Sand/Media Blasting

[skitchin]

Anyone have experience with sand blasting? Looking at maybe putting a setup together - already have an industrial size air compressor and tank, just not sure how expensive it is. Found this blaster on harborfreight, sounds cheap...too cheap?

 

http://www.harborfreight.com/portable-abrasive-blaster-kit-37025.html

 

AFAIK I'd also need a blasting helmet and gloves... I donno.

[mhildebrand]

I've used cabinets more than the open-air type, but i haven't used this unit before. If you're planning to use this for a full car body 15' of hose may be a little bit short, but that's not a huge problem. In my experience, the air compressor is the deciding factor. If it cant keep up, or has a small tank, it takes a hell of a lot longer to to blast. I know the cabinet that I use the most runs at 85 PSI using glass beads. If your planning on reusing the sand/media, your going to want a fine screen to filter the sand before putting it back into the hopper. That's the biggest problem with the cabinet, the nozzle gets plugged up from bits of pant/rust.

[skitchin]

I've used cabinets more than the open-air type, but i haven't used this unit before. If you're planning to use this for a full car body 15' of hose may be a little bit short, but that's not a huge problem. In my experience, the air compressor is the deciding factor. If it cant keep up, or has a small tank, it takes a hell of a lot longer to to blast. I know the cabinet that I use the most runs at 85 PSI using glass beads. If your planning on reusing the sand/media, your going to want a fine screen to filter the sand before putting it back into the hopper. That's the biggest problem with the cabinet, the nozzle gets plugged up from bits of pant/rust.

 

Great info, thanks! My compressor is a bit old, but should be plenty up for the challenge:

 

Think I'm gonna splurge on that kit I linked, unless someone knows something a little better? I literally know nothing about this topic, so anyone, feel free to chime in on any little detail.

[mhildebrand]

I think that compressor should handle it, as long as you give it a break every once and a while. I'm sure you've thought of this, but if you will be blasting in your garage, you are going to want plastic covering everything. I blasted once in our 3-stall garage, and hung plastic between the first and second bays to try to keep the sand/dust from getting everywhere.

 

I've got the same welder at home too.

[DefEddie]

I've got a large blast cabinet as well as one similar to the unit pictured.

I blast everything from engine parts,pistons,cranks to wheels etc..

 

Personally I would spend a bit more and pick up the large HF blast cabinet.

if you wait for a holiday sale and take in a x% off coupon then you can get for much less than advertised.

 

problem with a pressure or gravity pot is gonna be debris.

unless you have an unending supply of sand then you are wasting all the product.

not to mention you will need protective clothing,that stuff hurts and bounces back onto you no matter what you do.

 

For cost you will be pretty much stuck with sand unless you don't mind wasting other expensive blasting product like glass bead or aluminum oxide.

 

if your stuck with sand or another cheap product because of waste it will also limit what you can blast kinda.

aluminum and other soft metals are easily damaged and pitted by the wrong grit.

sand,beads,slag and other stuff also tend to get stuck in soft metals,which is not good for blasting things like internal engine components like pistons.

 

I use sand,black slag and aluminum oxide depending on size and composition of material.

Sand tends to be large grit like #40,slag #60-80. i use mostly aluminum oxide at #120 for prepping surfaces for thermal,lubricant and powder finishes.

Al oxide is like $80 for 50# so not a waste product.

Each different product is good for different finishes or uses,and it just takes elimination process.

 

what are you planning to blast the most of and why?

if it's mainly ferrous materials with random non-ferrous then just use sand unless you need a nice smooth finish.

Smooth finish go to glass bead or Al oxide,just no glass bead on anything prepped for coating or soft metals (it will embed)

for just ripping off paint and stuff from metal then use cheapest available (sand $15 truckload/black slag $8 #50)

 

I would strongly suggest a big cabinet though.

and whatever you get,take it apart and use rubberized spray coat on all the seams and fasteners,then again on outside of seams with a dab of silicone on all fasteners (easily removed for maintenance).

 

Start scouring garage sales now for a used wet/dry vac for cheap to evacuate the cabinet also.

don't buy new since it will eventually be ruined anyway (build a water trap to help)

you'll want to plumb exhaust outside,as well as keep cabinet away from sensitive engine build areas or places you want to keep clean.

 

sorry for the book,but I went through all this a couple years ago and hope something in here helps.

[RobertISaar]

my dad has a spot blaster like the one you linked.... that stuff does indeed hurt when it comes back after hitting something.

 

for that money, it's not bad. my dad's 60 gallon compressor kept up with it quite well.

[mhildebrand]

If you have seen the show on the History channel, American Restoration, i think they use walnut shells because it will strip paint with ease, but not damage the metal. I think it can also be used for hardwoods..

[skitchin]

Yeah, walnut shells seem to be the way to go for paint. Also, from what I've read you want to keep your air flow down or else you can bend/warp panels. Plan on getting this kit or something similar once my garage is cleared out. Just need to be careful so I don't get Pneumonoultramicroscopicsilicovolcanoconiosis

[Garrett Powered]

blasting is some fun shit. I miss those days back in highschool mechanics class they had a couple blast boxes.

[jimmyfloyd]

Watch Craigslist in your area for a decent used cabinet. I have seen some large ones come up local to me for $100-250 before, that far exceed the HF ones. I personally have the small HF cabinet, but it isn't quite large enough for what I was looking to do.

 

With sand blasting, you want the look at hte CFMs of the compressor, and you need I believe above 10, which you should be fine with.

 

If you are looking to do more than parts, and are looking to do whole bodies, look at a pressure pot from HF. the valves on them suck, but can be replaced. It gives a more consistant blast than a spot blaster (like you pictured) and a gravity fed one. Again, CL is good for these.

[DefEddie]

The friction and heat from blasting material can warp thin body panels and such pretty easily.

I didn't bring that up mainly cause most people don't buy small blasters for large stuff like whole cars lol.

If that's what your thinking then I personally would throw it out the window,cause you would need to do one panel at a time and constantly prime when your finished,it wouldn't be a one day thing at all.

If doing a large car your time would be much better spent selling stuff on craigslist and working to raise money for either a commercial setup or paying someone to do it.

 

If you plan to do alot of thin guage metal then just invest in a small soda blaster.

Soda won't strip rust but it will easily strip paint and doesn't heat the metal so it will not warp or etch the surface.

It also cleans up very easily with water.

 

I've used walnut shells and other odd stuff for blasting a few times before,but i'm unsure of whether or not it heats sheetmetal to the point of warping.

Using the American Restoration reference I have also seen them farm out sensitive stuff to the soda blaster,because of warping issues.

 

 

*Forgot to mention, BUY A HEPA MASK-ESPECIALLY if you use sand.

Silicosis is no joke-it's cumulative,not treatable and will KILL you.

Edited October 25, 2012 by DefEddie