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Yvan Richard Posted: Nov 22, 2010 08:40 PM	Coating I am currently quoting on 4 large tanks that are going to hold liquid CO2. We will be putting 5 inches of foam. The temperature inside the tank will have to be maintained at -28Celcius. There will be a coating that will have to be applied and the customer wants it in white to reflect the sunlight. (we don't do coatings) Does anyone have any recommendations for this type of coating?
SprayFoamSupply.com Posted: Nov 22, 2010 11:04 PM	What brand of foam are you using? Most of the name brand foam manufacturers have acrylic coating for their foams for roofing applications. I know that Bayer has a white acrylic coating which you can spray on like paint. 2-3 coats should last for 10-15 years before they need a recoat. Hope this helps. George
Terrance Harris Posted: Nov 23, 2010 03:14 PM	I'm not a coating expert but it would seem to me you have a hot to cold moisture drive in this type of application. I don't believe acrylic coating coating is the answer here. You may want to talk to a coatings rep.
John Shockney Posted: Nov 23, 2010 07:14 PM	I got into the same situation last summer spraying ductwork with 2# on a roof last summer. I didn’t have a spray rig that would handle the high solids acrylic roof coating and when I talked to some painters that do spray this coating they quoted a dollar per square foot plus the paint for 12,000 square feet. Well I thought that was a lot for just labor so I bought a used air driven paint pump, new hoses, paint gun, and spray tips. We rented a gas tow behind air compressor and sprayed the job ourselves and even though I was a little afraid of taking on the coating I found that spraying paint was simple compared to spraying foam. The worst thing on the whole job was fighting the weather I do like spraying foam inside better. Also most suppliers will tell you to put down two coats at 1gal per 100sqft I would figure 2gal per 100sqft for the first coat and 1.5 for the 2nd. It seems foam likes more paint. If you need help to spray the coating send me an email at airpro@gotsky.com I do go where the work is. Hope this helps Airpro
Daniel X Posted: Nov 23, 2010 10:34 PM	Airpro that is hilarious, sometimes we forget that there are people who spray everyday and their mistakes or runs aren't over an inch thick and hard to remove. I still don't envy most painters however.
chad harris Posted: Nov 24, 2010 05:32 PM	Sounds like your gonna need a vapor barrier. ( what Gunslinger was hinting at.) If you don't find out and just put acrylic on, it very well could end up being a total failure for ya.
Posted: Nov 25, 2010 09:07 AM	I'm surprised that they want to insulate the tank to begin with. I started with a CO2 Tunnel Freezer System in in mid 90's for IQF shrimp. Moved towards Nitrogen in early 2000 where we used six seperate 40' Tunnel Systems. Contrary to popular belief, Insulation is not going to help maintain the temperature all that much. Once CO2 begins to heat up, pressure builds up in the tank and and pressure release valve pops off to release the pressure. Most tanks have a compressor to help maintain temperature. You will find that the only areas of condensation or icing up on the tank during heavy use will be around the inlet and exit valves. CO2 moving at bulk rates tends to ice up, where there is a bottleneck. Usually the bottleneck happens around inlets and exits that have nipples less than 2". Acryllic, Silicone, urethanes and Polyureas will all work fine. You can contact Air Gas, Air Liquide or any of the other bulk gas manufacturers to ask their opinion. Call and tell them what you are doing and they will give you some really good insight. I will look through my notes and see if I can find Air Liquide's Technical Director if that will help!
Yvan Richard Posted: Nov 27, 2010 08:28 PM	Thank you for the insight. I have contacted a coating guy and he mentioned that he will be able to spray over the foam. The coating will be white to reflect the sun and then he will spray a type of acrylic coating so the foam is protected with a hard coating. He mentioned that they should never have to redo the tanks. Now the foam is my concern, someone mentioned that I would need a vapour barrier. But with approx 5" of foam I don't see an issue with condensation. The only thing is with adhesion to the tank. I believe the steel should be pressure washed to eliminate any grease and then left to dry , but if it rains it will rust. Would that be an issue for the foam? This could make the logistics of this deal a nightmare, since the tanks will be 2.5hrs away.
Gerry Wagoner Posted: Nov 27, 2010 09:36 PM	You will most definitely need to install a vapor barrier coating over the foam. Davlin 9150 or equal, then paint it white. Have fun, `oG
Yvan Richard Posted: Nov 28, 2010 02:43 PM	Thank you I am not exactly sure what type of steel the substrate will be, however do you recommend having it pressure washed first?
Dan Beecher Posted: Nov 28, 2010 06:03 PM	You need to find out what the substrate steel is. It may need to be sandblasted and primed if it is rusted. Your foam is only going to be as good as the substrate you are putting it on. You will definately want to put a vapor barrier on there. You really want to research this before you do it. Talk to your foam mfgr, if they can't help you find someone with the know how. Tanks like this if done right will last forever, done poorly a major headache, blistered foam, peeling coatings, etc. Also be aware of the drop down temps you must follow for such a vessel as it is put into service.
Terrance Harris Posted: Nov 29, 2010 10:03 PM
Terrance Harris Posted: Nov 29, 2010 10:05 PM	iinsul8 has apparently been down some of the same RR tracks as myself. Extremely well informed and excellent reply and advise on this topic. As he said, do your research before attempting this project. If not done right, it will come back to haunt you.
Yvan Richard Posted: Dec 01, 2010 12:56 AM	Thank you for all the insight, I will definetly do some more research and post whatever I find. The project won`t be ready until the summer of 2011, so I do have some time. The tanks are 100ft long, and I assume they will be shipped in 50ft lengths to fit on a truck. Would it make sense to spray the 50 ft lengths in the manufacturers shop, or even rent some space. then once shipped simply spray the joints on site. This way I would be in a controlled environment. It would also save on hotel rooms and being away from home. Your thoughts.

