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so what causes the "voids/pockets/holes" Post New Topic | Post Reply

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Posted: Aug 12, 2007 10:08 PM
so what causes the "voids/pockets/holes"
would be a good topic for discussion...
Gerry Wagoner
Posted: Aug 13, 2007 10:14 PM
I wonder if the extreme growth of the half-pound product has a built-in void manufacturing process. Traps CO2 quickly perhaps.

just foam it

og
Posted: Aug 16, 2007 06:21 PM
no other takers other than olger..here goes...
right on ger!!! about the c02,,i think...
we keep the nozzel of the none shooting gun(air purge,,this is important,,i think) away from the face of the rising foam...
we have found that when we point the air purge at the rising foam that we are more apt to get the damn pockets of stringy-air...
we feel that the air purge is blowing the resultant moisture vapor and c02 of the rising foam back into its non skinned rising face...and foam and water makes for funky reactivity...ie: the stringys...and the c02 helps reduce the rise,,causing the localized pocket...

have i been breathing to much fumes???
Matt Lehr
Posted: Mar 02, 2008 12:07 PM
Do these air pockets hurt the performance of spf sprayed to the underside of a roof?
Gerry Wagoner
Posted: Mar 03, 2008 08:04 PM
Well, it's always best to have solid foam if possible. A couple voids won't make the system fail, but they also slightly affect the quality well.


oG
David Kang
Posted: Mar 13, 2008 11:04 AM
what i have seen is that voids are generally due to a temperature problem. USUALLY, its because the temperature is too low...whether you use a petroleum or soy based product. try kicking up the temps and that should help a bit.
philip mullins
Posted: Mar 13, 2008 10:05 PM
i think the rite speed is important too. been trying some different foams lately and have noticed that i have to vary my speeds from one brand to another or i get more pockets. i dont mean the speed of the first pass. i am talking about 'lapping', if ya get my meaning. with some foams i have found that if i go a bit faster and 'lap' it quicker i get a better foam. it is a little more work since it requires a second pass to get the desired thickness but, it seems to make a better foam. other foams seem to work better if i just spray vertical passes instead of 'boxing' it. but my yeilds suffer. i am sorry for not being very technical. i still consider myself a newbie. and this is just what i am learning. besides, i aint realy all that smart. i just get by on my extremely good looks. and charm.

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