Side Cover Repair

If you've been into Kaws for any length of time you know what a pain in the arse broken side cover barbs are. Until recently my favored repair medium was JB Weld and fiberglass fabric. It works pretty well if you can really rough up the surrounding area. Lay down a layer of epoxy and bed a layer of fiberglass into it then add another layer of epoxy.

Unfortunately JB Weld is expensive and it just doesn't bond to plastic. I've never found an epoxy that really BONDS to plastic. The solution is to KISS it together with plain old plastic glue. Most side covers are ABS, usually black plastic. Black ABS pipe cement works for these covers. Some are chrome plated, these are styrene plastic, I think. Good old "Testors" brand model cement works with these. Of course you need a lot of surface area to glue two pieces of plastic together for a permanent repair and that just isn't likely when repairing body panels. That's where the fiberglass fabric comes in. It gives the repair the added reach that's needed to fix it right the first time.

Here's a styrene side cover from my 1300 Voyager that had the lower post broken off. In this first picture I’ve scraped off the chrome covering to expose the cream colored plastic, which I believe is styrene. I cleaned the whole area with denatured alcohol and then used plastic model cement to glue the post back in place.



Of course model cement alone would never be strong enough so I used fiberglass fabric to reinforce the base connection. Here’s a picture of the fabric laid into a wet layer of model cement. There are actually two layers of fiberglass fabric. The model cement anchors the fiberglass soundly to the base plastic.



Here’s the post after I’ve trimmed up the glass fabric and applied another coat of model cement.



One more view:



This repair is much stronger than the unbroken post ever was.

I went looking for a broken ABS side cover but just don't have one. If any one out there has a side cover they'd like to have repaired please send it my way. I'll fix it and return it to you better than new just so that I can photograph the result.

Thanks

KZCSI

Post edited by: KZCSI, at: 2007/12/20 01:20

KZCSI wrote:

...JB Weld...doesn't bond to plastic. I've never found an epoxy that really BONDS to plastic....

Am having excellent results with Plastic Welder (found at AutoZone) in situations where JB Weld had failed. It's packaged in the familar dual tubes that dispense the two parts in equal amounts, which are then mixed together and applied. It's a light cream color, and smells really bad, so you know it must be bonding really good. :lol:

Bondo Bumper Repair 2 part epoxy. It's black and has worked very well for me. Have repaired different plastics with it ie. snowmobile hood, kill switch housing,etc. It also sands down nicely. So far it's the only thing that I've found that bonded well with plastic. Model cement as some of you guys remember back in the day was some very sticky stuff until too many kids got caught sniffing the stuff, they changed the formula ( and a fresh lemony scent) then it didn't work very well. Haven't used it since, maybe it's better now?

When I used to build model cars as a kid the cement would actually almost weld the two plastic parts together. Pretty strong stuff back then!

The stuff I used came from behind the counter and smelled highly of tolulene. I experimented with it and it works by dissolving the plastic and then evaporating the solvent to leave behind a solvent welded joint. It's not as strong as the unbroken part but it's close. When used in conjunction with glass fibers the resulting connection is stronger than the unbroken piece.

The advantages to this sort of repair are:

The cements are liquid enough to wet through the fiberglass.

They will bond the base plastic without prep, except for cleaning.

They're cheap! My tube of Testors cement cost me $0.89.

kzcsi

Where did the glass fabric piece(s) fit, I don't really see them? Did you make 4 pieces, one for each quadrant of the post?

Hi Kent,

The pieces of fiber glass fabric are cut to be 3/8" by 3/4" and were bedded into each quadrant with a Q tip. I actually used two pieces in each quadrant. They are hard to see once wetted with the cement. After the cement cured I trimmed them up and applied a top coat of cement just to seal it all up. If you look closely you can see the tail ends of the some of the fabric out on the chrome beyond where I exposed the base plastic.

KZCSI

I've had great success with 3M plastic repair material. They have one for rigid plastic that works great.
Mark