Plastic Media Blasting vs Glass Media Blasting

I just retrieved my M-101A1 from the blasting guy I know. I had my entire '715 plastic media blasted a few years ago but when I picked up the trailer today I noticed a difference right away. He told me he now uses a 50-50 mix of plastic and glass in the blaster. The glass removes more material and will get into rust better he told me. However, like sand and other abrasive media, the glass "opens the pores" of the steel. It will quickly rust and you can see the rust film appearing in a few hours if the humidity is high. The M-101A1 was blasted yesterday and already the film is there. Priming must be accomplished immediately. I like the plastic better!!!

My blaster friend has an El-Camino in his shop for several years that he is rebuilding. It was plastic blasted 4 years ago and still no rust on the bare steel.

Thats good to know, even soda blasting only lasts about 2 weeks around here with the humidity during the Summer.
I have been using a new (or different, might not be new) process lately. They call it a sand bed tank, it has sand in a liquid solution that heats up to 700+ degrees and removes paint and rust. I was nervous at first about warpage from the heat, but it heats everything up evenly with no problems. Alot of my students and friends have been using it. After the sand bed it goes into a tank of acid to eat ALL the rust off then into a neutralizer tank which leaves a coating on the metal that lasts for months (It needs to be washed off before priming).
This process removes EVERYTHING including paint, sealers and the dampening materials between the inner and outter layers of the hood and doors so they will need to be replaced.
It works great on gas tanks too, I have a motorcycle tank and frame getting done right now.

Here at the shop we use glass beads, sand and soda blasting. I've not used the plastic media, but it was developed mainly for stripping fiberglass like on Corvette bodies.

Anytime you strip off any coatings on metal, if it is ferrous, then it needs to be primed very shortly thereafter. If not it will flash rust quickly. Even more so if there was any moisture in the compressed air used to do the blasting, or if it is a place where there are big temperature swings which will cause condensation.

That El Camino must be in a very well-controlled environment to not have rusted at all with bare metal in four years. Even just chemically stripping a motorcycle fuel tank and leaving it on the bench in the shop for a few days will cause some flash rust, and that is in an air conditioned environment at a constant 72 degrees in the Summer.

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Originally Posted by randyscycle

That El Camino must be in a very well-controlled environment to not have rusted at all with bare metal in four years. Even just chemically stripping a motorcycle fuel tank and leaving it on the bench in the shop for a few days will cause some flash rust, and that is in an air conditioned environment at a constant 72 degrees in the Summer.

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It is in a controlled area but I personally believe the 1/8" layer of dust and crap is protecting it!!

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Originally Posted by rboltz

It is in a controlled area but I personally believe the 1/8" layer of dust and crap is protecting it!!

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That may sound funny, but actually, I don't advocate cleaning or doing anything with something until you are ready to actually restore it. That layer of grunge does provide some protection.

An older gent that I work for once a week had a 77 chevy pickup soda blasted and they state to wash it down with Vinegar before painting.. (I got the info AFTER I painted it, masking tape peeled paint off:mad:)
Another thing.. We were told and friends also stated that "you just blow it off, wipe it down and you paint.."

WELL, now we are scrounging yards trying to find most all wiring because the humidity in the Memphis area caused severe corrosion in almost EVERY wire connection.. Even the steering column was too corroded to use. (we towed it as a NO-glass shell except wiring )
I don't know what the heck they used to blast it with (hose and pressure) but I couldn't blow it out enough.. IT KEPT COMING OUT EVERYWHERE!! Even when I thought it was enough and mixed up a quart of paint, and started to shoot... Crap would come out!
And re-assembling it, caked soda was still falling in my face from under the dash and bed.

I had the bed of my 715 sand blasted (only the outside) just because there wasn't any 'hidden' areas but that cose me 200.00:eek:

If I ever go that route again, I think that I'll try the plastic or chemical and a steam pressure washer.

OH, and watch using silica sand.. It can cause problems in your lungs without a respirator!! I don't know about playsand/white sand though.

Just my .02
Errol

Errol's experience is why I rarely will ever blast anything as big as a car or truck.

I do motorcycle bodywork and small parts, but even frames I hate to blast because they fill the tubes with media you can never get out. I am not sure the plastic media will take off powder coating either.

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Originally Posted by randyscycle

Errol's experience is why I rarely will ever blast anything as big as a car or truck.

I do motorcycle bodywork and small parts, but even frames I hate to blast because they fill the tubes with media you can never get out. I am not sure the plastic media will take off powder coating either.

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Plastic is still falling out of my M715 and its been years now. The floor gets full of white beads after a trip.

At least one good thing with the plastic is that it likely won't hold moisture, and it isn't so fine that it will stay there forever.

