I just wanted to give a quick writeup on a product I have been using on some of the cracked plastic pieces in my car. It's called Plastifix, and it can be purchased here:
http://www.urethanesupply.com/PlastiFix-Kits-1/
I have used it on several parts, and I have to say it is amazing. These are pics of a commonly broken part on Thirdgens - the roof trim between the headliner and the rear glass. The screw hole recesses always break off. I had 1 broken screw hole, and the rest had cracks. I used a product that comes with the kit to make a mold of one of the unbroken screw holes, and used it to repair the broken tab. I then strengthened the weak screw holes. From the backside, it's not pretty, but the repair looks perfect from the front, and once painted, it will be invisible. It is also very strong.



This is another commonly broken part on 1982-1984 Firebirds - the radio surround. This was my test piece, as I have a brand new one. I repaired the broken tabs, and embedded a piece of fiberglass on the tabs for strength. Then I re-textured the top with bed liner, because I had gotten adhesive on it and had to sand it off to smooth it out. Then I shot the whole thing with SEM Landau black.

I am in the process of repairing the shift plate that was missing a tab. I used the molding plastic to make a new tab. I will post pics of that tomorrow. Hopefully I don't go over the number of pics allowed.

 

nice , would be good just to have some kicking around

 

Nice Job! SEM paint is amazing, I have used it on a few parts. If prep right no flake, peel or fade. Great stuff

 

thanks for the tip

 

How well did this stuff work on cracked plastics? Looks great for rebuilding tabs and such. Did you just use a little fiberglass cloth on the backside of cracks? Would love to save some of the harder to find convertible trim pieces. A few have long cracks that I would like to stop in their tracks and fix.

 

It works great. The tape I used was fiberglass drywall tape.
If you decide to use it, buy the white repair compound. I tried the black compound and I did not feel that it worked as well.

 

Just wondering if you have used this stuff to fill in holes in plastic?

The previous owner installed a cup holder below the window and hatch switch thereby leaving three rough holes in an otherwise perfect console.

 

It will definitely fill the holes and come out strong, but you may need some sort of plastic filler glaze to finish filling in the outline of the hole. It does not make an invisible repair for something like that.

 

Just an update on this thread. This stuff will only work on the ABS panels in our cars. The large trim panels in our cars are made of Polypropylene, and this stuff is no good for that. It will work for most of the dash and console trim though. It will also work on that headliner piece I have pictured in this thread because it is made from ABS. If you are unsure of what the panel is made of, look for the part number on the back of the panel. If there is an ABS stamped in it, this will work. If there is a PP on it, it is polypropylene, and this stuff won't work.