Any way to mend smashed plastic?

[Cutty72]

Originally Posted by derf

You could try plastic welding, but it doesnt really hold up in the long run, maybe some duct tape would work?

I'm with the Jew... duct tape.

[Papa_Complex]

3M plastic repair and fibreglass mat. The 5885 works well with motorcycle plastics.

http://www.toolrage.com/prodview.asp?sku=3MA-5885

http://www.youtube.com/watch?v=gMr9aJ-j0NQ

[Kerry_129]

There are many ways to skin that cat, several good ones already mentioned.

Problem w/ plastic-welding, there's a fine-line between good penetration/adhesion & over-melting/distorting the plastic. Takes far amount of practice/feel to get a good quality repair - and you gotta buy a tool.

Various adhesives/epoxies can also do a good job - but they're still just gluing the pieces back together. I've used Devcon plastic repair epoxy with good results (~$3, WallyWorld), That 3M stuff PC posted would undoubtedly work great & also work as a sandable filler to prep for repainting - pricey though. Stay away from fiberglass-reinforcing resin - not good for adhering to ABS, and far better products available.

My favorite & IMO by far the best product for crack-repair is acrylic powder/solvent (I forget the chemical name). Cheap, easy to use, quick, no particular skill required - and most importantly STRONG. Like at least as strong as the existing plastic strong, since it doesen't just adhere to the pieces, it chemically fuses to them & the cured powder seems to be a bit stronger than regular ABS (made a test piece, and the plastic broke before the repair did).

The two brands I've used are Plastex (expensive), and http://www.plast-aid.com/ - from what I have read, it's the same stuff as acrylic nail powder/solvent avail @ beauty supply places, but the cost is similar & I figure the stuff specifically for plastic repair might be a different formulation/strength so I went with that.

My bro & I are resurrecting a CBR & just last weekend repaired a tail fairing which looks very similar to the damage you posted. He did a great job with it in an hour or so with zero prior experience. I'll try and remember to post a pic this evening. It will still need a bit of filler/high-build primer to complete the cosmetic repair on the outside - but the strength & ease of the structural repair is unbeatable, IMO.

[Papa_Complex]

I've seen the 3M stuff used to rebuild recessed fairing mount points, that were completely ground away in a lowside.

[Kerry_129]

Ditto with tabs & such using the acrylic powder (forms a putty with a few minutes work-able time) - the guy that turned me onto it used it to fill the headlight openings on his wife's SV, making it a 'track fairing'. I don't doubt it's an excellent product, though a bit pricey - I'm not aware of anything 3M produces which isn't on both counts.

[Papa_Complex]

Right on both counts

[101lifts2]

You going to Willow?

[derf]

Originally Posted by Kerry_129

Problem w/ plastic-welding, there's a fine-line between good penetration/adhesion & over-melting/distorting the plastic. Takes far amount of practice/feel to get a good quality repair - and you gotta buy a tool.

I dunno, I had a very easy time learning, the part in the thread below eventually did crack again, but it took 2 years and at least one crash. I aways felt that the welded area felt more brittle though and any decent bump or jolt has the ability to break it. I wish I knew where I have the photos with my CBR fairing fix on them, but here is my old ex500 with the repair I made.

so last season my lower fairing decided it didn't like staying in 1 piece and found itself a brick to crack itself with, pics in this thread:

http://www.ex-500.com/index.php/topic,2082.0.html

Anyway i went out this week and grabbed a plastic welder to try and fix it, well fix it i did...

I went out and bought the plastic welder today, and tried it out for the first time.

Wow it is easy. I think knowing how to tig helped out alot as it is very similar.

I was able to fix a rather large crack across the lower part of my bodywork that basically split it in 2 except for a two inch section. I also fixed some stress cracks around a mount point, which probably came from the same brick that broke the rest of it.

Anyway got the welder homehooked it up to the compressor, plugged it in and and went to town. First i grinded down the crack and took off some paint about 1/2" away from the crack, and heated it up with the welder, then I heated up the rod and mixed the 2 together.

After I was done adding filler plastic I took my sand paper and rubber the filler down to the same level as original plastic. I noticed that the filler rod definatly joined the 2 pieces together good, but I did melt away a little too much plastic in some places, not bad, I will just fix the rest with body filler.

[derf]

Ok found it: gonna copy paste from another forum to a new thread here.

If you are interested in plastic welding here it is

http://www.twowheelfix.com/showthrea...470#post459470