There are many here that have differing ideas of the correct material for sandblasting. I won't get into that, as I just usually use whatever is available.

As far as removing the undercoating, I usually use a heat gun or propane torch to heat the stuff, and a scraper to remove it. Sandblasting takes for ever, as the stuff it pretty resistant to it. You can also use a wire brush on a grinder, but that sends it everywhere.

Just make sure you wear plenty of protective equipment, such as gloves, eye wear, long sleeves, mask, etc.

Aaron

 

Plain sand is hard to beat for this type of blasting but be SURE to take precaution in dealing with the dust, that stuff can kill you and that is no joke. Also a buddy of mine blasted the underside of a GTO not long ago and reused the sand after collecting and sifting it but that turned out to be a bad idea. The tiny bits of undercoating that was mixed in with the sand then became embedded in the metal around the engine compartment where it caused major headaches with the primer. We discovered that even the clean looking blasted areas would produce a black residue when wiped down with thinner so it seems that reclaimed sand will be contaminated with whatever was removed the first time it was used.

 

Plain sand is hard to beat for this type of blasting but be SURE to take precaution in dealing with the dust, that stuff can kill you and that is no joke. Also a buddy of mine blasted the underside of a GTO not long ago and reused the sand after collecting and sifting it but that turned out to be a bad idea. The tiny bits of undercoating that was mixed in with the sand then became embedded in the metal around the engine compartment where it caused major headaches with the primer. We discovered that even the clean looking blasted areas would produce a black residue when wiped down with thinner so it seems that reclaimed sand will be contaminated with whatever was removed the first time it was used.

I've heard of that exact same problem but never heard anyone else mention it. Good to hear other's supporting evidence.

While not the healthiest of methods, kerosene or diesel fuel , usually turns even the hardest undercoating into a soft compound the scrapes easily. However, this method involves hazardous materials and waste. So, be sure that you comply with your local ordinances regulating the discarding of such waste.

At the very least, I would put down some heavy mil visqueen and use protection, i.e. thickster gloves, face shield, and an organic compound respirator.

 

There are many here that have differing ideas of the correct material for sandblasting. I won't get into that, as I just usually use whatever is available.

As far as removing the undercoating, I usually use a heat gun or propane torch to heat the stuff, and a scraper to remove it. Sandblasting takes for ever, as the stuff it pretty resistant to it. You can also use a wire brush on a grinder, but that sends it everywhere.

Just make sure you wear plenty of protective equipment, such as gloves, eye wear, long sleeves, mask, etc.

Aaron

Hey Aaron

THANKS for your impute. I never thought of your ideas about using a heat gun.
WILL DO.
AND THANKS AGAIN.

GOD BLESS
Schooner

 

There are many here that have differing ideas of the correct material for sandblasting. I won't get into that, as I just usually use whatever is available.

As far as removing the undercoating, I usually use a heat gun or propane torch to heat the stuff, and a scraper to remove it. Sandblasting takes for ever, as the stuff it pretty resistant to it. You can also use a wire brush on a grinder, but that sends it everywhere.

Just make sure you wear plenty of protective equipment, such as gloves, eye wear, long sleeves, mask, etc.

Aaron

Hey Arron

I came across this stuff " BLACK MAGNUM " have you or the other guys ever used this stuff.
Check below, let me know what you guys think ?


http://cgi.ebay.com/25-LBS-BLACK-MA...K-MAGNUM-BLAST-MEDIA-SAND-BLASTING-ABRASIVE_W0QQitemZ190052773247QQcmdZViewItem

GOD BLESS YOU ALL

Schooner

 

Sandblasting help needed also!

Hey, I am using aluminum oxide! Works great but way too expensive! I got some 20-40 grit black diamond at TSC store! Cheap but there is a problem! I can't find a nozzle that will fit my deadman valve that is large enough! Besides the oxide is cutting great just too expensive! I am using a typical body shop respirator that I use to when painting cars! Are you folks talking about using hardware store bought white fine sand??? Also, what are you folks sifting this stuff through so that you can re-use it??? I swept it into a pile on the floor and was going to vac it up with my 12 gal shop vac then sift it into a bucket and re-use it!

 

Are you folks talking about using hardware store bought white fine sand??? Also, what are you folks sifting this stuff through so that you can re-use it??? I swept it into a pile on the floor and was going to vac it up with my 12 gal shop vac then sift it into a bucket and re-use it!

If I'm sandblasting, I use either landscapers orange sand or brick mason's sifted white sand. As far as recycling sand, sweep up your blasting area before you blast. Then, once you have depleted your sand supply, sweep up your sand into a pile. Now you can use a metal screen to sift the sand.

I made mine out of fine metal screen and some ripped 2x4s, but Eastwood sells some round screeners that are great for those of us who own pressurized blasters. Just be sure that you get the finest screen you can that doesn't clog with each grain of sand.

Just remember what Oldred said about contaminants within your used sand.

 

Great info.

Fast reply! Cool!

 

Household window screen work?

Would household window screen work?

 

Hi Guys

I've got undercoating and light rust under my car that I want to get rid of by sandblasting.

Can you guys tell me what material do I use to get rid of the black undercoating and light rust with ?

Do I use WALNUT SHELLS ?
Do I use GLASS BEADS ?
WHAT ?

Whatever you think is the BEST way to do this procedure will be greatly appreciated.

THANKS
GOD BLESS YOU ALL

Schooner

The best way to do it is to take it to a professional media blaster - then pick it up in a couple of days completed!

Heat gun or propane torch to heat and scrape as someone else suggested - you'll still want to wipe down the area with some solvent/cleaner.

There is some spray on products that loosen undercoating - but I'd think this makes more of a mess than it would be worth...but this might be good stuff for cleaning after scraping?

 

hard ,cured undercoat will chip off with an air chisel and wide blade. i stripped the 62 vette this way. once you heat it or put solvents on it it is a mess. after it is chipped off a presure washer with 3k+ lbs will clean it up well.

 

Would household window screen work?

I've used household screen for years. But, as stated contamination can be a problem. I usually run back over it all quickly with fresh sand to remove contamination, if I blasted alot of under-coating.

p.s. Yes, I too have experienced the contamination problem. ain:

 

I heard dry ice blasting really takes undercoating off fast but not real common in this neck of the woods. I scrape it off with torches and heatguns before blasting along with any seamsealers.