Dustless Blasting or Sand Blasting - looking for advice

[SLP5357]

Does anyone have experience with dustless blasting?  I've gotten quotes lately from folks who do remote dustless and/or sand blasting.  The dustless blasting guy uses crushed glass infused with a chemical that slows oxidation.  The sand blasting guy uses only silicone sand and guarantees no warping.  I've watched youtube videos of the dustless blasting and it looks interesting, but it seems like they're focused on paint removal and not so much on rust removal.  I'm leaning toward the crushed glass dustless blasting but I'm hoping it's effective on surface rust.  I think the prices quoted are very reasonable - $850 to $1,000 to blast the body shell (no doors, front fenders, trunk lid or hood) as well as blasting the frame and spraying epoxy primer (on the frame only).  Any input is greatly appreciated!

 

                                                                           Thanks in Advance!

                                                                                     Steve

[old-tank]

Any blasting can cause warping and it is not just heat:  http://www.hotrodders.com/forum/sandblast-warping-heat-myth-76938.html

It can be minimized by blasting at a low angle, at reduced pressures and using very fine media, all of which increases production time.  Both silica sand and the glass will remove rust.

[60FlatTop]

Interesting topic. About 45 minutes ago I put some Rolls-Royce body parts into my storage unit. One item was an aluminum Silver Cloud hood. We leaned it against the wall and I said "I bet this one goes to someone who ruined theirs by soda basting."

Bernie

[old-tank]

TV show:  strip car, send out for blasting, coat whole car in bondo...now you know why.

[SLP5357]

Old-Tank - thanks for the link - it was a little on the technical side but I think I followed it O.K.  The more info I get on this subject, the more nervous I get about media blasting in general.  The guy who I spoke to who does only silica sand blasting said that he uses low pressure and a high volume of sand in order to avoid warping.  I'm not sure I want to take a chance as there's not too many replacement panels out there for a 46C - in fact there's probably none!  Bernie - I'm with you on the soda blasting - I've heard bad things about that too.  I may just have the frame sand blasted at this time so I can reach my goal of a "rolling chassis" by late Summer.  I plan to construct an electrolysis tank to strip the doors, hood, trunk lid, etc.  I've seen these tanks on youtube and they are pretty impressive.  I really appreciate the input from you both - I'll keep an open mind on the blasting subject as I get more info.

 

                                                                                                                          Thanks Again!

                                                                                                                                 Steve

[NTX5467]

The ONE thing these "blasting services" might not mention is "clean up procedures" and how LONG it might take to get ALL of the media out of the "cleaned" part!!  This makes the plastic or glass media a bit better as it probably absorbs much LESS moisture than sand or shells.  They might seek to minimize media loss to the surrounding areas, but it's what ends up inside the part that can be more important !

 

Depending upon the particular part, I tend to like "rust dissolvers" better.  Plus the idea of "rust encapsulator" coatings in some cases.  Might be some environmental concerns with the disposal of the liquid, but I believe there are many environmentally-friendly liquids on the market for this reason.

 

In some respects, depending upon where the rust might be, "mechanical removal" might be best in the long run.  You might end up having to patch something anyway, so why not just do that to start with?  While "rust" is oxidation of the base metal, it also "eats" the base metal too, weakening it in the process.

 

There are also "water blasting" mobile services which can do paint removal on vehicles, but I don't know if it will do rust.

 

Just be SURE to put some protective coating on the "cleaned" surface as soon as possible as rust can bead-up very quickly!!!  If not,  you'll probably end up having to de-rust the cleaned part BEFORE any primers can be applied.  If not, it'll be trapped under the paint.

 

NTX5467

Edited January 16, 2016 by NTX5467 (see edit history)

[g-g-g0]

Five or six years ago I was pondering the same question(s) when looking to clean a '57 Special body and body panels. Ended up having every thing acid dipped. Parts were washed and neutralized by the same vendor and then his instructions for washing and priming were followed to the letter. To date there are NO signs of corrosion any where on the parts. Planning on the same process for some doors and fenders on a current project.

Gary

[Guest]

Does anyone have experience with dustless blasting?  I've gotten quotes lately from folks who do remote dustless and/or sand blasting.  The dustless blasting guy uses crushed glass infused with a chemical that slows oxidation.  The sand blasting guy uses only silicone sand and guarantees no warping.  I've watched youtube videos of the dustless blasting and it looks interesting, but it seems like they're focused on paint removal and not so much on rust removal.  I'm leaning toward the crushed glass dustless blasting but I'm hoping it's effective on surface rust.  I think the prices quoted are very reasonable - $850 to $1,000 to blast the body shell (no doors, front fenders, trunk lid or hood) as well as blasting the frame and spraying epoxy primer (on the frame only).  Any input is greatly appreciated!

