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Soda Blasting?

Started by Brad Hemingson CLC #18437, September 01, 2010, 11:32:24 PM

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Brad Hemingson CLC #18437

Has anyone here done their own soda blasting? I've used a sand blaster for doing frames and suspension parts but you can't sand blast body panels because of the potential warpage from heat build up. I've seen the soda blasting demo on the Eastwood site and I'm considering getting one. The soda is expensive at $40 for a 50lb bag and I'm wondering what soda consumption is like and how much material it will remove, particularly grease and undercoat?

The Tassie Devil(le)

G'day Brad,

I had a '59 Thunderbird Soda Blasted, and I am sorry that the process was used.

Actually, the Painter was more sorry than me.   Every panel needed repairing, and the dust is still coming out of the crevices, years later.

The Painter inspected the car before it went to the blaster, and remarked that the body was so very good, and straight.   It was a Desert car, and the paint was very tough, being sun-baked.   The Blaster must have really hit it hard to remove the paint.

I have had a previous car Sand Blasted, and the operator was a fellow car-buff, and knew how to do it without over-heating the metal.

If you are going to do it yourself, do it slowly, and don't try to do it all at once.   Allow it to cool.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

Fred Zwicker #23106

#2
Sandblasting Information:

As Bruce mentioned, abrasive seems to get everywhere and will cause problems later, especially if the complete car is blasted, due to so many small cracks and crevices. Years ago I sandblasted a fireplace in my home in preparing it for sale. The fireplace came out great and helped sell the home.  However, for about 20 years, abrasive kept falling out of the lamps, and this was two homes later!  (I even built a protective cover out of visqueen around the fireplace before doing the blasting).  

The problem with using Soda for blasting is the high cost, as it can be used only one time (even within a closed cabinet), as it breaks on impact. If you plan to do the entire car with soda, your credit card might be maxed out fairly quickly!  There are many other abrasives that can be used that are lower in cost and are quite effective that can be recycled (used over and over).

As Bruce also mentioned, damage to the metal is possible when doing outdoor pressure blasting.  The correct way is to use a small orifice nozzle (5/32” or smaller) and blast at between 60-80 psi air pressure.  Results will be slower, but there is less chance of warping the metal, which is due to heat.   When blasting, do not stay in one spot at all â€" instead keep the nozzle moving back and forth, continually moving to the next area and taking off the paint and rust in layers. If you concentrate on one area and attempt to get that area to bare metal, you will do so, but likely warp the metal. Be extra careful of side panels, doors and hood, which are easily warped.  If you are doing your own work and use care, damage to the  metal is not likely if above method is followed. Commercial blasters may not be so careful and often use large orifice nozzles and high air pressure, with a high possibility of metal warpage.

We once restored a 1961 Lincoln Continental 4-door convertible and sandblasted the entire car. Using a small orifice nozzle at 60-80 psi air pressure, we were able to successfully remove all of the paint and rust to bare metal without damage to the sheet metal, but we were extremely careful to keep the nozzle rapidly moving back and forth and never staying on one place at all. The idea is to remove the paint and rust in layers, little by little. Car was later painted black lacquer and there was no evidence of any metal warpage.  It can be done, but is not easy until you get the knack of doing it correctly.

Grease and undercoating do not lend themselves to sandblasting with any abrasive, as sandblasting likes hard, dry surfaces.  Accordingly it is important that all grease and undercoating be remove with a putty knife, wire brush or chemically.  Even small areas of undercoating or grease will take forever to remove while blasting, so don’t waste your time even trying.

At work, we recondition used paint spray guns that are always covered with dried paint (enamels, lacquers, epoxies, etc.).  This paint cannot be removed chemically, so we use a small cabinet blaster and plastic abrasive, which can be recycled.  To minimize scratching of the chrome surface of the gun and the stainless steel cup, we blast at 50-60 psi air pressure.  This nicely removes the paint and restores the paint guns to a like new appearance, with very minimal scuffing of the plated surface.  We do not use soda for this application, due to high cost, since soda cannot be recycled.

There are many other abrasives that can be used.  In our restoration shop,we like glass beads for cleaning up cast aluminum parts where a satin finish is desired and we use a mixture of glass beads and aluminum oxide for general purpose blasting of small parts, such as air cleaners, under-the-hood components and similar items. It removes rust and paint quickly without damaging the surface, yet leaves a nice surface for primer and later painting.  We never use sand, due to health concerns. There are many abrasives with no silica or low silica that will do the job faster, last longer and minimize such hazards.  When doing outdoor blasting, always wear protective clothing (long sleeve jacket, heavy rubber gloves, and air-supplied hood/respirator).  Keep others out of the blasting area and clean up promptly at the end of each day.  The EPA has outlawed most outdoor blasting, particularly in the cities and your next door neighbor might not share the same enthusiasm for your restoration as  you do and might even blow the whistle on you.  Most small parts can be cleaned in a closed cabinet, minimizing all of the headaches.

