Media Blasting - What to use

[rlandrum]

We're in the middle of our frame off, and I'm about to order a blaster and blasting material to strip the body. The body is mostly metal, with two fiberglass rear panels. There's very little to rust on the car.

I've decided to purchase a soda blaster, although I won't do soda blasting for this frame off. Eastwood sells a $250 soda blaster that will do regular media and soda (which requires a special valve).

I picked, for paint removal only, a poly bead from Eastwood. It's a plastic, Poly 20/30 grit, and they say it's best for removing paint while leaving the sheet metal intact. To remove the few spots of rust, I've picked a 70 Grit Aluminum Oxide.

I've estimated that at 25 CFM, I can blast about 8 square feet per hour with the poly bead, and that the car is probably somewhere in the 60-80 square foot range. I'll blast through about 75 lbs of poly bead per hour. I plan to purchase 100 lbs of bead, and recycle it until the job is done.

To those that have done this in the past: Does this seem like a logical plan? Are these the right materials to use?

 

[PeterK]

When I did my frame, I used black beauty. I did the seams on the tub, a fews spots on the body and the frame. I used 1100 lbs in one afternoon. 2/3 way through, we had a summer cloud bust and had to reblast after it stopped. I rented a 4 cylinder diesel blaster, the kind you see doing overpasses on the highway.

Black beauty comes is both fine (used on the body) and coarse for teh frame and hard bits.

All 1100 lbs was recycled (not) into my field.

 

[Tinkerman]

When I did my frame it took 400 lbs of fine sand and two days. I would not do body panels with a sand blaster. The potential of warping the panels is too high. Having said all of that, IMA that maybe new materials and new equipment may help you do a better job.
I used paint remover to strip the body panels, messy but no warping. I am still sand blasting, wire wheels, tranny cover and I do a ton of bead blasting on small parts, in a cabinet type bead blaster. Best invention ever. I have heard of soda blasting for cleaning al but never used it.

My thoughts FWTW, good luck, Tinkerman.

 

[rlandrum]

Our frame was blasted by a local guy. He used black beauty. My father says it turned out great, even though I have yet to actually see it. It's off being coated with an some sort of heavy duty coating.

The body is a different matter for us, since it would be difficult to transport seperated from the frame. Since we're doing the painting ourselves, we decided that blasting it ourselves would give us the most flexibility in terms of when and how much.

At $85 per hour, our frame cost $118 to blast. I suspect that the body blasting would be close to $1000. The setup and materials we've selected would be about $550.

 

[DougF]

If you go through with your plan, I would consider buying several hundred lbs. of media. You will lose it through natural loss and through it wearing out. After a few uses, it will be dust.
We used playbox sand outside with good masks. A must since it will kill you slowly. After 2-3 uses, it was done.
Black beauty will hold up a lot better, but as with all medias, a mask is necessary.
I always use beauty in my cabinet.

 

[TexasKnucklehead]

Very interesting. I was planning to finish stripping the frame (removing everything but the frame) and taking it to a place that sand blasts and powder coats it, then taking the body to another place for media blasting and priming. I have a little rust, but also have some bondo, mostly on the rear apron. I've heard of some folks that were not happy with media blasting, and ending up also having the body dipped to get rid of all the bondo. I'm assuming the body will take much longer than the frame.

I'd like to know how that works out for you and what it ends up costing vs. having it done. My progress is a little stalled while I'm working on my house, and I want to get a title before I go much further. Anyone have a clear title to a 'parts car' they'd be willing to sell?

 

[Tinkerman]

When I lived in Texas I seem to remember that you could get a "junk" car title, or some such. Can you still do that type of thing?
I don't blame you I would hate to go too far without a title and then get bit in the end, so to speak.
Good Luck,
Tinkerman

 

[TR6oldtimer]

I faced the same dilemma as you. My choice was sand blast (with the finest sand available) the frame and use paint stripper for the body. Where there was rust, I sand blasted. This is working out well for me as I am doing the body piece by piece rather then the whole thing in one shot.

