[R-390] knob prep (glass bead)

[Richard Green]

Most areas have a local automotive machine shop with a glass bead machine that will do this quite reasonably. 

Make sure they are using medium or fine glass bead, NOT silica sand which really tears up the surface and is tough on panel lettering. There is also soda blasting that does a great job on chassis without leaving any embedded grit (it dissolves with clear water). I have also used walnut shell on rusty steel chassis' with decent results.
If you get stuck I can glass bead knobs or panels for a reasonable price. 

Skip Green

k7yooam@ gmail.com