My ? Has anyone had experience with dry ice blasting. No residue at all, it just vaporises! Heat from friction reduced becuz its frozen?

 

                                                                           Thanks in Advance!

                                                                                     Steve

[Guest]

Anyone used dry ice blasting? No residue, just vaporizes, reduced heat cuz its frozen? Warping risk?

[NTX5467]

To me, anytime you "blast" something against sheet metal, there IS the possibility of warping.  Just "the nature of the beast", I suspect.  Might be more of an issue with the more solid media (i.e., sand and other similar substances) than with liquid media, though.  The friction of the sand/soda/shells, etc against the surface will create some heat, as the liquid media might have a heat, then cooling, effect, possibly?

 

To me, "the dip" by a recognized reputable operation is the "high-end" and best way to go.  Some might have some "metal prep/protector" they can put onto the parts.  Hauling a body bolted to a trailer, in a HUGE plastic bag can get some interesting looks as it goes down the highway!

 

NTX5467
 

[g-g-g0]

.  Hauling a body bolted to a trailer, in a HUGE plastic bag can get some interesting looks as it goes down the highway!

 

NTX5467

 

 

You mean something like this 'sans the bag???

 

Actually at the time the cost was a couple of hundred dollars more than blasting. Well worth it from a rust removal stand point. Redi Strip used to be a franchise and went kuput but there are a few left that are privately owned and operate under the Redi Strip name. I used the one in Indianapolis.

Edited January 17, 2016 by g-g-g0 (see edit history)

[Ttotired]

I bought (have) a 60 plymouth that has been blasted using garnet (done by a previous owner), It sure lets you see where any rust is/was

 

I wouldnt do it myself as that stuff just gets everywhere and its impossible to get out

 

Every time you bang on the car (bodywork) some garnet falls out of somewhere (It could be a problem when it comes time to paint this car)

 

I have (a long time ago) looked into blast vs dipping and there are pros and cons to both

 

Biggest one with dipping is it gets into seams and is very hard to get out/neutralize/flush away, but similar can be said with garnet

 

Another thing with the blasting is lead fill, it really knocks it around and it will have to be re done or at least filled over and its the lead fill that I worried about the most with dipping because if the chemical (normally a corrosive substance) gets under the lead, it will be messy down the road

 

As much as its labor intensive, if you have the time and place to do it, judicious use of paint strippers and sand paper ect will strip the car safely

 

Mick

[NTX5467]

Great comments, Mick.  Hadn't heard of garnet as a media.

 

When the RediStrip people did a whole body, it was bagged when it left their facility.  Body was secured on a wood support structure, then loaded on a car trailer to return to the owner.  A BIG, opaque, plastic bag.

 

In some respects, if the liquid might attack the sealers, they might be needing to be re-applied anyway, due to age and cracking, which can let moisture get to the places they were preventing it from getting to.  Same with where the door skins wrap over the door shells, or other similar body panel situations, too.  3M has a huge number of body seam sealers, for use in caulking guns or with brush applicators.  Getting the old stuff out might be an issue, though, after it's found.

 

I believe that with any "media", you need to seal and tape-off the places you don't want the media to get to.  A friend acquired a Plymouth SuperBird and did a complete restoration on it, including stripping and media blasting the outer body "painted" surfaces.  With the entire car "open", it took some time to get all of the media out of interior nooks and crannies, but being plastic, no real issue with moisture absorption/retention, unlike sand.  So we got out all we could, manually and with a strong vacuum cleaner, and then put the car back together.

 

Body lead can be an issue, too, especially as seam sealer for body panel joints, as in where quarter panels mate/weld to roof panels, for example.  Which means some "body work" will need to be done in that respect.  Seems like 3M designed "Alum-A-Lead" for rear window rust on '71-style GM cars and others with that same "water retention" area at the base of the rear window?  That, plus some screen reinforcement fabric, might be another "mechanical" option?

 

When RediStrip moved into the DFW region, they had an old Ford "Model-something" door assembly that had been stripped.  It went into the tank at an angle, glass removed.  It was impressive how it cleaned it all, including the window regulator.  Later the gallon jugs for water-based paint strippers appeared.  These seemed to work pretty good, at swap meet demonstrations, especially as they would usually stop at the factory primer, if you did it right.  Then, all you had to do was to scrape off the paint "sludge" onto some newspaper for proper disposal.  I suspect you could take a small tank, fill it yourself, dip the items yourself, recycle the fluid, and do it again, if you wanted to.  Once you know how "bad" the rust might be, I believe that mechanical removal/panel patch is the best long-term fix, if possible.  Otherwise, one of the rust encapsulator coatings, then repairs, might be in order.  Just depends!

