Have you ever repaired a "plastic" built-in antenna for a portable device? Glue? (2 Viewers)

[e9999]

I guess I must be good at keeping my hardware for a long time. I have something like 7 or 8 walkie talkies of various kinds with broken antennas due to plastic embrittlement because of old age. They must all be at least 10 or 15 years old. The plastic casing for the antenna cracked and is clearly very brittle. I fixed a few with an epoxy sleeve of sorts and they promptly cracked someplace else. These were not flexible rubber-like antennas, more the rigid type black plastic and part of the external body of the unit. Vaguely looks like ABS but no idea really. Well, I have tried super glue and plastic cement and nothing, they do not seem to glue at all. Like it's not doing anything. I could try cement for plumbing pipes too but not gone to that yet as it's quite messy. So, thought I'd ask: Have you had any success doing something like this? What kind of glue did work out for you?

 

[Shortpencils]

Marine grade shrink tube (glue type). Sleeve the whole thing.

 

[e9999]

whoah, that's good thinking. Did not cross my mind. Will look into that. Would it be strong enough to hold two separate parts together? Can probably put more than one layer too. And one good thing is that it may give the antenna a bit of flex so less likely to break again. Nice!

Did you actually try that yourself or is that pure great lateral thinking?

 

[Shortpencils]

I've been down this road before... Electrical tape, gaff tape, duct tape, glues, partial shrink tube, yada, yada, yada.

I think what happens with the glue/epoxy method is that while the glue may stick to the material, the substrate on either side of the joint is not strong enough to keep everything together and continues to break under the bond. Basically the same reason the plastic broke in the first place.

A full tube acts as a cast, and there is enough glue surface over an entire antennae that the substrate hopefully holds together a bit better. If there is a dangling part, I would place a tube longer than the antennae on, shrink at the base, don't shrink the middle, shrink at the end, then go back and shrink the middle. This pulls the parts together, minimally, but it's better than nothing. If it's still delicate, place a stiffener such as a dowel next to the antennae and place another tube over that; essentially a splint. Tends to look decent too.

 

[e9999]

thanks. I wonder if I could find plastic tubes of the correct sizes and fit them on with an epoxy filler inside. May be ugly but would be stronger than shrink tubing. Or, yes, a metal splint could be pretty thin and unobtrusive.

 

[Skidoo]

One of my device's plastic antenna broke, exposing a spring which was the antenna.
I molded some Sugru around it, which worked.
Amazon product ASIN B089WHGQDP
Don't think you want to use metal splint as that would effect or block the antenna characteristics.