I have several spray tips that need to be cleaned out. They seem to have chips of some sort lodged in them. I know you aren't supposed to use tip cleaners on them, but was wondering what could be done. I have soaked them in lacquer thinner and then blown with 100 lbs of air pressure from the front side with little success. Can they be cleaned with a vacuum blaster?
There's a special pin type product called unclogging needles from Finishsystems.com. A must for aaa gun cleaning.
Comment from contributor G:
If material is building up on equipment through long periods of use, take a break to brush the gun, etc. down with appropriate solvent. Breaktime, lunchtime may require soaking gun in container of solvent (may not be the best practice in the case of really hot solvents) or even cleaning the entire system (lines, (airless) pump and gun) depending on material being sprayed (most particularly fast-setting epoxy, etc). Some hardening finishes may require periodic cleaning due to "boundary layer hardening". Essentially, the fluid in the lines etc. that is immediately adjacent to the line does not move. The material flow is through the center. The boundary layer is incredibly thin but will eventually harden in the case of fast-setting type materials and the hardened layer will get thicker over time. Not a problem for most materials in that once or twice daily cleanup will remove the very slow build-up.
As regards cleaning spray equipment in general, salvage any un-sprayed material as best possible (short of running an airless sytem dry). Set up a small container of solvent that will be wasted. The amount should be at least equal to the capacity of the system. For example, in an airless system, you would need enough of this waste thinner to fill lines, gun and a little extra for the initial flushing of finish. Start running that waste thinner through, directing output to another container to collect any nearly pure finish that is being pushed out and the initial bit of very dirty thinner. After the initial bit has run through, let the output be recycled through the system to thoroughly clean the lines, gun, etc. Loosen nozzle and other fittings a bit to blast clean the threads. In the case of airless, this past step would be done without the tip, but you would now replace the tip, reverse it, and blast it, too. For airless, all of the line cleaning, blasting, etc. can be done with the gun underwater in the solvent using pressure and trigger control to avoid making a big mess.
Then repeat the above process using another batch of clean thinner. When you're done, the clean thinner will not be totally clean, but it will be just what you need for the next session's dirty thinner, first wash. Even with 100' of airless line, you can get waste thinner per session down to about one quart. After flushing the equipment, a little brushing and wiping with clean thinner should finish the job. Now's the time to make sure parts are moving properly, etc. and consider wiping down with oily rag. Proper cleaning of the equipment should be part of the process in the case of professionals, and will eliminate your problem in the future.