Soda Blasting

[Hodgepodge]

Let's talk about Soda blasting vs. other media. I'd like to hear your stories.   

 

I have 4 known rust spots, very small and down low and some very uneven paint on the hood on my '75 2002.  

 

I searched the forum and see a couple of entries related to media blasting, mostly sand and plastic media.   There are a couple of places near me and one mobile soda blasting guy (called Stripper for hire...).   I would consider doing this myself, but I would need to do it outside as my garage houses other classic and newer cars and this is Pittsburgh....winter will be here very soon. 

 

There is one total-car restoration guy over in Ohio who immediately said he needed to media blast the entire car to make sure there aren't any issues.  When I told him I would let him know what needed to be done once I pulled all the trim off the car, he realized 1) I was one of THOSE GUYS who restores their own cars, and 2) I wasn't going to give him a blank check. So he stopped communicating with me.  I'm sure he's got plenty of business, but he won't be getting mine.

 

I like what Markmac said about soda being much easier to clean up than media but I've also read a lot of potentially dated material talking about how difficult it is to properly paint over a soda blasted surface.  Of course, I've also read that an epoxy etch primer is a good way to overcome any potential adhesion issues.  If I take the car to a soda blaster, I would be worried that I would get flash rust before I could get a decent coat of primer on it..   

 

I've read the same stuff that many of you have about sandblasting potentially warping panels, walnut shells being best, soda blasting changing the PH of metal, etc.  Unfortunately, the Internet is blind, so I've read just as many articles refuting the perils or benefits of certain types of media.  So let's keep the conversation to personal experience, OK?     

 

If you have had any media blasting work done, I'd like to know the size of your job, whether you did it yourself or farmed it out, and the media used.  If it was soda blasting (or any kinds of blasting, for that matter, what steps were taken to avoid issues and/or what issues you did you encounter?   Something nobody seems to talk about is how much it costs.  If you are comfortable giving a ballpark number for the work you had done, I think many in our community who are considering this type of work would appreciate it.    

 

Thanks in advance for your stories!  

 

Scott

  

  

[BMW2002_74]

Quote

I wasn't going to give him a blank check.

 

So true!!

[wegweiser]

For edges of hood / trunk, and non "big wide open flat parts of the car"... you might find regular glass bead (essentially sand, but a little more refined, less dangerous - no silica) to be ideal. I did my entire engine bay, not worrying a bit about warpage. Took me a long 8 hour day and a few hundred pounds of sand... sifting and recycling it several times.

 

It makes a BIG mess. 

 

On large door panels or hood / roof / deck lids... you'd massacre the metal with such beads, potentially. I've always been told the heat from the friction is one of the causes of the warpage... not sure if that's true. 

I epoxy primed mine within 24 hours. Sanded, did metal / body work / welding... then applied a sealer primer, that was sanded *again* and additional body work, as needed... then completely scuffed, before final paint was applied. Took about 80-100 hours including metal work.

 

Photo heavy..... sorry. Pittsburgh is ROUGH on 2002s! 

 

Edited November 3, 2017 by wegweiser

[Hodgepodge]

Wegweiser, that is really impressive.   

 

Slightly off topic....Did you pull the motor out the top and leave the front sub frame?    Was the car a roller or did you build a dolly? 

 

[wegweiser]

Drove the car in to the shop...had the engine out in about 60 minutes. (electric cranes are the COOLEST!!!) 

 

I pull engines from the top. Hood removed.

 

Install is easy, as you jockey bell housing / input shaft / clutch first, and lower to align the motor mounts afterward. That's just how I do it. Some folks prefer dropping the engine / SF....but not me. 

 

Left the car a roller. Took off the front wheels for some rust repair / frame rail work. That's it. Pulled heater box. Duct taped as much as I could, to keep overspray / sand intrusion to a minimum...but don't kid yourself... sand will get EVERYWHERE and you will never get it all out. Next time, I'll pull the gauge cluster out, so sand doesn't knacker up my speedometer (which went psycho one morning, about 3500 miles after the work was finished.) I'm convinced sand damaged it.  Luckily (after bad experiences with nearly every gauge repair shop in the US,) I have an ace gauge repair shop in Seattle that does top notch work. 

 

Edited November 3, 2017 by wegweiser

[Conserv]

Stymee’s amazing rebuilding of one of the rustiest ‘02’s ever saved from the crusher includes a fairly long discussion of dustless blasting (huh?), performed by a firm that comes to your site.  It’s on the 9th page (currently the last page) of his blog:

 

 

But we haven’t heard from him in a year or so....

 

Regards,

 

Steve

 

[Mike Self]

Have you investigated dry ice pellet blasting?  The AF uses it for stripping aircraft in depot for repainting as aluminum can't take media blasting, and paint stripper (think of how much it takes to strip a C5 or C17) was an environmental nightmare.  Best part about dry ice blasting is that it leaves no residue except the removed paint.  Dunno how it works on heavy rust, though.  

 

I had a trunk lid sand blasted to remove rust from the inner lip where the skin is folded over the edge of the frame.  I shoulda taped all the holes around the inner frame as I was weeks getting all the residual sand out of that space.   Had to make my own itty bitty nozzles for my shop vac to get into all those crannys.  

 

mike

[Hodgepodge]

9 hours ago, Conserv said:

Stymee’s amazing rebuilding of one of the rustiest ‘02’s ever saved from the crusher includes a fairly long discussion of dustless blasting (huh?), performed by a firm that comes to your site.  It’s on the 9th page (currently the last page) of his blog:

 

 

But we haven’t heard from him in a year or so....

 

Regards,

 

Steve

 

That dustless blaster chapter is a-MAZ-ing!  Far more involved than I want to be, but now I am wondering if it makes sense to strip the whole car...(It doesn't).   I have another car project that might go that route, though. 

