Fixing plastic

[aharbi]

Looking over the bike the other day and I noticed fine haireline cracks around the mounting bolt on the lower left fairing. Stress cracks? (ignore the spring bugs)

http://i278.photobucket.com/albums/kk100/aharbi/Motorcycle/IMG_0643r.jpg

 

So I removed the fairing, they appear tobe worse than originally thought

http://i278.photobucket.com/albums/kk100/aharbi/Motorcycle/IMG_0642r.jpg

 

and to add insult to injury, I noticed this as well when I removed the lower fairing

http://i278.photobucket.com/albums/kk100/aharbi/Motorcycle/IMG_0641r.jpg

 

Any ideas on how to fix both the cracks and repair the "push fitting'? Anyone have experience using this? Does it work?

http://i278.photobucket.com/albums/kk100/aharbi/Motorcycle/IMG_06481r.jpg

[ACE50]

That will work. Just make sure you get paint off and down to plastic.

[Marcarl]

I would use Plasti-fix.

http://www.urethanesupply.com/PlastiFix/

[bongobobny]

If you can get to the back side of the cracks, take a dremel tool and make "V" cuts along the crack. This will give you a lot more bonding area as opposed to just between the cracks. For the push fitting sand the areas all around the broken area so that you can fill the entire area with the 2 part epoxy stuff making in essence a solid block instead of a three sided wall. If you don't sand and remove the paint it will not bond properly.

 

The nice thing about the bike being white you can repaint the piece with a can of spray PLASTIC paint and it will match quite well...

[rougeray]

I repaired a broken trunk latch bracket using Devcon Plastic Welder. For the push fitting spread the Devcon liberally allow it to become tacky then place the push pin where it broke off. Give it 24 hrs and you should be good to go. The bracket I repaired has held for over a year. I'll take a picture of it tomorrow. As for the other stress cracks I think they are due to the crash bar being bent. I would make an aluminum doubler and attach it behind the cracks using the plastic welder. Agin spread the Devcon liberally then press the doubler in place. You could also fiberglass the cracked area but I would try the Devcon first. When putting it back together make sure everything aligns properly so there is no stress on the fairing.

[Venturous Randy]

Ditto on Devcon Plastic welder. I have had the best luck with this stuff.

RandyA

[aharbi]

... As for the other stress cracks I think they are due to the crash bar being bent. I would make an aluminum doubler and attach it behind the cracks using the plastic welder.

 

I don't recall the crash bars ever being bent, at least not during my ownership, it looks straight to me. But who knows about the PO. How would I know? or what should I look for?

 

I don't know what you mean nor how to make an aluminum doubler? I would appreciate more information, or a picture. Thank you, I appreciate the help.

[Wizard765]

Carbon One actually makes braces to beef up the roll bars

[saddlebum]

I would use Plasti-fix.

http://www.urethanesupply.com/PlastiFix/

 

:sign yeah that:Also sells under the name Plastex depending on the supplier but they are the same product and work excellent. I rebuilt my 89 with it in 2008 and 6 years /30,000 km later it is still is in great shape. See the thread below post #1 shows finished bike. Post #15 shows smashed up bike and some of the Plastex/PlastiFix repair work. Note the white tabs formed purely of white Plastex/PlastiFix using the included mold block. Also good for reattaching or forming pegs. When reattaching fill the entire void as Bobby suggested. I also embedded fiberglass drywall tape or fiberglass cloth wherever I could to reinforce the repairs. The stuff sands out silk smooth after a 20 - 60 minute cure time (no filler putty needed) and if you have any little pit marks just add more and re-sand. One last note the product does not act as a glue but actually welds the plastic together.

http://venturerider.org/forum/showthread.php?t=28291

Edited March 28, 2014 by saddlebum

[bongobobny]

What you are discovering Aharbi, is that there are several ways to do it and everybody insists THEIR way is the best...

[jet3279]

If you can find this stuff, use it! Its a 2 part powder and adhesive. My matco tool salesman has been selling it. Most amazing stuff I've ever seen!

 

Sent from my SPH-M930 using Tapatalk 2

[aharbi]

What you are discovering Aharbi, is that there are several ways to do it and everybody insists THEIR way is the best...

 

That's what I love about this site. The willingness to help and share their personal experience. I like to review them all and pick my options based upon what my skills require. There's always more than one way to "skin a cat". Thanks everyone, appreciate the help.

[joekay]

I had a crack at an attaching point in my lower fairing below the radiator that I bonded together with ABS cement that is used for plumbing fittings. Once bonded, I applied multiple layers to add strength. No issues after a year. Unlike the glues made for plastic, ABS cement actually melts the plastic so it can be reflowed together. There are ABS plastic sheets available in .060", and pieces can be cut and successively bonded in layers to make a structure.

