Walnut shells in a bead blaster

[Dave]

I searched and did not really find what I was looking for.

 

I have had a large Trinco bead blaster for years and thought I would try walnut shells instead of glass beads. So far its a waste of $23.00 unless I put the stuff in some paint for my front steps so they are not slippery.

 

Just what do the walnut shells work for? I have tried them on clean alternator cases and a aluminum manifold and I am not impressed. Further more cleaning small parts I have to hold in the rubber gloves in painfill.

 

I have a good supply of dry air and a good flow of walnut shells.

[JMortensen]

I haven't tried blasting with the walnut shells, but I was hoping they would work for that purpose. I can tell you that they're great for cleaning brass in the process of reloading ammunition, but that is done with a vibrator, not a blaster. I'm very interested in this thread because I just bought a cheapo sandblaster and was wondering if I might use walnut or something else (soda?) in it.

[Dave]

The walnut shells come out fast and plentifull and don't break up from what I can see. I have a piece of 2" copper pipe with copper caps soldered on the ends I made a radiator catch tank from, the walnut shells don't do much there. So far I found the walnut shells will clean some rust stains from a clear plastic box, but it does mark up the plastic. I stripped the paint from a 280Z plastic hood vent, but it beat it up pretty bad.

[zcarnut]

You need to use a pressurized blaster. Pressurized media is much more effective when removing surface containments. 99% of cabinets are siphon fed. They do make pressurized bead blasting cabinets, they just cost more.

 

http://www.kramerindustriesonline.com/blasting-systems/dp-series.htm

 

http://www.abss.com/Blast%20Cabinets.htm

 

http://www.kelcosales.com/html/page2.html

 

I use walnut shells to clean engine internals like removing carbon from pistons ring lands and cleaning carburetors. The best reason to use walnuts is that any trace amounts of walnut shells remaining after cleaning will not damage the engine. Whereas even tiny amounts of glassbeads can be disastrous.

[Tony D]

I agree with ZCarnut, walnut shells are best used in a pressure pot.

For a siphon blaster the best I have found for walnut-shell gentleness is Ballotini Glass Beads at fairly low pressure, like 40-60 psi.

 

If I recall, I may have tried Walnut Shells at 100+ psi through the gun, but the siphon orifices of my smaller unit just weren't big enough to give the blasting like my pressure pot gun. The volume of the shells is considerably greater with that setup than through my siphon rig.

 

And yes, walnut will not leave residues that will be harmful if you don't clean them up and get everything out afterwards.

 

Walnut is a VERY gentle cleaning medium, if you were marking plastic, chances are you are using pressure much too high, with insufficient media flow. Walnut shells should be able to clean plastic like tail light lenses and leave a bright finish on them afterwards. Are your feed lines clean? You have have contaminants mixed in with the media flow that marked the plastic, the walnut shells should not do it unless the plastic was really soft, and the presure on medi feed was very very high.