Steel Hot Water Tank | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

Q&A Forums

Author	Comments
Harry S Posted: Dec 18, 2008 10:58 AM	Steel Hot Water Tank I've got a masonry contractor that wants foam insulation on the inside of a tank. At present he uses blue-board for insulation. The tank is filled with water and heated for use in mixing mortar & grout. A couple of inches of closed cell & a coating of polyurea should do the trick, should it not? Has anybody ever done something like this?
mason Posted: Dec 18, 2008 02:50 PM	I am confused. Why would you insulate the inside of the tank and not the outside? I presume the tank is large enough to climb inside? SPF will withstand higher temperatures than EPS or XPS (blue board insulation). But, there is a chance of moisture absorption into the foam due to hydrostatic pressure and a thermal moisture gradiant. Polyurea is a low perm rated coating and should provide sufficient strength and adhesion to the foam to resist the water. However, if there is high chlorine content in the water, it may affect the polyurea coating. Ask your foam and coating supplier for their recommendations.
Harry S Posted: Dec 22, 2008 09:15 AM	I asked the same question and was told they haul it around with a forktruck and bang it up pretty good on the jobsite. As far as I know the water is out of a garden hose with a heat element placed in the middle at night to heat it for the next days use to mix the mortar and grout. They were just looking for an alternative to the blueboard and thought sprayfoam would work better(r value). Coating it is my problem tho' to prevent water absorption.
mason Posted: Dec 22, 2008 10:25 AM	Sprayfoam would work better than the blue board, just make sure the foam is coated well with the polyurea.

Author

Comments

Harry S

Posted: Dec 18, 2008 10:58 AM

Steel Hot Water Tank

I've got a masonry contractor that wants foam insulation on the inside of a tank. At present he uses blue-board for insulation. The tank is filled with water and heated for use in mixing mortar & grout. A couple of inches of closed cell & a coating of polyurea should do the trick, should it not? Has anybody ever done something like this?

mason

Posted: Dec 18, 2008 02:50 PM

I am confused. Why would you insulate the inside of the tank and not the outside? I presume the tank is large enough to climb inside?

SPF will withstand higher temperatures than EPS or XPS (blue board insulation). But, there is a chance of moisture absorption into the foam due to hydrostatic pressure and a thermal moisture gradiant. Polyurea is a low perm rated coating and should provide sufficient strength and adhesion to the foam to resist the water. However, if there is high chlorine content in the water, it may affect the polyurea coating. Ask your foam and coating supplier for their recommendations.

Harry S

Posted: Dec 22, 2008 09:15 AM

I asked the same question and was told they haul it around with a forktruck and bang it up pretty good on the jobsite. As far as I know the water is out of a garden hose with a heat element placed in the middle at night to heat it for the next days use to mix the mortar and grout. They were just looking for an alternative to the blueboard and thought sprayfoam would work better(r value). Coating it is my problem tho' to prevent water absorption.

mason

Posted: Dec 22, 2008 10:25 AM

Sprayfoam would work better than the blue board, just make sure the foam is coated well with the polyurea.

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