Idea for crack repair on plastic - will it work?

[Huffa]

I have no idea if this would work: Got some old red plastic lying around that matches a 200S. Got a 3+ inch crack in rear fender. I'm thinking of epoxying a plate (for reinforcement) underneath the crack so it won't crack anymore then (this is the part I'm not sure) take a piece of the spare plastic, completely melt it down in a jar and pour it on the top portion. Let it set up and sand down to blend in.

Would this work?

I can easily just rivet the plate underneath also but that won't hide the crack and you'll of course see the rivets.

[atczack]

I would think the plastic on either side of the crack would have to be heated almost to the melting point to get the melted plastic in the jar to adhear to it, not sure though. If you figure out the solution you can repair all the crack's in my fender's!

[Huffa]

I would think the plastic on either side of the crack would have to be heated almost to the melting point to get the melted plastic in the jar to adhear to it, not sure though. If you figure out the solution you can repair all the crack's in my fender's!

Yes .........agreed. I no sooner posted it and thought of that too. If it works I'll start a new plastic repair buissness. Maybe we should write to the company Plastic Renew and ask them to come out with such a product.

[kando]

I was just wondering if anybody ever tried somebody who welds plastic for a living if they could repair it.

[chris200x]

Hey huffa if you would take the red tape off my headlight on the top. That is exactly what that guy tried to do. It is held together solidily but he never took the time to sand it down with fine sandpaper. Looks like maybe he used 80 grit and that was it. I was just going to cover it with some sort of sticker or something. But to answer your question yes It will work. But lets face it...cracked plastic and atc's go hand and hand.
I have also heard of people just drilling two small holes at each end of the crack to prevent it from spreading more.

[faf_racing]

here is my bright idea and it did work, got this epoxy at the auto store for plastic and fiberglass filled the crack and heavily coated the crack with baking soda let it dry then when GOOD and dry lightly sanded to my satisfaction!!

[straight pipe]

i had cracks on my rear fender and there was a missing piece as well. i had the piece that was broke off. what i did and you can try this too.i plastic welded it in place. simple at home welder is a small flat screwdriver and a plumbing torch..clean the area well with soap and water---heat the screwdriver tip red at first to heat it up---let cool till the glow goes away---as soon as it does start stitch welding the plastic by pressing into the crack about 3/4 way deep of the thickness---pull out and go lower and repeat.....when you are done it will look like a train track. do this on the back side. remember a tip that is too hot will discolor the area welded badly and will also stretch the plastic too. take it slow and be aware of what you are doing at all times...when you are done the back side it should be prety strong. to smoothen the weld up i heat the tip and rub the weld with the hot end and smosh the plastic together until smooth.
on the outside of the crack i heat the same tip and use the edge of the flat screw driver to stich weld....this welds it together and makes smaller marks to smoothen off later when i am done++++ another tip is the screwdriver i use has been spooned out a little...kinda shaped like a banana. the curved area helps me smoothen the stitch easier......++++one more...when done the outside crack you may have some spots that are a little bumpy. i use a new one sided razor blade and scrape the area with quick motions till smooth. and polish when done. my rear fender turned out great and is as strong as it was before......and if you are wondering "yes" i am a bodyman and do plastic weld in occasion for a living.