About to pick up a used ground effect in good shape for my 89 GTA, but someone had previously drilled rivet holes and attached it to their body using rivets. My question is, I'm sure there are good fillers out there in the likes of
3M, but I'm wondering if anybody out there has a better technique in filling these plastic molded pieces ? These holes are in obvious view and I don't want to see no rings around the filler after painted. I'm hoping the top coat should cover everything...

 

J&B weld or if they are bigger, epoxy and fiberglass !!!!

 

3M makes a kit with patch and putty for flexible parts that works great. Can't remember the numbers on the kit but your local paint and supply store should have it on the shelf. The putty takes a special gun to dispense it but most stores have a loaner.

 

The 3M stuff is called DURAMIX and I got it from Amazon.com......it works well but I didn't use the dipensing gun which is $160 if you buy it btw. I just manually pressed out what I thought was equal portions. If you goto the 3M website and do a search there might still be a tutorial on how to use it. Epoxy and fiberglass might work in some areas but in my experience it just shears off after awhile. Don't forget to grind down the edges of the holes....otherwise you'll see a "lip" around the repaired area.

 

3M bought Duramix about a year ago. Not sure if they are phasing out them or not.

I'm thinking the part numbers are 5887 and 5888 for the 3M stuff. One is a patch for the backside and the other is the filler. It would work great for that type of repair. I'd get the kit as it contains adhesion promoter for both the filler and the patch. Like jb said, be sure and feather it out well.

 

Use SEM products they are the best in my opinion for plastics I used ther bumper repair kit on the front of my nose and it is real strong.

 

I haven't tried the SEM products for flexible part repair lately. We used to use a Fusor 114 I believe was the number. Came in a tube that fit in a caulking gun or you could push it out manually. It worked good but didn't have much of a shelf life. Got lumpy after a while. That 3M stuff is pricey but it's the best I've used in some time.

 

Why spend all this money.....J&B weld is the same , its EPOXY !!!!!!

 

Yep it'll work but it don't flex. I hate repairing plastic anyway. Too temperamental. Different materials expand and contract differently. Usually always shows back up after time. At least your repair area is small.

 

Well, before i painted mine...i fixed all the cracks and holes with J&B weld on the plastic parts, spoiler GE's and the front by the lights....not 1 crack showed back as of yet and u cant tell it was ever cracked !!!

So why spend huge money if its the same, i work on boats most of the time..so maybe i cant fix plastic on a car...lol

 

Glad it worked for you. I like to use what the manufacturers recommend when possible. Sometimes I'm a little too picky with my work. Especially with my own car.

I hate to even mention it but the drivers side corner of my front bumper, between headlights and fender, was cut through almost all the way back to the fender. Car came out of wore out wheel lift wrecker and ran into T-bar. Repaired it from inside like described. Never know it now, even flexes. Check out pics in my album if you want.

 

And what is the manufacturer's recommendation ?

 

Different repair material suppliers will be different. 3M is about what has been said. Use adhesion promoter on back side, apply patch, feather out top side, adhesion promoter, then wipe filler. The adhesion promoters are different for filler and patch. Kit is pricey but filler is by best flexible filler I have used.

On my car, it was much worse. Completely cut into over 5 inches. I was using something different then. Needed support Used 4040 Duramix for repair strength and Fusor 114 for filler. Both are good. 4040 and most other repair can be used to fill the holes, It is just harder to sand, kind of rubbery. Check with your supplier/paint store. There is also a 4041 they may recommend, can't remember differences now. 3M filler doesn't work over 4040 or 41. One is epoxy [4040] and the other is urethane[3M]. Store can tell you for sure.

If you want to see what GM says in they're FSM I have one for a 1985 Bird right now, not a AZ, C-ton, Motr. It still depends on what product you use.