therobski

What type of media should you use to sandblast the body on my 64 post?

MDchanic

What type should I use? Ahem. I ain't goin' near your sandblaster.

Personally, I'm partial to the black aluminum oxide stuff - cheap, sharp, easy to re-use, aggressive. Some might say it's too much for sheet metal, but I think it's okay if you're careful, and,, hey, this is no Dusenberg.

- Eric

joe_padavano

Sandblasting sheet metal runs the risk of warping it due to heat buildup. Definitely use low air pressure. This makes the work slow, but protects the metal. The type of media depends on what you're trying to do. Crushed glass is usually used for surface rust removal.

jensenracing77

you don't want to use sand or anything to aggressive. there are many differant choices for differant applications. you can ruin your sheet metal real fast if you use the wrong stuff and wrong pressures. a local guy is using soda for sheet metal but the equipment is real expensive to be able to even shoot soda. i have used glass bead for real small areas with low pressure but i don't think i would even use glass for big areas. i am no expert but have seen body parts ruined by blasting.

6inarow

You definitely want to be very careful when media blasting. The wrong media and too much pressure and you will be left with warped metal. I have used all kinds of media and I like plastic. With glass coming in a very close second. Plastic applies at a very low pressure and has a very low chance of metal removal. You can also recycle it until it's gone. If you use it in a blast cabinet it's nice because it is less dusty so you can see what you are doing.

mediaselection.jpg

joe_padavano

But what's the "probability of rust removal" with plastic media?

MDchanic

That's my question. If I'm blasting, I want to remove the deepest layer of oxidation, exposing bare, unoxidized steel. I may not want to use a full 150psi, or whatever's available, but I definitely would like to use the hardest, sharpest blast material I can get my hands on.

That being said, I do not blast sheet metal that much, as it is usually attached to a car, and I learned a long time ago that sandblasting parts that are attached to a car will acquaint you with nooks and crannies you never knew existed, but which can hold onto sand for years, releasing it a tiny bit at a time.

- Eric

therobski

This is good conversation. Because I want to call some media blasters and be some what intelligent during our discussion. I want to start taking the trunk lid, hood, doors get them cleaned up for the body finishing work and primer.

Gary's 2 442-S

I used "SUGAR SAND" it was very inexpensive cost about 8.00 for a hundred lb bag. It is very fine. I was very happy with the results. I also used a siphon type blaster which take forever to blast but you do not have to worry about it heating the metal and warping it.

oldzy

What would be best/safest to use on a rear end? I have sourced a soda blasting shop nearby who uses soda mostly, but has other media available, and can adjust PSI as needed. They do not use sand at all. I have another source (huge place called Peen & Clean) but they use steel shot in a huge closed tank.

My rear end is gutted (except for pinion bearing races yet to come out), and I am likely having it powdercoated before before being completely rebuilt (new gears, axles, bearing, seals, etc.).

6inarow

This was my biggest question too. There are different types of plastic media. The urea is the most common and it works well at paint and filler removal. Pretty good at surface rust removal. You can take it up a couple of notches by using melamine plastic media. Melamine is the most aggressive and works well at rust and it is not as harsh as glass. Just to reiterate, we are talking about cleaning up sheetmetal here. Plastic is less likely to damage the sheetmetal when you are learning as you go. I am sharing my experience at trying each of these. I don't do this for a living (though I would like to) but I have spent some time media blasting and I am getting ready to do a great deal more. As soon as I get the body off the frame of my Cutlass I will be blasting it with plastic first. I do like the results I get from glass beads and aluminum oxide as well. I hope this thread gets some traction because I would like to hear what other people are doing.

citcapp

I have used silica sand at low pressure with great results in a siphon blaster for removing surface rust and paint works fine but takes a long time

J-(Chicago)

I used to work for a sandblasting company, and the best media was a coal slag and silica sand mix. We would use the coal slag on iron railings and lawn furniture, and use the silica on graffiti removal for brick walls.

We would then vacuum up the spent slag and silica, mix it, and use it for automobiles.
Under high pressure I might add.

Straight coal slag would warp wimpy parts like....say... inner fenders on an 80's car, but most of the older stuff isn't very flimsy, and has a lot of curves, which add strength to it's form.

Parts with long runs of flat sheet metal like hoods and deck lids, are the only parts prone to warping.
Spent silica and new corn cob would work the best without warping.

For frames, and rear axle housings, I'd go straight for the black beauty coal slag. You're wasting time otherwise.

jensenracing77

[quote=j-(chicago);
for frames, and rear axle housings, i'd go straight for the black beauty coal slag. You're wasting time otherwise.[/quote]


x2
or silica sand. just watch out for silicosis. the dust from silica will kill you if you are not carefull.