The Stovebolt Site Forums The Shop Area Paint and Body Shop to blast or not to blast that is the ?

Should I sand blast the whole truck or not? I say yes dad says no. Also thoughts about painting frame same color as the truck or Balck roll on bed liner. Need some advice from all thoses who have been there done that already.

63,
I have heard good and bad about blasting. I hear it will pit the metal. You will not get to all the areas of certain parts. I hear good things about soda blasting. I am thinking of dipping my stuff in acid. But, then I heard the parts may not get all acid out fo the little areas.

It is VERY easy to warp the metal when sand blasting body parts--VERY!
Especially on the newer trucks (post 40s). Soda blasting is much less likely to cause warpage, so that is the better alternative of the two.
Never tried acid, so can't comment.
Good luck.

They all have their down-sides (Hmmm...that'd be a good magazine article!)
Sand blasting can pit or warp the metal. A warped door skin or hood is junk.
Soda blasting is pretty thorough, but if it isn't neutralized properly, paint won't stick to it. I'm told by a guy who does it that soda will not remove rust (even surface rust), and it won't touch plastic filler either.
"Acid dipping" is actually sodium hydroxide (or should be--if they place you're using really is using acid, run away.) It's the most thorough of the three, but I've heard you can end up with black "yuck" dripping out of seams years later. It also COMPLETELY strips inside every joint and panel, so you've then got bare metal. It also needs to be completely neutralized (with water). Because it's hard to neutralize without submerging the car (which nobody does), it's likely you won't get full paint adhesion in every nook and cranny. It does not, however, continue to "eat" any of the metal.
The sodium hydroxide just dissolves paint, grease etc. It does not touch rust. However, most places then put it in a "derust" tank that runs a low-level electrical charge through the metal, breaking the chemical bond between rust and the parent metal. The sheetmetal comes out perfectly clean, with the surface as-delivered from the factory.

If I could do it any way I wanted, it's hard to beat the chemical dipping, but it is expensive. I'm going to soda blast the body of my Suburban, and sand blast the chassis.

-Brad

I've used walnut hull medium on the more delicate parts on my old printing presses and glass bead or sand on the items that heat build up is less of a problem . Have had no problems with painting after using walnut .When I get to the blasting stage on my truck that's how I will go . The down side is it costs more to use.

All very good advise, one thing I can add is don't spray the frame with bed liner. There are plenty of very good paints out there just for this application. Bed liner is made for beds, and cannot be touch up if you need to drill and weld. I also don't recommend powder coat if you drive in a wet areas. I have seen to many new trucks (Fords) that are rusting away because water got under the powder coating. Joe

I do not understand how it can warp the sheetmetal? I do not want to sound to dumb but i would notthink enough friction heat would be built up to cause the metal to warp. Pleasr fill me in. I have already done some of the area around the back glass and top part of door jam. Found some small areas of rust. I will stop until you guy fill me in. Thanks for the warning

Sand blasting will warp if the blaster is not skilled. However the thicker gauge metal in the AD makes it less susceptible to warping than later vehicles. I had mine sand blasted by an experienced restoration shop and have had no problems.
The frame can be blasted by any yokel without harm.
If I had it to do over I would have it dipped. That is a more perfect method, more expensive but better results. With the blasting you should remove every part completly to get sand into all crevasses. My frame, when blasted consisted of 3 crossmembers and the rails period.

And tell your dad to do it all because you won't get another chance.MHO

I use solvent or simple green on the frame and pressure wash. I repeat this several times. Quite often a person will be surprised that the original black frame has been preserved by years of oily dirt build up. I don't blast any greasy spots because it makes a mess. On a rusty spot, you do what you have to do.

My surprise would be that the frame was ever painted.

My dad has as much time behind the gun as i do so i guess either one of us will do the damage. If i had the money a dip would be the way but no money so blasting will have to do

Now can someone tell me how this can warp metal by sand blasting

The friction of the sand on the metal creates heat. If you stay in one place to long it keeps getting hot until it warps.

I vote electrolytic rust removal.

It all has already been said so we're down to the two main items.
Blasting media will/should be determined by the condition of the metal as in rusty or just paint removal.
Second, is how deep is your pocketbook which also help determine the above process.

A blaster should work as he would mig welding, a little at a time.

Blasting in the corners and around windows should befine if you watch what you are doing. Its out in flat areas like doors and hoods that will warp. If you can push on the sheet metal with out bouncing, you should be OK. Joe

I'm not sure if the AD were ever painted, but I have uncovered black paint on blue chip series that was in places that I am quite certain that it was original.

with a home blaster you should be fine, I did my whole cab and doors with a harbor freight pressure blaster and had no problems at all. just use a little comon sense and you will be fine. they warn against epoxy priming over soda blasted panels.

So let me get this right. !) do not stay in one spot long 2) Take my time do one area at a time. I have heard of using play sand to blast with. I know one thing that would be a heck of alot cheaper. Any thoughts on that?

