Plastic panel repairs

[Blackbird]

I have a friend in the UK who recently hit a seagull at speed and did some damage to his fairing. He decided to have a go at his own repairs and they turned out very well. I've "borrowed" the write-up from his website and converted it to a PDF if anyone wants to experiment with repairs or modifications. Who would have thought that plastic coat hangers are practically identical to the plastic used on bike parts? (Makes sense when you think about flexibility and strength considerations).

[bert_is_evil]

I can see how that would work but how do you get it flush on the front, does it just flow into the join? if so how hard is it to sand back?

[Blackbird]

Will email my mate and check for you.

[bert_is_evil]

Will email my mate and check for you.

Thanks Blackbird!

[Blackbird]

I can see how that would work but how do you get it flush on the front, does it just flow into the join? if so how hard is it to sand back?

Emails are truly wondrous things and my mate in the UK just happened to be on line. Here is his reply and hope it makes things a little more clear!

Cheers

Geoff

The answer to the query is simple; you don't allow the finished side to melt. The repair is done on the non-visible, inner side, and the plastics are only melted far enough to weld the inner half, or so of the depth of the plastic. So, this works great for clean breaks, where the two broken edges mate perfectly. If there's any distortion, from the damage, or missing sections, then this form of welding won't do an invisible mend. If you look at http://www.flyingferrets.eclipse.co....es/dales06.htm, the first photo shows a plastic section that's been added to plug the pheasant hole, just under the mirror stalk. The alien plastic panel has been welded in but does not form a cosmetic solution - purely to make the fairing weatherproof. Basically, if you can hold the two broken edges together and not see the break, then this'll work perfectly. If not, then you're into in-filling with the coathanger plastic (for small gaps), rubbing down, and repainting, as your aquaintance surmises.

The plastic that fairings are made from usually break cleanly and sharply, so lend themselves to this form of repair. Provided you can recover all the missing sections - some of my fairing bits just fell onto the road and were lost!

Hope this helps,

Clive

[bert_is_evil]

Thanks for that, think I'll give it a go

[vifferman]

Handy hint, Geoff!
I have a comment, though; there are several kinds of plastic coathangers here. I've seem both soft semi-flexible ones (polyethylene) and more brittle ones that are presumably PVC or similar. I know that fairing panels are almost always ABS plastic now, of the kind used in refrigerator linings and for wing mirror housings. If in doubt, I'd suggest getting some discarded broken fairings or plastic bits from a wrecker, rather than risk using the wrong kind of plastic by Sammy Coathanger.

[Blackbird]

Good point - might well have a play myself for future reference. Let me know if you're motivated to have a tinker.

[bert_is_evil]

I read in another thread that Lego blocks are perfect - just googled them and it seems they are ABS. Now, who do I know with kids.....

[Pixie]

Handy hint, Geoff!
I have a comment, though; there are several kinds of plastic coathangers here. I've seem both soft semi-flexible ones (polyethylene) and more brittle ones that are presumably PVC or similar. I know that fairing panels are almost always ABS plastic now, of the kind used in refrigerator linings and for wing mirror housings. If in doubt, I'd suggest getting some discarded broken fairings or plastic bits from a wrecker, rather than risk using the wrong kind of plastic by Sammy Coathanger.

The brittle ones will be styrene of some form.This is probably the cheapest type of polymer.ABS is Acrylonitrile Butadiene Styrene.
You can buy plastic welding rods of all kinds from Techspan in New Lynn

[Attract Promotions]

My regard for Pixie increases. Acrylonitrile Butadine Styrene.
Great post Blackbird, wanna practice on my old farings?
But to further your post..... I reckon a good way of testing if it's Lego plastic is to make like a 2 year old and bite em

[Blackbird]

My regard for Pixie increases. Acrylonitrile Butadine Styrene.
Great post Blackbird, wanna practice on my old farings?
But to further your post..... I reckon a good way of testing if it's Lego plastic is to make like a 2 year old and bite em

Pixie's a good guy alright - helped me out with an accidental disconnection problem I was having with my radar detector helmet speaker a year ago.

Errr.... no I don't want to practice thanks unless I bin my B/B then I'll practice on yours to stop ruining mine

[Kflasher]

True I had done very similar with my Ducati fairing, being a PVC plastic (same stuff most gutters and downpipes are made from) I over filled the crack sanded flush and sent in for painting. All done with soldering iron and smal cut strips of downpipe (thanks to my landloard), By the way I have old fairings of a ZX7R if anyone needs scrape to play with. (just PM me)

[Pixie]

TECHSPAN NEW ZEALAND
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Phone ++64 9 8276567 Fax ++64 9 8276596
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They sell plastic welders too

[Clive]

Hi all, I'm the friend of Blackbird's in the UK who started all this, thanks to him 'pinching' my article But then, what're friends for

I don't pretend to know a great deal about plastics, and was only presenting the results of applying advice I was given. So, to add a little bit of clarification, the coathangers I used were the brittle ones, which I believe (but don't quote me) are some form of ABS - as are most fairings. They certainly worked fine for me on this one application.

The other thing I wanted to do was to point out that Blackbird pinched the article before it found its final form. One thing that's missing from the PDF given on this thread is the actual use of the plastic coathanger - A bit of an initial oversight, I admit! There's also a bit more advice on using alien panels, to fill-in for missing sections, where a good cosmetic finish is not necessary, like when you're waiting for replacement parts on a long lead-time, as I was.

If you want to see the original page, and hence the latest version, then pop along to http://www.flyingferrets.eclipse.co....dy%20parts.htm

Finally, I'm indebted to the providers of the technical plastics knowledge, and the pointer to Lego blocks Next time (hopefully a very long time off) I'll give them a try.