Author

Comments

Yvan Richard

Posted: Nov 22, 2010 08:40 PM

Coating

I am currently quoting on 4 large tanks that are going to hold liquid CO2. We will be putting 5 inches of foam. The temperature inside the tank will have to be maintained at -28Celcius.

There will be a coating that will have to be applied and the customer wants it in white to reflect the sunlight. (we don't do coatings)

Does anyone have any recommendations for this type of coating?

SprayFoamSupply.com

Posted: Nov 22, 2010 11:04 PM

What brand of foam are you using? Most of the name brand foam manufacturers have acrylic coating for their foams for roofing applications. I know that Bayer has a white acrylic coating which you can spray on like paint. 2-3 coats should last for 10-15 years before they need a recoat.
Hope this helps.

George

Terrance Harris

Posted: Nov 23, 2010 03:14 PM

I'm not a coating expert but it would seem to me you have a hot to cold moisture drive in this type of application. I don't believe acrylic coating coating is the answer here. You may want to talk to a coatings rep.

John Shockney

Posted: Nov 23, 2010 07:14 PM

I got into the same situation last summer spraying ductwork with 2# on a roof last summer. I didn’t have a spray rig that would handle the high solids acrylic roof coating and when I talked to some painters that do spray this coating they quoted a dollar per square foot plus the paint for 12,000 square feet.

Well I thought that was a lot for just labor so I bought a used air driven paint pump, new hoses, paint gun, and spray tips. We rented a gas tow behind air compressor and sprayed the job ourselves and even though I was a little afraid of taking on the coating I found that spraying paint was simple compared to spraying foam.

The worst thing on the whole job was fighting the weather I do like spraying foam inside better.

Also most suppliers will tell you to put down two coats at 1gal per 100sqft I would figure 2gal per 100sqft for the first coat and 1.5 for the 2nd. It seems foam likes more paint.

If you need help to spray the coating send me an email at airpro@gotsky.com I do go where the work is.

