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spray gun question3/5/20
Maybe to limit bounce back, in corners, inside boxes, door details ?
I believe reduce pressure air cap is so that it will comply with laws in some jurisdiction
The RP cap has much better atomization, and is compliant with the 65% transfer efficiency rule.
For jurisdictions that require *HVLP* you cannot use it.
The advantages: Better atomization, lower CFM requirement, wider fan pattern/speed of spray.
The disadvantages: Lower in-practice transfer efficiency than HVLP.
Thanks for all of your answers.
I mean lots of people can get 75-85%+ transfer efficiency out of an HVLP cap with good technique.
That is a lot less likely from an RP cap.
(I have a bunch of CA Tech guns, including the CAT-X and CPR)
Danny is spot on.
Old school high pressure(auto) 30% transfer easiest to use.
New school high transfer 65%
Accuspray’s been doing real HVLP 80-90% transfer since the 1990’s. Many other brands since the 2000’s.
I usually use the RP.
Mainly because i'm lazy and willing to deal with the material wastage.
I also spray a wide variety of stuff (urethanes, CV's, etc).
With water based coatings and the HVLP cap, i find i have to be significantly more careful with technique and setup to avoid issues (microbubbles, etc).
I do actually have a dedicated HVLP gun set up perfectly for some of the high cost 2k urethane product i spray.
If i was spraying one product and one kind of thing consistently (or maybe one kind of clear and one kind of pigment), i'd probably just dial in settings perfectly and go with HVLP cap, and leave it alone.
We have been using CAT pressure fed guns for years. Mostly in the "Feline" line as in FEFF or finish excellence(they have some weird naming schemes).
By naming confusion I bought a CPR-FE that came with the reduced pressure aircap. We all love it for lacquer and conversion varnish clears. The HVLP cap goes unused. Weirdly, the RP cap yields what we think is a finer atomization. With a bit more overspray - kind of like an HTE gun. The cap orifices are certainly smaller. Both the HVLP and the RP cap call for 29 psi inlet pressure.
When we get on the HVLP FEFF gun, we are like "Whoa, the line pressure is too low, look at those huge droplets." Usually the finish is fine regardless, but the difference out of the gun is noticeable.
If the CoronaVirus doesn't kill me, I'm gonna try the CAT-Xpress on our topcoat pot, move the CPR-FE to the sealer pot and the FE-FF to the pigment pot.