Blast Pot and Petrol Driven Compressor

[rory1]

i am looking to do a bit of blasting on a few pieces of plant and machinery,

i have a petrol driven compressor on a 50l tank, honda 6.5hp engine.

cant find any specs on the compressor (its old and has had quite a lot of overspray on it over the years, but is still servicable) however i belive it is putting out around 15cmf..... but i could be wrong.

on paper this seems good enough to run a ebay type blast pot but i am trying to find out if the compressor output will be sufficient to do any real blasting.

after all, what works on paper doesnt always work in practice.

thanks in advance.

rory

 

[stormin]

15cfm if it's still putting that much out will be very slow blasting. You're probably looking at a 3mm nozzle at most to maintain sufficient pressure to properly clean steel. And the machine will be working very hard.

How are you getting your breathing air? If that has to come from same compressor you will really struggle.

 

[rory1]

i could take brething air from a little 25 litre comp that i use for blowing swarf off the machines. i do have another 50 litre electric comp that i could possibly couple up to the petrol comp.

realistically what output am i looking at to achive for resonable blasting??

 

[stormin]

i could take brething air from a little 25 litre comp that i use for blowing swarf off the machines. i do have another 50 litre electric comp that i could possibly couple up to the petrol comp.

realistically what output am i looking at to achive for resonable blasting??

All depends how fast you want to go. The more cfm you can sustain the bigger nozzle you can run and the faster you will get through the task and the blast media.
I'm running a 135cfm road compressor with a 5/16 (8mm) nozzle on my blast pot and still find it slow. Way better then the 3mm nozzle I was running before though.
Professional blasters will be running well in excess of 200cfm.

Bear in mind that priming should be done within 20 minutes of blasting a surface to stop corrosion re-forming.