First of all, budget.. I'm thinking a HF model.. but which one?

I've come to the conclusion that with two project cars, I've got too many large-ish items that'll need to be media blasted. So, I'm thinking about purchasing a blaster, instead of paying someone to do it. I already have a small blasting cabinet (that I hate), that I can deal with for small stuff.. but I have various wheels, frt and rear control arms, cross members, sheet-metal, etc..

I do have a 25gal 5hp (8.2@40 - 5.6@90) direct drive compressor AND a separate 25gal tank (That I used to know how to run in tandem w/the compr. - but need to relearn). I also have an old 6-man camping tent that I plan on using for blasting (may be able to re-use some media, besides keeping the crap contained in general).

Not trying to blast the body, only medium large stuff. Anyone used an economical unit that they can recommend?


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It depends on what you’re blasting. I’d only use soda on anything near the engine, for example. I set up a great compressor (2 stage 5HP 65 gal), bead blasting cabinet and soda blaster to clean parts for my bumblebee, so my recommendation may sound surprising, but….if I were you, I’d send the parts out to a blaster who’s set up to do this for a living. A few reasons: 1) mess, 2) cost of media and gear, 3) safety (they have the right respirators), 4) time. Or maybe just buy a soda blaster for the delicate work you don’t want to entrust to someone else. I’m all about DIY, but after doing a bunch of blasting, for me, it’s worth sending out.

I dealt with the same dilemma. Here's what I did, and the link to my build thread (page 5 towards the bottom)...

I was really struggling trying to figure out how to get a wire/fiber brush down into all the nooks & crannies in the frunk area, and the area under the gas tank. I thought I had found a flexible extension for my drill, but then received an email that it was no longer available from the supplier! headbang.gif

At that point I gave up and got a abrasive blaster from HF. I decided on the 110lb model since it was only $20 more than the 40lb model. After reading reviews, I stopped by Tractor Supply and got 100lbs of the Black Diamond fine blasting media (coal slag). It's $9.99/bag for 50lbs. The HF media is $24.99/bag for 50lbs!

I have a 2HP Kobalt twin cylinder compressor that's plumbed in to another 32 gallon tank left over from my old compressor that died. So, 62 gallons of 150PSI air, theoretically...

http://www.914world.com/bbs2/index.php?sho...43765&st=80

Mike

Continuous Duty Cycle rating for the comp is pretty important. The comp has to be able keep up with the tool. CFM.

Great info Mike !! Like I mentioned I'll not be doing body or panels, just the items too big for my smallish cabinet, and I'd be doing it in a contained space (large old tent).

Is coal slag gonna be ok for aluminum wheels and/or fan shroud (magnesium?), stock transmission (magnesium?) ?

No trying to be tone deaf to you other guy's suggestions - I appreciate all info and experience! I'm gonna have to do this 'cause hiring it out is too costly, and I'm not in a huge hurry to get it done quickly and once my projects are done I'll probably recoup some of the investment if only a fraction.




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+1, Ian nailed it again. Several years ago I went for the HF unit and it works to some degree, but these days I have made pals with a local metal prep service. Its value

Ian is right. Small cabinet and only do the small stuff.

Ingersol Rand 3hp 60 gallon tank single stage compressor doesn’t allow for 100% duty cycle and media efficiency falls off when pressure and flow drop.

Just bought a big blaster. Pressure fed and suction fed in the same unit. The air supply is really important. The spec on the blaster is usually the minimum needed.

Blasting inside a tent sounds miserable.

Oh my God, I can only imagine.. we've got rain and unbearable humidity constantly this spring/summer.. so yeah, that would suck. Nice blaster btw.


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Well... I blasted my whole frick'n chassis on a rotisserie in an HF garage tent using an HF 40 lb. blaster on a 5HP 80 gal. compressor. Time consuming? Yes! Fun? Hell NO! Satisfying? yes. Would I do it again? Sure, but consider that I live in the sticks where it is a royal PITA to haul chassis or parts down to the valley and wait weeks for one of the few guys who can do blasting to get around to it.