 

NTX5467

[Smartin]

I had the doors and fenders blasted with plastic on my Limited.  Worked great.  I don't like the idea of it or any other blasting on large body panels like roofs or hoods, though.

[buick man]

Good comments.  Regarding our Buick box cross X frames.  There are a lot of areas up front and along the rear wheel arch area that the frame is boxed and open.  A lot of crap can fill in there if sand is used and it is almost impossible to get it out.  If you should decide to use an acid, then make damn sure you get some kinda written confirmation from the Epoxy Company  that their proprietary form of Epoxy can tolerate previous substrate acid etching.  SPI and House of Color cannot just to mention a couple of the best ones out there.  That means you cannot use Etch primers before applying their Epoxies.  That also means they do not want you to acid strip and then use their epoxy.  Of course the caveat here is proper neutralization of the work piece before adding the Epoxy.  This holds the same with Soda. 

 

If one uses HCL based acids i.e. Muriatic Acid, then you run up against free CL- ions lurking about on the metal surface after even a diligent course of neutralizing has been performed.  These Cl- ions are a bugger to convert/neutralize/remove from the cell structure of the metal surface.  Therefore, folks look then toward using Phosphoric Acid based systems.  Even with PhosAcid, it is required that once applied after blasting, it can stay on and dry to protect the metal from flash rusting. However, when it comes time to paint, one is required to reapply the PhosAcid, let set to reactivate what is dried on the surface, then flood it with repetitive & copious amounts of water to neutralize/wash it off followed by immediate forced air drying.  Usually a previously cured PhosAcid surface, will if dried quickly present little to no flash rust occurring.  Once completely dry, then the epoxy paint can be applied.

 

Rust Encapsulation products work by cutting off atmospheric conditions & O2 from the equation when applied over existing mild to average oxidized surfaces. Know also that rust is known to attack and grow on a surface very much the same fashion and manner as a Vine or Ivy Plant does over the face of a wall or over your house surfaces. Knowing this then, keep in mind that if any nick or scratch occurs on the Applied Encapsulated Medium applied, rust will be rescued via the exposure to the atmosphere and this Ivy / Vine growth will begin up again growing out and under your Encapsulated area.  Failure is the result and rusting will continue then unnoticed under the Encapsulated areas.    

[buick5563]

I had my convertible body blasted with no ill effects. The biggest problem was that there were beads left in every nook. Like every venture in restoring a car, you must find somebody you trust and who knows what they are doing.

I don't recall what medium these guys used. It was neither soda (which doesn't touch rust), nor silica sand (which is bad for body panels, and paint doesn't like silica dust).

I had my frame sand blasted and powdercoated by a different company. You can't sand and paint a frame for what they charged me.

[Ttotired]

Heavy metal parts I dont have a problem with getting blasted and as said above, "You can't sand and paint a frame for what they charged me."

 

It is so nice to then work with nice clean metal

 

Mick

[NTX5467]

One thing which is "bad" about "sand" blasting is that IF the supply sand container has ANY moisture in it, the sand coming out of the blast nozzle will be inconsistent.  My ONE foray into that, with a friend, was that he rented the blaser unit and he hauled it back to his house.  We started the blasting one night, under the cover of darkness, with a little light bulb illumination beside his garage.  He got dressed in the "space suit" and began blasting, as I watched, on the '52 Plymouth he'd found.  Things worked decent for a while, until the moisture in the container happened.  Then it was "moist sand blasting".  Due to his general demeanor, he'd "tap" the nozzle on the fender to get it openned back up, only to clog again.  I termed those "h_ll dents", rather than "hail dents".  We were going to "experiment" with bondo later, anyway.

 

The paint store claimed that after the surface was blasted, to wipe it down with paint thinner and then spray the primer on, which we did.  Looked pretty nice for about 2 weeks, when the little rust spots appeared in the primer.  We didn't expect a "primer" to be "porous" as we'd all seen cars sit primered at body shops for quite some time without showing "rust".  But they normally didn't deal with a somewhat "rough" metal surface that was "bare metal".  This was mid-1970s and it was a learning experience.  I started doing more research a few years later.  When paint strippers became more prevalent, I always asked if they went straight to "bare metal" or would stop at the factory primer.  Learned about using "metal prep", too.

 

Later on, I did more research into how the factory does their sealing and such.  Then I could better read the 3M body supplies catalog and know what I was looking at.  By that time, too, I had met some of our customers who were doing body work at home, for themselves and others.   Each one had their own "tricks" they'd learned and they worked for them.

 

NTX5467 

Edited January 19, 2016 by NTX5467 (see edit history)

[smithbrother]

Regular primer will allow moisture to enter, two part primer WON'T.

Dale in Indy