Repair of Plastic Parts

Does anyone have experience with gluing broken or cracked plastic parts? I was considering using the adhesive used for PVC pipe to repair some black colored parts in a non-stress application. I have some broken attachment brackets on some fairing around the wiper motors. Of course knowing the type of plastic these parts are usually made of would be helpful in selecting the correct adhesive/

Thanks John

Reply to
John Reichert
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I have never successfully repaired a plastic part... if I was to take a guess... I'd use red Oatey All Purpose glue to see if it will work.

Otherwise, I'd gamble on a hybrid epoxy glue... scruff up the plastic with sandpaper and give it a shot.

Reply to
Tiger

If you can determine the type of plastic, there are a number of products from Weld On that fuse plastic very well. You can call them and ask them for a recommendation or go to their website. It works by melting the plastic slightly and then creating a fused bond. As another person pointed out, if your plastic is weakened by age, you may experience break after break.

Reply to
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John Reichert ha scritto:

I guess it's a question again related to your '91 300 SL. If I'm true, it's probably indicated in the plastic part. AFAIC remember in '91 the German law imposing to mark indelibly any plastic part was already active, thus you might find a mark with it's component name: ABS, PVC, etc... Check it out: it's usually in the most hidden surface of the part... You might find it with the triangle with 3 arrows (recycling) and the clock indicating the month and year of production.

Reply to
Cordy

Thanks for all comments. I had some broken tabs on several panels which are used below the windshield. Since I'm a DYI at home, I had some cleaner and glue for connecting PVC pipe. I wiped off the dust from the parts, used the liquid cleaner and the glue. The glue is full body, has some viscosity like corn syrup, which may have helped hold the pieces in place.

After letting it sit undisturbed for about an hour it seemed to have worked. I can lift the part at the repair. The plastic was probably PVC since the glue appeared to fused the parts together.

Good idea to check for a marking on type of plastic. I could not find any parking on the parts. We used the same when deciding what plastic at home can be taken for recycle.

John

Reply to
John Reichert

Plastic comes in several kinds. If you have a polyethylene (think Tupperware) or polypropylene you are going to have to heat weld the parts as they do not glue or solvent bond. Most plastics used in cars however can be solvent bonded. This is where solvent is used to melt the edge of the plastic and it then evaporates after the two edges have been placed in contact (think model airplane or plastic pipe) the third way is to use an adhesive (silicone, epoxy or crazy glue) the latter method is used on thermo-set plastic like bakelite, Formica etc. this method can also be used to join metal to plastic.

If it is black plastic I would try some plastic pipe cement for ABS. It is probable that the solvent will work and the filler will probably be compatible with black plastic used in most cars.

Reply to
Roger Shoaf

I've been helping a buddy with his plastics factory and have learned more about plastics than I want to know.

It would help a lot if you knew exactly what the material is.

Having said that, urethane glue will almost certainly work. It's in the hardwars store. It takes 24 hours to cure properly.

Epoxy is too brittle to be of much use here.

Reply to
Richard Sexton

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