best mixing chamber for wall stud application | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

Q&A Forums

best mixing chamber for wall stud application Post New Topic | Post Reply

Author	Comments
Gary Myers Posted: Jul 13, 2011 09:54 PM	best mixing chamber for wall stud application I have only been spraying for about a year and I use an ar4242 chamber. I find that it puts out a little too much foam for a 16" stud cavity and if my spray pattern goes for a dump I get lots off over spray on the studs. I just wanted to know if it's me or maybe I could use an ar2929 instead for a more accurate spray?
Brian Bothun Posted: Jul 14, 2011 02:08 AM	I bought a 3737 from spf depot. works well.
mason Posted: Jul 14, 2011 07:49 AM	It is a common mistake that I see applicators make, spraying between studs with too large of a pattern. It is very difficult to spray smooth uniform foam with a minimum of overspray with a spray pattern that is too large or the wrong shape. If you are spraying a closed cell foam, then the best mixing chamber would be one that would give you a slightly oval shaped pattern about 6-8 inches in diameter from 2 ft away. The oval shape is longer which allows you to spray next to the studs without getting as much on the areas you don't want to spray. You spray parallel to the studs with the long end of the pattern going lengthwise. This gives you great control, allows a smooth uniform application of foam while keeping it off the front of the studs. The slightly oval shape allows you to get into tight corners without a lot of foam on the areas you don't want to hit. The old Gusmer "D" guns with a 62 chamber were great for this. But, their valving rods were prone to stick which made it frustrating to spray. I know the new Graco fusion guns have a pattern control disc that provides a smaller oval shaped pattern, but don't know if other guns have them as well. Contact your equipment supplier for their recommendation. If you can't get an oval shape then use a round pattern that provides the same size pattern. In either case, picture frame the stud first, then fill in the middle overlapping at least 60% with passes that make the foam grow at a uniform rate. I have a presentation I developed for ICAA and an article on quality control that addresses this. Just email me at masonknowles@aol.com for a copy. If you are spraying open cell the pattern should be around the same size but you would fill in the space going back and forth rather than parallel to the studs.
SPRAYFOAM GODDESS Posted: Jul 14, 2011 09:06 PM	AR3737 is next step down round , wide AW2828 or 3333

Author

Comments

Gary Myers

Posted: Jul 13, 2011 09:54 PM

best mixing chamber for wall stud application

I have only been spraying for about a year and I use an ar4242 chamber. I find that it puts out a little too much foam for a 16" stud cavity and if my spray pattern goes for a dump I get lots off over spray on the studs. I just wanted to know if it's me or maybe I could use an ar2929 instead for a more accurate spray?

Brian Bothun

Posted: Jul 14, 2011 02:08 AM

I bought a 3737 from spf depot. works well.

mason

Posted: Jul 14, 2011 07:49 AM

It is a common mistake that I see applicators make, spraying between studs with too large of a pattern. It is very difficult to spray smooth uniform foam with a minimum of overspray with a spray pattern that is too large or the wrong shape.

If you are spraying a closed cell foam, then the best mixing chamber would be one that would give you a slightly oval shaped pattern about 6-8 inches in diameter from 2 ft away.

The oval shape is longer which allows you to spray next to the studs without getting as much on the areas you don't want to spray. You spray parallel to the studs with the long end of the pattern going lengthwise.

This gives you great control, allows a smooth uniform application of foam while keeping it off the front of the studs. The slightly oval shape allows you to get into tight corners without a lot of foam on the areas you don't want to hit. The old Gusmer "D" guns with a 62 chamber were great for this. But, their valving rods were prone to stick which made it frustrating to spray.

I know the new Graco fusion guns have a pattern control disc that provides a smaller oval shaped pattern, but don't know if other guns have them as well. Contact your equipment supplier for their recommendation.

If you can't get an oval shape then use a round pattern that provides the same size pattern.

In either case, picture frame the stud first, then fill in the middle overlapping at least 60% with passes that make the foam grow at a uniform rate.

I have a presentation I developed for ICAA and an article on quality control that addresses this. Just email me at masonknowles@aol.com for a copy.

If you are spraying open cell the pattern should be around the same size but you would fill in the space going back and forth rather than parallel to the studs.

SPRAYFOAM GODDESS

Posted: Jul 14, 2011 09:06 PM

AR3737 is next step down round , wide AW2828 or 3333

You need to login to reply to this topic. Please click here to login.