Patching up plastic?

[PUSHER]

Call me ghetto, but I have a torn up front spoiler with a couple of good sized holes on it and instead of buying another for 130ish I was wondering if their is some way to fix it? Considered fiberglass but im sure I can only get that to work on steel. Other solution is spraypainted duct tape I guess =P

[EScanlon]

If you don't already have a buddy that has done bodywork, it can be frustrating to get it done right.

If you are talking a true blue plastic spoiler, then you need to identify the plastic. Some plastics can be heat welded with more material in order to patch, others just scorch away with heat.

Fibreglass can be repaired, but you need to prep the area well in order to get it to stick.

Check the library for some books on how to repair those items and they will help you decide if the $130 is too much to spend.

Enrique

[PUSHER]

I dont really care if it looks perfect, I just want it to not drag on the road and fill in some holes. When I said fiberglass I was wondering if fiberglass on plastic would work.

[EScanlon]

As far as dragging on the ground:

That could be a function of many things. The suspension, the placement of the spoiler, prior damage etc., not to mention the applicability of the spoiler itself (too large/tall), all have bearing on how high off the ground the spoiler lip will be. I'll leave it to the mechanical guru's to advise you on that.

As far as just a fast repair, if it is a FLEXIBLE spoiler, that is more than likely made out of the same material as the "rubber" coverings on 90's era bumpers, you can get a can of "Bumper Filler" which is more flexible than your standard Bondo.

Since you mention that you actually have HOLES, I would provide some form of framework for the flexible bondo to adhere to. This can be as simple as screen door mesh that has been fastened to the back of the spoiler. This will provide support for the bondo so that it won't sag and be a pain to work with. You could use fibreglass strand in it, but the main thing is to make sure that it adheres to the old plastic.

That preparation can be as simple as a rough grind (24-30grit) or by adding holes to the plastic so that you can "squish" the material through so it will bond to itself. (Mind you the latter method is not a very good nor permanent fix as the bondo can crack inside the hole just as readily).

If the spoiler is a RIDGID one, then it is either made from steel, fibreglass or thick ABS. If Steel, then grind and weld.

If fibreglass then use a fibreglass repair kit. Don't worry about gelcoating it since you will probably paint it. Grind from the back such that the edges are tapered, lay a "wetting" coat of resin and apply a piece of fibreglass MAT that has has the edges frayed and fits inside the hole. Allow the strands to stick out to BOTH sides of the hole, apply resin to remove any bubbles then apply a second layer of MAT that is a bit bigger than the hole. Saturate with Resin again and repeat until you have somewhat filled in the thickness of the spoiler missing from the hole. Finish with at least one layer of Fibreglass CLOTH. This will provide even further strength to your repair.

Allow to finish curing.

The next step is to do the same from the front of the spoiler. Just like for the back, Frayed Mat, Mat as needed, Cloth. All saturated with resin, then allowed to cure.

Remember that the average fibreglass kit available to the home body man is GENERALLY slower to cure than the commercial kits available out there. I'm not saying that you have an HOUR to work with the stuff, but more than likely 10 to 20 minutes depending on temp, and the amount of activator you kick into the resin. You can speed / slow by use of more / less activator, but remember that if you speed it up it can get HOT! (hot enough to burn you) Additionally, if you "spike" it, you could end up with an unevenly mixed batch. The bottom line here is that you will probably be working in LAYERS.

Depending on the type of resin (with wax or not) you will need to grind off the skin that will develop with the waxed resin whereas non-waxed is a layering type of resin. As long as the previous layer was not contaminated you can just lay a new coat on top. Personally, on this type of repair, I grind both types just to ensure mechanical as well as chemical adhesion.

Once you've done front and back, grind to shape, sand smooth and then paint it. Don't forget that any fibreglass work needs a sealer applied over it. Whether that sealer is Gelcoat or Sealer/Primer is up to you. The sealer / primer will allow you to finish it off with automotive style paints and not worry about crazing or lifting of the paint.

Enrique

[PUSHER]

Wow thank you very much, since you seem to know allot about body work I was wondering if you could tell me if their is a correct/good way to strip/sand paint off of a 280z. I have some thick paint that is chipping that I need to strip off before I have a friend paint it. Also, the weather stripping allong the glass outside is bad and I was wondering If you replace that after or before you paint the car? Thanks.

[EScanlon]

Yikes!

That's a mighty tall order there pilgrim!

There are a BUNCH of variables to consider when sanding a car for re-paint.

Read some of my other posts in the Body / Paint forum and you'll get an idea of what to consider.

In brief, from what you describe, I would opt for a Dual Action (D/A) Sander with 220 grit. But...... it depends.

As far as the weatherstripping, if you are doing a complete repaint, then by all means remove the weatherstripping. If you're only doing panel work, then mask it off.

But then again, that my:

2¢

Enrique