Keeping abrasive out of engine parts is a hazard when using most abrasives, so be sure to carefully cover and mask any engine or any  other mechanical parts of the vehicle.  Duct tape is better than masking tape for this purpose and should be doubled in critical areas.  Even then, the edges of the taped surface will be damaged in most cases. After blasting, remove any and all traces of abrasive from engine and other mechanical parts. If blasting the surface of a vehicle, it is important to remove or protect chrome, window glass, headlight and tail light lenses, engine and steering parts, under the hood, brake drums, and other critical areas.

For blasting inside a closed cabinet, Glass Beads are the usual favorite abrasive, as they leave a "factory finish" on most parts.  Crushed glass (also called, "Skat Magic") is also another option and looks about the same as glass beads (looks like salt or sugar).  While lower in cost, it cuts faster than glass beads, but leaves a slightly coarser finish and can be a little dusty in use.  Other abrasives that can be used are Silicon Carbide (diamond sharp & very expensive), Walnut Shells, Plastic Abrasive, Steel Grit, Garnet and other products. There are also other special abrasives and abrasive mixes for other applications (First Choice, Speed Bead, Fast Cut Max, and others.).

When purchasing abrasive, always ask the supplier if their abrasive is made in USA or imported.  USA abrasives are graded carefully and most are to military specs.  Imported abrasives may or may not be the same quality or of the same consistency, and in some cases has been recycled (used previously).  Recycled abrasive does not cut fast and does not last long.  Regardless of which abrasive you use, change abrasive on a regular basis, as visibility problems inside a closed cabinet will increase as the abrasive breaks down in consistency.  Once the abrasive breaks down to a consistency of a fine powder, the fine particles will pass through most vacuum bags or cartridges, resulting in failure of the vacuum or dust collector motor, and often blowing dust into your shop.  It is not economical to blast with worn out abrasive and doing so is one of the chief causes of vacuum motor failure.

An excellent source of help regarding choice of many abrasives can be seen at www.skatblast.com and click on the Abrasives & Parts link on left side of Home Page.  


Attached are pictures of Glass Beads, Plastic Abrasive and Soda for your information.

Fred
1930 LaSalle Convertible Coupe, CCCA Senior
1939 LaSalle 2-Dr. Conv.  CLC Senior in 2008
1940 Cadillac Series 75 4 Dr. Convertible
1947 Cadillac Series 62 Convertible Coupe
1948 Cadillac Convertible - modified by Holly (driver)
1966 Cadillac DeVille Conv. Restored - Red
See Pictures at www.tpcarcollection.com

mgrab

I use to work in a pharmaceutical packaging plant. We brought in an outfit that specialized in dry ice blasting.  Its rare....and always wondered how well it would work on a car.  It worked well for us since it was an FDA regulated plant.  The dry ice would sublime and the only material remaining would be what you blasted off so you could contain the mess much easier.....not cheap though....
Mike
1941 Cadillac 6267D
1948 Packard Custom Eight Victoria
1956 Oldsmobile 88 Sedan

Fred Pennington 25635

I bought the Eastwood conversion for my blaster to do my car body.
I found out very quickly that the soda blasting is slow and you use a lot of media to make any progress you must use the coarse media
The main problem is dry air. The soda absorbs moisture and clumps up to clog the system
I live in New Mexico where we have no humidity and still have the problem, Eastwood sells a treated soda media to alleviate the problem but it is much more expensive.
They also advertise you can work with a 6 CFM compressor. I don't know how you could possibly do a complete car with that small of a compressor.
I have a 23 CFM compressor and I gave up on blasting the complete car after 2 hours and 200 lbs of soda for a quarter panel
I ultimately had it done professionally and I think I saved money and a great deal of time
Yes there is soda in every nook and cranny but I am doing a body off and it sucks up in a shop vac well
The beauty of soda blasting is the residue left behind. The car will not rust for several weeks outside or indefinitely inside
however you must wash it with warm soapy water before paint
The wash job also takes care of allot of the stray dust problems the soda dissolves in water and washes away

I have found the it is wonderful for small to medium jobs like interior pieces
I have no skills at all and the metal comes out  looking like it just came out of the stamping machine in some cases the original  steel suppliers mark is visible


Hope this is helpful

Fred
Fred Pennington, CLC 25635
1940, LaSalle 5019
1940 LaSalle 5019 parts car
1968 Ford Bronco
1973 Mustang Convertible
2012 Shelby GT500

Ralph Messina CLC 4937

Brad,

Fred’s comments above are, at least, a college education in media blasting. I helped a friend with his ’61 Vette that was stripped with media â€" I believe plastic beads. We never got all of it out of the hidden spots in the body. Later we found out the company he used had workers who had ruined metal panels by overheating them. We were lucky that the A Team was working on this car that day.

