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

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Author	Comments
Ted Mac Posted: May 31, 2014 09:34 PM	ISO blockages New component why do check valve screens block ever 1 maybe 2 hours.
SprayFoamSupply.com Posted: Jun 03, 2014 08:36 AM	Has your machine been sitting for a while? The ISO crystals could be breaking free from the walls of your sprayfoam hose. How old is the "new" component? George
Ted Mac Posted: Jun 03, 2014 10:59 AM	New as in week old from wholesaler. But yes machine has been through a down period of some months.
SprayFoamSupply.com Posted: Jun 03, 2014 12:26 PM	OK, if we assume the foam is good and the crystals are not coming from the drum, then you must have some crystals in your spray hose. When the equipment sits for a length of time, the ISO starts to crystallize on the walls of the hose like a clogged artery. The longer it sits, the more crystals form. When you start spraying again, the hose expands from the heat, and then expands and contracts from the pressure and the crystals start to break free. This will continue for some time, but will eventually stop. If you put a high pressure 3/8" Y strainer between the last 50' of hose and the whip, it will hold alot more of the crystals and you won't have to clean it as often as the gun filter. Hope this helps, George
mason Posted: Jun 06, 2014 04:09 PM	Thanks for the help George, I was out of commission for a week, had some surgery and just got out of the hospital yesterday. Nothing serious but could not get to a computer, still a little foggy from pain killers. George of course hit the nail on the head. ISO can set up if left exposed, particularly in high humidity. Tips: Always spray enough foam after working on your equipment so that you get any residual moisture out of the system, (At least 150-250 pounds) I found this was a good time to make samples. This goes for cleaning pump screens, transfer pumps, changing packings, putting on new hoses, anytime you expose the innards to the outside. Be sure your air is dry, use water traps and air dryers on the compressor and make sure your A side drums are sealed overnight with desiccants or nitrogen blanket Don't let your foam equipment sit for more than a week. Run material through it so the A side can't set up in the hose. Check you hose fittings and connections for leaks or tears in the butyl rubber wrappings. Once you get crystals set up in your spray hoses, it is real difficult to get it out. Prevention can save tons of time and money.
Mark Upton Posted: Jun 13, 2014 06:43 AM	Hi there. I too have a similar issue. Y-screen on A side is always full of crystalized Iso. I recirculate my a side every 2 weeks when not in use, as per my foam suppliers recommendation (Icynene). I don't use a desicant cartridge on either side. I also noticed that there were lots of crystalized Iso in the end of my a side drum when I went to change over to a new drum. Should I put a desiccant dryer on both the a and b drums? And, I assume every 2 weeks is too long to be recircing? Thanks for your help!
mason Posted: Jun 16, 2014 04:20 PM	Yes, use a desiccant on your a side drum. Also, instead of recirculating the a side liquid, actually spray some foam so that new material is getting to the proportioner and hoses.

Author

Comments

Ted Mac

Posted: May 31, 2014 09:34 PM

ISO blockages

New component why do check valve screens block ever 1 maybe 2 hours.

SprayFoamSupply.com

Posted: Jun 03, 2014 08:36 AM

Has your machine been sitting for a while? The ISO crystals could be breaking free from the walls of your sprayfoam hose. How old is the "new" component?

George

Ted Mac

Posted: Jun 03, 2014 10:59 AM

New as in week old from wholesaler. But yes machine has been through a down period of some months.

SprayFoamSupply.com

Posted: Jun 03, 2014 12:26 PM

OK, if we assume the foam is good and the crystals are not coming from the drum, then you must have some crystals in your spray hose. When the equipment sits for a length of time, the ISO starts to crystallize on the walls of the hose like a clogged artery. The longer it sits, the more crystals form. When you start spraying again, the hose expands from the heat, and then expands and contracts from the pressure and the crystals start to break free. This will continue for some time, but will eventually stop. If you put a high pressure 3/8" Y strainer between the last 50' of hose and the whip, it will hold alot more of the crystals and you won't have to clean it as often as the gun filter.

Hope this helps,

George

mason

Posted: Jun 06, 2014 04:09 PM

Thanks for the help George, I was out of commission for a week, had some surgery and just got out of the hospital yesterday. Nothing serious but could not get to a computer, still a little foggy from pain killers. George of course hit the nail on the head. ISO can set up if left exposed, particularly in high humidity.

Tips:
Always spray enough foam after working on your equipment so that you get any residual moisture out of the system, (At least 150-250 pounds) I found this was a good time to make samples. This goes for cleaning pump screens, transfer pumps, changing packings, putting on new hoses, anytime you expose the innards to the outside. Be sure your air is dry, use water traps and air dryers on the compressor and make sure your A side drums are sealed overnight with desiccants or nitrogen blanket

Don't let your foam equipment sit for more than a week. Run material through it so the A side can't set up in the hose. Check you hose fittings and connections for leaks or tears in the butyl rubber wrappings.

Once you get crystals set up in your spray hoses, it is real difficult to get it out. Prevention can save tons of time and money.

Mark Upton

Posted: Jun 13, 2014 06:43 AM

Hi there. I too have a similar issue. Y-screen on A side is always full of crystalized Iso. I recirculate my a side every 2 weeks when not in use, as per my foam suppliers recommendation (Icynene). I don't use a desicant cartridge on either side. I also noticed that there were lots of crystalized Iso in the end of my a side drum when I went to change over to a new drum. Should I put a desiccant dryer on both the a and b drums? And, I assume every 2 weeks is too long to be recircing? Thanks for your help!

mason

Posted: Jun 16, 2014 04:20 PM

Yes, use a desiccant on your a side drum. Also, instead of recirculating the a side liquid, actually spray some foam so that new material is getting to the proportioner and hoses.

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