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Caleb DeFord Posted: Aug 08, 2012 11:14 AM	Changing from Open Cell to Closed Cell and vice-versa What are the recommended practices for changing over from oc to cc foam without contaminating your drums, messing up the foam, and unnecessarily wasting valuable product? What kind of problems will you face if you do mess up the process? (No exaggerated horror stories, please.) -Foamilyman
John Shockney Posted: Aug 08, 2012 04:12 PM	We change from open to closed and back to open so much due to customer requirements or requests, that I have installed two pumps one for open cell and one for closed cell with a 3-way valve between the pumps and our guardian A5-6000. With this setup we just plan ahead about 100sqft and switch the valve and keep spraying till the foam changes, I try to do this in a noncritical location in case we get some funky foam. Airpro
Mark Mouton Posted: Aug 08, 2012 04:51 PM	airpro sounds like he has a good set-up. We generally take the stick pump out of one drum, wipe it off a little, put it in the other drum. Pump it through the recirculation line into the drum it came out of until the color changes a little, then pump through the spray hose back into the drum it came out of until the color changes a little, then go into a 5-gallon bucket until the color is true to which product you are using. We usually waste about 2 gallons of B-side. I used to swap drums and spray it out, but I had problems with the 2 different B-side reacting in the gun and causing gun problems. It may just have been the particular foam product I was using at the time causing the B-side reaction. We waste some foam, but either way it cost me something.
Cory Boehs Posted: Aug 08, 2012 08:04 PM	We find that you don't need to waste very much at all going from Open Cell to Closed Cell. Going from CC to OC is a bit different. We have started running about a gallon of water through the B SIDE ONLY!!!!!!! So just pull your stick pump out of CC, put it into a bucket of water, pump about a gallon and wait for the water to start coming out of the manifold of gun. ( do any of you "sea hags" know if the new AP2 is as awesome at this as the Clearshot?) you will only waste a bit of chemical like this. I take no responsibility if your minimum wage Wunder Sprayer dips your A side stick pump into the water!
John Shockney Posted: Aug 09, 2012 03:30 PM	Boy! That water idea doesn’t sound like a good idea to me! So you keep pumping the closed sell resin back into the drum until you get water? What happens if you don’t stop soon enough and get water in your closed cell drum? Or are you one of those guys adding water to the closed cell so it yields more foam? Our system works good we get no air and don’t get any wasted foam if we plan ahead and make the change where it doesn’t matter what the foam looks like, like here on my shop roof or the customers attic. Airpro
Cory Boehs Posted: Aug 09, 2012 11:35 PM	AirPro, we try to spray to manufacture's specs, which would include not watering down foam, or spraying a mixed foam "no matter what it looks like." We find that we get back to good cell structure way quicker with the water. You remember the whole thing about cell structure, right? :)
John Shockney Posted: Aug 10, 2012 09:04 AM	So what do you do with the water contaminated resin? Dump it into trash bags? With our system we get less than 20bdft of “bad” foam that may be blown into a trash bag or used as attic over fill and covered with good foam. I try to plan the change ahead and with our hose length it takes about 75-80 pump strokes to change types of foam, about 300bdft of open cell, or 100bdft of closed cell. If the job requires we will recirculate some chem back to the drum and blow the rest into a trash bag. But that is rare. Airpro
mason Posted: Aug 10, 2012 10:28 AM	Sorry I am a little late to the discussion. The best solution is to use 2 rigs, one for open cell and one for closed cell. However, if you can only use one rig, then the best solution is to purge your lines out of the open or closed cell foam, before spraying on the job substrate. You can calculate how many strokes the proportioner takes to eliminate the foam in the lines. The first 2/3rds of the liquid can be re-used but after that, it can be kinda sketchy. Do Not Flush Your LInes With Water!!!! Bad Idea!!! You are just introducing a contaminate in your system that can affect the quality of your foam.
steven argus Posted: Aug 13, 2012 12:44 PM	There are manufactures that reccomend purging the b side with water. Seems like a pain to me. What to do with the old water. We are all supposed to be green, remember?! We use a manufacturer that uses the same iso for both CC and OC. So no need to drain w/ the A side. We use graco paint sprayer 36" whips before the gun. Our shut off valves are between the whip hose and paint sprayer lines. We've installed high pressure "T"'s after the shut off valves. This allows us to screw a sort section of hose to the "T" and drain the hose with out breaking down our P2. (Check the filter?? What filter?? Ha Ha) We drain into a 2 1/2 gallon jug and fill er up. (213' of hose will hold about 2 gallons) That jug gets dumped into a fresh barrel, not a partial barrel or old barrel. New barrel. I figure maybe we dump about a half gallon of the other material in the new barrel. Never had a problem. We don't even whipe off the pump. We then spray out in a bag or area of the building that doesn't matter. Of course we explain to the customers why we would do that. This does not work w/ all foams. We have sprayed just about every foam out there and have seen contamination switching between OC and CC fist hand, even with this technque. Hmmm, maybe I'll buy another rig today... sounds much easier.
steven argus Posted: Aug 13, 2012 01:10 PM	As far as horror stories... Tearing out bad foam and looking like a bunch of rookies. A former employee, would just drain back into the barrel until, "ahhh, looks good. It'll be fine". (while smoking and texting)
Mark Mouton Posted: Aug 16, 2012 10:27 AM	This is a poor boy way you can do when you swap and it will work every time. When you pull your stick pump out of the drum you are using and wipe it down(be sure pump is in the up-stroke position so the small cup-like area on the top of pump will not be full of material), lift pump up and push the ball check valve open in the bottom of the pump and let the material drain out into the drum. Then move the pump to the new drum. Remove gun and pump b-side material into the drum it came out of until you get air. Then purge into 5 gallon bucket until pure.(Don't forget to purge recirculation hose). Then replace gun and build your pressure. Then, spray onto plastic or cardboard or whatever. Hold the trigger down on your gun and let the new material go through the gun(about 7-10 seconds). This will keep the 2 b-side materials from reacting in your gun and giving you problems.
mason Posted: Aug 16, 2012 11:38 AM	Good advice billygoat, wiping the transfer pump and letting material out of it by pushing the ball is the way we used to do it. Just make sure you get all the air out and that the foam (if it is 2 lb is not sprayed too thick (can catch on fire)

