Removing drum pumps | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

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Author	Comments
Bryan Kwater Posted: Nov 18, 2010 03:11 PM	Removing drum pumps Do you think that removing the resin drum pump at the end of each day and capping the drum makes much difference in yield? We keep our trailer about 60 degrees at night and spray nearly every day. Not sure if we are gaining much by removing them. If we leave them in overnight, there is still quite a bit of pressure when we remove the cap.
mason Posted: Nov 18, 2010 03:32 PM	I wouldn't remove the drum pumps. But, you can and should seal the bung and use a dessicant dry air system on the small bung side. That way you can keep the blowing agent from off-gassing and prevent moisture contamination from condensation overnight.
Rodney Schares Posted: Nov 19, 2010 06:33 AM	So this "whoosh" of pressure we all experience from time to time on the B drums,is this the blowing agent that has evaporated over night or throught out the day on a new drum? Will evaporation of blowing agent cause a more dimensionaly unstable foam?
John Shockney Posted: Nov 19, 2010 09:37 AM	Having worked with liquefied gases in HVAC and refrigeration for the past 30+ years I can tell you that yes you are losing some of the blowing agent anytime you have an open drum. But how much you will lose is very dependant on the temp, how big is the opening is to the outside, and how long it is stored. The best way I could explain this is that our blowing agent is like a liquefied refrigerant gas called R-111 that was shipped in 55gal drums, it is a lot like lacquer thinner can be stored on the shelf at any temp in a sealed can forever. But put a small hole in the top of the can and it will evaporate away due to its vapor pressure this generally takes a long time due to the saturation of the lacquer gas in the container and the condensation of that gas on the cool sides of the can. But if you add heat the gasification of the liquid speeds up radically!! With that said if you are using an open set of closed cell foam up in less than a month in cool weather I wouldn’t worry about removing pumps and sealing the drum up. In hot weather if I know that I’m not going to use an open drum of closed cell for a week or two then I will remove the pump and seal the drum. And as I understand any loss of blowing agent should only reduce yield and increase the density of the foam, 2# foam = 2.5-3# = lost $$$. Hope this helps Thanks Airpro
mason Posted: Nov 19, 2010 11:02 AM	The boiling point of HFC 245 fa (used in closed cell sprayfoam) is 62 degrees F. So if the drum is above those temperatures, some blowing agent will vaporize. If you keep the drum sealed and under a slight pressure from the dessicant air, then the blowing agent tends to remain in solution. Of course as airpro points out, the higher the temperature the more blowing agent vaporizes. Yes, that is why the foam drum has a "whoosh" when it is opened. The main concern at high temperature storage is the foam drum bulging and the foam system becoming a higher density and possibly a slower reaction as well. It could affect the dimensional stability of the foam if so much blowing agent is lost that the foam cell structure is affected. But in this case the foam would look real weird and easy to spot.
Daniel X Posted: Nov 20, 2010 10:58 PM	Schares95 please seek any sort of formal training you can possibly find. You NEED to know what sort of chemicals and gasses you are dealing with on a daily basis and how they might affect you. Please do not get ISO on your skin, and always wear a respirator with proper (fresh) cartridges anytime you're spraying.
John Shockney Posted: Nov 20, 2010 11:02 PM	Thanks Mason, I hadn’t looked up the boiling point of 245 but you also have to consider the latent (or hidden) heat needed to boil off the gas. In short it is better to keep the drum sealed tight unless you can store them below 62 or keep busy and use more foam. Thanks Airpro
John Shockney Posted: Nov 20, 2010 11:12 PM	Sorry but I forgot to say that you can raise or lower the boiling point by changing the pressure. We would use a gas like 245 in a chiller to make 40 degree water to air condition a building by boiling it under 2-4 inches of vacuum then compressing and cooling the gas back into a liquid. Thanks Airpro
mason Posted: Nov 21, 2010 08:59 AM	I wanted to remind everyone that each manufacturer publishes their recommended storage temperatures for each of their foam formulas. Typically the optimum storage temperature is around 70 degrees but can go up to 80 degrees F. The HFC 245 fa blowing agent is part of the whole package of ingredients (surfactants, catalysts, resin, fire retardents,)including a little bit of water. The type of surfactants, resin, fire retardents, etc can influence the ability of the batch of ingredients to stay in solution at temperatures above the boiling point of the HFC 245 fa. So I did not want to suggest that everyone store their chemicals at temperatures below 62 degrees F. Rely on the manufacturer's published literature and recommendations from their technical staff. Just wanted to make that clear.
Bryan Kwater Posted: Nov 21, 2010 10:01 AM	Thanks for all of the info everyone.
Rodney Schares Posted: Nov 21, 2010 02:48 PM	Are you available for a course for training dl123? Thanks for the heads up on the fresh cartrides! I always thought the paper masks I wear were adequate. The only gas I am dealing with is from and azz like you.
steven argus Posted: Nov 22, 2010 06:09 PM	I'm starting to feel sorry for dl123. Seems like he has alot of know how, just no social skills. (although he did say please twice) Maybe someone should invite him to Thanksgiving dinner.
Rodney Schares Posted: Nov 22, 2010 08:19 PM	Maybe ,just maybe Santa will bring him the ENZYTE he has on the top of his list for being a good boy this year.......
quentin Posted: Nov 23, 2010 08:38 AM	Hey, give him credit! After that bad posts he is improving and working on being nice. I was one of those reaming him there but here he does not deserve it guys, ok? Give credit where credit is due and knock people off thier soapbox if they need it but remember we all make mistakes and his advise was spot on from what I saw.
Daniel X Posted: Nov 23, 2010 10:32 PM	No, I'm not available sorry. I'm very busy. Please at least read the MSDS sheets your supplier provides.
Gerry Wagoner Posted: Nov 27, 2010 09:43 PM	olger saw this thread and laughed.