I will continue to use the blaster for small parts/projects. Even with my compressor, I spend a lot of time waiting for my compressor to catch it's breath. It can keep up for a long time running full on, but I try to keep it to a 50% duty cycle or less and found the pace was nice to let you take frequent breaks to do something else. This is true for parts large and small so you will need to be patient with your two small compressors in tandem. To give some examples: I blasted my windshield trim for painting in about 1.5 hours. About 2.5 - 3 hours to do the rocker covers and front and rear valances.

+1 on Black Diamond. I bought a few bags form my project and it worked well. Unfortunately the nearest Tractor Supply Co. is a 300 mile round trip so I mostly used crushed glass from a local lumber yard. The glass was cheaper than HF prices but not as cheap as the Black Diamond. I thought the glass blasted better than the slag and also recycled better, but if I had Black Diamond easily available, I'd have gone with it.

We live in the sticks but I guess we aren’t that far out.

Well, when a larger used blaster pops up local for cheap, I'm gonna snag it. May have to do a little in the morning and a little in the evening, but I've not got all that much to do when compared to a whole chassis (that I'm seeing is actually even do-able with some patients).

Question: Why is pressurized necessary? I mean I have a blast cabinet (something like 24"x24" squared) - why not just fill it up with fresh media and use it's siphon hose to shoot at the items outside it's cabinet?



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Ha ha. It's more than 2.7 miles just for me to hit pavement! Worth it though. I woke up to the sound of elk bugle grunting to their calves through the open window this morning.

Increased productivity. Generally, you will be able to clean surfaces about 3 to 4 times faster using direct pressure as opposed to siphon blasting. More aggressive force than siphon / suction blasting. Pressure blast cabinets deliver abrasive media at about twice the speed of siphon blasting cabinets.

Also, siphon blasting requires a minimum amount of material before The siphon gun will work.

Here's a good comparison video - https://www.youtube.com/watch?v=uGVrAGSBr0M

Thanks for educating me on that!
What about the aluminum and magnesium items, should I look to run a different media thru it for those pieces? ..or just turn down the pressure maybe?


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Just start with lower pressures. The media is also like sandpaper. Use the correct media and pressure for the finish you want to produce.

A cabinet is a cabinet. How well you can see what your blasting depends upon how well it is lit it and how well it evacuates the dust. A really good blaster has this covered. You can add lighting or increase vacuuming power to a cheap cabinet as well. The main tool is the gun. The HF gun is anemic at best. Buy their cabinet but toss their gun. TP Tools sells a great gun that runs about $90 IIRC. You won't be disappointed.

I have and use a Texas Blaster. It will do soda, sand, mixed compounds, and coal ashes.
Can handle 10cmf-90!
I like the idea of using my compressor for smaller things. Or renting pull behind compressor like the state uses in construction, for doing a whole car in a few hours.

Matt

A good cabinet is worth the money. You will find projects to blast and refinish. A mediocre cabinet is a pita. Guns clog or don’t drawl media. Cabinets leak and fittings pull away and visibility is poor. A foot pedal is nice for a lot of blasting.

I have blasted two complete cars and all the associated parts plus much more. I did all of that with a harbor freight tank and a harbor freight cabinet. Both I made new media control valves. I also used the special high wear tips. Had no issues at all. I think I used garnet for the media on the bodies and I mostly use aluminum oxide in the cabinet.
Make sure you have a good water trap.
For large jobs you need CcccccFfffffMmmmmm.
I also used the HF tent.
Some window screen over the face shield makes it last longer.
I use a respirator.
Good luck.

I made a short review video on the 50lb Harbor freight blaster.

Video here: https://www.youtube.com/watch?v=eGtldNb9I3w

I should have waited to get more footage for the video, it actually works great now, with play sand and a water trap.
I am using this for my 912 body. Large and odd spots.

If you are using a tent and a big compressor it will work great for you.

