sandblasting

[stillute-ed]

got a question im using my sand blaster for the first time and the garnet is comming out of the hose steady then it will pulsate as it clears the nozzel when it pulsates it like some ones just put a supercharger on it . then it goes back to normal .when its behaving itself there's a lot of garnet comming out but it dosn't work as good as when it goes up a gear .any idears on whats going on

its one of those little red sandblasting units
the garnet is dry
compressor puts out 240 litre's per minute
conection hose from compressor to sand blaster is 4 meter's long
when the garnet gets low it works well only for thirty seconds befor it runs out


and why do i keep getting static shock when im sandblasting and i touch the ute .i weare those white disposible overalls and thats through welding gloves .(hate to get zapped without any gloves on its a decent boot through the thick gloves .

ANY IDEAR'S ANY ONE .

[Rusty EK]

Sounds like you are getting to much medium into your hose , can you adjust the flow of it ?

[stillute-ed]

not sure rusty i'll have a look to morrow.

[bootlegger]

I've never had much luck with those sandblaster things.
I t was the same for me comes out fast slow hard soft.
Drove me nuts in the end and I took it all to the sandblast guy down the road. Paid him a hundred bucks and it was done.
One bit of advice. Lay a plastic drop sheet under what you are doing and recycle the grit.

[robbyrr]

only quarter fill tank with garnet, and open bottom valve a little bit,

[Harv]

Static buildup during grit blasting is pretty normal - the flowing air can generate quite a charge. Industrial practice is to earth out the gun tip. Consider running an earth lead from the gun back to whatever you're blasting (maybe trial it with an old jumper lead). Make sure the earth is nowhere near anything flammable, as some arcing at the connection can occur.

[baker12]

I have a litlle 20litre unit cost $150 bucks or thereabouts and $15.00 per 25kilo bag of garnet.
Worked a treat, you need to adjust the flow by not opening the nozzle valve to much and not over filling the unit.
ensure that the pressure in the compressor is set to not blow the pressure valve and it will go all day, 10minutes of correct set up will save 200minutes of wasted time.
you can re use the grit about 3 times before it comes out like fine sand and does nothing.
The biggest problem I had was having to refill the little bastard every 5minutes, but I did my whole car inside and out for under $400 dollars and was quoted by the sandblaster $2500.00 and the soda blaster $1800.00.
If you have the time and the patience it is the way to go.
If you want it done yesterday spend the money and get it done professionally.

[rusted]

I have one of those sandblasting units and had the same problem.Was using a 15cfm compressor.It was pathetic.

I ended up hooking my 85cfm atlas copco compressor to it.Made a real good sand blaster.Cut the pressure down to 70lbs.
Just cracked open the garnet tap on the bottom a little.Secret is lots of air and a little grit.Too much pressure smashes the grit and turns it to dust making it difficult to reuse.
My problem is it now eats through the taps after a hour and I had to use a double braided steel hydraulic hose as the garnet soon wore holes in the original hose.Also modified the nozzle.
Now have a good sandblaster.I also ended up using a supplied air mask,long gloves and a heavy coat to keep the shit out.