naterman35

I was just reading a thread that mentioned sand blastign for rust and paint removel. On that they mentioned Coal slag, but i knwo theresother things you can use also...So whats recomended for removing rust,paint,and filler but all with out damaging the sheet metal.

ntomsheck

iTrader: (1)

I use coal slag, works great. Also, fine sand I've used before and that doesn't hurt the sheet metal. You have to keep it moving though. Don't let it sit in one spot and see how deep into the rust you can cut; move it around and then come back.

One thing to keep in mind is that if you do thinner parts of sheet metal that are rotted out (for example: floor pans, or wheel wells), you might tear a hole in it if it's rotted out enough. If this is the case though, you should cut out the bad part and patch in a new peice.

Coal slag and fine sand (alone with other media) will remove a fraction of a percent of the sheet metal, but not enough to jeopardize it's structural integrity unless it's heavily rotted out (like I explained earlier)

Here is a set of before and after pictures of my radiator support (the bottom of course)

Before:
http://www.securityvoid.com/personal/rad-before.jpg

After:
http://www.securityvoid.com/personal/rad-after.jpg

As for paint, you can still use coal slag and sand. Again though, move fast so there's no warping (don't worry too much about it however, it's surprising how little heat is given off during the blasting procedure). Baking soda is definitely something to look into. Doesn't do a single thing to the metal.

For body filler (like bondo) a blow torch works wonders. Heat the bondo up and scrape it off.

naterman35

Regular baking soda? or is it like "special baking soda"?...Im debatign about gettign a cheap bucket blaster then using that and doing some blasting. Ive done blasting in the cabinet ones... Im not sure what was in each one (ive used 2 before) but i understand how to do it pretty well. And between mine and a few other peoples cars i figure it wouldnt be a bad purchase and its only liek 13 bucks. But now say you do your blastign with like sand or coal slag... and so you have a big pile of the sand and stuff when yu get done.. Can you take a sive ( im not for sure on the spelling there) and filter the sand, take out any chunks of rust or anthing, and reuse the sand?

PROPHET69

Speaking of Sandblasting, mine will also have to be done in certain areas, Seems like in order to be able to sandblast, a 60 gal compressor is needed. I have 2 friends with 80 gals. Is there a way to do such a job on a car without such a huge compressor, I could consider buying something portable for myself like a 25 gallon, 150 psi. I've just been told and it does look like regardless, a 60 gallon is necessary.

mustardgass

I've heard from several people that blasting can warp the panels and cause more work. I don't know if this is true or not, but i'd rather be blasting right now then grinding. I probably would if I was sure it wouldn't warp the pannels.

John

ntomsheck

iTrader: (1)

Naterman: yes, you can seive out the crap and reuse the abrasive. On coal slag I think 80% is recoverable or something like that. I never do since it's about $6 for a 50lb bag of coal slag (which will do a lot if you're only removing paint. For rust however, that 50lb bag will go by quickly. Sand is about $4 for 50lb also.

Prophet, In the pictures I provided, I only used a 15 gallon compressor with a 3hp motor on it. The tank fills to 150 psi, the gun only needs 90-100 psi, so considering the size of the tank, I get about 20-30 seconds of run time before I have to stop and let the compressor refill. The compressor can't keep up with the gun, so it has to refill. Also, you can't run the gun much below 70psi because you're just wasting sand at that point (or whatever abrasive you're using). Because of this, it took me a couple hours to do that bottom piece, as opposed to the 10 minutes it would have taken me to do that if I ran continuous.

One thing to keep in mind is that any hardware store type compressor is not built to sandblast. It's just really taxing on the compressor and it's wise to give the compressor some cool down time once in a while. Even for those who have 80 gallon compressors.

Mustardgass: It can warp the panels if you're not careful enough. You must keep moving around instead of staying in one spot. On really thin pannels, this may mean that it takes a couple passes on one spot to get the paint off. Remember, certain panels are more susceptible to warping than others just by placement, so keep that in mind.