Why does every manufacturer of 2K (two-component) cartridges instruct users to equalize and purge the cartridge before attaching the static mixer? Here's your answer. 

Importance of equalizing and purging 2K cartridges: 

Each side of a 2K cartridge is filled at a different point in the manufacturing process, this means the pistons may never be perfectly even. Equalizing and purging balances the pistons on the bottom of the cartridge, allowing you to visually confirm both sides are dispensing product before attaching the static mixer.

How to equalize and purge a cartridge:

To equalize and purge the cartridge, place it into a manual or pneumatic applicator. Slowly dispense a small amount of product onto a shop towel and watch closely to see that product is coming out of both sides of the cartridge. Next, attach your static mixer and run a small amount of product to ensure proper mix, with no marbling coming out of the tip. 

What happens if you don't equalize and purge?

Neglecting to equalize the cartridge before attaching the static mixer can knock the tip "off ratio" causing the components to mix improperly. Correcting an off ratio tip takes more than just running a little extra product through the static mixer. 

When a tip is off ratio, it can take up to a 1.5-foot bead to achieve proper mix.

Watch the Quick Tips video for a complete overview of equalizing and purging 2K cartridges.