I'm filling a small hole, between a quarter to a half inch in size, in a plastic piece. I just went out and got my first can of bondo and read all the directions through and then used that to fill the hole. To finish it, I sanded it down first with some 100 or 150 grit sandpaper to get rid of all the excess. Then I used some 320 grit to make it flat and smooth with the surface of the plastic. I've now sprayed three coats of primer onto to plastic piece, and I can still just barely make out where the hole was. It's like the primer there is different looking or something, and I don't mean in color. Should I just try a couple more coats of primer to see if it goes away or sand it down and try another layer of bondo or what? Any help here? I know some of you guys are bondo experts....

It's important what exactly you are seeing. First hold it up to flourescent white light if you have that available. Also close your eyes and run your fingers over the patch job in both X and Y directions. This well tell you what the surface is actually doing.

Then if it's concaved, put more bondo in the groove, I suggest using some insulation foam or some sort of sanding block, soft wood works the best. For this kind of patch you HAVE to have a sanding block, hand sanding just doesnt cut it your skin is too pliable and WILL without a doubt conform to the hole on some level. If it's still too strange looking, then it could be the opposite problem, in which case you will then take sandpaper and sanding block and go back over it till it's flush.

by sanding block i just mean somehting large enough to get your hand around, and wrap the sandpaper around the half of th block that will contact the surface. This gives you a pefect straight surface so when you are done sanding you have...a perfect straight surface! WOOHOO.

How exactly does it look different?

Also keep in min that when your filling this hole that your not going to want to sand all the bondo away from the hole. You want to basically blend it in with the surrounding parts of the bezel so that even you cant tell exactly where the hole is. Once youve achieved this look and the bezel is also as smooth as a babies butt, your good to go man.

Edit: I was out on my porch and noticed my bondo can, if you want a good example of what to do take a look at the pics on the back of the can. Thats pretty much what you need to do.

I say put a little bit of extra bondo on it, and then get some 1200 grit and just sand till the bondoed part is even w/ the rest of the case

good point but i think he might be sanding for awhile.

Yeah.....you want to use the primer as a filler too......if your reall close to being smooth.....give the piece another coat of primer and sand until smooth....the keyword is blending.......

If it looks a diffrent color, all cheapo primers do that. It wont show when you are puttnig the real paint on.

Do you have a camera? Take a pic, it will help us a lot more.

My suggestion is put a lot on there, so you can tell that its sticking out and then sand it down with a sanding block. If not a real block, anything, just not ur hand.

HAhAHAhA man sparky, you got red dots under your name !!! !!! Im gonna guess the duck did that hahah

I am being lazy and not reading all the thread so if I am repeating let me know... but.... Bondo has a tendency to absorb this may be causeing the look... have you tried a base coat to see if it covered it properly?....

Another thing you might try using a thin layer of Glazing Putty which is just thick primer.... sand it back down but not all the way and then apply your base primer and then base coat....

I am by no means a paint expert and there are others around here that most likely know MUCH more than me.. And we also have Luna and Insom so I am sure you will prolly get better advice but thats all I know to suggest.. good luck....

HAHAHAHAH Igave you a rep point and made it two black ones so it wouldnt be red, i felt sorry for you lol....

It's not that it isn't flush with the surface of the plastic, it's more like where the bondo is the primer kinda dries with a different texture than the rest of the piece. I sanded it down real smooth and flat, and there were no little pinholes when I started with the primer. I just put a coat of real paint on it to see how it goes so I guess I'll know soon.

Quote: Originally Posted by Psylariser It's not that it isn't flush with the surface of the plastic, it's more like where the bondo is the primer kinda dries with a different texture than the rest of the piece. I sanded it down real smooth and flat, and there were no little pinholes when I started with the primer. I just put a coat of real paint on it to see how it goes so I guess I'll know soon.

good idea that would have been my next suggestion.