Spray foam cans are expensive, and if you’re like me, they almost always clog up or dry out before you get a chance to use the whole can. In this blog post, I’ll tell you how to fix a clogged, dried out can of spray foam so you can use more of it and save time and money.
Clearing the spray foam nozzle
To clear the nozzle on a clogged can of spray foam, first break off any foam that protrudes from the nozzle. Next, take an ordinary drywall screw and slowly and carefully screw it into the nozzle. The threads on the screw will cut into the clog and grip it surprisingly well. Pull the screw straight up, and the clog will lift out along with the screw. Now as long as the can still has propellants in it, it will work again.
Spray foam cans have an expiration date printed on the underside. If the can is expired, there’s a good chance there isn’t much propellant left in it. But it also doesn’t hurt to try.
Clearing the applicator
The nozzle isn’t the only thing that can clog up. If you don’t unscrew the applicator as soon as you finish using the can, it tends to fill up with foam and gets clogged up. The can itself may not be clogged and me still be usable, but it’s not much use without the applicator.
To clear the applicator, pour a little bit of acetone or Goof Off into each side of the applicator. Acetone is cheaper in quantity, but the six-ounce Goof Off can has a convenient spout that makes it very easy to pour into the applicator. Acetone will work, but you’ll need a way to pour it into the tiny opening, so I prefer the Goof Off. The can of Goof Off costs as much as the can of spray foam, but it will unclog dozens of cans.
Let it sit for about 5 minutes so the cleaner has time to soak into the clog and debond the adhesive in it. After about 5 minutes, you should be able to push on the clog with a toothpick or metal rod small enough to fit into the tube. Once the clog protrudes far enough down the other side, you can simply pull it out with your hand. Both acetone and Goof Off do a very good job of debonding spray foam from plastics.
Stopping your half used can of spray foam from drying out
To keep your can of spray foam from clogging up so you can use the rest of the can later, remove the applicator from the nozzle. Next, push a drywall screw down into the nozzle of the can. Whatever spray foam is currently in the nozzle will still cure, but it will cure around the drywall screw, including the threads. When you go to use the can again, pull the drywall screw out, and it will pull that small amount of spray foam along with it.
With these tricks, now you have until the expiration date, or perhaps even a little bit longer, to use up that spray foam can, instead of only having about 72 hours. Spray foam isn’t terribly expensive, but it does seem like every time I go to buy a can, it costs more than the last time.
The last time I needed spray foam, the hardware stores were all closed for the evening, but I had a dried out can from my last project. I remembered fixing a dried out tube of construction adhesive with a drywall screw, so I decided to try the same trick with my dried out can of spray foam. I didn’t have anything to lose, and I’m happy to report it worked.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.