My preference for paint removal is aircraft quality paint stripper. I tend to favor media blasting for rust only. We did the exterior of my Brougham with relative ease. We then went after any rust spots with glass beads once we had the doors, fenders, hood and deck lid off the car. This way there was no chance of getting beads in the body’s nooks â€" crannies â€" and hiding places. Every day we spot primed everything we had cleaned.  While working with strippers be sure to wear protective clothing on any appendage you’re fond of….It’s nasty stuff, but controllable.  As bad as my car’s body was, I found the rust was localized and dealt with it as necessary rather than blasting the whole body. Also, I believe you’ll find the cost the paint stripper is significantly less than blasting equipment and media, and the cleanup is much easier and localized.

If I recall correctly, your car is black. I found that original body panels had stamping imperfections in the steel . In bare metal and wet sanded primer my hood looked perfect. A coat of black and a swirl showed up on the passenger side. We painted it again, same problem. The third try we used a high build epoxy primer and block sanded the hell out of it in order to get it right. I believe we were encountering stress marks from the stamping process. The imperfection was difficult to see, but I could find it. I guess it was good enough to sell when new, but not up to today’s restoration standards.

Now, if you’re gonna ask questions, please post progress pictures so we can help restore it …..at least vicariously.  :)

HTH,
Ralph
1966 Fleetwood Brougham-with a new caretaker http://bit.ly/1GCn8I4
1966 Eldorado-with a new caretaker  http://bit.ly/1OrxLoY
2018 GMC Yukon

Dan LeBlanc

I still prefer the old tried and true method of a DA sander and 80-grit paper.  Yes, it's slow and time consuming, but it has always worked for me.  Plus, when you're done, you're ready for epoxy primer to seal the works and do the body work right over the primer.
Dan LeBlanc
1977 Lincoln Continental Town Car

Wayne Womble 12210

Who says you cant sand blast them?  I have done hundreds, no problems whatsoever.  If you know what you are doing, it is the best and cheapest way.

John Tozer #7946

I'm a bit surprised that chemical stripping such as Redistrip hasn't been mentioned in these posts. Is there an environmental or other problem with their process in the US? I had all my panels, engine block and chassis dipped at Redistrip, sprayed as soon as they come out of the tank with lanolin and couldn't be happier with the result. The subsequent removal of the lanolin is a bit os a pain in the butt but not more than any other job that I have come across in restoring my car ...and at least it stops rust "bloom" again for about three years (which is handy when you are taking as long as I am to do my car).

I am told a water pressure gun will remove the lanolin and a standard should-be-doing-it-anyway prep-wash before priming takes care of any residual.

I haven't painted anything yet so I can't swear that this is correct and would appreciate any feedback on it.

Regards,


John Tozer
#7946

Wayne Womble 12210

Hmmmm, spray water on your stripped metal?  I don't think so.   Never heard of the lanolin thing, most treat the panels with phosphate. 

Steve McCarthy

Perhaps he means washing it with an additve such as metal wash.
Eastwood sells it, you add it to hot water and wash the part/panel, it prevents flash rust for up to three weeks.

Virgil Perkins #19943

I had my 1941 6019 SF soda blasted in the spring of 2009 and painted the following month. You do find soda everywhere no matter what precautions you take. And it must be washed very well prior any paint work. There was no damage to the metal and my painter did multiple washings prior painting. Paint came out very nice. The only causality was the stainless steel tail pipe deflector that I forgot to remove. As with any blasting process, you gotta have someone who knows what they are doing and cares.

Beege Givens

I'm with John on with the Lanolin thing. I chemically stripped the fender mount covers for my 36 back to bare metal about 6 months ago then covered them in lanolin and theres no sign that the rust will be back any time soon. Thinners gets it back off pretty quick

Beege
36-7513

The Tassie Devil(le)

Maybe Redistrip is another good Aussie thing.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

John Tozer #7946

About that water spraying thing....

From Redistrip's web site:

"Redi-Strip's process is perfect for cleaning components where avoiding metal fatigue is crucial, because it removes no metal and cannot cause stress cracks, etching or embrittlement. Yet the process thoroughly derusts every pit, crevice and cavity, and releases "frozen" threads.

And the rust does not come back. A protective residual film remains on all surfaces, eliminating the need for expensive greasing and degreasing. When ready for use, the parts are simply water-rinsed and dried."

The usual recipe for rust is:

Steel or iron + water +oxygen ....+ time so I'm guessing that the bloom will appear if you don't dry it fairly quickly. I haven't run out of time yet so it would appear that the time period to start rusting again is quite long.

