E-Bodies.org Cuda Challenger Forum

I'm posting this info in case someone has a similar problem doing a repair to some plastic components.   

In my case, the plastic mounting point for the cable on the back side of the heater control has disintegrated into a couple of pieces when I originally took the dash apart a couple of years ago.   I was believing I'd probably have to replace the whole control if this didn't work.  It did. 

Fortunately, the fragments were still safely taped to the inside of the heater control as I ended up using them in the repair.   I was able to re-create the mounting point using the fragments and a product called Plastex. 

As explained in the YouTube videos that are available (here's one: https://www.youtube.com/watch?v=dIPyDh-1_UI) , there are 2 approaches to doing the repair:  filling in the area with powder and then applying the solvent, or creating wet clumps by dropping the solvent into the powder that can be transferred to the area being repaired.   I used the first approach.

A Plastex comes with two primary components:   a powder and a solvent.  Tape can be used to hold the powder in place long enough to put some drops of solvent on it.  The powder will dissolve rapidly into a paste that stays put.   The material that's left over after the solvent flashes off appears to be as solid as the original plastic.  The instructions indicate it will harden in 30 minutes but I let it dry overnight just to be on the safe side. 

There are 3 colors available (black, white and clear).  The black worked fine for me.  The promo videos indicate that a block of molding rubber included with the kit can be used to copy a shape (like a broken tab) for use in the repair - didn't try that.   It does seem to sand easily.   It supposedly take paint well but I didn't have a need to try that feature either.

I'm happy with the repair.  :banana:  The only adjustment needed was having to bend the spring clip a bit to fit over the new plastic as it's now thicker than it was originally.

I didn't think to take a picture before I started, so this is after the first fragment was in place and reattached.

Next piece in place...

Bring on the powder...

Solvent, then a little more powder, and some more solvent...

Finished product....

I also used the Plastex to reinforce some repairs to some cracked dash trim pieces where I used a soldering iron to "weld" the pieces back together.   The Plastex was easy to use to fill in the gaps in the backside of the piece.

That's it.  Hope this helps someone else too.

Good to know and thanks for sharing! Where do you get it and how much does it cost?  :cheers:

I think the kit was purchased at a local auto parts store for around $30.  It's on Amazon and eBay for the same price but shipping can be a little expensive ($13 from one vendor).  There is a smaller kit on eBay for $21 including shipping which would've been good enough for what I needed. 

Interesting!

thanks for sharing  :bigthumb:

I haven't tried this kit but I did a similar fix with super glue and baking soda. They react in a very similar way, its gets hot and melts the plastic together. I've tried it on several things and it worked out well. I relocated mounting tabs on a headunit and a year later it's still holding strong.

This lot does looks like it's a bit easier to work with though and a better finish. I wouldn't recommend the super glue and baking soda if its in a place where you will see it but in a pinch it works great.

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That could save a few headlights w broken tabs over here... thanks!

That looks a decent product. Thanks for sharing, I might give that a try.

I also used this to repair several cracks in my grille.  It does work well.  When repairing cracks in things that are fairly long and therefore flexible, ie the grille or filler panel below the grille, after repairing the crack I added a piece of drywall tape to the back of piece over where the crack was and then coated it with a two part epoxy.  This gives the area more stability from flexing and cracking again.   It's sort of like using fiberglass matting to reinforce but much quicker and easier. Just remember when repairing cracks to use a dremel type tool to cut a groove in the crack and then use the Plastix to fill/repair.  Also, if its a large crack, don't fill it all the way to the top the first time.  Add a little bit at a time until it's smooth enough  to sand.

I'll throw one more picture in about uses for this stuff.  I found another crack on the heater control. The crack was widened and filled with Plastex - been three, done that before.  The "new" use involved a line of the Plastex powder in the corner formed by the brace and the heater control body.  Hitting with the solvent formed a fillet of plastic to reinforce this area against future cracks. 

Old thread but, @Dakota (https://forum.e-bodies.org/mlist/dakota_973) , I found a Plastex set that I had for a few years, probably bought it at SEMA. Was gonna try it out for the first time, my Cuda grille is broken in a million places. Now, have you tried it on the material thats in the door panels? On their website they have another product for "oily plastics", maybe the door panels are considered that? Have a cracked door panel also, and tons of other broken plastic things.

https://www.plastex.net/ (https://www.plastex.net/)

Quote from: usraptor on June 18, 2020, 03:06:18 PM
Soundcontrol, did you grind a small V channel in the crack first before adding the Plastiex? If you just apply it on a flat piece it won't adhere.

Hmm, no I didn't. Just wanted to test if it would stick to that type of plastic. Would there be a difference if I did?
I did it on the back side of a kick panel. I figured if I grinded the crack in the door panel, it would be hard to use another type of glue there,
if Plastex didn't work. I do have a set of badly cracked panels for my Challenger, I'll give it a real try there.
My Barracuda Gran Coupé panels are perfect except for thet one 4" crack on the driver door panel, I need to know that it works before I try it on those.

Grinding the crack does two things, first it opens up the "pores" so to speak of the plastic and gives it a fresh surface to adhere too, secondly it also provides more surface area for the plastex to adhere to.  Make sure you follow the directions about putting the powder in the crack first then added the catalyst.  Depending on how deep/wide the crack is, it make take more than one application to fill/bond the crack.  You don't want to have too much plastex powder in the crack otherwise the catalyst wont' completely penetrate and activate it.