How to Repair Plastic, Part 1

part two? ..

 

No time Go4...

but will answer questions.

BZ

 

ornin bz.

i would assume the proccess for broken parts is the same as cracked? tho perhaps use a stronger material to reinforce the back? wire mesh for example.

the whole part with the front turn signal is broken off of mine.

how do you go about fixing scratches and gouges?

 

Plast-Aid is really strong stuff Go4. It works really well.

If however you have a massive crack you can do all the prep and lay a piece of screen (wire, plastic, fiber glass-I think fiber glass would be easiest to cut and use) down on the area to be prepared and pour the Plast-Aid on and let it set up.

As far as little pieces, put them all togetehr and make sure you have 'every' piece, then we can figure out the next steps.

How do you fix scratches and gouges? I don't LOL!

Regular old bondo would work for that. Again, surface prep is key.

Post up some pics of the damage in a new post so we can see what we are dealing with and let us all argue over how to do the repair best!

BZ

 

Bubba,

I used Plastex, I blieve a similar product you used with a different name. It filled some cracks great but I had to join two piece and if failed reall bad. Your thoughts?

 

Hey Randy:

Well my knee jerk reaction is either something in your surface prep was off OR you did not use enough product.

But since you strike me as a guy who reads the directions BEFORE you use a product. (I base this on you a Canuck and not American. That’s why we have forums to ask questions because we don’t read manuals or directions LOL!).

1. OK, Did you sand the surface at least 3 inches out from the crack with 100 to 80 grit sandpaper?
2. Did you clean the surface off with acetone? And then did you let it dry or the solvent flash off?
3. When you poured the product on did you give it enough time to ‘set-up’ and not move the piece?
4. Was the crack in an area of high stress? What I mean is the crack in a bend in the plastic that when put together held it in a certain shape?
5. How much product did you use? Just enough to cover the crack or did you spread it out over the crack and three inches out if possible?
6. Is the product compatible with ABS plastics?

Sorry for the questions, let me know.

BZ

 

I've used PlasTex to make new side tabs to hold on my tail section. Also to repair a mounting point on my fairing. It's been over a year and 3300 miles. Everything is fine. If I didn't find this stuff I'm not sure if I could have fixed the tail section tabs. I've used this on other little projects with great success. It doesn't really work well if the plastic is the nylon type slippery plastic. For ABS material it works very good.

Randy may be something in your prep went wrong or you didn't leave enough space between the two pieces. You should cut a groove between the two so the Plastex to fill and bond with both pieces. What type of plastic is it? May be something that it won't work with.?

 

Well Bubba and Grey, You have restored my faith. I will have another go at it when I get back from the Olympics in March. Bubba, I did follow the instructions as per the product but can't say I follwed your proceedures. Guess what I will try next time. As far as the plastics type, it is the fairing so I think that is ABS am I correct? Now Grey, you raise a point. I did cut a groove as per the instructions, but hte peices did join together tight. other than the actual goove. I let that set up for about 12 hours then flipped it over a did the same on the reverse side, cutting a groove there as well. The portion I tried to join is the very narrow neck near the side stand on the left side. It must be something I did wrong cause I have heard nothing but praise about this product. Don't sneeze around it though. Talk about a finely granualted powder.

BTW...I did this repar the day following my stripping the threads on my oil pan. Am I painting a picture here?

 

Randy:

Thanks for the additional info brother. The ‘procedure’ is as important as the directions LOL!

Your fairings are ABS plastics. It’s rare to have OEM fairing on sport bikes be something different. Aftermarket yes or possibly so and ATV’s and dirt bikes for sure.

Another tip is once you have the product spread into place take a small piece of fiber glass screen (the kind used for screen porches) and imbed that into the product. This will add more strength to the weld. Kind of like re-bar in concrete. Cut the screen just under the size of the whole repair so none is sticking out.

Keep us posted!

BZ

 

Hell just go with the re-bar. It don't break. I know I seen re-bar once. She sings real good!! :blabla::focus:

 

Bubba,

To imbed the screen in the product, you would have to sand an indentation fairly deep into the plastic otherwise you would end up with a bulge similar to a mud line on gyproc walls would you not? Or are you suggesting this screen re-inforcement go on the inside of the faring?

 

Sorry Randy, yes the screen would go on the inside (i.e. the side you don't see) that faces the engine.

BZ

 

Bubba,

Right on about that removal of paint several inches back from the repair, V grooves ect. Next time you are messing with all this, try MEK instead of Acetone for final prep.Methylene Chloride works but that is some bad juju even in limited exposure. Another couple of tips: Nothing wrong with a little dealership dumpster diving for some scrap ABS for fixes.
Almost any screenwire works as a reinforcement patch. Some is even ABS. The best firbreglass cloth I have found for those really bigass repairs is the triaxial weave. For holding stuff together when everything from medical clamps (yuppie roach holders) C clamps and clothespins fail or when the busted part is like those *&^%$$ seat tabs that break, a lil dab of gel type superglue works wonders. Just a dot or three to hold the parts in place before application of the working adhesive.

I have not found any of the "Bondo" type mixes adhere to ABS. They all eventually fail by just debonding.

Not much help here as far a VFR's are concerned but if somebody lives near a roadrace track, most of the guys that have streetbikes that are converted to serious racebikes use fibreglass fairings and don't have much use for the ABS anymore.

Good stuff..

 

Thanks BB, but MEK?

Bad juju is not the word brother. That solvent is only good for cutting coal-tar epoxy and washing the Sudafed pills in making meth. LOL!

BZ

 

Agreed, too much up anybody's nose will make a meth.

Can't buy Sudafed over the counter here. Oregon seems to be the meth capital of the world. The idea is good prima facie. The author of the legislation cops votes from the "save the chirruns" crowd in his or her next campaign but in reality in the streets that very legislation creates a flourishing black market for the little "brown not blue" pills.

MEK is "the" solvent for ABS. The main component (fraction) for ABS pipe dope. The main fraction in paint remover and small amounts are added to too many brands and types of rattlecan paint as an anti caking component. Another saving grace bad as the shit is, is that it's not flammable.

 

Randy here's some fixes I've done. They have held up fine...so far. If you go on their site they have tips for repairing. If your panel is broken in half, then I would think that the fiber glass screening or like is a must. When you get it done let us know how it worked. Info from experience is the best.

 

So the trick then is Bailies in the coffee. I shudda known.I'm going to be gone from the house for a month so nothing is being done for now. But I will let you know how it turns out. I make lots of mistakes...but only once.

 

What a great thread! Thanks, BZ! :smile:

 

don't use the glass bondo for repair there is better shit out..... go to your local auto body shop and get their blue 2 part puddy.... its made of mostly rubber and is sand-able. I used it on pqatching the 5 th gen signals.... If u use the fiberglass bondo or crappy tire bondo brand it will re crack due to heat and it isnt as flexible..... I went thru this last yr....... with one yr the crack Will come back thru your paint.

 

I tried getting some of that Plast-Aid a wile ago but they don't ship to Canada. I used the plastic weld 2 part epoxy (same one in the picture). Only problem is that there isn't a whole lot of it in that package. What other glues are out there?