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

Q&A Forums

Author	Comments
Jethro Posted: Jun 25, 2015 04:41 PM	Moisture Mason - Hello. Provided a drum top desiccant dryer and properly sealed transfer pumps, how does moisture get into a spray system?
jimcoler I have over 10 years of experience specifying and installing open and closed cell spray foam. I've sold my business but I'm still selling for the new owners and consulting on large and custom specific jobs. I've expanded my knowledge into t Posted: Jun 26, 2015 07:46 AM	It's my understanding, it can still seep through the hoses themselves. That's how you can still get iso crystals in the hose even with all of the moisture preventative measures.
mason Posted: Jun 29, 2015 04:26 PM	Jed, I used to work down in South Texas where it is always hot and humid. It was a chore to keep the drums and equipment from being exposed to moisture. Your compressor can create a lot of moisture that can be transmitted to your airlines to your pumps and spray gun. So make sure your water trap and air dryer on your compressor is working to keep the air dry. Also condensation can form inside your drums in high humidity even with an air dryer on your drums. Be sure to store your equipment in as dry conditions as possible. Condensation can also occur in your pump screens, transfer hoses, fittings as well as the foam hose. Keep material moving and don't store equipment in the weather if you can help it. Once moisture gets in the system, it feeds on itself and can cause your A side to crystalize from the drum pumps all the way to the spray hose. If you do get crystals in the system, flush the system out and pump a plasticizer such as TCP or DOP through the equipment and let it stand a couple of days then flush out with new good material. It should take care of any residual moisture and get the crystals to stop forming.
Jethro Posted: Aug 14, 2015 06:49 PM	I understand moisture in a compressed air system. My interest is moisture in the fluid side of a plural component spray system. Concerning condensation inside the drum, even with a drum top dryer - Condensation is the effect of existing moisture in the air that has reached the dew point and thus the moisture 'drops out' of the air OR condenses. If the drum is properly sealed and all the inbound air travels through a desiccant dryer, where does the 'existing' moisture inside the drum originate for condensation to occur? Regarding moisture migration 'through' the lining of a heated spray hose - Is there any documentation or report supporting that this actually occurs?

Author

Comments

Jethro

Posted: Jun 25, 2015 04:41 PM

Moisture

Mason - Hello. Provided a drum top desiccant dryer and properly sealed transfer pumps, how does moisture get into a spray system?

jimcoler

I have over 10 years of experience specifying and installing open and closed cell spray foam. I've sold my business but I'm still selling for the new owners and consulting on large and custom specific jobs.

I've expanded my knowledge into t

Posted: Jun 26, 2015 07:46 AM

It's my understanding, it can still seep through the hoses themselves. That's how you can still get iso crystals in the hose even with all of the moisture preventative measures.

mason

Posted: Jun 29, 2015 04:26 PM

Jed,

I used to work down in South Texas where it is always hot and humid. It was a chore to keep the drums and equipment from being exposed to moisture.

Your compressor can create a lot of moisture that can be transmitted to your airlines to your pumps and spray gun. So make sure your water trap and air dryer on your compressor is working to keep the air dry. Also condensation can form inside your drums in high humidity even with an air dryer on your drums. Be sure to store your equipment in as dry conditions as possible.

Condensation can also occur in your pump screens, transfer hoses, fittings as well as the foam hose. Keep material moving and don't store equipment in the weather if you can help it. Once moisture gets in the system, it feeds on itself and can cause your A side to crystalize from the drum pumps all the way to the spray hose. If you do get crystals in the system, flush the system out and pump a plasticizer such as TCP or DOP through the equipment and let it stand a couple of days then flush out with new good material. It should take care of any residual moisture and get the crystals to stop forming.

Jethro

Posted: Aug 14, 2015 06:49 PM

I understand moisture in a compressed air system. My interest is moisture in the fluid side of a plural component spray system. Concerning condensation inside the drum, even with a drum top dryer - Condensation is the effect of existing moisture in the air that has reached the dew point and thus the moisture 'drops out' of the air OR condenses. If the drum is properly sealed and all the inbound air travels through a desiccant dryer, where does the 'existing' moisture inside the drum originate for condensation to occur? Regarding moisture migration 'through' the lining of a heated spray hose - Is there any documentation or report supporting that this actually occurs?

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