I bought the HF media blaster cabinet which didn't work at all until ....

.... added two lights and an exterior switch
.... changed the configuration to pull from the bottom and feed into the gun through the back
.... added an adjustable air intake feed to optimize media flow
.... added a window screen glass protector
.... modified the vacuum to pull from the back with the air inflow from the side
.... just purchased a foot pedal and an improved gun so I don't know how well they will work

I've been using the Medium Coal Slag from Tractor Supply and it works pretty good, now.

George

A tent doesn't sound that bad...
My blasting experience ... 50 years of soot build up on the bricks above the wood burning fireplace mantle. Rented a 5 hp gas powered compressor ran a hose from outside and used soda to blast the soot off the bricks and mortar. Cleaned up amazing without damaging the brickwork. Of course even with taping plastic curtains everywhere with drop sheets and an open front door 15 feet away I spent days vacuuming up the soda residue. The wife was not amused - somehow she was over looking how clean the bricks were - I don't understand why...

If you do use soda for blasting, remember it is a one time use material- it cannot not be recycled like other abrasives. Once the crystals shatter on impact (which is what does the cleaning) the soda turns to flour and won't flow properly from the hopper again. A full face respirator is also a necessity if you are not in a cabinet.

I wear a respirator when I use the blast cabinet. Even with a good vacuum system, there’s plenty of blasting dust floating around. I know some guys will brag about never using ppi. I just wish I used it more when I was younger.

Check out https://www.tptools.com/. I have one of their larger cabinets and have been very satisfied. One thing to keep in mind, you'll want a water separator as the media will clump if you don't remove the moisture from the air. As all the others have stated, PPE is a must as you will breath in stuff you can't even see.

Cheers,
Chris

If I was buying one for myself, I would get a mid range unit from TP Tools. They make nice stuff.

I rebuild brake calipers so I do a lot of blasting. I have a 5hp 2 stage 80 gallon ingersoll compressor that realistically is about 1/2 as big as you should have for any sort of continuous blasting. I have 2 different cabinets...one with aluminum oxide and one with glass bead, both run 1/4" nozzle guns, because that's really about all the abuse I want to put my compressor through.

What I've learned about blast cabinets:

The ones where the front/window opens to load parts are way better than the ones with the door on the side...you don't lose a bunch of media out the door when you open it from the top.

The Harbor Freight units are sort of OK....as an enclosure, but everything else is garbage.

The slope of the hopper is critical. Get something with the steepest hopper walls possible, otherwise all your media just piles up around the side and you suck air instead of media.

If you do buy a cheapo blast cabinet, throw most of the parts directly in the trash and go to TP tools and buy their retrofit gun/suction tube...Don't even try using it with the harbor freight parts, they're that bad.

Buy the largest cabinet you have space for....the farther the workpiece is from the glass, the longer the glass will last.

Glass is a double edged sword....you can use the protectors, which are softer than the glass, and waste a lot of time changing them often, or you can just run the glass, and change it as it gets fouled up. I typically have windows cut 10 at a time at the local glass shop...If a piece of glass last me more than 2 protectors, then it's worth the $5 or whatever it costs to skip the extra time to remove the glass and change the protector.

The media plays a big roll in glass life...aluminum oxide will kill glass in short order. Glass bead obviously won't.

I would try and buy a higher quality used unit than a crappy new harbor freight unit. I have a Kelco and a Trinco...both excellent, but I prefer the Trinco.

Very cool 912 project you're working on and best wishes with it!

Not to be a naysayer, but in case you (or others) don't know, silica or play sand is unsafe for media blasting (banned in many places). Here's an article of many available:

https://pittsburghsprayequip.com/blogs/pitt...ety-suggestions

1/2 of the stuff we did when we were younger should have put us in the grave years ago. You don't know what you don't know. I can recall blasting a speedster in the '70's with silica sand in my dad's garage, it worked great and who knows what my lungs look like, of course NO PPI at all