I have a 6hp 60 gallon compressor and a Maxus 6ZA39 blasting pot with a water trap and psi gauge. I cleaned the pot out today and hooked it up for the first time to the compressor. Compressor ran up to 125 as usual. I opened the valve and the pot gauge only went up to 50 psi. Is this normal? The pot was empty but I figure that shouldn't matter or am I wrong? If this is not how it should be what could be wrong?

 

Its probably as high as the guage went. Try a regulator at the tank and mount it to a Tee with the regulator and coupling in one and a coupling only in the other, then you have regulated air from one and full pressure in the other for whatever you desire, mine works just fine for blasting with a HF lg pot sand blaster and a through away dryer when the color changes on it.
As a $ saver i buy tube sand around this time of year in MI and pour it through a sifting screen into a bucket (50#) in about 15 min. for under4$, thats if you have time and are as tight as i am.