishments. Co2 pellets are used and there are no sparks in potentially explosive environments, no water, no dust, just the stuff you remove.

I like the sound of the dry ice blasting but I bet it is expensive if you can even find anyone that does it. It is probably only used in commercial applications.

We are a pressure washer/compressor repair shop and am interested in more info on using the pressure washer sand blaster? I have used the water blaster with excellent results on wrought iron projects.
Or am I better off using a sandblaster with certain media for the bodywork? Plan on doing a frame off restore on my 54 GMC Truck. I can blast the frame with glass media or coal slag, but what is best for the body work? Still learning as I go. I do have some bad body parts I can practice on.

You need to select the grit size for what you're doing. Heavier grit (larger number - coal slag?) is appropriate for heavier metal parts like a frame. But glass media (fine grit) should be used for body panels. You also need to adjust the pressure for what you're working on. Lower pressure would lessen the chance of warping the metal, although if you linger too long in one spot, you could still warp sheet metal.

Guy got here, looked things over and decided dry would treat me the best. Took him 3 hrs. I have a very little bit of touch up sanding to do and then shoot it with some primer.

It showed up a couple of tender spots and I need to touch up a bunch of my welds.

Did he do the bed and fenders, etc?

No. Just cab and hood. I had done the other stuff at a buddies shop.