When sand blasting I wear a very good dust mask, and when stripping, an appropriate mask as well.

 

[angelfj1]

/bcforum/images/%%GRAEMLIN_URL%%/nonono.gif<u>DON'T EVER USE SAND</u>!!! You only get one pair of lungs and the silicon in sand can cause silicosis and an early grave. Use the proper media. It's cheap enough. AND use a good respirator not merely a dust mask. In the past 2 years I have used many forms of media.

coal slag -(called black beauty) for heavy rust and oxidation of steel parts - I use medium grit.

aluminum oxide - for a finer finish and softer material like aluminum, magnesium and pot metal parts. I use 40, 60 and 100 grit, depending on the job.

plastic beads - for delecate jobs and to remove dirt and grime - very low abrasion.

walnut shells, corn cobs - similar to plastic beads but even more gentle.

A good source with fair pricing is Grainger. Depending on the media, expect to pay about $1 per pound for 50 lbs.

Again <u>DON'T EVER USE SAND</u>!!!

 

[rlandrum]

At 75 lbs per hour, I will burn through about 750 lbs of media, which if I recycle my 100 lbs of plastic, means a 7-8 time reuse rate. Another 50 lbs would make that a 5 time reuse, which is probably perfect.

Since I'm blasting inside, I'm not worried about media loss, since I will use the shop vac and a strainer to reclaim the media.

Is plastic the right choice? Or would we be better off just using the Aluminum Oxide for everything.

 

[Gordo]

I think your estimate of reuse of 7-8 times is very optimistic. After the second or third pass the particles are going to be very fine. Which is ok, but the cutting action will decrease and you will have to keep the wand moving to not overheat the metal and get a good cut. I think you'll need at at least 300 lbs of media.

Gordo

 

[Tim Tucker]

I personally use extra fine Coal Slag ($13.39/100#). I use this in my booth and my pressure blaster. I build a crude booth and blast inside to help recycle 1x-2x.

I am planning my TR6 project. I am planning on using Eastwood's DeKote to strip the more delicate areas of the body panels and media blast using 50psi the areas that are difficult to strip. I will use my booth for the body panels (except the bonnet). I personally feel that the low pressure helps to ensure no damage. IMHO. I wear my painting respirator and keep the fans going when I'm not blasting in the booth.

Good Luck on your project!

Tim

 

[rlandrum]

Hey Tim:

Where'd you find that price?

Rob

 

[PeterK]

I pay a bit less for Black Beauty at my local auto parts store. Check a REAL parts store that sells to garages, not an AutoZone type store.

 

[billspit]

Black Beauty can cause health problems too so I've been told. I sandblasted a large part of my car using fine (#55) sand at 55 psi. I never warped a thing. I used aircraft stripper on a lot of it too. I did the sandblasting outside and used a proper respirator with HEPA filters. I made sure the neighbors weren't outside. Sand is definitely to be respected. I believe its outlawed in England.

 

[Tim Tucker]

I buy from SandMasters in Knoxville, TN. Here are some MSDSs for various blasting media: MSDS . 55 psi...good to know...I'll crank mine up a bit. Is that the pressure you have prior to blasting or while your actually blasting? I see about a 5# drop through my plumbing at full flow.

I know one thing: It's hard to beat a media blasted car for paint adhesion! I did the wife's VW that way in 1990...17 years later and not a single problem with the paint.

I wish my TR6 had been so lucky! The PO had the color changed and the work was done with stripper. I have no idea what was used or how. The paint has flaked off in sections. Thank God it was never driven. The good news: I have only one layer to strip off...

Tim

 

[DougF]

Yes, black beauty can cause health concerns. Same thing miners get, black lung.
I'm am quite aware of silicosous(sp?). That is why I wear a respirator. I value my health as much as anyone else and take care in wearing the proper the clothing and safety equipment to do the job.
It's the same with isocyanates and lacquer thinners and all the other dangerous substances that cross our paths while working on these cars. When handling, always wear the proper protective clothing and equipment.