Bruce - Redistrip is an American process but the lanolin appears to be all ours. Don't see any mention of it on their US or Canadian web sites. Had to do something with all those sheep when their wool wasn't worth anything I guess...

John Tozer
#7946

Steve Passmore

Not at all Bruce, Redistrip has been around in the states for years and a company now does it here in the UK. I had my 37 striped in this way, by far the most affective way of rust removal, and treated with phosphate after, about the only drawbacks are the cost, and the inconvenience of having to have everything ready at once and transporting it to the strippers, I tend to sand blast as I go,  In the US and Aus you could be many hundreds of miles away from the plant.
I always do my own blasting using a cheap filtered kiln dried sand thats good for 3 to 4 recycles using an air fed mask I hasten to add, the reason for having the 37 done was so much rust inside the body making blasting very difficult.
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

Wayne Womble 12210

Try this. Strip a panel clean to bare metal, then drip water on it and let it run off. when it drips off the bottom it will be red. That's how fast rust starts. I know the treatments use a protective coatings, usually phosphate, but I just cant bring myself to wash my clean metal with water. I just cant do it.

I sand blast, clean the metal with air, and quickly spray with zinc chromate primer, and or a epoxy primer with chromate ingredient. I have never had a problem with this method, and I am old and set in my ways to change..

Fred Zwicker #23106

Per Wayne: "I sand blast, clean the metal with air, and quickly spray with zinc chromate primer, and or a epoxy primer with chromate ingredient. I have never had a problem with this method, and I am old and set in my ways to change.."

I agree with Wayne - This is the exact same procedure we have used for years and years in our restoration shop at TP Tools (Canfield, Ohio) and we would never think of washing down freshly sandblasted or bead blasted metal with water.  A good cleanup with air removes all traces of dust created in the blasting process. Sometimes we will use a shop vac to remove any dust that might remain in crevices or cracks, but never water.  The key to Wayne's method is the word "quickly".

As to paint stripper, I can recall that on occasion we have had problems with the paint lifting later if the paint stripper is not removed completely and thoroughly, especially in cracks and crevices.  The same applies to using acid when leading - in that case a wash down is required to remove the remaining acid used in the leading process. But once a leaded surface is washed down and dried, either blast or somehow clean the surface and then apply the primer - again the key advice is to do this quickly.

Fred
1930 LaSalle Convertible Coupe, CCCA Senior
1939 LaSalle 2-Dr. Conv.  CLC Senior in 2008
1940 Cadillac Series 75 4 Dr. Convertible
1947 Cadillac Series 62 Convertible Coupe
1948 Cadillac Convertible - modified by Holly (driver)
1966 Cadillac DeVille Conv. Restored - Red
See Pictures at www.tpcarcollection.com

CRAIG LEWIS

Ok Several years ago I decided Soda Blasting was the way to go and since I researched the cost I figured I might as well start a side business doing it. I did one car and determined Soda isn't really the way to go on car bodies as a standard there are some occassions when it is best. for example, I did a 66 Mustang for a customer and used soda on the inside door panels since it had a pattern stamped into it that we did not want to affect. Soda will leave the metal with absolutely no profile just as smoot as the day it left the factory. However soda must be washed down with a vinegar solution or you will have paint issues in the future. I also use it on engine parts and degreasing. For bodies and frames I used a recycled crushed glass product. Leaves a great paint profile similar to the surface of 400 grit sandpaper. I use a very fine glass. Been doing this for 6 years and have done many cars. I use 185 CFM compressor at around 60 PSI.
Pictured is an idea of what I am talking about the first is the mustang door panel using Soda. The second is a close up of the surface after soda. The third is the outside of the same door but with crushed glass. If you know what your doing you gan strip it and not even damage the bondo too much. I can also balst the bondo right out with a little more focus on the area. the key is standoff, preasure, angle and smooth even passes like laying down paint. You will fight it all the way with the small units at Harbor Freight or Eastwood. I can do a whole car in a weekend without killing myself and buying media in bulk drops the cost significantly. I used about 1200 lbs of glass on the mustang and did every component inside and out including suspension and rear end. i charged $1400 for this job. You will spend at least that on media before your done.  Hope this gives you an idea of what your looking at. Not all strippers will treat you with care so find someone that is also into car restoration and would perform as if it was their own car. Talk to you media guy if he is good he will suggest several differnt types of media for different aspects of the job. I have done corvettes using a totally different meda that will cut the paint but not the gel coat, aluminum which requires a different meda since the metal is soft, soda will etch it, etc.       good luck and take it to someone who knows what they are doing you will be much happier.

bill henry

I prefer the DA but use a 36 grit disc.
Bill Henry