Author

Comments

Caleb DeFord

Posted: Aug 08, 2012 11:14 AM

Changing from Open Cell to Closed Cell and vice-versa

What are the recommended practices for changing over from oc to cc foam without contaminating your drums, messing up the foam, and unnecessarily wasting valuable product?
What kind of problems will you face if you do mess up the process?
(No exaggerated horror stories, please.)

-Foamilyman

John Shockney

Posted: Aug 08, 2012 04:12 PM

We change from open to closed and back to open so much due to customer requirements or requests, that I have installed two pumps one for open cell and one for closed cell with a 3-way valve between the pumps and our guardian A5-6000. With this setup we just plan ahead about 100sqft and switch the valve and keep spraying till the foam changes, I try to do this in a noncritical location in case we get some funky foam.

Airpro

Mark Mouton

Posted: Aug 08, 2012 04:51 PM

airpro sounds like he has a good set-up. We generally take the stick pump out of one drum, wipe it off a little, put it in the other drum. Pump it through the recirculation line into the drum it came out of until the color changes a little, then pump through the spray hose back into the drum it came out of until the color changes a little, then go into a 5-gallon bucket until the color is true to which product you are using. We usually waste about 2 gallons of B-side. I used to swap drums and spray it out, but I had problems with the 2 different B-side reacting in the gun and causing gun problems. It may just have been the particular foam product I was using at the time causing the B-side reaction.
We waste some foam, but either way it cost me something.

Cory Boehs

Posted: Aug 08, 2012 08:04 PM

We find that you don't need to waste very much at all going from Open Cell to Closed Cell. Going from CC to OC is a bit different. We have started running about a gallon of water through the B SIDE ONLY!!!!!!! So just pull your stick pump out of CC, put it into a bucket of water, pump about a gallon and wait for the water to start coming out of the manifold of gun. ( do any of you "sea hags" know if the new AP2 is as awesome at this as the Clearshot?) you will only waste a bit of chemical like this. I take no responsibility if your minimum wage Wunder Sprayer dips your A side stick pump into the water!

John Shockney

Posted: Aug 09, 2012 03:30 PM

Boy! That water idea doesn’t sound like a good idea to me!

