Made a pop bottle soda blaster as per one of those You Tube videos.
Bought a 25kg bag of animal food grade soda ( sodium bicarbonate ) from the local farm supply to see if it works
Works like a dream save for the tendency of the soda to cake, even with a water filter on the air line.
Have not bothered to play with blast pressures, my set up is at 120 psi for the air tools.
Animal feed grade is a little coarser grained than the food grade you buy at the supermarket but not as large as the blast grade from a tool supply.
OTOH it was about 50¢ / kg
Totally by accident I used a bent shaft air duster , cause I had a box full of them bought cheap at a clearing auction.
The bent bit is good as it stops the bottle rotating around the duster shaft and I use a little ( lot ) of hot glue as well to seal it off.
After that it was a case of trial & error
The feed hole is a bit bigger and I am now using a flavoured milk bottle as the wider mouth makes easier to fill.
The bottle pressurizes a little so when you want to stop you have to turn it upside down or you blow 1/2 the contents out .
And because of the same thing, when the soda cakes & stops flowing a quick flick of the trigger will have it cleared .
Just take a bit of getting used to .
Don't know how it would go on wood but really good on plastic and soft metals but needs a dip in boiling water to clean it out
and so I found, a wipe down with slightly acid ( dilute vinegar ) solution if you want to paint over it or the paint does not take.
The stock feed soda also cakes really badly so I seive an ice cream containers worth which is kept sealed so I have some ready to use when needed.
IT has saved me a fortune in cans of carb cleaner & degreaser .
The landlord bought a blasting kit and it will not work with anything other than the expensive blast grade as it clogs badly.
The gravity spray gun type set up works beautifully
