Spray Foam System Maintenance: How To Get Rid of Isocyanate Build Up

You wouldn’t let a clogged carburetor stop you from getting where you need to go, so why would you let your a sluggish A-side hose stop a paying job in its tracks?

Heated hoses are critical to the consistent flow of material, which translates to a uniform spray and ultimately, better foam. However, the material that runs through the hoses can leave buildup over time. As such, hose lines need to be flushed out periodically to keep them flowing smoothly. The only question is, how do you know when you need to schedule in a couple of hours to run a thorough flush and which flush on the market will do as promised.

Signs of a Clogged Spray Foam Hose

As a spray foam technician, there’s a lot of mistakes that we tend to see pop up fairly frequently- especially among newer contractors. Everything from not heating foam to the correct levels before spraying, to improper handling and storage of tools, etc. The most common problem often experienced by spray foam contractors, however? Allowing a build-up of spray foam materials to persist long enough to cause permanent damage to their heated hoses. So how can you tell if your hoses are overdue for a thorough flush procedure? Check for these signs:

If you are facing any of these problems than rest assured, now is definitely the time to schedule a time for your hose to be flushed, as soon as possible. Not sure what you should use to flush your hoses? Watch as David Faghani, Technical Director of Global Specialty Products, Inc (GSP) layout the most effective and safest products (for both your employees and the environment) or continue reading below.

Traditional Methods

Prior to 1986 one of the more popular choices for completing a flush was to use NMP (N-Methyl-2-Pyrrolidone). A general-use industrial solvent and cleaner it was later found to cause significant harm to and potentially long-lasting damage to the reproductive and nervous systems, as well as to the eyes, nose, mouth, throat & skin when inhaled and/or otherwise come into contact. Since then NMP products have been listed on both California’s Prop 65 List, as well as NMP-based Products that are also listed on the Hazardous Air Pollutant list.

In addition to NMP and NMP based products, other traditional methods have included using Methylene Chloride, Kerosene, Methyl Ethyl Ketone (MEK), Acetone (a slightly safer alternative to using MEK), as well as some other highly hazardous chemical compounds. The problem with many of these options is that they haven’t taken worker safety and disposal regulations into account.

The Fresher Alternative

As David explained in the video above, GSP has created safer alternatives to all of these; options that are non-hazardous, non-HAPS, non-flammable, have reduced VOC, and are both environmentally friendly and safe for your workers. NZD ISO Flush Isocyanates Neutralizer & Cleaner and Surf X Flush 2000.

Both products were designed to flush and clean liquid and/or partially hardened Isocyanate from hoses, feed lines, feed tanks, mixing and metering equipment, spray foam guns, and other spray foam equipment without causing the same type of damage you would see with the more traditional methods. Where they most differ is in their correct applications.

NZD ISO Flush vs. Surf X Flush 2000

NZD Iso Flush excels at removing Liquid Diisocyanates Polymer from the A-side of your spray foam equipment, hoses, feedlines, and spray guns. With its thin viscosity, NZD Iso will flush easily, remove a small amount of hardened isocyanate in the lines, and can be left in the proportioner overnight. For systems with a significant amount of hardened part-A Isocyanate, it is recommended that you use Surf X Flush first and then follow up with a flush of NZD Iso to ensure complete removal. While Surf X Flush is a much more aggressive cleaner compared to NZD Iso, it is also important to ensure that the area where you are performing the procedure is clean and dry, as Surf X will gel if it comes into contact with moisture.

Surf X Flush 2000 can also be used to remove industrial resins such as Polyester, Vinylester, Epoxy, and Fiberglass from spray foam equipment and guns, as well as over-sprayed Polyurethane foam (A&B) from any unpainted surface.

How to Perform a Proper Isocyanate Flush

Below is the recommended procedure for performing an effective Isocyanate Flush, it is important however that you have first ensured compatibility between the old and new Iso, Polyol, and required solvents just like with any other chemical change you are making.

  1. Remove Spray Gun and Coupling Block from hose ends and secure in waste containers.
  2. Lower material dispensing pressure to the transfer pumps to 30 psi.
  3. Fill one clean 5-gallon bucket with 2 gallons of NZD Iso Flush for flushing” A” ISO side and, in a separate 5-gallon bucket, Surf X Flush 2000 for flushing “B” RES side.
  4. Remove transfer pumps and supply hoses from the material drums; lift the inlet balls to drain material from inside the transfer pump and clean exterior. Insert into the separate buckets and secure to prevent tipping.
  5. Activate the transfer pumps to move slowly and purge both chemicals into waste containers/buckets.CAUTION: Do not activate the Primary Heaters or Heated Hoses.
  6. Stop the transfer pumps as soon as the ISO and RES are purged from the hoses.
  7. Once you have a good amount of material in the bucket (about a gallon) you can safely dispose of the solutions in accordance with applicable federal, state, and local regulations.
  8. Securely fasten the ISO material hose end into the respective bucket of NZD Iso Flush on the ISO side and begin to recycle the NZD Iso Flush at the highest (and safest) possible cycle rate. Repeat this process on the resin side using Surf X Flush . Allow NZD ISO FLUSH™ and Surf X Flush 2000 to re-circulate for at least one (1) hour.
  9. Turn off the air and remove the transfer pumps from the material, lift the inlet balls to allow for drainage, and wipe down the exterior of the pump. Insert each pump into a clean bucket filled with two (2) gallons of clean NZD Iso Flush and Surf X Flush 2000.
  10. Repeat the process until you have purged all remaining dirty NZD Iso Flush and Surf X Flush out into the two waste containers, filling the proportioner with only clean material. Take care to dispose of these in accordance with all applicable federal, state, and local regulations. Stop the transfer pumps and insure all pressure is removed from the proportioning unit and material hoses.
  11. Reinstall the Coupling Block. Activate the transfer pumps to move slowly and purge all remaining flush out disposing of it in accordance with all regulations. If you want to store it at this point you can keep draining the cleaners out while pumping in Surf A Lube Storage Fluid, just make sure that you have parked the proportioning pump and have all valves closed with the power off.