Problem with Blast Cabinet Setup

[Chosen_1]

So, I finally saved the funds to buy my own blasting setup (I already have parkerizing stuff). After spending the entire afternoon assembling the harbor freight blast cabinet and this

http://www.harborfreight.com/air-compressor-cast-iron-vertical-25-horsepower-21-gallon-125-psi-67847.html

(It's the central pneumatic 21 gal 2.5 hp 125 psi model)

air compressor, something went wrong. I can only get a quick burst of pressure before its totally gone. I am using 3/8" 30 foot hose, and I had the pressure regulator all the way open, but it does not seem to be releasing the advertised 125 psi.

Help!

[ExtremeX]

Link doesn’t work...

[klewan]

Take the regulator out of the system and stick the hose right at the tank output. Try another hose if you have it. Something is blocking the air flow, be systematic to find it.

[ar15barrels]

A 20 gallon compressor is most likely not going to supply enough air volume to blast with.
Read the blaster CFM requirements.
Then read the compressor's CFM output.

Try turning the pressure down to 90psi so that your 125psi tank pressure will last a couple seconds longer.
Next, get a bigger diameter and shorter air hose.
You can't flow much air through the 1/4" air line you are probably using.

[Chosen_1]

A 20 gallon compressor is most likely not going to supply enough air volume to blast with.
Read the blaster CFM requirements.
Then read the compressor's CFM output.

Try turning the pressure down to 90psi so that your 125psi tank pressure will last a couple seconds longer.
Next, get a bigger diameter and shorter air hose.
You can't flow much air through the 1/4" air line you are probably using.

By short burst, I mean less than a second. The psi on the gauge is still reading basically full. And as I said, I am using a 30 foot 3/8" hose. It would seem to me that the pressure regulator is the problem.

[freonr22]

which cabinet? my 3ph 5hp 80 gal ingersoll rand tank really had a hard time keeping up with the large hf blast cabinet

[Chosen_1]

which cabinet? my 3ph 5hp 80 gal ingersoll rand tank really had a hard time keeping up with the large hf blast cabinet

http://www.harborfreight.com/40-lb-capacity-floor-blast-cabinet-68893.html

The 40 lb. capacity ~$200 one. Maximum psi 125, which is what the compressor output should be.

[freonr22]

you very well may have a restriction, but its about VOLUME and psi

here is your cabinets' air consumption:
Average air consumption 9.5 @ 90

Here is your air compressors output
Average air consumption 4.7 CFM @ 90 PSI

just sayin

[Chosen_1]

you very well may have a restriction, but its about VOLUME and psi

here is your cabinets' air consumption:
Average air consumption 9.5 @ 90

Here is your air compressors output
Average air consumption 4.7 CFM @ 90 PSI

just sayin

It should still be able to run it for more than one second though, right?

[L4D]

It should still be able to run it for more than one second though, right?

what happens when you run the compressor wide open without the hose attached? Does it flow freely? ( im assuming you went through the break-in process of running it this way for 30 minutes) did you?

[Chosen_1]

what happens when you run the compressor wide open without the hose attached? Does it flow freely? ( im assuming you went through the break-in process of running it this way for 30 minutes) did you?

I did, but I may have left the regulator partially closed during the break in. All I can say is now, even with the regulator totally open, it trickles out at a very slow rate. Maybe the regulator is stuck partially closed?

[SMR510]

Sounds like its the regulator, take it out and try again. Replace with another regulator if it runs good without it (you will want one on there to adjust pressure for different things).

[kcstott]

Remove the regulator and inspect the lines for little pieces of teflon tape. They can get stuck in the passages and completely shut off you air supply.
What you are doing is only using the air in the hose. 1-2 seconds worth of air. As you are reducing the pressure in the tank the obstruction (Possibly Teflon tape) is clapping shut.

I've seen this happen more then once.

[ar15barrels]

If the regulator is setup to flow 4.7 CFM, it might have a pretty small metering hole that restricts the flow so you don't run the tank down too fast.
Get another regulator that is happy flowing 20CFM or more and mount that regulator directly to the tank.
Run the regulator at 80-90 psi to make your120psi tank last a few seconds longer.
Go to a 5 or 10ft long 1/2" hose between the regulator and the blaster.

Put a smaller nozzle in the gun.
With 4.7 CFM, you want to be using about a 1/8" nozzle where the air picks up the media.

I have a 5hp 80 gallon compressor and it works my compressor pretty hard running the 1/4" carbide nozzle I have in my blast gun.
I run a 3/4" regulator right off the side of my tank that is rated for 200CFM.
I run a 5ft 1/2" hose to my foot pedal.

[ar15barrels]

It should still be able to run it for more than one second though, right?

No.

4.7 CFM will not magically grow to 9.5CFM.
Reducing your nozzle size will reduce your CFM requirement though.