THANKS FOR ALL THE ANSWERS SO FAR

I have used a sears portable blasting tote for parts to make my blasting booth in my garage. I can also use the portable container on bigger projects that won't fit in my booth. I have used plain river sand for years and, although not quite as good as some other more expensive stuff, it works great for the price. I use a screen wire as a sifter on recycled sand and my booth is hooked up to my central shop vac upstairs with a remote on and off for convenience. The hoses are grounded and it works great.

play sand wil cause problems it is not uniformly sized and will be harder to control, also it may have impurities in it that you are forcing into the metal only to show up later when you paint it

My experience with blasting:

EQUIPMENT: I bought a Clark 90 pound syphon feed blaster from Tractor Supply and it's paid for itself many times over. I'm sure it doesn't cut as quickly as a professional setup but I'm VERY pleased with the way it works and can see no reason to buy a pressurized blaster. It's never clogged and I've done everything from doors to bolts with no warping or other problems. When I blasted my replacement doors they were heavily pitted and there was absolutely no warping despite some pretty aggressive blasting on my part. Syphon blasters also require much less volume of air to operate making it ideal for the casual user.

Other benefits of a syphon blaster include not having to wear special protective clothing. I wear a respirator, light leather gloves, jeans and a t-shirt along with a full hood which I bought at Tractor Supply. I bought a cheap sheet of clear plastic glazing (Home Depot) and make my own lenses for the hood. You can also clear any blockage by simply holding your finger over the nozzle and pulling the trigger. This back-flushes the feed tube.

I also have a HF Tabletop blaster that, once modified, works very well for small parts but finding an efficient way of keeping the dust down inside the thing (without spending a lot of money) has proven to be an issue.

COMPRESSOR: I have a 60 gallon Kobalt unit I bought from Lowes. This is the absolute minimum for blasting. I run my blaster at 80 psi and the compressor is probably running 60% of the time. I also try to take it easy as not to overwork the compressor.

ABRASIVES: I started using Sakrete Builders Sand (Home Depot) sifted through a home made sifter made from aluminum window screen. This worked very well and was cheap. I now use Black Diamond from Tractor Supply, slightly more expensive but you don't have to sift it and it cuts faster. It's all I use now. Always sift recycled abrasive.

WARPING: There are two schools of thought on why sandblasting warps body panels.

One theory is heat buildup, which doesn't sound very logical when you consider that along with the abrasive you are also blasting the area with large volumes of air which you would think would be cooling the surface.

The other theory is that each grain of abrasive is hammering the surface causing it not only to stretch but also work harden. Although I've no proof that either is the culprit I tend to agree with the second theory.

WORKSPACE: If you have a shady place large enough to lay out a 20 x 20 tarp that will work just fine. The tarp makes it very easy to recycle your abrasive. I do all my blasting in the carport using a tarp to keep the abrasive off the siding and to speed abrasive recycling.

BLASTING A CAB: I doubt I'll be blasting the inside of my cab. It's almost impossible to clean out the abrasive from all the hidden areas inside the cab and I've heard too many horror stories of the abrasive blowing out onto fresh paint. I'll wirebrush loose surface rust and treat with Eastwood's Rust Converter.

That's my experience, YMMV

i had my 46 blasted the guy knew what to do and not do and did not warp the metal. it takes a lot of blowing and vac work to get the sand out but what a clean start on the body work cost me 250.00
to get a 46 2 ton cab and chassis done. also dont let them blast the axles or hubs you dont want sand in there. philip

keep your pressure down to 90 or 100

Man, you guys are awsome. I also have the 90 galon syphon blaster from tractor supply.I think i will stay away from the hood and doors but everything else is fair game. If i do not blast the axels then how am i going to get the rust off?

Don't blast axles, engines or transmissions or anything like that if assembled. A bare axle housing can be blasted, but I'd think a wire brush or POR15 would be allot easier. If your flat panels are not rusty, a DA will do a nice job of removing paint. They could then be lightly blasted where pitted or in nooks and crannies the DA can't get to.

Woody, great post, it should be a sticky.

WOODYS RIGHT ON, THOUSANDS OF LITTLE HAMMERS POUNDING ON YOUR FLAT PANELS CAUSE THEM TO STRETCH !

Every piece of my 49 sub has been sand blasted. The body, frame, running boards, hood, fenders, doors, radiator support etc etc. Nothing warped. I couldn't see myself grinding away for months with a DA sander or a wire brush. The key to this whole thing is to find a blaster that knows what he/she is doing. An experienced blaster will NOT warp the sheet metal. I found my blaster guy through one of my sons who had an entire 69 Judge project sand blasted with absolutely NO warping. I think there is a lot of misinformation/mythology out there regarding warping of body panels from sand blasting. It just does not happen with someone who knows what he is doing. The mechanics of what actually happens to cause the warping (heat,pressure,hammering etc.) did not interest me. You can analyze this phenomenon forever and not get an answer. Not that it really matters anyway. What really matters is finding a person that knows how to do this. When I asked my guy if he could sandblast my stuff without warping it he chuckled and said yes and since he had just done the Judge project I had him do my sub. Nothing warped. This sandblasting/warping subject can be argued ad infinitum, just find a guy who knows what he is doing and have your stuff blasted. Just my 2 cents or maybe nowadays its 2 dollars.

