Dustless Blasting

shine

Member
why do these guys still push the 0 warpage because the water cools the piece ? over the years i have seen at least a dozen threads where the temp of metal was measured while blasting . we all know heat has nothing to do with it but you will get pummeled if you say that in one of the other forums or worst yet on fakebook . i've also notice a majority of them have no experience other than buying a trailer full of equipment and reading the manual . my media supplier sells used rigs because the guy who bought it went out and destroyed a bunch of sheetmetal and bailed .
 
I can confirm first hand. My blaster swore up and down that he's never had a problem, my hood determined that was a lie.

I had concerns about it before hand and told him to go very easy on it, if it wasn't totally cleaned up I would take car of the rest. I cant imagine what it would have looked like had I not said that. My blaster was a really nice guy, but I don't think a ton of experience. The hood on my pickup is really flat with hardly any support. I knew better than to take it to him, but had a lapse of judgement.
 
Back in the eighties it was plastic media. Then came soda and walnut shell blasting. After that dustless blasting etc. etc. I can't count the number of times some customer hauls a panel into my shop and says "I've saved us a bunch of time and had it (trending media of the day) blasted". Each and every time the panel is warped causing more time and money. If they came out with cotton ball blasting I'm sure some dumbshot could warp a panel. ~BOB
 
my media guy tells me the majority of them who buy the rigs are early retirees who drop a butt load on a trailer and blasting rig . bad part is they dont listen to him and just get after it . he buys back the rigs for 50 cents on the dollar .
 
It has the potential to warp worse, the media has the added weight of water riding on it so it hits the panel harder. Plus the media packs down into crevices and is near impossible to get out if its allowed to dry. A friend of mine let a local dustless blaster strip a perfect '67/68 C10 hood when it was the new thing to do... the top of the hood is floppy now, and he had to find another hood for his project.
 
Funny Shine My ex salesman told me the same story about the retired guys getting into this great side line Dustless Blasting.
 
this is something ive read about often and something ive thought about:
suggestions ive read MANY times to newbies when they purchase their first spray gun is to practice. im sure we have all read a time or 37 newbies pulling the trigger on a gun...on their project car they spent countless hours on prepping. end up with a mess.

do these dustless blaster guys head to the nearest boneyard and practice? or do they practice on their own rides first?
 
I know the owner of the company, and have used a "test" machine several times. It has NEVER warped anything I've blasted. Ive blasted my entire 1970 camaro and many parts. I have no history using the machine, besides initial training from one of the company engineers.

There is so much misinformation about these rigs, its ridiculous.

1. Pressure matters. If you crank the pressure up, yea, your ganna mess up whatever your blasting.
2. Tip selection. There are several different tips you can use. If you use the tip that puts all the pressure in a small area, you will have issues.
3. Media. There is a specific type of media you use, if the blaster tries the go cheap and not use the recommended media, you will have issues.
4. Technique. If you bare straight down on the metal, and not at an angle, you will have issues. This is probably the most important aspect of using one of these machines, all the previous issues can be overcome if the user knows what's going on.
5. Time. If you slow down and do the job right, you will have less issues. Most independent blasters out there rush jobs, thus more pressure, less time, less technique.
6. Thickness of metal...obviously blasting thin metal will warp...again, nothing on my camaro warped. Including aftermarket hood.

The only thing I would say from a negative perspective, and this was my own fault...is that media goes EVERYWHERE. I should have blasted car completely disassembled. The opportunity came up, after I had put engine and transmission in car. It was a choice of pulling everything back out, or trying to tape it up. I failed miserably to tape it up. Media went everywhere. I spent a LOT of time vacuuming and air blowing media out of every nook and cranny on my car.

Anyone has any questions about Dustless Blasting, Id be glad to answer, or relay them to company. From what I can see, issues that arise from DB, is 90% user error, if not higher. There are many elements to using the machines.

Of course, I sprayed everything with SPI epoxy.

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the problem is the guys who go around claiming the water stops warpage . i call bullshit . temp has 0 to do with it . i can blast with any equipment and any media . i can blast sheet metal or fiberglass . my first experience with blasting was in 1970 blasting aluminum skin on aircraft .
the dustless crowd is just like the soda crowd . making claims they know nothing about .
soda was designed for the food industry and printing industry . dustless was designed for commercial blasting such as water towers and such to avoid the huge tarps they had to use . neither was ever intended to be used in automotive .
 
@giggity i think you made the point in your great response that you need to know what your doing. people buy these things without any idea what they are doing then ruin the sheetmetal. blasting is blasting and will warp metal no matter if water is in the process or not. the water does nothing but control the dust. it has nothing to do with controlling the warping. for that you need to know what your doing like any blasting system or media. like shine said it has nothing to do with heat. every grain of grit is like a little body hammer and you will stretch the crap out of the metal.
 
Sorry if I was misunderstood, I was not endosing the wet blasting process. I have never used it and don't plan to, just pointing out the importance of equipment operators in general.
 
All the drawbacks of dry blasting apply to wet as well, though wet has an advantage of not creating a dust cloud, which can be really important in a populated area. That's it only real advantage imo, it helps keep the neighbors off your back.
 
I had the floor pans of a car dustless blasted on a rotisserie. It made a huge wet mess. And also ruined the wheel bearings on the rotisserie. Ill never have that done again.
 
I would guess that dry blasting would not do bearings any favors either. I think mine are just bushings, they have shrugged off the sand so far, but I don't roll them around much.
 
I would guess that dry blasting would not do bearings any favors either. I think mine are just bushings, they have shrugged off the sand so far, but I don't roll them around much.
Yes. I had same thing done dry and was able to go around with my leaf blower and blow all the sand off into the grass...the wet was like taking a blower to wet sand at the beach...needed to shovel it out. And ironically, the guy who did it was a retiree who bought a rig lol.
 
Ill admit I was skeptical using the rig. But taking a car down to metal, you can use aircraft stripper....Ill never do that again. The chemicals, fumes, and cleanup are bad.

The other option is sanding. If you are planning to take the car down to metal, this is not a good option.

Only other option is blasting with some sort of media. My interest here isn't to argue or persuade people, its to put out the facts. People are going to do what makes sense to them, which is highly subjective.

All I can say is that the Dustless blasting rig, if used correctly, does not warp metal. And yes the biggest benefit of dustless blasting is the water carries off most of the air contamination. Not all of it, I still wore a respirator, full union suit, and rubber boots. It absolutely, 100% makes a mess.

Id agree that a lot of the people buying these rigs are retired, or small business owners, or generally people who will not be operating the machines themselves.

Id suggest if you do contract with a owner of a dustless blaster rig, you require a few things.
1. some sort of insurance on work in case they do mess something up.
2. ask what kind of media(they should be using the dustless blasting supplied media) and rust inhibitor(waterborne is best IMO) they are using.
3. make sure they do a full cleanup when done.
4. be prepared to clean, prep, and epoxy immediately after blasting.
 
I strip my outer body panels with stripping pads on a 4 1/2" angle grinder.

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I'll will follow that up with 80 grit on a D/A before I spray it with epoxy primer.

I blast everywhere that can't be done with a stripping disc like the door jambs, floor, underbody and etc.
I do all my blasting using a pot blaster and Black Diamond coal slag media.

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