The Project Pad

I'm tearing apart an old coupe that has lived its hard life in the northeast. Before I put it back together I want to take the time to bring the parts down to bare steel and paint/protect them.

What strategies are you all using?

I'm looking at mostly suspensions parts (control arms, strut housings, hubs... etc. etc.) where the paint is cracked and flaking and rust is the only way to describe the "finish"

I have wire wheels for the drill and flap disks for the angle grinder but is something like a media blast cabinet worth the money? I don't have shop air so it would be a bit of an investment.

Find a local sandblaster and get a quote. Kind of a pain but easy in the short term

I have a cheapo Harbor Fright Blast cabinet and I use it all the time. I have back beauty media in it. That stuff is pretty aggressive, but if you are careful it doesnt do too much damage. I also use a lot of knotted wire wheels on grinders, and smaller brass wheels on an air grinder for the smaller, more delicate parts.

I always like to clean and paint rusty bits when I have them apart on most any project. That little blast cabinet is awesome for that.

its def worth getting a full setup, that said you could probably get everythign on the entire suspension and engine bay done for 150-200, as it does take time.

Hmmm... I didn't even realize this was a job that could be outsourced. I'll keep that in mind...

If I go media cabinet, that means getting cabinet, compressor, lines, gun, and connections... starting to sound a bit expensive...

I guess I'll give it a go with power hand tools for now and keep in mind I could look for a local shop...

dalspaugh wrote:Hmmm... I didn't even realize this was a job that could be outsourced. I'll keep that in mind...

If I go media cabinet, that means getting cabinet, compressor, lines, gun, and connections... starting to sound a bit expensive...

I guess I'll give it a go with power hand tools for now and keep in mind I could look for a local shop...

Ahh yes, I was assuming you had that stuff. You need a pretty significant compressor to run a blaster for any amount of time. I have a 60 gallon 3hp ingersoll-rand. I think its about 11-13 cfm. It cycles that pretty heavily. A little crapsman compressor would let you blast for 30 seconds and wait for 5 minutes to fill back up.

This is what I am using

dalspaugh wrote:Hmmm... I didn't even realize this was a job that could be outsourced. I'll keep that in mind...

If I go media cabinet, that means getting cabinet, compressor, lines, gun, and connections... starting to sound a bit expensive...

I guess I'll give it a go with power hand tools for now and keep in mind I could look for a local shop...

Yeah, a media blasting setup is a slippery slope.
I blasted for a few years with a 4-5cfm compressor, but you had to take a lot of breaks or else you'd see a noticeable decrease in cleaning potential as the pressure dropped. You'll want a 10cfm at a minimum for any kind of prolonged cleaning. My setup is an 80gal 2-stage 175psi compressor that flows 15+ at 100psi. It works amazing, and cycles even during continuous blasting with a siphon feed and pressure pot blaster. Watch craigslist, mine was only $200 and I put probably another $200 into it for upgraded wiring, plumbing, and paint. If you want to do any painting or powdercoating, you definitely need an air dryer (desiccantor refrigerated). For blasting, you can get by with cheaper filters and moisture traps, but you might get some clogging in humid climates or if your compressor is running constantly. There's also ways to design piping to help remove water, like a long downhill run on a wall with a drain tap on the end.
In addition to a cabinet, you'll need some kind of dust collection so you can see while you're blasting. I'm still experimenting with this one, but it's another source of $$$. You'll need a shop vac with a HEPA filter at a minimum.

Bare minimum cost for a budget setup would probably be:
$2-300 compressor
$200 blast cabinet
$50 shop vac

That'll take care of rust and thin paint. For thick paint and some powdercoat, I still chemically strip parts as it'll take way too long to blast off or I'll have to use too agressive of a media for my liking.

As far as media, I pretty much just use aluminum oxide nowadays. I've experimented with walnut shells, glass bead, and coal slag (black beauty), but aluminum oxide gives me the best balance of cleaning strength and finish for my needs (generally powdercoat prep). Black beauty is too agressive (works great for thick paint removal and heavy rust), but for a smooth PC finish it would have to be re-blasted with a less abrasive media. Walnut shells leave a great finish, but not agressive enough for a lot of stuff. Glass bead is also a nice finish, but isn't good for cast aluminum parts that are going to be powdercoated. The beads will embed themselves in the aluminum and then cause outgas problems with the finish. I've also done sodablasting, which gives the best finish, but is expensive.

