By the way, I should add I’ve learned much by reading the consultants’ specifications. They have prompted me to ask questions over the years which have always been graciously answered. I guess others are pleased when someone expresses interest in their work just as I am when someone asks me about mine.
Mark - My reference to needle guns was performance-based. In many cases I have seen corners where grinding just can’t provide the degree of preparation necessary for a successful coatings application. In lieu of spot-blasting (which is often not allowed or impractical) needle guns can do the job.
No, they can’t make the surface as smooth as grinding - but in a “pickle” I give the client two choices - a visible weld where the coating will fail, or a somewhat less visible (but not perfect) weld where the coating will probably perform fine.
If it can be ground that’s the way to go. But if it’s physically impossible to grind the welds smooth some type of compromise is in order.