Hello Gentleman and maybe Ladies to.
Nice to meet you. I'm new here and this is my first post. I'm Chris.
I don't restore autos as you do meaning I don't bondo, deal with dents or paint.
I'm a welder, fabricator and sandblaster that owns my own business. I do dustless wet blasting and traditional dry blasting.
https://after-hours-welding.com/
While browsing around and snooping, I noticed many of you had opinions on sandblasting. Some of your opinions are correct and some not so correct. But I did notice most all of you wanted to know the truth of the matter. If you'll forgive me for appearing egotistical, I'm somewhat of a true expert in many of these matters and have a
long public track record on my performance delivered.
Because I do dustless blasting and traditional blasting, which is super rare, I could do a auto either way. There is no price difference as they both cost the same. So I would not care what you chose. I love dustless blasting but not on vehicles or metal. If your a potential client I would try to convince you to get dry traditional blasting done on your vehicle. Unless it is only the outside your stripping.
As many of you have already noted here and discovered from personal experience, dustless will pack the nooks, crannies, corners and holes of your vehicle with wet mud that does not want to come out later. I blast 99% of autos with dry traditional blasting so when I'm done, I take my 1" air hose pushing 185 CFM at 100 PSi, and I blow all the sand/abrasive/glass/media out of my customers vehicles.
And I do not charge for this. I just want happy repeat customers. Yes, I can push 185 CFM (cubic feet a minute) while still maintaining 100 PSI with no pressure drop. It takes me 5 minutes to blow ALL the abrasive out of your vehicle so all you have to do is apply your coating of choice. I want happy customers in case you didn't notice from my reviews.
I had one customer who was convinced from Dustless Blasting Brand videos that traditional blasting generates heat, so he insisted I shoot his dismantled vehicle with wet abrasive. He didn't want to listen to me and I didn't want to argue so I did it his way.
OMG, what a mess. He had mud stuck everywhere inside his vehicle. Of course it wont blow out because its to sticky. So he took a power washer to it and rinsed it out which washed off the Hold Tite 102 and he got flash rust everywhere. In 5 minutes his vehicle was orange from flash rust. Then many of his holes held water puddled and just kept on rusting. And it still did not get the abrasive out of all the holes. The ricochet effect will put mud in places you nearly cant imagine. Whats your worst nightmare? I will never have sex on a beach again. Its something I will never forget nor repeat.
Does traditional dry blasting generate heat?
Does traditional dry blasting warp sheet metal?
Actually those are the wrong questions to be asking as those answers do nothing to protect your auto from warping.
Yes it generates heat. But how much? And what effect does heat have?
Yes dry blasting can warp sheet metal. But so can wet dustless blasting.
How much heat will dry blasting generate? If the sheet metal is 80 F degrees in ambient air before dry blasting, it will elevate to 120 F. So what? Are you afraid of 120 degrees? I guess you better never park your car in the sun again as it will bake and warp.
When metal gets hot it expands and when it cools it shrinks. Heat is not the cause of warping. Metal is always changing shape as temperature changes. But its not enough to notice and its not permanent because eventually it cools and goes back to its original shape. So yes the sun can warp your car, but if its not enough to notice, do you really care?
Does shooting it with glass protect it while shooting it with sand damage it?
No. Neither is true.
I hate to say it, but size matters. Dam, I never thought I would admit that one.
How big is the hammer your hitting it with? How hard is the impact? How much energy are you transferring with each blow? How big is your point? How deep are you driving it in? The last girl that asked me that, I never called her back. I knew the next question would be, how much money do you have in the bank and what do you earn?
Ok, lets examine the real point. No, this ones not dirty. Your just dirty minded and you know it.
The real point is: Let me drive 2 thumbtacks into your leg thigh. How much swelling did it cause from the displacement of the point being driven in to full depth? Nothing that you can notice. We're not talking about pain here so quit your whining and wincing.
Now let me drive in 50 railroad tie spikes in to full depth into your thigh. Now we have massive displacement and your thigh will swell/warp. Now its very noticeable.
Is it sand or is it glass?
Is it wet or is it dry?
Is it warm or is it cold?
It doesn't matter.
How big are your nails/balls/grit/hammer?
That's the
1st million dollar question.
How big is the point and how deep are you driving it in and what displacment can you expect, is what matters. When she told me that I knew I was in trouble.
Grit size. Is it fine or is it course? A larger abrasive chunk has more momentum, it carry's more energy, it drives in deeper, it displaces more metal when it punctures into the surface as it creates a hole/profile. Big grit carries more potential for damage. Grit is a single piece of abrasive in case you didn't know.
Was it a glancing blow as it chipped off a little paint and rust, or was it a direct hit while it moved the paint and rust aside as it continued to drive straight into the metal deep as it caused much displacement?
Gentleman, that is the
2nd million dollar question. I cant believe I'm going to teach my competition how to stop warping cars. I'm such a F...ing idiot for revealing this. Just shoot me now and put me out of my misery.
Fine small light weight abrasive shot at a 45 degree angle will remove paint and rust and shot at 70 PSi will not warp metal.
Course large heavy weight abrasive shot straight on at high PSI (100 or up) will penetrate the top of the metal, displace it moving the metal outwards to the side causing waves.
There you go. The secret of the universe.
How to warp metal or prevent warping.
Heating metal will cause it to expand and warp, but when it cools down it will shrink and go back to its original shape.
Displacing metal pushing it aside powerfully will expand it causing it to warp,
but it will now be permanent and will not go back into its original shape.
There, did I answer some of your questions? Ask on. Maybe I have another answer, maybe not.
Next thing. How can you tell a good automotive sandblasting service from a bad one. Who will warp your auto and who wont?
All of us guys in business need efficiency and fast turnaround to make money to pay for our blast rigs. We will all use as much course abrasive as possible as its much faster. We all want to get more done in less time don't we?
A true professional will carry 2-3 pallets of abrasive on our rig so we can swap abrasive size upon demand.
A amateur can only carry one pallet of abrasive, and chances are high its course large abrasive.
Also a real professional can shoot wet or dry upon demand. Dustless Brand blasting rigs cost less money so they are the most common purchase to new people jumping into blasting business. Plus they will finance them. Dustless Brand can only shoot wet mud. Sometimes I love wet mud when I'm stripping paint off brick or concrete. But I would never be caught dead only being able to shoot wet only.
Traditional dry rigs of my caliber cost more money to purchase, plus they wont provide financing. So amateurs nearly never buy a dry blaster because they don't have that kind of money.
So who do you want to hire?
Ask your potential blasting contractor to be specific and tell you exactly what he does to prevent metal warping. If he does not tell you all the things I've pointed out here, then he does not know how to prevent warping and you need to run. Run fast away from him unless your a gambler and enjoy determining your results with the flip of a coin.
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Or for those of you that want to watch it on youtube so you can read or leave comments,
I know some of you may wish to hire me, but please forgive me as I'm not always available for little blast jobs as autos, as frequently I'm busy with restoring large commercial steel staircases that need lots of welding and sandblasting. Sometimes I cant blast an auto for months. Sometimes I can fit them in within a week or two. So don't get your hopes up. I hate disappointing people. But you might be the lucky one, who knows?
So have I helped any of you? I would hate for all this writing to be a waste.
Just relax. Don't take life too seriously.
It was nice meeting you all.
Chris