Best blast media before Epoxy

C

cstrom72

I'm stripping the engine compartment of my brothers 67 Mustang in preparation for Epoxy- I know that soda blasting needs special instructions before epoxy but what about just sand blasting? I have a small gun that ill be using for all the nooks and cranny's, can I epoxy directly after w/g remover? Also is sand the best material? Ill be doing this in the driveway so I dont want to use glass.. Im mostly just stripping paint, very little rust..Thanks!
 
As I am getting deeper into my project im thinking of taking the car to a sand blaster and having them strip everything from the cowl forward. I'm assuming they don't use "Starblast". Would just a regular sand they use be ok or is there something special that epoxy can go right on immediately after cleaning? What do I need to know or talk with the blaster about? I would like to shoot my epoxy as soon as I get the car back home... thanks
 
Shine would be concerned more with the hardness of media vs. the shape and coarse-ness?

Round over sharp profile, 5 vs. 9 on Mohs scale?
 
Pretty sure Shine is commenting on using SAND as the blasting media. There is strong evidence that breathing in asbestos fibers is bad for you. There is also strong evidence that smoking cigarettes is bad for you. It has been mentioned on this site that breathing paint fumes is bad for you. There is also strong evidence breathing SAND dust is bad for you.

The primary component in sand is silica. When the silica breaks up into fine particles and you breathe them in, you may develop silicosis. The Centers for Disease Control (CDC) describes Silicosis like this:

When workers inhale the crystalline silica* used in abrasive blasting, the lung tissue reacts by developing fibrotic nodules and scarring around the trapped silica particles. This fibrotic condition of the lung is called silicosis. If the nodules grow too large, breathing becomes difficult and death may result. Silicosis victims are also at high risk of developing active tuberculosis.

My childhood home was covered with asbestos siding and I helped put down an asphalt/asbestos tile floor in the basement family room. In my youth I smoked cigarettes. I have painted things without a mask. I have used sand to blast rust off a frame. I just turned 69 so my risky behavior hasn't killed me yet but your results may vary.

Rather than buy a 50-pound bag of play sand from Home Depot for $3.76, the elders on this site are recommending you buy a bucket of Starblast for $80 or so. If that's out of your price range, you can buy a 50-pound bag of recycled glass abrasive for $10. I'm quoting those prices from Northern Tool, who sells many different kinds of blasting media but they don't sell SAND. Here's a link to their media offerings: http://www.northerntool.com/shop/tools/NTESearch?storeId=6970&ipp=24&Ntt=blasting+media
 
sand contains caustic salts which will promote rust. starblast does not . it contains less than 5% quartz . last time i bought starblast it was 11 dollars for a 50lb bag. glass works well also . just be careful with the dust from it .
 
Starblast ,sand, coal slag, crushed glass, there's a lot of choices that will work good. I've been using clean silica sand for over 30 years and always had very good results, I don't think the sand from the Great Lakes area contains the caustic salts that are found in other areas. But the hazards of silicosis are always there and the safety is always the responsibility of the user. An 80-100 grit sized media works best IMO.
 
Thanks for the replies, I guess I didn't mean "sand" like what a guy would find at home depot. What do sandblast shops use as a "standard" media? since im sure they buy in extreme bulk quantity. Basically like this post started, I want to be able to go straight into epoxy when the car comes back from the blaster.
 
it has to be washed first. dawn soap and water then rinse well. as long as it is a place that does cars . anyplace else will likely have some inexperienced guy just blasting horse trailers and cement trucks and using river sand. will promote rust and likely warp the panels.
 
I understand silicosis and related ailments, my question was regarding at what point does media aggressiveness start to warp panels?

There must be a profile or Mohs hardness maximum that would be allowable before damage would occur to panels, yes?
 
no. anything that can remove paint and leave an anchor pattern can warp metal. even soda or plastic. they are 2.5 moh and 3.0 moh .
 
We use recycled crushed glass. Produces nice clean white metal.

Shine is right, you have to think.....high air pressure AND abrasive material. You can warp just about anything with any media. It comes down to the guy behind the hose. The reason we got into the blasting business was because we had a mobile unit come out and blast a 65 Rolls Royce for us and completely destroyed the hood..with soda. Just can't go out and find another one of those. Never again.
 
I just scheduled a day with the sand blaster. He uses a silica sand and has been sandblasting cars for 20 years, he even claims to be a SPI epoxy fan. Nov 1st she will get blasted if the weather permits. Thanks for the info guys. From further reading ill be getting solvent based AND water based W/G remover for cleaning of the bare metal. Thanks guys! Ill post some pics
 
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