Hi LJ and ALL
Quote from LJ above """I use just ordinary sand but sieve it first using a kitchen flour sieve. Be careful to avoid using silica sand normally used in block paving ( I dunnow why), often there is a health warning about this. To be extra sure and to keep viewing area clear, I hook up a vacuum cleaner to the blast box. Good bit of kit.""""
**WARNING** DO NOT USE ORDINARY SAND UNDER ANY CIRCUMSTANCES, !!!!!!!!!!!!!!!!!!!!!!!!!!!!
Ordinary sand breaks down when used as a blast media and releases silica's,(silicates) these give you silicosis
sometimes called "miners lung" this will kill you very very slowly and painfully
Use proper bought blast media, recommended for the particular application!
If you are using glass bead keep the air pressure below 60psi, or the glass breaks down and releases the above mentioned silica's, same consequences
HTH
John O R