Adding water to resign | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

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Posted: Nov 06, 2010 10:21 AM	Adding water to resign Mason There are a few contractors in my area that are spraying closed cell foam incomprehensibly cheap. I have heard rumors that it is possible that some contractors are adding 1 cup of water to the resign which increase the yeild from 4,000 to 6,000 BF. Is there such a trick? If so, wouldn't this change the physical properties of the foam?
mason Posted: Nov 06, 2010 10:47 AM	Water is a blowing agent and will react with the A side causing a lower density (and possibly off ratio) foam. This is not a good idea for a number of reasons 1. The foam will have poor physical properties ie. low density, low compressive strength, poor dimensional stability and possible mix and odor problems 2. The contractor by adding water has voided any supplier responsibility for the foam if something negative happens. He in fact has become the manufacturer of the foam with all the liability entailed. 3. Any approvals, fire ratings, ICC reports etc. are voided because the material is now something else than was tested. 4. The R value is probably negatively affected as well. So, very bad idea
Bryan Kwater Posted: Nov 06, 2010 08:49 PM	Would the yields change by that much with just a cup of water? I have heard rumors of people "spiking" their foam, but never really believed it. Hmmm.
Posted: Nov 07, 2010 06:48 AM	...we prefer a can of mountain dew/drum resin.... the caffine makes it spray faster!!!
John Shockney Posted: Nov 07, 2010 04:36 PM	I think the good old Kentucky mountain dew would work better!! Airpro
Gerry Wagoner Posted: Nov 14, 2010 10:10 AM	We have experienced some of those low ball contractors as well. I scratch my head how people can sell "closed cell" foam at near cost. They must have some sort of an angle... Have fun, `oG
mason Posted: Nov 14, 2010 12:53 PM	Yes, even one cup of water can significantly affect the density and strength of the foam. Try it yourself, Take a couple of drops of water and mix it with a half of cup of A & B with a high speed mixer. Compare it to the same amount of A & B without the water. You can see about a 20% increase in yield.

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Posted: Nov 06, 2010 10:21 AM

Adding water to resign

Mason
There are a few contractors in my area that are spraying closed cell foam incomprehensibly cheap. I have heard rumors that it is possible that some contractors are adding 1 cup of water to the resign which increase the yeild from 4,000 to 6,000 BF.

Is there such a trick? If so, wouldn't this change the physical properties of the foam?

mason

Posted: Nov 06, 2010 10:47 AM

Water is a blowing agent and will react with the A side causing a lower density (and possibly off ratio) foam. This is not a good idea for a number of reasons

1. The foam will have poor physical properties ie. low density, low compressive strength, poor dimensional stability and possible mix and odor problems
2. The contractor by adding water has voided any supplier responsibility for the foam if something negative happens. He in fact has become the manufacturer of the foam with all the liability entailed.
3. Any approvals, fire ratings, ICC reports etc. are voided because the material is now something else than was tested.
4. The R value is probably negatively affected as well.

So, very bad idea

Bryan Kwater

Posted: Nov 06, 2010 08:49 PM

Would the yields change by that much with just a cup of water? I have heard rumors of people "spiking" their foam, but never really believed it. Hmmm.

Posted: Nov 07, 2010 06:48 AM

...we prefer a can of mountain dew/drum resin....
the caffine makes it spray faster!!!

John Shockney

Posted: Nov 07, 2010 04:36 PM

I think the good old Kentucky mountain dew would work better!!

Airpro

Gerry Wagoner

Posted: Nov 14, 2010 10:10 AM

We have experienced some of those low ball contractors as well. I scratch my head how people can sell "closed cell" foam at near cost. They must have some sort of an angle...

Have fun,

`oG

mason

Posted: Nov 14, 2010 12:53 PM

Yes, even one cup of water can significantly affect the density and strength of the foam. Try it yourself, Take a couple of drops of water and mix it with a half of cup of A & B with a high speed mixer. Compare it to the same amount of A & B without the water. You can see about a 20% increase in yield.

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