Stripped threads in plastic?

#1: Post by **mgrayson** » March 18th, 2019, 7:03 am

I have one place where a metal screw goes into plastic. It holds a lever for locking the drip tray in place. The plastic is stripped, so I can't really tighten the lever, and it keeps working loose.

Is there a better repair than breaking a toothpick in the hole? Some goop that hardens and then the screw can hold?

Thanks,

Matt

#2: Post by **shotwell** » March 18th, 2019, 7:43 am

You could epoxy a screw in, but you probably won't get it out. I'd probably consider using a self tapping screw one size up if there is clearance, but you could also fill the hole with epoxy, drill, and tap.

March 18th, 2019, 9:22 am

The screw has to apply pressure when tightened, and it goes through a bushing and three washers, so I don't know if I can use a larger thread. Epoxy and drilling sounds right.

Thanks,

Matt

March 18th, 2019, 1:27 pm

Blue loctite might be an option

Randy

#5: Post by **Randy G.** » March 18th, 2019, 1:42 pm

It depends on the plastic. JB weld makes a two part epoxy called Plastic Bonder. It won't work on plastics like polyethylene or polypropylene but I have used it with excellent results on other plastics including a turn indicator's cruise control module which broke in half. If it is a machine screw you could retap the threads. Otherwise, just drill a pilot hole into the epoxy. If there is room, you can also buildup the area around the hole as well. If you use dental tools you can work the epoxy until it hardens/thickens. moisten the working surface of the tool with a bit of water or saliva and the epoxy will not stick to the tool so easily. I speak from experience- I've broken a lot of stuff!

March 18th, 2019, 2:59 pm

Thank you for the suggestions. I tried some plastic epoxy and screwed it up. To add insult to injury, my drill poked through into the drip tray. Sigh. So I got a larger screw, covered it in Teflon tape, and it seems to be both holding and waterproof.

If this fails, I'll bore it out further, try the epoxy again, and let it cure for a day first

Matt