[davide62]

Use Gorilla Glue and some drywall mesh. Paint on the glue (with an artist brush) and watch it bubble all over. When it dries, it is easy to cut off the excess with a utility knife. Gorilla glue will get into those nooks and crannies and seal it up good. the key with the glue, is to lightly wet the areas that you will be gluing with water first. Good luck.

[Ace]

If you can find this stuff, use it! Its a 2 part powder and adhesive. My matco tool salesman has been selling it. Most amazing stuff I've ever seen!

 

Sent from my SPH-M930 using Tapatalk 2

 

I used this stuff to rebuild the plastic on my buddies '84 GL1200, it is amazing stuff but a word of caution, it bonds instantly!!

[Evan]

:sign yeah that:Also sells under the name Plastex depending on the supplier but they are the same product and work excellent. I rebuilt my 89 with it in 2008 and 6 years /30' date='000 km later it is still is in great shape. See the thread below post #1 shows finished bike. Post #15 shows smashed up bike and some of the Plastex/PlastiFix repair work. Note the white tabs formed purely of white Plastex/PlastiFix using the included mold block. Also good for reattaching or forming pegs. When reattaching fill the entire void as Bobby suggested. I also embedded fiberglass drywall tape or fiberglass cloth wherever I could to reinforce the repairs. The stuff sands out silk smooth after a 20 - 60 minute cure time (no filler putty needed) and if you have any little pit marks just add more and re-sand. One last note the product does not act as a glue but actually welds the plastic together. http://venturerider.org/forum/showthread.php?t=28291

 

 

Pus one from my own experience

[AKRefugee]

Like bongobobny said, “there are several ways to do it and everybody insists THEIR way is the best”. This past winter I had some plastic repairs to do on my bike. Before doing so I read up on it and found a lot of different ways to do it. I selected several different ones, and one I made up, and tested to see which actually worked best. For each result I tried it two time. I used a dremel to clear all paint and dirt from all surfaces. All work and curing was done at room temp of 72F. I gave every result two full days to cure before trying to break it. I did not have the equipment to measure the breaking point so the breaking point is subjective. Here are my results

 

1 - Soldering iron and a plastic tie wrap

this was probably the worse method I tried. The results were quite messy in appearance and the strength was horrible. Even when reinforced with metal paperclip or heavy gauge wire it was still weak and very easy to snap apart after the repair. I was able to easily break it apart with just my fingers. I found this method to be totally unacceptable.

 

 

2- PLASTEX

I found this quite great for making missing parts however it didn’t work very well as a bonding agent between two parts. The agents did not seem to penetrate into the materials being bonded. Was just slightly better than method 1. It was easy to get the appearance looking good. Found this method to be inadequate for repairs but great for making parts.

 

 

 

3 – Slurry made with acetone and ABS parts

This method involved making a slurry using acetone and pieces of ABS pipe. It took about 24 hours for the ABS parts to melt. And then I added more acetone after 24 hours to get the slurry to the consistency I wanted. I set the consistency between the consistency of cold syrup and toothpaste. I did not measure the acetone or parts so I cannot tell you the ratio. The slurry bonded well with the two parts however there was some air bubbling in the repair. I think this had to do with the slurry generating some heat when it “melted” the two parts together. It was also easy to get the appearance looking good. The strength was ok. I had to use several fingers to break the pieces apart and after doing so was able to easily see the air pocketing inside the repair. I considered this method barley adequate. Ok for points that have little to no stress.

 

 

4 – Loctite EPOXY – PLASTIC BONDER

This is a two part epoxy that you mix together before applying. This also does some “melting” of the parts however I did not find the air pocketing like I did with the slurry. This method requires you work fairly quickly to smooth out the surfaces to get a nice appearance but it was not difficult to get that nice appearance. I was not able to break the bond with my fingers. I had to press quite hard against the part with the heal of my hand. I considered this method quite adequate for parts with low to moderate stress loads.

 

 

5 – Mixture of Slurry made with acetone and ABS parts/ Loctite EPOXY – PLASTIC BONDER

I made the slurry the same as above but this time I mixed it with the epoxy. The ratio was about 50/50. This was by far the best. It bonded extremely well with the parts. It was easy to smooth the surface before it dried for a nice appearance. This required the use of pliers with me pushing all my weight down and using the corner of my tool box at the repair point to get it to break. I did not find any air pocketing. I found this method to be excellent for parts with high stress loads.

 

 

So which one will I use? Well other than method 1 I will use them all. It will depend on what I want it to do and what stresses the repaired will be under. Will you get the same results? I have no idea. All I can do is share my results. Good luck on trying to decide how to do it. Hope you are successful in the repairs.