RE: APS F4 gun problem
You may have already solved your problem by now...But I have also had these issues in the past.
I noticed your nozzle damage is localized to one side (at least it looks like it in the picture). In my experience, that can be caused by the electrode not being centered properly. During installation, it can easily be offset .010" .015" to one side causing it to wear out the nozzle on one side prematurely. Before installing the nozzle, i center the electrode as best as i can (within about .0005")
Another possibility that could cause "small dots" in your coating is the distance from your gun to shadow masking. I find that the closer my shadow masking is to my gun, the more "dots" that i get on my coating, because the closer my shadow masking is to my gun the more powder build-up i get on the masking, which eventually breaks off from the masking and gets pushed into the coating. I try to keep my shadow masking as close to my part as possible. It helps minimize this problem for me. Although i still do get a few random "dots" on my coatings but i just use a small diamond file to gently file them off as i see them appear between powder cycles. The coating adheres over top of the gently filed section nicely.
Hope this helps if your still struggling!
|