I am trying to repair a broken plastic headband on a racal, and was wondering (before I do REAL damage) what kind of glue might create the best fusion. Anyone have a clue what the type of plastic is?

Specifically, anyone know what kind of cement might melt the plastic a bit to get the best fusion? I know a 2-part epoxy is useless because it doesnt flex at all when dry. I need to fuse the plastic bits back to gether, not just "glue them".

I have pvc plumbing compound, regular testors model glue, and the glue designed for "plastruct", but dont want to gum it all up with failed attempts if someone already knew.

Thanks for any help.
(glue is only part of the solution btw, I plan to get clever with the reinforcement as well)

CA Glue doesn't work either.

I can let you know on the plastruct cement.

I'd appreciate that. I can say I did the ever smallest test using the "non-toxic Testors" model cement, and early returns are not good!

I did such a small sample that I didnt destroy anything, but I fear we will have to bring out the 'toxic' stuff for this 70s/80s plastic. Today's new age stuff didn't dent it, let alone secure anything.

Just updating this in case it helps others avoid wasting time. I have since tried:

-Plastruct Plastic Weld (orange label) = complete failure.

-Oatey brand PVC cement = Complete failure.

They join the list of testors model paint (the non-toxic one), super glue and two part apoxies that are 100% useless in repairing the plastic parts of a racal headset. If anyone knowledgeable in plastics has another suggestion designed for a type of plastic not yet tested, please give a shout.

Bummer, man.

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Two words: DUCT TAPE

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AKA: Simon

Have you ever tried to "pin" it with little peace of vire and use Quality CA glue (For example Eurobond)?

Chears

Akos

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"12 Cheeseburgers and a Light Coke please!"

CA glue, baking powder, sanding and touch up with some paint, its what I do with my warhammer stuff when stuff snaps

Using grooves with metal reinforcement is in the plans (I think that is what you mean by 'pinning' it) but still, the problem with CA glue is it doesn't flex. Sure, it looks good and clean at first, but the minute you spread the headset back to fit around your head, it will snap.

I am looking for something that basically melts both sides so that a re-fusion occurs in the plastic and maintains the semi-flexible nature of the plastic headband.

Isn't there a steel band inside the plastic cover (that goes over your head) or is that the part that's snapped?

Harry

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Yeah it snapped right at the base where the steel starts. There is a tiny 'nub' where the steel can still be inserted just enough to hold in place while the glue dries, but once I stretch the headband over my big mellon, it just re-brakes. You can even scrape out the glue residue with your fingernail as nothing truly "bonds" to the plastic.

Have you tried melting it slightly with a candle (ideally a lit one) and quickly pressing it back on?

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AKA: Simon

What about scoring the parts that re to be glued together? Just take a knife and cut multiple small grooves into the pieces that need to be re-attached and use whatever adhesive?

For an adhesive I might suggest JB Weld. It has iron inside of it and I believe it has a tiny amount of flex to it.

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"Awww, someone tell me that's a boot!

It's a boot!"

III drops

Hot glue?

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AKA: Simon

I found my other half (cracked head band) finally.

Nothing works.

I suggest a small piece of metal underneath with some screws.

Then wrap with duct tape.

Try UHUPor!

It is an adhesive good for plastoc, and metal aswell, and it is flexible.

Cheers

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"12 Cheeseburgers and a Light Coke please!"

Sorry it took so long to post the pic of the actual 'break' but this is what I am dealing with. Also I tweaked the title of this thread to focus on "repair" rather than composition of plastic.



The break is where the slits for the metal headset adjustment begin (the weakest point by far as above it is solid plastic and below it the adjustable metal band fills in the slits). This no-mans land is never ever going to be glued in pace. The contact points are too small for the amount of pressure put on them from both sides.



After abandoning simple glue, if figured why not try melting it as suggested earlier? Nothing to lose right? So I cut some small slices of steel to 'fill in' the empty slits and hopefully provide reinforcement. I then used a butane lighter and strategically melted the fragmented parts back into place. It sort of worked.



It was strong enough to put back on the small styrofoam head I had displayed it on. So that was something! Of course I had to press my luck and try it on myself...snap.

So again I melted everything back into place, THEN wrapped it tightly with fiberglass twine and glassed it.


I checked on it this morning and it feels decent. I will sand and clean it up tonight. I am cautiously optimistic this repair will hold. I will of course update how it turns out.

So far so good. I didn't sand too heavily as I didn't want to remove too much of the material that is actually holding it together, but I think it worked!



I put it through the paces of adjusting it, putting it on the mannequin and myself and removing it several times. It made just a little cracking sound the first time I spread it to fit over my melon, but it didn't creek or crack after that and seems to be holding strong. I lost about 3/4" of adjustability on the broken side because that space is filled with metal and fiberglass and it aint pretty, but it is usable again. (at least so far, knock on wood)

Did something I suggested actually work??

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AKA: Simon

I would suggest using a bit of black shrink tubing to cover up the repair work, but that would take away from the "screen look". Plus you might not be able to do that since it's all assembled now.

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"Awww, someone tell me that's a boot!

It's a boot!"

III drops