As for shot/grit blasters - that's one I'll give a miss after a couple of bad experiences with them. I dare say it may well have been down to operator error but I'm not willing to take the risk again. It was a couple of tenders I'd built which were then cleaned with a grit blaster, unfortunately the grit blaster deformed the tender sides. It was nickel-silver rather than brass and the tender sides ended up being bowed out in the middle. I think what I ended up doing was effectively shot peening one side of the metal, this stretched the metal on the outside resulting in the bowed sides. As I say perhaps I was using the wrong grit or the wrong pressure, although I started off on what I thought was the low side ( certainly lower than that quoted by Ozzyo). Anyway it's not something I'll experiment with again.
Hello Adrian, all,
reading what you have said I do think that have shot peening the thin sides of the tender. Do you know what your mate had in his grit blaster? If he had any form of steel ball shot (this would peen) the surface of the metal and then stretch it on the outer surface. Think about a lot of small ball bearings hitting the surface of N/S. These may only be 0.05mm dia. but this will do a lot of damage. Due to the amount of them hitting the part. If you want to clean up a steel part of a car these will do a very good job, but on a model NO.
In my grit blaster I'm using approx 180 grit (0. 0018"?) it's not much more than dust, to give an idea of the grit size that I use, think of the grit on wet'n'dry paper that is 180 grit,
That is what my M/C blows over over the model at about 50 P.S.I. and as the grit is used the particulars ware out and give a finer finish. Then I have to top up the grit tank to just to make sure that I can get the "cut" that I want.
Please don't forget a good tool just because of one bad experience if it,
OzzyO.