Spray Gun Tips & Sins.
03/04/2019 | ARPSHOP
1. Inappropriate cleaning utensils:
Unfortunately, in many cases wrong cleaning utensils are being used (e.g. paper clips or wire brushes).
Resulting from this, the spray fan pattern is severely affected making it necessary to install a new nozzle set in order to achieve perfect finishes again.
Therefore, it is recommended the use of the cleaning set to ensure an effective yet gentle cleaning process.
2. Forcible disassembly of nozzle components:
Often, the sealing surfaces on the fluid tip on both sides are damaged when using inappropriate tools.
To preserve the required sealing function of the fluid tip, please only use the special tool included in the scope of supply when loosening or tightening the fluid tip.
3. Soaking in contaminated cleaning solution:
When spray guns are regularly soaked in cleaning solution or thinner, the air passages inside the gun will become clogged over time.
As a result, the spray gun can no longer be used and must be either very costly repaired or even replaced with a new one.
This is the reason why modern gun washing machines allow the application of counter-streaming air through the gun to keep the passages free.
When cleaning manually, also make sure that no particles will enter the spray gun body through the air inlet or via the fluid tip drillings, which will result in problems.
4. Contaminated compressed air:
Unfortunately, contaminated compressed air (e.g. by water, particles, oil) very often leads to costly coating flaws. To achieve perfect finishes, therefore requires the optimum filtration of compressed air.
5. “Deadly sins”:
Combining nozzle components of nozzle sets:
An optimum spray fan patterns require a perfectly working nozzle set. To this end, every single spray gun nozzle set, i.e. the interaction of its individual components (air cap, paint needle and fluid tip),
is checked in order to separate and bin bad combinations, if required. By this process, producers of guns are ensuring highest precision levels, whether it be complete spray guns or replacement nozzle sets.
The combination, i.e. the mix of nozzle components from different nozzle sets – even if they come from a nozzle set with the same nozzle size - will usually lead to bad results.
6. Wrong spray gun inlet pressure
To ensure perfect color match in the repair process, it is vital to set the inlet pressure correctly.
Please keep in mind: The pressure inside compressed air hoses and fittings is decreasing over the length of the hose and due to flow restrictions caused by the reduction of the inner diameter.
As a result, the effective pressure is reduced from 3.0 bar (45 psi) at the filter regulator unit to only 1.5 bar (22 psi) at the spray gun (with a 10 m hose and 6 mm inner hose diameter).
Therefore, it is important to always measure the pressure at the gun inlet, e.g. with SATA Digital spray guns or retrofit solutions.
7. Missing breathing protection :
Vapors and dust found in paint shops are harmful to the human body from day one. The serious, partly irreversible consequences, however, are noticed sometimes only after a few years.
Aren’t you also familiar with the phenomenon of a sputtering spray fan? This can be caused by a fluid tip which is either insufficiently tightened or not or badly cleaned on the back.
Both issues can be easily fixed by tightening and/or cleaning the concerned fluid tip. Another cause, however, could be a damaged air distribution insert which needs to be replaced.