Contact Adhesive Clogging Feed Line

With the wrong hose, adhesive may thicken overnight. May 10, 2005

Question
I use a pressure pot spray system to spray contact adhesives. If I don't use the gun for a few days, the CA dries in the feed line to the gun. In the pot, all is still in good shape. Is there something I'm missing here? I used a siphon gun before and it was always good to go. I think the solvent is escaping out the line, leaving the adhesive to thicken. Is there a special type of hose I need?

Forum Responses
(Laminate and Solid Surface Forum)
From contributor S:
I use the same type of system. We use it every day and do a lot of spraying. We found that if you submerse the gun in solvent, it will keep it from clogging. We use a coffee can. Give it a try - I think it will help solve your problem.



From the original questioner:
Thanks for the tip. The blockage is not in the gun - it happens about midway down the fluid feed line. When you pressurize the pot, you can loosen the line at the gun and no fluid will come out. Starting at the pot with my fingers squeezing the line, I feel pressure in the line till I get to a hard lump about 6" long. When you massage this lump, the fluid again starts to flow, but very slow till the thick adhesive comes out, usually followed by solvent, then the usual adhesive flows again. Sometimes, when I let the system stand for a day, the next time I use it, the solvent comes out in a fine mist followed by lumpy adhesive, then again normal flow. I can't help but think it somehow separates in the feed line. The line is still somewhat new and it is starting to show signs of dry rot.


From contributor S:
If the line is still somewhat new and it is showing signs of dry rot, I canít help but wonder if it is the correct type of hose. I have replaced mine only once in fourteen years. And that was just last year. So maybe it is the hose?


From the original questioner:
That's my thinking too. I spoke to the dealer about this problem and he blamed the contact adhesive solvents. He could not recommend a line that would not do this, as in his opinion, CA should not be left in the line and the system should be cleaned after each use. (I don't leave it pressurized - I vent the pot and seal it again to store it.) I was looking for longer lines to begin with, but is there a grade of line that is CA compatible? The lines I have now are what came with the pot and in my opinion, a little thin walled. Maybe fuel grade line will work. Trip to the automotive store maybe.


From contributor S:
I went down to the local auto paint store that sells Binks parts and bought the original replacement hoses and they work fine, and I always leave the CA in the line and have no problems.


From the original questioner:
Got the Binks fluid-all yesterday. I think this will do it. Very heavy line.