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View Full Version : Which sand blasting material is best for aluminum



Hugues
22 September 2012, 0752
Hi guys,

i found a nice sand blasting cabinet (http://www.otelo.ch/cf/catalogue/cabine-sablage-detabli/otmt-0001150102-skg.html), all equipped, not expensive.

But i was wondering what kind of abrasive material is best for aluminum , to get a nice finish ?
sand ? glass beads ? other ?
grain size ?

thanks for your feed-back,

teddillard
22 September 2012, 1129
I use glass beads. I did a "note to self" post a while back on that:
http://evmc2.wordpress.com/2011/06/26/notes-finising-alumnimum/

That cabinet looks sweet, although:

a) The first Law of Sandblasting is that your cabinet is always about 2" too small to fit your part.
and...
b) I use a big tupperware container that I just cut holes out of for my hands. For my frame I used a discarded Epson 9800 (48") printer box with some plexi over the top. I used the plastic bag that the printer came in to collect the grit.

http://sphotos-b.xx.fbcdn.net/hphotos-prn1/162840_1774813769647_8058809_n.jpg

For the few times I actually use the sandblaster, it's awesome, and when I'm not using it it's stored out of the way. Plus my wife doesn't think I bought another big tool, she just thinks I stole one of her storage containers.

Which I did. :D

__Tango
22 September 2012, 1205
Hey Ted. What kind of sand blasting unit do you use?

Hugues
22 September 2012, 1213
I was also contemplating the "big tupperware" solution...

In your chronicle, you described a couple of steps to get a nice finish: grinder, sand paper rough grain, wet sand paper fine grain, sand blasting, then polish.
I admire guys like you who have the patience to go through all these steps to get a nice work done, i wish i have this patience too, maybe one day i'll get there.
But what happens if you just use sand blasting ? might take a little longer, but can you get the same finish ? (probably a dumb question from a lazy and impatient guy) :p

...and you must have followed the first law of large printers when you bought that one too ! :rolleyes:

teddillard
22 September 2012, 1405
I bought the cheap gun from Harbor Freight, about $30. Works awesome. No, if I could get the same finish easier, I would. lol! :D

skyclark
22 September 2012, 1435
The amount of prep depends on media and the desired finish.

I often just deburr and bead blast parts we machine. Glass beads leave a great surface but don't cut much.
Aggressive media will cut through lots of stuff but will not leave a smooth finish.

Scotch brite is also something it use a often.

Square Wave
24 September 2012, 0921
Walnut shells leave a really beautiful finish on aluminum (seriously, you can buy them ground for that purpose). They don't remove any metal but they make it very clean and satin finished. They leave a little oil film, too, which helps prevent corrosion. I have also used baking soda, which is finer and has less mass than glass beads and so does not remove material but leaves a lovely finish. Soda is water soluble, so you can wash it out of oil passages and other crevices.

Here's a link:
http://www.kramerindustriesonline.com/blasting-media/walnut-shells.htm?gclid=COjg-IjQzrICFYio4AodoyoAfA

skyclark
24 September 2012, 0943
Walnut shells leave a really beautiful finish on aluminum (seriously, you can buy them ground for that purpose). They don't remove any metal but they make it very clean and satin finished. They leave a little oil film, too, which helps prevent corrosion. I have also used baking soda, which is finer and has less mass than glass beads and so does not remove material but leaves a lovely finish. Soda is water soluble, so you can wash it out of oil passages and other crevices.

Here's a link:
http://www.kramerindustriesonline.com/blasting-media/walnut-shells.htm?gclid=COjg-IjQzrICFYio4AodoyoAfA

These are both great suggestions. I have had engine cases soda blasted and they come back looking amazing.

Hugues
24 September 2012, 1219
Walnut shells, I like that . Baking soda too.
And from a health point of view, I presume it's not too bad ? I read silicium based material are to be avoided because of the nasty dust ...

Hugues
01 October 2012, 1254
Hi guys,

i found a nice sand blasting cabinet (http://www.otelo.ch/cf/catalogue/cabine-sablage-detabli/otmt-0001150102-skg.html), all equipped, not expensive.

....

finally i made the jump for this little sand blasting cabinet linked above.

received it tonight, almost plug and play, already built, quite solid, got a lamp in there, paper filter to suck the air out if you want, a couple of extra plastic sheet to protect the window on top, not huge but you load it from the top. For the price, i think you get quite a good product. In video here, my first blast ! (video ready in a few minutes after youtube has digested it)

i bought it in Switzerland, not sure where it's made, the brand is OTMT, you can find it here for example in the US for 160 usd, comes with the air gun, so you just need a compressor, mine is 24 liters only, and that's working ok. I received also glass beads (the one i'm using in the video) and crushed wallnut shells.
http://www.otmtmachines.com/otmt-blast-cabinets.html

EDIT: not sure why, the video below says unavailable, but this link should work:
http://www.youtube.com/watch?v=4rwXsMf089s&hd=1


http://www.youtube.com/watch?v=4rwXsMf089s&hd=1