I'd be interested in knowing the details of how you're planning to put
an internal blower in the gun.

While the HF gun is infinitely better than spray painting, it still has
some things to be desired. I powdercoat mostly round tubing, and seem
to get a substantial amount of overspray that doesn't adhere to the
tubing at moderately high flow rates. I'd guess my transfer efficiency
under these settings is under 50%. At these high flow rates is when I
also get occasional surging,

But since this is the only powdercoating equipment I've ever used, I
don't know what is reasonable to expect. If I am powdercoating, say,
1" round tubing, what would be a reasonable coverage rate (in linear
inches of tubing per minute) and transfer efficiency? As things stand
now, I'm getting a lot of dust settling on everything in my shop, and
am getting the parts together to build an air filtration unit.

-Jim