Whats the best product to glue plastic to metal?

[Chris142]

I reciently bought a 1970's radio controled toy truck.

It has a little transmission! The plastic gears are pressed onto a steel shaft with a press fit.

One of the gears is slipping on the shaft which makes the truck not move.

The O.D. of the shaft is about .035 and the same for the hole in the plastic gear. The shaft appears to be chromed.........Very slippery.

I tried super glue but it didn't hold. What can I use on these 2 parts to glue them together?

I have very limited working conditions in this transmission to work in so I can't build up the sides of the gear to get a better grip.

I was considering taking the thing to work and sand blasting the metal shaft to help the gear get a bite.

Any ideas?

 

[tom slick]

check out this site!
This To That

 

[TallPaul]

I would go with Household Goop. I use it for all sorts of things.

 

[Pablo]

Any glue will require a very clean surface - super glue (cyanoacrylate) even more so and is not your best choice.

Find a relatively thin epoxy, degrease both parts as well as posible. Maybe burnish just a little.

With this kinda work I like to do it under some magnification....you would be surprised what the nekid eye missses.

 

[Spitty]

If you could get a small metal washer on ether side of the gear it would increase the contact area for the glue.

 

[TallPaul]

quote:

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use something like a silicone adhesive

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I believe the this to that site said Goop is a silicon based adhesive. I used it to fix the plastic gear to metal shaft on a heavy duty, office-grade pencil sharpener.

 

[Chris142]

I ended up using pliers to roughen up the metal shaft(knurling if you will)and Permatex Ultra Black silicon.

I had to really press the gear to get it onto the rough shaft, seems to be working so far

 

[1sttruck]

You may not enough surface area for a lot of glues. We use to often knurl shafts for press fits, something that you could try doing with a tool steel or carbide cutting tool, scribe, etc., whatever is handy. Just make a series of deep, parallel lines around the shaft, trying to raise material, degrease, and use something like a silicone adhesive unless you can determine the type of plastic and find a specific adhesive.

If you're ambitious and there's room you could make a collar that slips over the shaft, epoxy it to the shaft after roughening it, and then drill and pin the gear from the side to the end of the collar. The idea here is that you could increase the surface area for the adhesive.