How to Repair Plastic, Part 1

Here it is! The first in a 3 part series on how to repair your damaged plastic. I am braking into 3 parts because…well I have a lot of ground to cover.

Part 1 will cover small repairs in hard to reach areas (i.e. when you don’t want to remove the whole fairing to do the repair).

Part 2 will cover larger area repairs, like a fairing almost snapped in two, as well as strengthening areas were a “stress” crack has appeared.

Part 3 will cover paint prep and painting!

Ready? Here we go!

The high majority of motorcycle plastic is called ABS (acrytlonitrile butadiene styrene) and you can normally find the ABS letters printed somewhere on the ‘inside’ of a fairing where the product codes are located. The great thing about ABS plastics is many, many, many products can bond it together and it even can be welded with a plastic welder.

OK, so you purchased a 97 VFR like me that was laid down and has the following cracks in the upper and mid-fairings





The plastic can be pushed back together and it still lines up! Well let’s get to work! Remember, if a fairing is smashed to a thousand little pieces, just get a new one!

You’ll need the following items:

80grit sandpaper
Quart of Acetone (for wiping prepped surfaces)
Clean cotton rags
Plastic repair product (of your choice)
Applicator to apply repair product

Now there are many plastic repair products to choose from that bond ABS (look at label to see if it will!) and cost ranges from 5 bucks to the 120 dollar product Tbones talked about that comes in caulk tube form. It’s all in what you want or can afford. But I warn you all to read the labels and directions and FOLLOW THEM! The product I am using for today’s repair is called “Plast-Aid”, the product all the way on the left.



And it can be ordered from a small place in Colorado (970-577-1000 or www.plast-aid.com). I like this product for three reasons. One, it does not break the bank (20.00 dollars for the kit I purchased). Two, it bonds to ABS like…well insert whatever phrase you want LOL! And three, its cured in 15 minutes! No waiting four hours or more! Once it’s hard it is time to go riding! Also, when plast-aid is mixed together it goes through three stages:

1. Watery in form
2. Thick/ runny like snot
3. Moldable Putty

During any of these stages the product can still be used!

Lets get started:

First, wash the area to be repaired with dish soap and rinse thoroughly! You want to make sure all oil, dirt, etc. is gone. Then dry thoroughly!

Second, the area around the break must be well sanded, ON BOTH SIDES, with the 80 grit sand paper. How well? Sand area until black plastic is showing on the back side and sand the area at least 2 inches out from the crack, on a small cracks like these (3-4 inches on larger cracks). I used a Dremel tool with an 80 grit sanding bit in conjunction with the 80 grit paper because the areas where hard to reach.

Third, drill two small holes (1/4 inch or less)
in area were product, Plast-aid in this case, will be applied on the BACK SIDE of the repair (The reason you drill the holes is it adds extra strength to the repair. The product not only is ‘on’ the surface, but it is now part of the surface too! This trick only works with products that can be forced into the holes.)





Take the dremel tool and while you hold the cracked plastic together (like it was not broken) scribe a V-notch on the outside. Be careful not to burn thru the crack when making the V-notch. You are only making a small valley for product to fill. You can use a file if you do not have a dremel tool. I used the flat panel because it was easier to show the method one handed while I took the picture too!



Blow dust off prepped area and next wipe the prepped area with one of your cotton rags soaked with a small amount of acetone. Make sure the acetone does not get on parts of the bike that don’t need fixed or being prepped, acetone is a mean solvent and it eats nice finishes! Give time for the acetone to dry or flash off (it flashes off quickly).

Since I am not removing the fairings that have the damage, you have to use something to keep the Plast-aid in place so it will bond the breaks/ cracks together. I have chosen a small piece of wood from a paint stick stirrer and a small piece of aluminum can for variety. Cut the pieces to the size you need. The nice thing about aluminum is you can easily cut it to the size you need and it easily conforms to the curves of a fairing when you apply pressure to it and hold it in place to allow the product to set up. Make sure you sand the side of the aluminum that will have the product on it and wipe it off with acetone BEFORE you apply the bonding product.



Time to mix the product! As said before Plast-Aid goes through 3 stages before it totally sets up. With the Plast-aid mixed, per the directions, I double check how the plastic goes back together in perfect alignment, just like a puzzle piece! Once the Plast-aid stiffens up enough that it will not run right off the aluminum, I apply a liberal amount all over the aluminum piece and hold the cracked plastic together and applied it to the BACK SIDE of the crack. Look for the shiny aluminum piece!



The plast-aid oozes through holes I drilled and basically I have to hold the plastic together and keep pressure on the aluminum piece until the product sets up, which is about an additional 8 minutes. How do I know the time? Remember, Plast-aid sets up to cure in 15 minutes from when it’s first mixed and I set a timer! That way, when my fingers are aching because I have been holding the fairing together I know when I can let go!

OK, the back side is set and the cracks are bonded together. Now I mix up more Plast-aid and I use a thin metal blade from my spark plug gap tool. (cake decorating tools work well too) and use the blade to apply the Plast-aid pretty much like Spackle and fill the front V-groove with product. I recommend a thin metal blade because it flexes and “gives” so you can shape and control the product a little better. Don’t forget to wipe your tools off with acetone immediately after there use!