So you keep pumping the closed sell resin back into the drum until you get water? What happens if you don’t stop soon enough and get water in your closed cell drum? Or are you one of those guys adding water to the closed cell so it yields more foam?

Our system works good we get no air and don’t get any wasted foam if we plan ahead and make the change where it doesn’t matter what the foam looks like, like here on my shop roof or the customers attic.

Airpro

Cory Boehs

Posted: Aug 09, 2012 11:35 PM

AirPro, we try to spray to manufacture's specs, which would include not watering down foam, or spraying a mixed foam "no matter what it looks like." We find that we get back to good cell structure way quicker with the water. You remember the whole thing about cell structure, right? :)

John Shockney

Posted: Aug 10, 2012 09:04 AM

So what do you do with the water contaminated resin? Dump it into trash bags?

With our system we get less than 20bdft of “bad” foam that may be blown into a trash bag or used as attic over fill and covered with good foam.

I try to plan the change ahead and with our hose length it takes about 75-80 pump strokes to change types of foam, about 300bdft of open cell, or 100bdft of closed cell. If the job requires we will recirculate some chem back to the drum and blow the rest into a trash bag. But that is rare.

Airpro

mason

Posted: Aug 10, 2012 10:28 AM

Sorry I am a little late to the discussion. The best solution is to use 2 rigs, one for open cell and one for closed cell. However, if you can only use one rig, then the best solution is to purge your lines out of the open or closed cell foam, before spraying on the job substrate. You can calculate how many strokes the proportioner takes to eliminate the foam in the lines. The first 2/3rds of the liquid can be re-used but after that, it can be kinda sketchy.

Do Not Flush Your LInes With Water!!!! Bad Idea!!!

You are just introducing a contaminate in your system that can affect the quality of your foam.

steven argus

Posted: Aug 13, 2012 12:44 PM

There are manufactures that reccomend purging the b side with water. Seems like a pain to me. What to do with the old water. We are all supposed to be green, remember?!

We use a manufacturer that uses the same iso for both CC and OC. So no need to drain w/ the A side. We use graco paint sprayer 36" whips before the gun. Our shut off valves are between the whip hose and paint sprayer lines. We've installed high pressure "T"'s after the shut off valves. This allows us to screw a sort section of hose to the "T" and drain the hose with out breaking down our P2. (Check the filter?? What filter?? Ha Ha) We drain into a 2 1/2 gallon jug and fill er up. (213' of hose will hold about 2 gallons) That jug gets dumped into a fresh barrel, not a partial barrel or old barrel. New barrel. I figure maybe we dump about a half gallon of the other material in the new barrel. Never had a problem. We don't even whipe off the pump. We then spray out in a bag or area of the building that doesn't matter. Of course we explain to the customers why we would do that.

This does not work w/ all foams. We have sprayed just about every foam out there and have seen contamination switching between OC and CC fist hand, even with this technque.

Hmmm, maybe I'll buy another rig today... sounds much easier.

steven argus

Posted: Aug 13, 2012 01:10 PM

As far as horror stories...

Tearing out bad foam and looking like a bunch of rookies.

A former employee, would just drain back into the barrel until, "ahhh, looks good. It'll be fine". (while smoking and texting)

Mark Mouton

Posted: Aug 16, 2012 10:27 AM

This is a poor boy way you can do when you swap and it will work every time. When you pull your stick pump out of the drum you are using and wipe it down(be sure pump is in the up-stroke position so the small cup-like area on the top of pump will not be full of material), lift pump up and push the ball check valve open in the bottom of the pump and let the material drain out into the drum. Then move the pump to the new drum. Remove gun and pump b-side material into the drum it came out of until you get air. Then purge into 5 gallon bucket until pure.(Don't forget to purge recirculation hose).
Then replace gun and build your pressure. Then, spray onto plastic or cardboard or whatever. Hold the trigger down on your gun and let the new material go through the gun(about 7-10 seconds). This will keep the 2 b-side materials from reacting in your gun and giving you problems.

mason

Posted: Aug 16, 2012 11:38 AM

Good advice billygoat, wiping the transfer pump and letting material out of it by pushing the ball is the way we used to do it.
Just make sure you get all the air out and that the foam (if it is 2 lb is not sprayed too thick (can catch on fire)

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