Weeds

I agree well said. you hear all this about warping but how often does it really happen. there are some areas where blasting is the only way you are going to get it done.

I just came across this string. I've called around for prices on soda blasting and dipping. The cost was a problem so I tried a test patch of Peel Away and it looks pretty good. Do any of you know if there is a down side to Peel Away?
Thanks in advance

The problem with my truck is it looks like someone (hopefuly a well meaning kid) Put what looks like house paint on this truck. We tried to sand it off but it was like sanding a piece of sand paper made of diamonds. The sand blasting is taking off this junk quick. I still think i will try something else on the hood and door. I hope the more in depth in this truck i get you guys will be here for me

This was a great topic. I concur with an experience blaster can get the job done right.. An amateur can too, if he/she take his/her time and has been taught the right way !! .

Remember - Quality is remembered long after price is forgotten

BUT - with prices these days... this may take a while :-)

I would stay away from sand as a blasting media as it can destroy your lungs. Ever heard of Silicosis? I'm having my cab blasted with soda first because it is gentle and will get most stuff off. Then it will be blasted with glass beads for the stubborn rust areas. I tried blasting stuff on my own and found it to be dirty, slow miserable process. I think its worth having someone professional do it.

Good luck

I look at sandblasting/stripping like I look at cat work- sure, I could rent a bulldozer and do it myself, but I'm time, money, hassle, and sunburn ahead to hire somebody else to do it. Sandblasting just goes that much easier if somebody else is pointing the gun.

Any thoughts on the crushed walnut shells idea? I am looking into blasting my 57 Chevy truck. Also, POR 15, powder coating? What would you all suggest. Thanks for all the writting on this topic...Jon

for what its worth, I have done chemical stripping - both paying for dipping and using aircraft paint stripper (caution, eats skin). . I have also had items sand blasted, soda blasted, walnut blasted, bead blasted, shot blasted, baked, acid dipped, etc. I now like using a 20:1 ratio of Muriatic acid for cleaning followed by a soda ash neutralizing bath on fenders and other small things. Sand Blasting is still best for frames, etc. I now pay to have others blast as I have done it myself, and now lean towards 4ontheFloor's method. Hire someone to do it. There is a really nice shop between my house and work. And the best part is if he blasts a car, he also primes it with PPG self etching epoxy primer and a primer sealer as standard practice. If you refuse the primer, he makes you sign a waiver indicating such.

Scott

Figured I'd put in my $0.02...

I've done sand blasting and have both warped panels and had it come out perfectly. When I was back in high school (10 years ago) I blasted the rear fenders of my '47 Chevy coupe with play sand. With using the sand, being inexperienced, and trying to be thorough I warped both fenders, one really bad. Since then I've blasted using coal slag (available in 100lb bags at the local hardware store for $13) on the cab of my '55 3200 2nd series and it worked extremely well. I was told to avoid the roof because that could easily warp, but everything else would hold up just fine. I've also been told that play sand is extremely cancerous and you should never blast with actual sand, only blasting media (coal slag, glass, walnut, etc).

As for the frame, I've just been going through mine with a wire brush and Por-15, and it looks amazing and seems like it will hold up extremely well. I've been working on the same gallon of Por-15 for almost 10 years and it has been well worth the price.

Good luck with the blasting! I'd love to see some pictures

Neil,
On the POR 15 I hear you can just coat the frame and not really have to worry about the rust. Is that true? I have never heard about a product that really "stops rust." Can you sand blast the frame, and soda blast the thinner parts? Then put the POR 15 on the frame? Thanks! Jon

I started to sand blast mine, but the mess just wasn't worth it. Sand still shakes loose every time I jostle the cab. I also tried chemical stripping, but again the mess was too much to handle. It was a lot of work, but I ended up just using stripping discs.

What the H,

might throw in my 1.8 AUS cents worth too!

RE: Sodium Hydroxide Dipping.
I run a HUGE dip tank at work.
We use it to clean machinery parts before rebuilding.

It WILL clean off ALL rust, from light surface to full scale.
It WILL NOT remove thick grease, only light oils and even then this contaminates the strength of the mixture, as such all parts need to be thouroughly de-greased before dipping.

I have done many engine blocks, fuel tanks, diff housings and many othr parts over the years, and the results are hard to compare with any other method.Especially good as it gets to every surface of the part, even cleans the water jackets in an engine block!

I have found an engine block on the ground in a paddock, completely rusted, dipped it and had it come out with the original machined surfaces shining like they were done yesterday!

But this not really a good method for doing whole cabs.
Too many nooks and cranny's for the stuff to hide in, and it needs a good water rinsing before priming.
Use it for all your mechanical parts, guards, bonnets etc as it will find and destroy all rust that it touches no matter how bad it is.

I'd stay on the path of blast all you can, but leave the body to a professional.