Sticky-backed plastic comes Of Age

Dick Henneman

There can't be many, if any, modern bikes that haven't got something made out plastic on them somewhere. And that being the case, Murphy will sooner or later decree that a bit of it will break. As an extension to this well known Irish law of contrariness. the bit that breaks will be a part of the most expensive plastic component on the bike.

So what do you do?

Well, the "rich kids" go down to the local dealer and order a new component; the less well-to-do, ie. you and me, start calling the breakers, searching for pattern parts and looking for someone who does plastic welding; while the paupers amongst us use gaffer tape and tie-wraps to bodge the whole thing together and hope no-one will notice. And more importantly, nothing falls off.

Now if you've got a teenage daughter with a 50cc scooter like I have (do you want one? - comes as a complete package, no reasonable or unreasonable offer refused), then eventually there's going to be a spill and bits of broken plastic will appear. She's had a couple of 'incidents' in the three years she's been riding, but all the damage has been cosmetic and pretty easy to rub out and polish up. Then the other week, some caring individual drove their car into the back of her scooter, knocked it forward off the centre stand, and then drove off without a care in the world. Fortunately, the scoot was undamaged mechanically, but the left side of the plastic panel below the seat was cracked right across, with a piece broken out of it, and three plastic fastening lugs had been snapped off.

As she's still at college, a student grant was not going to pay for the cost of new panels from Peugeot - the sticker kit alone costs over £70! - so it looked like the local guy who welds bits of plastic back together again was going to see some extra business. And then I remembered that there was this 'plastic repair kit' that was supposed to be able to mend virtually every kind of hard plastic around, including carbon fibre! Got to be worth a try. And because I don't want to keep you in suspense any longer than necessary (undue stress is one of the biggest killers in modern society), I can say that it really does work.

Plastech repair kits come in three sizes; the Handy Pack that costs around £10 (this is the one that I bought); the Garage Pack for around £30, so you can mend your mate's bikes as well; and the Workshop Pack is about £70 for those of you who have a really big thing about lots of broken plastic.

What I got for my money was a small pot of very fine, free-flowing powder, an applicator bottle of extremely pungent aromatic-smelling liquid, a needle to fit the bottle, a stick of a strange rubbery material called a moulding bar (more about this later), and some instructions. And this is how it works.

You fit the needle onto the bottle and squeeze one or two drops of the liquid into the powder. This forms a small bead of powder which you can pick up with the end of the needle and transfer to the parts to be mended. Squeeze the bottle again and the bead will liquefy and run into the repair. Hold the parts together for around 5 minutes to allow the "glue" to set, and then leave to harden fully for another 25-30 minutes. The material has excellent gap-filling properties and can be used to fill holes and even replace 'missing' pieces of plastic. Cracks and splits are repaired by filing a V on the inside of the join and then filling the groove with the Plastech material. You can even repair threads with the stuff.

The moulding bar can be used to take an impression of a part, and then a new piece made using Plastech to fill the mould and then attach it on to the damaged part. I used this method to replace one of the broken lugs which had somehow not made it back to my workshop with the rest of the scooter.

When everything's fully set and hardened, say about 60 minutes, the material can be filed, sanded and drilled to finish off the repair, and then re-painted if necessary. The resulting job is just as strong, if not stronger than the original component.

So the next time you have a problem with some broken plastic, don't throw the whole lot away and then go looking for replacement parts. There's a very good chance that a little time spent with a Plastech repair kit can have everything back together in one piece for a lot less than a pattern or even a secondhand part.


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