My setup:


4'x2'x2' cabinet

Keep in mind that while sandblasting equipment is pretty specialized, an air compressor is a helluva nice thing to have around if you're a gearhead, for 100 different reasons.

But I'll second what Dana said, sandblasting takes a compressor with some oomph. I have a 2HP compressor and was sandblasting some small snowblower parts last weekend... I never actually had to stop and wait for the compressor to catch up, but the pressure was really dwindling at some times.

I had a feeling I might get a response from Alex, I saw you hint at this topic in your build thread. Damn. I had no idea it took that much air to use a blaster effectively. Glad I'm finding out this way....

I usually do keep my eyes open on CL, a buddy of mine pulled a large compressor that needed only a belt for a good price. I've kind invested in tools around the air thing, electric impacts and angle grinders etc. etc. but I know I'll be getting one eventually.

Problem is, with a rented garage and no truck, I'm hesitant to buy anything I can't haul around in a car... unique problems to work around here.

How are you chemically stripping parts? Some sort of Acid dip/wash?

To be fair, you can also buy sand blasting guns that are designed to work with lower CFM compressors.

I bought a SKAT gun for my "portable" blaster setup when I had to blast my 4000's body to get all the flash rust that had accumulated through the year w/o it having any paint on it.



I got gun on ebay: http://www.ebay.com/sch/i.html?_from=R4 ... n&_sacat=0

So depending on compressor size, you can get a gun that's rated for that compressor.

I ran my setup w/ a 30gal craftsman compressor. It essentially ran non-stop for about 45 min until it started spitting out more water than sand (it was middle of summer w/ 90+ degree heat). Still did the trick, though!

FWIW, I made the above setup for about $10 w/o the gun. No cabinet, but it did what it needed to... but full projection was required!

dalspaugh wrote:I had a feeling I might get a response from Alex, I saw you hint at this topic in your build thread. Damn. I had no idea it took that much air to use a blaster effectively. Glad I'm finding out this way....

I usually do keep my eyes open on CL, a buddy of mine pulled a large compressor that needed only a belt for a good price. I've kind invested in tools around the air thing, electric impacts and angle grinders etc. etc. but I know I'll be getting one eventually.

Problem is, with a rented garage and no truck, I'm hesitant to buy anything I can't haul around in a car... unique problems to work around here.

How are you chemically stripping parts? Some sort of Acid dip/wash?

My setup may be a bit overkill, but it works extremely well and does all that I need without breaking a sweat (and I also wanted it to be able to do HVLP painting). All of my stuff was bought used on CL or through clearance deals. I have <$800 into all of it and that includes both a siphon gun for in the cabinet and a pressure pot blaster for outside blasting. You could get by without a blast cabinet (I did that for about a year), but it's messy and wastes a lot of media. You can try and blast on a tarp to try and reclaim some of it, but the blast cabinet pays for itself quickly on media costs.

I use Klean-Strip or Aircraft Remover (from a gallon jug, not that aerosol cans) for removing heavy paint. I don't like the aerosol versions, most of the times you'll be lucky to get through half the can before it clogs. So I buy it by the gallon (at Lowes/Home Depot/etc) and paint it on with a paint brush. These don't work well cold, so if it's <70F you'll want to put a space heater on the parts. It'll probably take several coats to get it all off, or enough for blasting. A pressure washer helps immensely (yet another expense).

So, depending on how many parts you need to do, it might make sense to just find a local blaster. Or try the chem stripper and pressure washer for any paint/grease. Then a wire wheel for rust.

Dave: Check out Preprite in Tewksbury. http://www.preprite.com
I'm considering using them for sandblasting a rear CQ subframe that I will later have seam welded and powder coated.

I've used http://www.centralmasspowdercoating.com ... Offer.html in the past for powder coating, and they can have items sandblasted for an additional charge (If you need a lot done like an entire suspension, this may be more economical than doing it yourself)

Thanks for the local links Peters!

I'll definitely consider them when it comes time. Still pulling it all apart currently and then I'll evaluate how to proceed.