plastic welding?

does anyone know anything about plastic welding? I've got a crack on the mudguard of my new bike, a new mudguard is about £30, is it worth getting a new one or to weld it?

 

I know a lot about plastic welding, occupational hazard you might say.

£30 for a new, genuine, colour matched, ready to bolt on mudguard? I'd say buy it.

You could always pick up a cheap soldering iron for £5-10 and have a dabble on your old mudguard anyway. But once you add in paint, filler, time spent. You'll be on or over £30 either way.

That said, if it's only a crack then you could fix it from the underneath and not disturb the paintwork.
A better option might be to buy some polystyrene cement, carefully widen the crack by flexing the fender and running a thin trail into the gap then strapping it in the desired position.
Poly cement will breakdown the plastic and cause it to fuse with itself.

Ebay soldering irons are ideal for occasional use jobs, unless you're overly flash with cash or very lucky it's hard to justify the cost of a proper plastic welder for the amount it's used.

 

il second that.. i use a £6 soldering iron for plastic welding , i also have a weller gun type soldering iron that has plastic welding tips that i aquired from my father in law... but as skortch says, at 30 quid for a colour matched item you are much better off buying it , or if the crack isnt too bad try the polycement..

 

would upvc superglue work Dave?

 

Mebbeh, never used it. Probably not as well as poly cement.

Cyanoacrylate is an adhesive, with a low sheer strength so could be 'undone' fairly easily.

Whereas Butanone is a solvent that breaks down the surfaces before evaporating and causing them to set in a bonded state, so is more closely related to a welding agent.

 

just a note , if your going to use polysterene cement, clean the crack with isopropyl alcohol first , then give it a few mins for the fluid to evaporate.. just in case any road grime, oils etc has worked its way in there which could possibly cause issues with the glue not bonding the plastic properly.

 

Where's the advice about using Duct Tape ...

Oh, probably because Tom still at work...

 

oh right, thanks everyone, i'll see what i can do with the old one, if it doesnt work i'll go for a new one

 

Have u tried Butylcryokryptonite ? Melts superhero's I think...