the cheapest $15 gun from harbor freight works well too
i use a discarded paint gun from my buddies shop
amazingly the glue does not harden in the canister, i've had the same gun for 5 yrs
turn the fan spray all the way down and plug the vent hole when not using it
i usually just keep it plugged unless i'm doing a lot of spraying.
welwood contact cement works ok but trim cement is better