A hand or power tool is an investment that can last many years when properly maintained.
I assume caring for your tools is a ritual you follow, but what about your spray equipment?
This seems to be a stumbling block for some folks, because over the past 35 years of crawling through finishing shops, I have come across some really mangy looking spray guns.
And that’s a shame, because a poorly maintained spray gun can cause all sorts of finishing problems, despite the best sanding, the best coatings (such as Emtech!) and the best application technique.
Let’s talk about the basics of spray gun maintenance when using water based finishes and how you can avoid problems.
Here’s a quick checklist of do’s and don’ts to ensure your spray gun isn’t the culprit…
1. Flush your equipment with water and alcohol at the end of each finishing session or production day. Do not hang your gun, still loaded with finish, on the hook overnight (or over the weekend!) and expect it to perform well the next time you pull the trigger. Flushing the fluid passage, cup or tank assembly clear of acrylic or urethane finishes will prevent the clogging of the passages and tip set.
2. Remove the air cap and clean it under running water with a fine-tooth brush. Make sure all the atomization ports (the small holes found on the air cap) are free and clear of dried finish. If these ports are clogged, you will get a split fan pattern and your finish will not atomize properly. If you get tiger-striping or highs/lows in your wet film, it is due to a split fan pattern.
3. Check your trigger assembly to ensure the needle set is sliding in the packing nut and spring center. A sticky needle will not allow the coating to start/stop when you need it to. And speaking of needles, make certain the needle tip is straight. I have seen many bent and damaged needle tips – which results if the needle not seating in the nozzle set, causing poor fluid flow.
4. Check your fluid and air flow control knobs. Ensure that they are not sticky or have stripped threads. These controls must work properly to ensure a correct fan pattern and fluid volume.
5. If you are using a compressed air spray gun, ensure the mini air regulator at the handle of the gun (you ARE using one, right?) is working properly. Ensure the protective glass or plastic covering on the face of the gauge is clear of any over-spray. To this day, I have yet to figure out how finishers forget to care for their air regulators – I worship mine!
6. Last but not least, check the seals on your fluid cup assembly or pressure pot. These seals ensure the vessel will hold the correct amount of fluid and pressure – leaks are common when the seals are broken or ill-fitted.
If you’re using a quality spray system, and you’re maintaining the gun as explained above, there’s a good chance you can eliminate your spray setup as a possible cause of any finishing problems you’re having.
And as we all know about troubleshooting, eliminating possible problems gets you one step closer to the solution.
What’s your take on this? Any other spray gun maintenance / operation tips you’d recommend? Please share your thoughts or read what others are saying in the comments section below.