Author

Comments

Bryan Kwater

Posted: Nov 18, 2010 03:11 PM

Removing drum pumps

Do you think that removing the resin drum pump at the end of each day and capping the drum makes much difference in yield? We keep our trailer about 60 degrees at night and spray nearly every day. Not sure if we are gaining much by removing them. If we leave them in overnight, there is still quite a bit of pressure when we remove the cap.

mason

Posted: Nov 18, 2010 03:32 PM

I wouldn't remove the drum pumps. But, you can and should seal the bung and use a dessicant dry air system on the small bung side. That way you can keep the blowing agent from off-gassing and prevent moisture contamination from condensation overnight.

Rodney Schares

Posted: Nov 19, 2010 06:33 AM

So this "whoosh" of pressure we all experience from time to time on the B drums,is this the blowing agent that has evaporated over night or throught out the day on a new drum?

Will evaporation of blowing agent cause a more dimensionaly unstable foam?

John Shockney

Posted: Nov 19, 2010 09:37 AM

Having worked with liquefied gases in HVAC and refrigeration for the past 30+ years I can tell you that yes you are losing some of the blowing agent anytime you have an open drum.

But how much you will lose is very dependant on the temp, how big is the opening is to the outside, and how long it is stored.

The best way I could explain this is that our blowing agent is like a liquefied refrigerant gas called R-111 that was shipped in 55gal drums, it is a lot like lacquer thinner can be stored on the shelf at any temp in a sealed can forever.

But put a small hole in the top of the can and it will evaporate away due to its vapor pressure this generally takes a long time due to the saturation of the lacquer gas in the container and the condensation of that gas on the cool sides of the can.

But if you add heat the gasification of the liquid speeds up radically!!

With that said if you are using an open set of closed cell foam up in less than a month in cool weather I wouldn’t worry about removing pumps and sealing the drum up. In hot weather if I know that I’m not going to use an open drum of closed cell for a week or two then I will remove the pump and seal the drum.

