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.
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