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Justin Hren Posted: Jul 21, 2008 02:13 PM	Gusmer/Graco Gap Pro gun help I'm having a bit of trouble with my gap pro guns. It seems like no matter what I do lateley the spray pattern is no good and I am having to constantly change mixing chambers. I've tinkered with the heat thinking it was humidity/heat related, and I messed with the pressures a little bit on the proportioner, but it only seems to make it worse. Plus the gun has to be drilled constantly and seems to be just a big headache. I've done some research and found that there is no adjustment on these guns however, I wonder if there are any specific parts that wear out that would cause an incorrect alignment of the chamber and side seals? I haven't got any idea what else to check, and it seems like it's always worse in the summer than the winter. We're spraying closed cell stuff for the record. Thanks! Justin
mason Posted: Jul 21, 2008 02:20 PM	Have you really cleaned your gun thoroughly? Just a little bit of trash can mess up your pattern. Other things to try: Start with the heat and pressure low (100 degrees of heat and less than 500 lbs of pressure) then gradually build up your pressure until you have as full a pattern as possible. Then start building up heat. If you can't get a good pattern, you have either a mechanical problem with the mixing chamber or there is trash somewhere in the system, either in the gun, the gun block or the whip hose. Yes, depending on how you clean your gun, you can score the metal causing a poor spray pattern. The holes in the mixing chamber that let the liquid into the chamber were specifically sized to provide the right amount of flow and the nozzle is shaped to provide a round pattern. Try to be very careful when cleaning out the tip. Another thing that I have seen in the field is folks not having the air turned up enough to clean your tip off good. I know it blows foam off the wall, but if it is not enough to clean the tip, your pattern will suffer. So, if you start with a good pattern and after a few triggers get a poor pattern, increase the air to the tip.
Linerman Posted: Jul 21, 2008 07:59 PM	how new is your mix module? they only last about a year or two.

Author

Comments

Justin Hren

Posted: Jul 21, 2008 02:13 PM

Gusmer/Graco Gap Pro gun help

I'm having a bit of trouble with my gap pro guns. It seems like no matter what I do lateley the spray pattern is no good and I am having to constantly change mixing chambers. I've tinkered with the heat thinking it was humidity/heat related, and I messed with the pressures a little bit on the proportioner, but it only seems to make it worse. Plus the gun has to be drilled constantly and seems to be just a big headache. I've done some research and found that there is no adjustment on these guns however, I wonder if there are any specific parts that wear out that would cause an incorrect alignment of the chamber and side seals? I haven't got any idea what else to check, and it seems like it's always worse in the summer than the winter.

We're spraying closed cell stuff for the record.

Thanks!
Justin

mason

Posted: Jul 21, 2008 02:20 PM

Have you really cleaned your gun thoroughly? Just a little bit of trash can mess up your pattern.

Other things to try: Start with the heat and pressure low (100 degrees of heat and less than 500 lbs of pressure) then gradually build up your pressure until you have as full a pattern as possible. Then start building up heat. If you can't get a good pattern, you have either a mechanical problem with the mixing chamber or there is trash somewhere in the system, either in the gun, the gun block or the whip hose.

Yes, depending on how you clean your gun, you can score the metal causing a poor spray pattern. The holes in the mixing chamber that let the liquid into the chamber were specifically sized to provide the right amount of flow and the nozzle is shaped to provide a round pattern. Try to be very careful when cleaning out the tip.

Another thing that I have seen in the field is folks not having the air turned up enough to clean your tip off good. I know it blows foam off the wall, but if it is not enough to clean the tip, your pattern will suffer. So, if you start with a good pattern and after a few triggers get a poor pattern, increase the air to the tip.

Linerman

Posted: Jul 21, 2008 07:59 PM

how new is your mix module? they only last about a year or two.

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