Using a sandblaster with crushed walnut shells ?

[Kern Dog]

In 2013, a guy gave me a Harbor Freight sand blaster. It is very simple, it has a single tank mounted vertically with a 6 foot hose. I ran it until the sand ran out, then I tried using walnut shells. The guy included the shells because he thought they'd be less likely to warp thin metal. The shells are a lot bigger in size compared to the grains of sand.....The shells clogged instantly. The hose plugged up. I tried running long screwdrivers through each end to clear the blockage but had no luck.
Is there something that I should have done differently?

 

[khryslerkid]

Yea, don't use walnut shells in that blaster!

 

[khryslerkid]

Couldn't help myself.

I know they have different size porcelain inserts for the nozzle. Maybe a larger one would let them through. I like the Black Diamond sand from TSC.

 

[moparmarks]

Ya use a bigger nozzle. Shouldn't plug the hose but don't know about the HF ones. I've never tried walnut shells in mine.
Walnut shells are mainly for blasting softer metals like copper.

 

[Kern Dog]

The nozzle didn't seem to clog, the hose did. I've beat on it with a hammer, tried pushing a long screwdriver through the blockage and still am having trouble. I might just go get a replacement hose and switch back to sand.

 

[Photon440]

Ya use a bigger nozzle. Shouldn't plug the hose but don't know about the HF ones. I've never tried walnut shells in mine.
Walnut shells are mainly for blasting softer metals like copper.

I remember my dad telling me (he used to be an aircraft mechanic in the early 60's) they used walnut shells to blast the fins clean when overhauling radial engines on the DC-6.

 

[OKDart]

Mine clogged using black diamond when it was new, a co-worker had his clog with garnet. He said medium crushed glass worked good though. Seems they are finicky with what you run through them.

 

[moparmarks]

Actually my HF blaster had real stupid cheap design for push button valve that would clog real easily now that I think about it. Been a few years but I ended up removing the push button valve altogether and just using the air valve to turn it on and off. This was just with glass bead. Pull it apart and you'll see what I mean.

 

[gkent]

Is the blaster a "pressure pot" style or is it just a tin can with gravity or suction feed ? A "pressure pot" is the way to go because it will blow air along with the media through the hose - but you have to remember to turn the air on to the pot! The only issue will be the nozzle size.

If its a gravity or suction feed unit, put it out at the curb with this week's trash.

 

[moparmarks]

Sounds like it the pot style like mine. 5 gal bottle.
Mine works good once I remove the piss poor push button valve.

 

[Lee Robinson]

Sounds like it the pot style like mine. 5 gal bottle.
Mine works good once I remove the piss poor push button valve.

Excess moisture in air supply can also aid in clogging the media.

 

[CudaChick1968]

When it clogs up, firmly place your gloved hand right over the sprayer and hit the trigger until you see a cloud. (Any room between your hand and the nozzle will simply blast your glove; you want to press hard enough to interrupt the airflow.) This method should remove the clog but only temporarily ... until that offending particle works its way back to the bottom of the hopper again.

Screen ALL media first if you have concerns it may be too large for your nozzle tip.

If you blast a lot, TPTools.com has a wonderful gun upgrade kit that has served me well for over a decade now.

Ceramic tips are all right for occasional use but the carbide ones are MUCH better and last literally for years.

There are many different blasting medias available. Your choice should be based on your compressor's cfm rating, what you're blasting AND what you're trying to remove from it. Some are good for softer metals, rust and scale removal, old paint, etc., so a little research before you shop or stand at the cabinet can save you hours of work.

https://www.grainger.com/know-how/industry/metalworking/kh-blast-media-chart

I hope this helps!

 

[1 Wild R/T]

Walnut shells for blasting are normally ground into a semi fine powder.. Living in the valley when lots of walnuts a harvested & processed I'm guessing the guy came up with walnut shells that haven't be finished down to a useable point? Post a picture of what your working with....

The other possibility is moisture... Sand will clog due to moisture but walnut shells are more prone to it...

 

[Kern Dog]

The sand was working great. So great, I was amazed that this is a Harbor Freight product!
I have a water trap that I can use but I'm thinking that the particle size of these shells is too big. There was no obvious moisture in the spray. Maybe the chunks got built up near the nozzle. When I unscrewed the hose from the tank, the shells sprayed out quite well from the tank itself but it is about 7/16" of an opening there.
I'll replace the hose and just use sand. I only used these shells because the sand ran out and because the shells were here to use.

 

[Kern Dog]

Here is what the crushed walnut shells look like:

I went to Hazard Fraught today....They don't sell replacement hoses for the sand blasters. Nothing at Home Depot or the NAPA auto parts store. The Wife found a site online that sells 10" lengths of the approved hose.

 

[1 Wild R/T]

That stuff should work.... Go back to sand & see if it works... But be sure to wear good protection... Stuff is bad for your lungs.... Silicosis is real..

 

[Kern Dog]

Silicosis ???

 

[OKDart]

Silicosis ???

The sand gets jagged when it's blasted, and when inhaled will get trapped in your lungs (like sand burr stickers in your dogs fur). Your lungs can't get rid of it through mucus, etc., so it creates scar tissue around it. Before you know it your lungs are a big ball of scar tissue.

I've read that crushed glass has very little free silica, and I've bought 50 lb bags for $7-8. One of the downsides is that it can only be used once.

 

[YY1]

I pull the gun out of the supply hose, turn it around, cover the gun inlet, and use the air to blast backwards through the supply hose.

I had one of those HF pressure pots given to me with a deadman valve gun.

I spent more time trying to fix the system than I did using it and sold it for $25.

It wasn't any more powerful than an open hopper on my 30 CFM compressor but it was a hell of a lot more trouble.

 

[Lee Robinson]

I pull the gun out of the supply hose, turn it around, cover the gun inlet, and use the air to blast backwards through the supply hose.

I had one of those HF pressure pots given to me with a deadman valve gun.

I spent more time trying to fix the system than I did using it and sold it for $25.

It wasn't any more powerful than an open hopper on my 30 CFM compressor but it was a hell of a lot more trouble.

Kern Dog, Temple Associates in Sacramento carries all kinds of media and supplies. On Ramona Ave. off Power Inn Rd.