Two Graco 3900s

Hi there, First time, long time! I'm having trouble with TWO out of three Graco 3900s non stop clogging at the tips. I have tried everything. New tips, new gun, flushed machine (clean Xylene, 4 times), cleaned filter (intake and top filter) and it will spray with the tip out no problem. As soon as the tip goes back in - it will spray lines for a short while (a line's worth), and then clog up. I do the "clear the tip" turn around, it works but that side eventually clogs up too. Could it be the paint? Has anyone experienced this?

If it's latex try straining the paint and see what you get you can also try going up a size on the tip and check the filters on the gun.

Tried going up a size to no avail, I don't think it's the tip. The gun itself doesn't have a filter outside of the top filter there. The paint is SW Low VOC Acrylic acetone base, will definitely try straining the paint after a good long flush Thanks for your reply!

From what I've experienced the filter is the main problem for tip clogs. Check the mesh on the filter to see if it is worn out anywhere or has large holes or tears where junk can get through. If your filter is good then it could be the paint. You said you cleaned the filter 4 times so if it was really dirty each time you cleaned it then it would be the paint. Also Glass beads are a nightmare if you get any in the paint. An 80 mesh filter won't catch them and they will clog any tip every time. Lastly tip size could be a problem especially with Latex paint. I only really feel comfortable using a 319 tip or bigger. When using a 317 or anything smaller I always know that I am going to have a clog at some point unless you thin it just a bit and strain it twice. If you have filters on the gun take them out they clog too fast and are unnecessary. Flex guns do not have filters at all.

The filter may not be seated right or it has a tear in it, it may need a new filter. After cleaning the filter you should run paint thru the hose with the tip out to get any trashy paint out of the hose and gun. Chances are that it's not the tip, you have junk in the hose.

If the above doesnt solve your problem, make sure you match the filter size to the tip size. If you are using a X17 tip, you probably should have a 100 mesh filter in the machine. If you use a larger tip, you can go to a larger mesh filter. 60 mesh is standard for us when using X19 or larger.

I had the same problem with that paint a week ago and I just cleaned the machine and switched to a freshly shook bucket. Its getting warm for that paint.

I tried your method, kcchief, as well as a full flush and a cheesecloth strainer at the intake pump and it seems to be working fine. Definitely the paint, not sure how or why. Might have been a bad batch or not mixed properly.

Did you ever use these machine with latex? If you did, that's your problem. THe acetone paint is making the dried latex fall off the walls of your hoses. If this is it, change your hoses. Jim

I'm sure my problem was the result of not using the bucket quick enough. It sat for a couple days on the machine thinner on top. Its a newer 200hs that's never had latex in it. Love that paint though

Try modified acrylic low voc from sherwin Williams, a couple weeks ago we were doing a parking lot, after striping about 30 parking stalls, the tip starting to plug, maybe about 3 times after using 3 buckets of paint, I thought it was the paint, but for my surprise, the last guy to clean the machine he forgot to put the filter back on, so needless to say we hardly have any issues with tip clogging, because of the paint we use, it's more expensive but we don't have any problems with it.

Is that the promar low voc TM5713? That's what I get. I know there is a setfast also.

Set fast

chitown wrote on Jun 1, 2013:Go to #11

Try modified acrylic low voc from sherwin Williams, a couple weeks ago we were doing a parking lot, after striping about 30 parking stalls, the tip starting to plug, maybe about 3 times after using 3 buckets of paint, I thought it was the paint, but for my surprise, the last guy to clean the machine he forgot to put the filter back on, so needless to say we hardly have any issues with tip clogging, because of the paint we use, it's more expensive but we don't have any problems with it.

We have started using this product for our red fire lanes as of a few weeks ago. Boy... it sprays REAL nice vand it also has a very nice color to it. Its a little bit more than the chlorinated rubber that we had been using. I'm a fan of it. I may ask my rep about other cdolors.

I strain every gallon of paint that goes thru my machines. Nearly eliminated all clogging problems I had before...

TruColors wrote on Jun 7, 2013:Go to #14

chitown wrote on Jun 1, 2013:Go to #11

Try modified acrylic low voc from sherwin Williams, a couple weeks ago we were doing a parking lot, after striping about 30 parking stalls, the tip starting to plug, maybe about 3 times after using 3 buckets of paint, I thought it was the paint, but for my surprise, the last guy to clean the machine he forgot to put the filter back on, so needless to say we hardly have any issues with tip clogging, because of the paint we use, it's more expensive but we don't have any problems with it.

We have started using this product for our red fire lanes as of a few weeks ago. Boy... it sprays REAL nice vand it also has a very nice color to it. Its a little bit more than the chlorinated rubber that we had been using. I'm a fan of it. I may ask my rep about other cdolors.

All the colors look and spray just as good as the red, you'll like it better then the CR.