AIRLESS PAINT SPRAYING 101
I sold an Airlessco LP500 last week to a new customer. It started like many other deals, with the customer asking for a price on a specific sprayer. We came to terms and I shipped him his sprayer. Later he asked me if there is anything he should know about this sprayer and with a few basic questions, I found out he has never used an airless sprayer before. I sometimes assume that everyone has been exposed to airless spray equipment and all I have to do is dis-spell rumors or fill in the gaps. This set me back for minute. Usually, I am with the customer and as I show him how to work his sprayer, I talk about all the tips and tricks. I have never had to do this via email. When it came time to write a blog page, I thought this would be perfect, so here is a starting point with airless:
1. Injection. I think I freaked my customer out when I told him to go to the hospital in case he injects himself and have it cleaned out. In 26 years I have only heard of injections twice, both simple, no amputations. That said, don't ignore it and wake up to a swollen hand or something. I'm sure the nasty pictures I have seen from the factory resulted from guys not doing anything about it until it got bad.
2. Static electricity. In my 26 years, I have heard of 3-4 cases where static electricity started a fire. This isn't such an issue with water-based coatings as the worse it gets is a "carpet zap" shock. When fluid moves through a hose, the friction causes static electricity. Airless hoses conduct electricity and the static generated gets grounded out through the ground prong on the cord or the grounding wire on your gas or air powered sprayer. When cleaning out epoxy or lacquer, keep the gun in contact with the bucket, that way it too gets grounded.
3. Moving parts. A lot of times you forget your sprayer is on during idle moments and then you hear it run for a second to maintain pressure. One of my competitors either forgot it was on, or didn't think it would turn on when he tried securing the little cap onto the packing nut when it turned on and squished his finger. These machine have a lot of power and it's all centered on making that piston go up and down. If you do any fiddling with it, be sure to unplug it and dump the pressure.
1. Wash out. If it's a water-based coating, use water. If you want to be really official, use warm soapy water. Don't leave the water in there long enough for the guts to rust and get damaged. If storing, use anti-freeze or spirits. If it's an oil-based coating, use spirits or stronger solvent if it's epoxy or lacquer. Don't leave the stronger solvents in for extended storage because it can damage the leather packings (if you have leather packings).
2. Oil packings. All piston pumps have a little reservoir surrounding the piston to hold oil. When the piston goes up, it collects a film of oil. Any debris or overspray sticks to the oil and not the piston. On the way down the debris goes into the oil bath and not into the upper packings. This prolongs the life of the upper packings as well as the piston rod.
3. Tighten packings. Most pumps but Titan Impacts and Speeflos have a packing nut to tighten the upper packings. On Airlessco’s, this tightens both packings. The packing nut is also the oil reservoir, so when you are adding oil, check to make sure the nut is "snug". If paint starts leaking through there, try to tighten the nut. If that doesn't help, repack your sprayer before the leaking paint scratches the rod. Faint evidence of paint doesn't really count, but noticeable leaking has to be addressed.
4. Gas engine. Everybody knows the gas engine needs its first oil change after 8 hours of work and every 40 hours after that... Right?
1. Won't turn on. The machine may already be under pressure with a clog somewhere. Proceed carefully when undoing hoses. If it's coming out of winter, the transducer probably got frozen. If it's not those, it can be a bunch of stuff.
2. Won't prime. There are two balls inside your pump. They are the inlet valve and outlet valve. If either one of those are stuck shut or open, you won't catch a prime. Don't just watch it pump dry until the packings melt. Try gently hitting the fluid section to jar the balls loose. If that doesn't get it going it's probably a piece of debris holding the ball open. If that's the case, you'll have to take off the intake valve housing to clean the lower ball. At that time, look up into the pump to eye the upper ball as well.
3. Won't keep up. Assuming you don't have a tip too big for your sprayer (remember they wear one size for every 50 gallons of latex), you probably have a piece of debris holding one ball open. You can determine which one it is by watching which stroke the pump stops on. If it stops only on the down stroke, the upper ball is bad, if it stops only on the up-stroke, the lower ball is bad. If the pumps keeps running in both strokes without anyone spraying, either your prime/spray valve is leaking or your packings are blown.
4. Bad pattern. If you have "fingers" on each end of your fan, it means you don't have enough pressure. If you have the pressure jacked all the way, you will have to do at least one of the following: a. Use a smaller tip, so it doesn't fly out of the gun faster than the pump can push it through the hose. b. Use a larger diameter hose to eliminate some pressure loss due to friction. c. Heat up the material to thin it down. d. Thin the material with water or solvent. If the tails are in the middle of the fan, try reversing the tip to clean as if you had a clog. If that doesn't clear the tails, try a new tip.
5. Leaking. This is caused by either an o-ring failing or worn packings. If it's packings, try tightening the nut. If it's somewhere else, and you don't have a replacement o-ring, wrap teflon tape around the o-ring or the threads it's leaking from until you can get it repaired. Don't let stuff leak for long because many paints are abrasive and can cut steel parts as they leak out.
The above is a good starting point for every sprayer who is responsible for production. It doesn't replace the owner's manual and it's safety warnings. It also doesn't replace specific instructions regarding a special coating. Some coatings behave different. Some pumps misbehave different. I consider the above the bare minimum you should know when you leave with your new sprayer. If there is anything not covered that you would like to know, just ask.