Codybones
Active Member
I read someone said that they had a hood sandblasted and the guy didn't warp the hood. Can someone explain what that means and how do you warp it by sand blasting?
sand blasting
- Thread starter Codybones
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Heat. By concentrating too long in one spot which is EASY to do with sand. Glass beads or crushed glass is much more forgiving.
Demonic
Well-Known Member
X2 like Rusty said. There is also dry ice or soda blasting, which is lower heat than sand. It's the sheet metal part that's vulnerable to the warping. The hood bracing underneath is a bit thicker metal and less likely to warp.
Blast body panels on an angle not straight on.
I blasted a lot of cars,
I blasted a lot of cars,
Wet/sand blasting is best if yoou can do it.
JDMopar
Well-Known Member
yes thats me. i am running late but when i get back later ill answer the question.Who is the guy inthat is a professional sandblaster? @chrisf maybe?
to help with the question. Yes you can blast a hood and not warp it. BUT not for the first time blaster or an industrial blaster who does train cars all day long. .
lots of false info/wives tales out there on blasting so ill condense it down to MY reason why stuff warps. DIY people are sold rocks for media and are shocked when those rocks peen the surface and warp it. "fine" media to industrial supply places is usually around 30-60 grit. in my blasting world 30-60 is for gravel boxes and swimming pools. 100-200 is what i use for sheet metal
soda and walnut. great for paint removal. not great at rust removal Wet is 100% a dust suppressant and now you have shitty mud to clean out where you cant get to. wet blasting isn't for cars, its for concrete and still makes heat.
under hood bracing is easy to blast. where the bracing meets the underside hood skin is where the warpage happens. hitting it at a low angle (like 15 degrees) you can get under the brace and work the paint and rust down that way rather than a 45 degree and hope the metal doesn't move. its still tricky and not a fool proof method. (70-80psi at the nozzle)
if i get a hood that i am not 100% sure i wont damage i will do the bracing underneath, edges and 6" or so on the the perimeter topside and let the shop finish the rest (or work down 90% of the paint and primer and leave finishing to the shop)
that being said. in 15 years and hundreds of cars i have replaced stuff three separate times. (i warp it i replace it, no questions asked) all three times were hoods. third time was a couple months ago on a jeep wagoneer hood. i was so careful and didn't see the warping happen. it was the bodyman who found it.
so yes, there are blasters out there that wont warp the hood but its tricky. if its a rare hood you could always get it dipped as well and save the possible chance of damage.
not sure if that helps but gives you a bit of insight.
lots of false info/wives tales out there on blasting so ill condense it down to MY reason why stuff warps. DIY people are sold rocks for media and are shocked when those rocks peen the surface and warp it. "fine" media to industrial supply places is usually around 30-60 grit. in my blasting world 30-60 is for gravel boxes and swimming pools. 100-200 is what i use for sheet metal
soda and walnut. great for paint removal. not great at rust removal Wet is 100% a dust suppressant and now you have shitty mud to clean out where you cant get to. wet blasting isn't for cars, its for concrete and still makes heat.
under hood bracing is easy to blast. where the bracing meets the underside hood skin is where the warpage happens. hitting it at a low angle (like 15 degrees) you can get under the brace and work the paint and rust down that way rather than a 45 degree and hope the metal doesn't move. its still tricky and not a fool proof method. (70-80psi at the nozzle)
if i get a hood that i am not 100% sure i wont damage i will do the bracing underneath, edges and 6" or so on the the perimeter topside and let the shop finish the rest (or work down 90% of the paint and primer and leave finishing to the shop)
that being said. in 15 years and hundreds of cars i have replaced stuff three separate times. (i warp it i replace it, no questions asked) all three times were hoods. third time was a couple months ago on a jeep wagoneer hood. i was so careful and didn't see the warping happen. it was the bodyman who found it.
so yes, there are blasters out there that wont warp the hood but its tricky. if its a rare hood you could always get it dipped as well and save the possible chance of damage.
not sure if that helps but gives you a bit of insight.
Thanks Chris, I might also point out, that it's not legal in the States any longer to sell real sand for 'sand blasting'...at least to the best of My knowledge. I had blasted the Olds 15×7 Rallys with dried & filtered play sand from Lowes, but don't tell them that's what You're using it for, better yet.....protect Your lungs & just use Black Beauty or the like. Silicosis is chronic, so unless You're looking forward to a life of asthma attacks, just don't.
most "sand" guys don't give two ***** about their health. lol My local "blast for beer" guy uses a welding helmet with no respirator with beach sand, after he is done he pushes used sand and waste/lead paint into the creek below his place. downstream people actually get their water from the creek. he amazingly does not have silicosis after 30 years...yet its a terrible way to die.
i use recycled glass, it has no active silicate in it so no chance of silicosis, respiratory problems, yes but not silicosis. i am very aware of dust related issues so i am diligent about safety equipment and supplied fresh air.
most big suppliers have no problems selling you sand for blasting as they just want the sale.
its a crappy job but some days its almost fun. i get to see some amazing car collections that most people don't ever get to see.
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