the gun. Once the fluid nozzle is out, it will expose the needle. It will
come out the back when the flow adjustment is unscrewed all the way.
There will be a spring that tensions the needle — don’t lose it, either.
Now the paint chamber is exposed and can be cleaned. Be mindful of the
needle packing and don’t damage it. When the needle is cleaned, it
needs to be lubricated with gun oil before it is re-installed. A good paint
supply store will have gun oil (a good cleaning kit will have gun oil,
too). The air cap and fluid nozzle can be cleaned individually and then
re-installed. Don’t over-tighten these parts.
After the gun is back together, run plenty of thinner through it to
remove any excess gun oil from the front part of the needle and readjust
the gun for a medium pattern. Check for leaks and wipe down the spray
gun’s housing so it is stored completely clean. If the gun uses a cup filter,
install a new one at this time. Pressure pots will require more cleaning,
because the pot and lines have to be cleaned, too. Siphon guns need to
have the siphon tube removed and cleaned and the coupling between the
gun and cup has to be disassembled and cleaned.
Final tips
In most cases, a painter is better off using a middle-grade gun. A good
quality primer gun will be around $100. This same amount will usually
buy a good color gun as well. Material is expensive, so a gun that doesn’t
waste it quickly pays for itself. When stepping up, the Devilbiss GTI
Millennium is a good value in the $300 range. For most hobbyists, a top-
flight paint gun is not worth the expense, because the extra durability
will never be an issue.
Used paint guns are almost always a bad investment. Part kits have
become less common and even the big-name manufacturers no longer
stock parts for older guns. Don’t expect to be able to find odd-and-end
parts for paint guns. Common wear items are about all that is available
without going to a specialty provider.
Remember to save the instructions that come with the gun and follow
the manufacturer’s recommendations as a starting point. From there,
review the technical data sheets that come with the liquid product and
adjust accordingly. When in doubt, a little more air pressure seldom
hurts. After painting, clean the gun diligently — it is a useful tool that