And as I understand any loss of blowing agent should only reduce yield and increase the density of the foam, 2# foam = 2.5-3# = lost $$$.

Hope this helps

Thanks
Airpro

mason

Posted: Nov 19, 2010 11:02 AM

The boiling point of HFC 245 fa (used in closed cell sprayfoam) is 62 degrees F. So if the drum is above those temperatures, some blowing agent will vaporize. If you keep the drum sealed and under a slight pressure from the dessicant air, then the blowing agent tends to remain in solution. Of course as airpro points out, the higher the temperature the more blowing agent vaporizes. Yes, that is why the foam drum has a "whoosh" when it is opened.

The main concern at high temperature storage is the foam drum bulging and the foam system becoming a higher density and possibly a slower reaction as well.

It could affect the dimensional stability of the foam if so much blowing agent is lost that the foam cell structure is affected. But in this case the foam would look real weird and easy to spot.

Daniel X

Posted: Nov 20, 2010 10:58 PM

Schares95 please seek any sort of formal training you can possibly find.

You NEED to know what sort of chemicals and gasses you are dealing with on a daily basis and how they might affect you.

Please do not get ISO on your skin, and always wear a respirator with proper (fresh) cartridges anytime you're spraying.

John Shockney

Posted: Nov 20, 2010 11:02 PM

Thanks Mason,

I hadn’t looked up the boiling point of 245 but you also have to consider the latent (or hidden) heat needed to boil off the gas.

In short it is better to keep the drum sealed tight unless you can store them below 62 or keep busy and use more foam.

Thanks
Airpro

John Shockney

Posted: Nov 20, 2010 11:12 PM

Sorry but I forgot to say that you can raise or lower the boiling point by changing the pressure.
We would use a gas like 245 in a chiller to make 40 degree water to air condition a building by boiling it under 2-4 inches of vacuum then compressing and cooling the gas back into a liquid.

Thanks
Airpro

mason

Posted: Nov 21, 2010 08:59 AM

I wanted to remind everyone that each manufacturer publishes their recommended storage temperatures for each of their foam formulas.

Typically the optimum storage temperature is around 70 degrees but can go up to 80 degrees F.

The HFC 245 fa blowing agent is part of the whole package of ingredients (surfactants, catalysts, resin, fire retardents,)including a little bit of water. The type of surfactants, resin, fire retardents, etc can influence the ability of the batch of ingredients to stay in solution at temperatures above the boiling point of the HFC 245 fa.

So I did not want to suggest that everyone store their chemicals at temperatures below 62 degrees F.

Rely on the manufacturer's published literature and recommendations from their technical staff.

Just wanted to make that clear.

Bryan Kwater

Posted: Nov 21, 2010 10:01 AM

Thanks for all of the info everyone.

Rodney Schares

Posted: Nov 21, 2010 02:48 PM

Are you available for a course for training dl123?

Thanks for the heads up on the fresh cartrides! I always thought the paper masks I wear were adequate.

The only gas I am dealing with is from and azz like you.

steven argus

Posted: Nov 22, 2010 06:09 PM

I'm starting to feel sorry for dl123. Seems like he has alot of know how, just no social skills. (although he did say please twice) Maybe someone should invite him to Thanksgiving dinner.

Rodney Schares

Posted: Nov 22, 2010 08:19 PM

Maybe ,just maybe Santa will bring him the ENZYTE he has on the top of his list for being a good boy this year.......

quentin

Posted: Nov 23, 2010 08:38 AM

Hey, give him credit! After that bad posts he is improving and working on being nice. I was one of those reaming him there but here he does not deserve it guys, ok?

Give credit where credit is due and knock people off thier soapbox if they need it but remember we all make mistakes and his advise was spot on from what I saw.

Daniel X

Posted: Nov 23, 2010 10:32 PM

No, I'm not available sorry. I'm very busy.

Please at least read the MSDS sheets your supplier provides.

Gerry Wagoner

Posted: Nov 27, 2010 09:43 PM

olger saw this thread and laughed.

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