New sandblaster, but no pressure

My compressor (see pics below) puts out 6cfm of flow at 40psi, and 4cfm of flow at 90psi.

I have a new sandblaster. I tried both a large-opening nozzle on the spray gun (called a 'deadman' for whatever reason, I've learned) and I tried a small-opening nozzle on the spray gun.

I get a larger flow when I use the large-opening nozzle on the spray gun. I tried different nozzles to figure out why I have the following issue:

- with my compressor feeding 100psi into my new Harbor Freight sandblaster, I can easily, painlessly block the flow of sand out of the spray gun -- with my hand.

There I was today, dressed head-to-toe in a protective suit, a respirator on, huge safety goggles, *AND* a "blast hood" that came with the compressor. AND I HAD my freaking longjohns underneath to protect me from, thee uh......the 'blast.'


I disassembled the sandblaster and checked it, check the spray hose, checked the spray gun -- no blockages at all. All valves working fine. And I know the tank is pressurizing, when I pull the safety valve there is MONGO freaking pressure inside the tank.

And sand *is* flowing out of the gun -- but it's acting like it's on qualudes, just *no energy*, no "blast force." I open all valves on the sandblaster as per the instructions to put the thing in operation -- check. The tank is pressurized to 100psi from my compressor - check.

Yet I can block and stop the flow of sand out of the spray gun with my gloved hand.

I WAS EXPECTING THE FREAKING THING to bore through my glove. Limp as chinese noodles.

I used pretty-fine sand (see pic) so I don't think the sand was the problem -- it is bone-dry and flows easily.

WHY AM I GETTING no flow out of my gun?

MY 4cfm-AT-90psi COMPRESSOR, MAXES OUT AT 125psi


MY NEW SANDBLASTER -- I only filled it 1/3 full of sand before starting it today


THE SAND -- it is a pretty fine, not very coarse at all, variety of sand


MY ENGINE WAS HEARD SNICKERING TODAY, "Whoa, is that all ya got buddy?"

Most compressor mfgr's boast theit output the last soda blaster I used had an 80 gallom tank ans a profeesional compressor 10 or more techs used it was lack luster to say the least

the company I hang out at anhd do a little front end work for has a giant 3 phase compreesor that
opperates their sand blast room 40x100 doubt a sma;; compressor will function ass we would like spray wait spray is about all you can expect

You need a bigger compressor,that tank doesn't have enough reserve capacity to keep up when you pull the trigger on blaster.
Heres your frame parts for the z1r,need your address again to ship it off to you.

Its actually a good thing your compressor didn't keep up,that sand would go terrible things to the aluminum on your motor.
Try glass beads instead.

wireman wrote: Its actually a good thing your compressor didn't keep up,that sand would go terrible things to the aluminum on your motor.
Try glass beads instead.

I posted in my original thread too about the weak result today, wasn't sure where to put this question.

I bought the glass beads, but the crud on my engine is pretty caked on so I got some fine-ish sand. Plus the sand cost $3 a 50-pound bag, the glass cost $42 a 50-pound bag, so I figured with the heavy whitish build up I'd spray with sand and if it was too aggressive, I'd switch to glass.

So wireman as usual you have the right answer, tomorrow I'll buy a bigger compressor -- I read the sand blaster's instructions just now and I found a part in there that says it can take up to 25cfm from a compressor -- and there's my little 4cfm compressor, laughing at my azz today. Sheesh.

I love learning this stuff, I had a good time getting it all ready to go, tomorrow I'm deploying some real horsepower, and wireman I'll stick to the glass based on your advice -- thanks for clarifying the compressor issue.

dont want to be rude but really I used an 80 gallon 5 horse single sTAGE AT THE CORVETTWER SHOP
small parts it did great


at the truck shop they hasve a 3 stage industria; for the sandblat booth that honestly the electric bill is more then the cost of the harbor freight perfect scenerio reality is professionals pay big money for the results we want at a discount real price for a blasted [product if I pay obamas 7.25 an hour it takes an hour i have used 40. dollars worth of media recoverable at 80% it cost me nearly 40 juy7st to provide the service jeff knows this

comercial sabdblasting is not a profible field just do you knoe know the EPA sucks!!!!!!!!!!!!!
if you live outside of california painting for a buddy isnt profit drivin justy like allot of thr [eople on this site we want to keep our objective alive it isnt about the profit margien

Yeah by the time you pressurize the hose hose compressor and the pot blaster that poor little compressor is out of breathe. :laugh:
Id take a wire brush to the heavy cast parts of the motor(not engine covers)to knock the heavy crud off first,then you can glass bead it if you want.
Beware though those glass beads will work there into the motor ,so be prepared to pull it all apart and clean everything really good.
Id also suggeast stripping the bike down to a bare frame before trying to strip paint off of everything,life will be much easier for ya.
Then you can always bolt the motor in temporarily when you replace backbone pieces on frame to keep everything straight while welding it back together.

You generally need a minimum 14 cfm @ 90 psi to power a sand/bead blaster.

Ideal compressor would be a rotary, but they're big bucks. For a one person operation you can get a 14 cfm single stage for $600 - $800. Just make sure it's a true 5 hp motor (current draw 21 amps or more), and the 14 cfm is at 90-120 psi.