Hope this helps

Airpro

Daniel X

Posted: Nov 23, 2010 10:34 PM

Airpro that is hilarious, sometimes we forget that there are people who spray everyday and their mistakes or runs aren't over an inch thick and hard to remove.

I still don't envy most painters however.

chad harris

Posted: Nov 24, 2010 05:32 PM

Sounds like your gonna need a vapor barrier. ( what Gunslinger was hinting at.) If you don't find out and just put acrylic on, it very well could end up being a total failure for ya.

Posted: Nov 25, 2010 09:07 AM

I'm surprised that they want to insulate the tank to begin with. I started with a CO2 Tunnel Freezer System in in mid 90's for IQF shrimp. Moved towards Nitrogen in early 2000 where we used six seperate 40' Tunnel Systems.

Contrary to popular belief, Insulation is not going to help maintain the temperature all that much. Once CO2 begins to heat up, pressure builds up in the tank and and pressure release valve pops off to release the pressure. Most tanks have a compressor to help maintain temperature.

You will find that the only areas of condensation or icing up on the tank during heavy use will be around the inlet and exit valves. CO2 moving at bulk rates tends to ice up, where there is a bottleneck. Usually the bottleneck happens around inlets and exits that have nipples less than 2".

Acryllic, Silicone, urethanes and Polyureas will all work fine. You can contact Air Gas, Air Liquide or any of the other bulk gas manufacturers to ask their opinion. Call and tell them what you are doing and they will give you some really good insight. I will look through my notes and see if I can find Air Liquide's Technical Director if that will help!

Yvan Richard

Posted: Nov 27, 2010 08:28 PM

Thank you for the insight.

I have contacted a coating guy and he mentioned that he will be able to spray over the foam. The coating will be white to reflect the sun and then he will spray a type of acrylic coating so the foam is protected with a hard coating. He mentioned that they should never have to redo the tanks.

Now the foam is my concern, someone mentioned that I would need a vapour barrier. But with approx 5" of foam I don't see an issue with condensation. The only thing is with adhesion to the tank. I believe the steel should be pressure washed to eliminate any grease and then left to dry , but if it rains it will rust. Would that be an issue for the foam? This could make the logistics of this deal a nightmare, since the tanks will be 2.5hrs away.

Gerry Wagoner

Posted: Nov 27, 2010 09:36 PM

You will most definitely need to install a vapor barrier coating over the foam. Davlin 9150 or equal, then paint it white.

Have fun,

`oG

Yvan Richard

Posted: Nov 28, 2010 02:43 PM

Thank you I am not exactly sure what type of steel the substrate will be, however do you recommend having it pressure washed first?

Dan Beecher

Posted: Nov 28, 2010 06:03 PM

You need to find out what the substrate steel is. It may need to be sandblasted and primed if it is rusted. Your foam is only going to be as good as the substrate you are putting it on. You will definately want to put a vapor barrier on there. You really want to research this before you do it. Talk to your foam mfgr, if they can't help you find someone with the know how. Tanks like this if done right will last forever, done poorly a major headache, blistered foam, peeling coatings, etc. Also be aware of the drop down temps you must follow for such a vessel as it is put into service.

Terrance Harris

Posted: Nov 29, 2010 10:03 PM

Terrance Harris

Posted: Nov 29, 2010 10:05 PM

iinsul8 has apparently been down some of the same RR tracks as myself. Extremely well informed and excellent reply and advise on this topic. As he said, do your research before attempting this project. If not done right, it will come back to haunt you.

Yvan Richard

Posted: Dec 01, 2010 12:56 AM

Thank you for all the insight, I will definetly do some more research and post whatever I find. The project won`t be ready until the summer of 2011, so I do have some time.

The tanks are 100ft long, and I assume they will be shipped in 50ft lengths to fit on a truck. Would it make sense to spray the 50 ft lengths in the manufacturers shop, or even rent some space. then once shipped simply spray the joints on site. This way I would be in a controlled environment. It would also save on hotel rooms and being away from home. Your thoughts.

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