And here is the finished repair!




I know the product needs sanded out on the front side, but I am not painting just yet so its time to ride!

TIPS FOR BEST RESULTS

Surface prep is the key to good results! If you don’t want to do the prep; then stay away from this type of work!

Patience and planning out the repair are important too!

There are various ways to conduct a repair. Base your repair strategy on the bonding product you purchase.

Make sure the plastic is in its “correct” shape, bend, etc. as you begin to bond it together. If not, you’ll have a piece of bonded plastic that will not fit properly when you try and re-attach other fairings.

DON’T MAKE A MESS! Many of these bonding products bond to everything, and once they are dry/ cured it may bond to something you wish it had not.

DON’T WORK IN DIRECT SUNLIGHT! Some of these products cure even faster in the direct sun, which can leave you with little time to do the repair. Do it in the shade in the temperate range recommended in the products directions. (Spoiler: These products work best on days we all want to be riding LOL).

FOLLOW THE DIRECTIONS ON THE BONDING PRODUCT(S). I know this may seem obvious, but many people try and take a shortcut (i.e. don’t mix the product thoroughly, etc). Again, if you do it half-assed, then that’s what your results will be!

Test some of the bonding products on something you do not care about just to get a feel for how the product works and how quickly it may set up, etc.

Since the evolution of the ‘third’ arm is slow in coming. You may need a second person to assist with your repair. Sometimes the fairing may have to be held together, in the correct position, while you apply the bonding product. That’s fine; just make sure the person understands what you want them to do and that they may not be able to move for 5-15 minutes!

Good Luck on your repairs and here’s a preview to part 2 with a new product and method!

 

Sticky?

Or is there a better place to put it so it can be found quickly?

 

Thanks reg71! The next part is a bit easier to do! IMO!

dskelton, I have no idea what you mean???

BZ

 

Bubba,
That was really more directed at Reg. Just wanted to be sure this would be easy to find in the future.

 

Sorry dskelton...I was worried I put odd directions or something in the post LOL!

Talk to you all later!

BZ

 

Awesome Bubba!!!!!!

Did you take any pictures of how you made new mounting tabs? (Was that you who said you could do that with Plast-Aid?)

 

Chris:

Yes, I made a tab for my seat cowl. But that was another section and a real PIA. I took the long way around in doing it and after some research found a much faster way.

Since I took the long way, I don't really want to post that information.

BZ

 

really awesome guy i am wondering when the next part of the saga will arrive??eagerly waiting

 

Funny you should ask!

I am actually working on it now (typing it up) and have it slated to be put on VFRWorld in February sometime.

Patience grasshopper!

BZ

 

You mentioned a better 'faster' way of creating the tabs. Care to expound on that statement (maybe with a pic or two)?

:biggrin:

 

still patiently waiting for part 2 and 3.
No rush.

 

Well, I found the way I construted a tab for my seat cowl probably could have been done easier.

A description will be about 4 pages long at this point so I'd rather someone PM me and we discuss over the phone or if they lived near me I come over and help.

It wasn't an exact science, it was trial and error so I'd rather not document it.

The long and the short is it took about three days in time, a dremel tool a piece of hose clamp, JB Weld and some Plastex.

I worked harder not smarter.

BZ

 

I already wrote part 2 FrankoQ. Should be in the modifications section

As far as part 3 I still haven't decided what I am going to do. I painted my seat cowl, but am not too happy with the clear coat, so I need to do more research.

:smile:

 

Great write up, I am getting ready to get a 1994 750 that has been dropped on both sides. It has been fixed with zip ties and red tape, so sometime this summer I may get motivated and fix the fairing up.

 

for small cracks or cracks that can be pushed back together try,




Acrylic Adhesive SC-125
Very thin methylene chloride and should be applied with a dropper or syringe. Exceptionally fast setting cement for acrylics.

Acrylic Adhesive SC-125 - US Plastic Corporation

 

Hey Bubba,

on the repair part of a crack, I found that if you drill a hole at the end of the crack, it can't continue on, just throwing that in here it may work for you it may not. I also take the smallest router bit I have and "remove" the crack itself. that way the fill material gets al the way to the frontside as well as the back side. my weapon of choice is fiberglass resin, or this boat repair resin. mix it with the fiberglass sheet and its pretty solid. the trick is to get it to cure the right amount of time so it doesn't become to brittle.


nicely done. when is part 2? (cause you havent been asked that before)

CR

 

I agree the fiber glass resin (AKA Kitty Hair)works nice. If you look at the bottom two pictures, that's what I used. Probelm is I did THAT repaire before Part 1. So I wrote Part 2 already have done the fiber glass repair.

That's why there are no real pictures.

One major draw back to the fiberglass is you often need ALOT of product over a large area to get it to work. The "Plast-Aid however fits into small cracks and is way more powerful bond wise.

You are right crusty, many different ways to fix the ol ABS plastics!

BZ

 

I love the red levers. Gotta get me some