[Hodgepodge]

8 hours ago, mike said:

Have you investigated dry ice pellet blasting?  The AF uses it for stripping aircraft in depot for repainting as aluminum can't take media blasting, and paint stripper (think of how much it takes to strip a C5 or C17) was an environmental nightmare.  Best part about dry ice blasting is that it leaves no residue except the removed paint.  Dunno how it works on heavy rust, though.  

 

I had a trunk lid sand blasted to remove rust from the inner lip where the skin is folded over the edge of the frame.  I shoulda taped all the holes around the inner frame as I was weeks getting all the residual sand out of that space.   Had to make my own itty bitty nozzles for my shop vac to get into all those crannys.  

 

mike

Nobody near me does dry ice blasting.   This area is sort of anachronistic when it comes to car repair, painting and maintenance.  That is great for costs but not for tech.  

 

[markmac]

I recently had my front/rear springs powder coated at a local place (accessories plus, Belmont, CA) that does ceramic, powder coat + media blasting.  The day i was picking up my gear they had what looked like a '66 Shelby GT350 on a rotisserie getting ready to go into their blast booth, I asked him about it and whether they were using Soda or what.  They don't.  Asked about warping of panels, he said it really comes down to the equipment (theirs sifts the media so you aren't re-shooting the crap that comes off the car, this may be standard in the industry I don't know), then it sounds like it comes down to the operator (no surprise)....it makes sense that if you aren't paying attention to what your doing and leave the gun in one place too long you are going to get a warped panel(s).  It all makes sense to me.  Maybe you could do a combo, blast the inside, underside, engine and trunk and then do the exterior manually (sand it off), more labor of course but less opportunity to eff it up if you don't fully trust the blaster.  Just an idea.

 

When I had my race car media blasted (15 years ago), they used plastic media. The guy that did the work had a friend that had a button factory.  When you make buttons, you get button holes.  He used the material that came out of the button hole as the media.  Was able to actually use that on some of the fiberglass bits without completely wiping them out....worked pretty well really.

 

http://www.accessoriesplushhc.com/media.html

[Vicleonardo1]

From what I remember, (and thus accuracy is in question).

I saw a few videos on dry ice blasting. It seemed nice, but took a lot of work to cover a few square inches on the car for paint removal. (The air force doesn't really worry too much about cost and time I guess) 

But it looked painfully slow, even with the video sped up a few frames/sec. I think it may be good for a small clean up project, or as a nice means to keep equipment clean for food handling etc..

But not too sure about paint removal on a car. But if someone has an awesome experience, I am all ears. 

[Hodgepodge]

I just got off the phone with the guy at "Stripper for Hire".   He uses soda blasting and can do the work at my place or his (probably his since I don't have any room here for that).  I'm not sure what I was expecting, but the price is very reasonable.  

I asked him a couple of questions.  

 

Question:  What's the deal with paint/primer not sticking to metal after soda blasting.   

Answer: Because most primers are acid based etch primers, the base baking soda neutralizes the acid in the primer and the stuff doesn't stick.  To eliminate that issue, he uses a wash product that cleans off any remaining baking soda residue and returns the metal to a neutral PH.  (What an awesome answer!) 

 

Question:  How do I avoid flash rust?  

Answer: Initially, the base baking soda residue actually helps to prevent flash rust (unlike other media, that is nuetral). However, the wash product I use to neutralize the baking soda also has a rust inhibitor in it.  We recommend that primer be applied within 7 days once the surface has been washed with the neutralizer, but I have a few parts and panels in my dry shop that were soda blasted months ago and they have not rusted at all.   

  

Question:  What kind of job does soda blasting do on rust?   

Answer:  Soda blasting is not abrasive enough to remove heavy rust scale.  The idea is to use soda blasting to remove paint and body filler without etching or damaging the metal in any way, so you can see what you have in terms of rust.  Then you can choose another method to remove the rust or, if appropriate, seal the surface to contain it.     

 

Question: What are your rates?   

Answer:  He gave me numbers, but I'll just say that he charges by the hour and that hourly rates are comparable to trained mechanics shop rates.  He said it takes about 6 hours to soda blast an entire car, depending on what kind of prep work and clean up is needed.   That's pretty reasonable from my perspective.    

 

I feel like those answers provided an excellent education for me on soda blasting and I know some of you are wondering, too, so there you go!    

 

Take care!  

 

Scott

 

 

[PaulTWinterton]

I've experimented with soda blasting ONCE at home.  I have a decent compressor and a handheld applicator that holds a quart of media.   Made a HUGE mess (outdoors) and didn't get the results I expected from the amount of media used.  The upside is that you can use a hose and wash the area down without harm to anything or anyone.

 

Locally we have DIY blasting shops for the small stuff.  I LOVE cleaning stuff in the cabinets.  We have one or two shops that will do your entire shell.  I suggest you look further for an experienced and personable shop.  My favorite shop does car bodies and has 100% success.  Also, they would do whatever the customer asks.

 

Edit: I was a little late on my submission.  Sounds like you found your guy. Congrats!

 

 

Edited November 3, 2017 by PaulTWinterton

[Tsingtao_1903]

At the speed my project is going (years ), I think I can wait for a laser system to become more affordable to a custom body & paint shop:  http://www.laserphotonics.us/handheld-laser-cleaning-system , and

https://www.digitaltrends.com/cool-tech/handheld-laser-cleaner/ 

[PaulTWinterton]

1 hour ago, Tsingtao_1903 said:

I think I can wait for a laser system to become more affordable to a custom body & paint shop

 

Truly awesome.  Digital alternative to analog blasting.  Wow!  The future.

 

In most of the demos there seems to be little to no dust created.