Selecting proper gun attachments is another important consideration in powder delivery systems. There are a host of
different tips available today by all manufacturers for all equipment. There are flat spray nozzles, extension tips, various deflector sizes and shapes. Each of these tips serve different purposes and create
different cloud patterns for penetrating different areas.
It is important to have flexibility with cloud patterns, particularly when you're
running a job shop with multi-metals and lots of different geometries. The
powder cloud adjustment is really important. Normally when
you receive these guns, (when they're brand new) they come
with a very large deflector, creating a very large cloud pattern.
Well, if you're coating very small parts with a very large
cloud pattern, what are the chances of you getting down to
a reasonable transfer efficiency rate? Very slim, because
you're coating a lot of air surface and very little parts
surface.
If you have too
fine or too tight of a powder cloud, changing the deflector
can cause too much velocity unless the powder delivery system
is backed off accordingly. You can see all of the over-spray
behind the part here? The proper setting is a small tip for
a small part with just enough powder to get coverage on the
part. Remember that the goal is to get the powder out of the
box onto the part, not through the collector system.
Powder cloud adjustment
is something that requires a little skill, a little time behind
the gun and trying different tips. There is no perfect tip
for all applications. Experiment with them.
Extension lances will help you get into recessed areas. It also makes it easier for the
applicator. Think about it, you're covering a two-foot area and you're trying to do that with a manual gun with a short tip. You spray like this, it takes a lot of arm action to cover a certain area. If
you've got an extension, this much action covers this much area. A lot less effort by using a lance. My applicators love to use the 6" extension for the guns. |
