Flushing Waterbornes from Spraygun Lines

Quick tips for clearing finish out of your spray lines so they won't harden up on you. May 17, 2010

Well, I made the switch back to waterbase after spraying solvent for the last few years. After spraying the Fuhr 380 for the first time and being fairly happy with the results, I left it in my lines and system like I did with my solvent based pre-cat. A week later I go to spray and nothing. Check everything and after an hour or so figure out my fluid line is solid with finish all the way through. Yikes! So I just put on a new fluid line today and am going to flush out the system each day after spraying. Is it safe to leave water with a mix of Fuhr's 330 cleaner in my system between spraying sessions?

Forum Responses
(Finishing Forum)
From contributor L:
Just have two cleaning buckets - one that has mostly water and some residual Fuhr and another that is clean water. Do two flushes, the first with the mix and then with the clean. Then you can leave that in the lines. After the clean water becomes contaminated, switch it to the first and throw the other bucket out and refill with fresh clean water. Repeat. Running denatured alcohol through the lines once in a while would be a good idea too.

From contributor P:
Several years ago, when I was spraying Fuhr 255, I was told to flush the lines with a bucket of water which had a cup or two of regular household ammonia added, then clean water. It worked really well.