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Graco 7900 work for spraying silicone Post New Topic | Post Reply

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paul rogers
Posted: Mar 29, 2013 06:19 PM
Graco 7900 work for spraying silicone
Roofers: I am a not a foam roofer. Insulation 98% of the time. but my 2% is acouple of spray foam roofs a year.
one roof is mine. I can roll on the silicone, but I would rather spray it on. I have rolled it on and thinking spraying it on is faster, easier. 1.5" of Bayer 2.7 and 50 mils of silicone. 1/2 gray and 1/2 white.

2nd building we would spray only silicone on top of the asphalt. one layer of roofing on top.

I have a Graco 7900. I know I would need a supply pump, but let me know if this could work.

Graco 8300 costs too much. Used ones are out there on occasion, but I don't do enough to justify a new sprayer.

If you want me to contact you by phone that is fine too.

Cory Boehs
Posted: Mar 29, 2013 10:35 PM
We used our 7900 to "spray" a roof once.... Basically all you can do is use it to get the silicone to where you can back roll it. We had it totally pressured up, but it wouldn't even make a pattern through the tip, so we took the tip out and streamed it out so we could use rollers. Good luck!
Jesse Michalski
Posted: Oct 22, 2013 01:14 AM
Spraying silicone is a nightmare on equipment. It's a great product but you better have a gameplan on how to clean your equipment properly. Silicone is moisture cured, which means humidity in the air causes it to cure faster. Good luck.
Posted: Oct 23, 2013 09:04 AM
Not a good machine for silicone, max pressure is 3300 psi and 2 gpm with water. All my contractors who spray it use 6500 psi air machines where they feed them. Graco did introduce the 933 this year for that application, direct immersion into the drum and 7250 psi.

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