Of course AFTER that experience, then was told by a friend that one should run a tape strip to seal ANY cracks, such as door jambs, hood/fender seams to block stripping media and go after the 1/4 - 1/2 of paint left (under the tape) to some 60-80grit and save the hassle.

I'm not changin the subject here BUT..
I stripped a roof of my ol 72 Monte Carlo and then coated with Por-15's Metal prep. NOW, that sat outside for over 4 months without even getting flash rust!!
So, if I ever soda blast again it will be wire free and get a bath/shower with the steam pressure washer and some metal prep after.
The directions state to wash that off with water also, let dry and proceed with the other Por-15's products. BUT, I've just gone right to primer and paint with good results (so far..)

E

Bringing up a dead thread..

I'm having to come out of retirement and thought of using my loader to do 'dirt work' but with the price of insurance and to be bonded (more like afraid of getting accused of damaging someones lawn, septic..)
I am getting into this:
http://www.Dustlessblasting.com

Already picked up an Ingersoll rand compressor, DB500 blaster, water tank, etc.. The truck is going to be a '64 Chevy stake truck, that I'm going to blast down the center and restore the drivers side only. Kinda as a rolling testament/advertisement.
Going to do an axle swap f/r, to get 4 wheel discs and better bolt pattern for the rims I want. (Michelin Super Wides to get away from the dually look. Probably give a little rake too.)

anywho, Take a look at the video's that are shown. My "M" will be getting a '74 J10 cab that will be getting the whole truck blasted even the frame and axles.
It's uses are only limited to your imagination (and local laws..)
YES, there IS left over material but nowhere as messy as 'sand blasting'
The glass pretty much get's pulverized down to a powder that get's rinsed away with the water/rust preventative.

After working on that chevy truck for that friend, getting under the dash was big trouble because it seemed that EVERYTHING I TOUCHED dropped soda/crystals/CRAP in my face.
As you can see, the size of the hose for the Dustless blaster, you wouldn't be able to bend/turn to get into nooks and cranny's but I'm sure a good rinsing should help remove most residual glass.

The only "ISSUE" so far is ambient temps. I'm not about to try to be blasting in these low temps. Don't want any frozen up lines/nozzles to blow up or fail..

Going to get the crushed glass today and we'll see what the temps are going to be in the next couple of weeks..

If you're in the Memphis area and want parts to get blasted @ YOUR location, I should be up and running for business in the next month or so.
To keep customer's cost down, I Don't prep, tape, block off and Don't clean up.. That would be cost prohibitive for most. I just come in, blast, get paid and leave. Plus, the 'clean up' can just be rinsed off with a garden hose from drive way and won't kill grass like soda.

"Blown Away Surface Prep" Just PM me.

Errol

I saw a demo on this just yesterday on the "old car guy" program,and I was impressed with it and they are locally here in Houston too.

Good luck on the venture!!

I designed and operated one of the largest PMB (plastic media blasting)facilities back in the 1980's. The one issue no one addresses is the collection of the removed paint. Since PMB was a dry blasting we had a contained room with dust collection. Upon testing of our dust it was found that due to the older paints containing lead, our dust had to be disposed of as a hazardous material. It concerns me that these newer wet blasting techniques appear to let the removed paint go down the drain.

EXACTLY!! That's what I was wondering also..

That's why I am just going to offer the service and let the owner etc. deal with the disposal of said surface whatever it's made from/of..
Like, offering the service to a body/restoration shop. They are discarding the previous surface application in their business anyway, so this can be done in the same way. It's just wet.
No matter what type of 'resto', Car, farm implement, boiler, rust, fire damage (smoke/flame marks) or these construction companies that 'resto' old warehouses to loft style living, removing decades of webs, dust, etc.. NOW, that's a stretch since I'm just starting out and don't have the help to setup scaffolding make sure the product level (water, glass, fuel) is UP, hoses not tangled, etc.. The resto garbage/left overs will be the responsibility of the one hiring me.
If it comes down to it, I'll just not do the job. "NEXT"..!

Now if it's say, a contract with a local govt. office, like removing street/traffic lines on the road, graffiti, recycling/garbage dumpsters, yadda yadda. They would decide that.
With cut-backs, everyone's re-habbing what they have and not really buying new. Yippie!!

Errol

RBOLTZ..
SORRY if it seems like thread jacking..
I thought that i started it long time ago. THEN I went back and OOOPPS
Sorry. It's been a while.

Anyhow, This process uses a product called "Hold-tite 102" and I'm looking at using a local chemical product to save on shipping. (It was designed to be used with high pressure/steam washers) It gives apprx 48hrs. When I did my Monte carlo, I used POR-15's metal ready or metal prep and DANG! it sat outside for about 6 months and just started to flash.

SO, how did it turn out?

E