Most epoxy these days comes on dual syringes. The separate tubes of 40 years ago are now 400% more expensive & unobtainable. The syringes never dispense equal amounts & are impossible to push.

The system that works with the syringes is to cut them apart with an xacto knife or a box cutter. Then squeeze equal amounts on your scrap cardboard, independently. If the handles are too hard to press, the trick is to press the handle down on a table to force the product upward. Force enough upward to then wipe a small amount off on the cardboard.  Then pull the handles back out to stop the outflow.

Usually, the hardener runs out before the resin. It seems to be because the resin makes a wider, flatter blob while the hardener makes a taller blob.

Make a specially designed stir stick out of 16 gauge wire. This design has evolved into a small bend on 1 end to pick up glue & a loop on the other end to hold it.

Tape the tubes together for storage. Use the provided plug on the tips.