Best thing to smoothen abs plastic

So I'm trying to primer a replacement left rear panel for my 4th gen. It's an OEM part I got from a junkyard, but some work has already been done to it since there's a white primer-like layer already on it..

Anyways, the freaking primer I'm trying to put on it won't stick to it- it keeps cracking on the areas of the old primer is laid on (or whatever it is)

So I stripped everything off with a a wire brush drill attachment, but now I have some nice grooves in the ABS plastic from the wire brush itself.

So what should I use to fill in the grooves? Or should I keep adding layers of primer & sand down until it looks smooth?

I'm no expert, but I think you should have left it on and sprayed over with a sealer.

A wire wheel?? Really??? [image: Posted Image]

I'm sorry if this sounds mean, but if you thought that was a good idea at the time, you're going to want to enlist someone to help you with the fix. I'm not sure I can type enough to give you the help you need.

Let's start with some pictures of what you're working with... you should have used sandpaper to take that stuff off, and it might still be fixable with sandpaper, but we NEED to see what you've got!

[image: View Post]SEBSPEED, on 26 June 2010 - 11:44 AM, said:

A wire wheel?? Really??? [image: Posted Image]

I'm sorry if this sounds mean, but if you thought that was a good idea at the time, you're going to want to enlist someone to help you with the fix. I'm not sure I can type enough to give you the help you need.

Let's start with some pictures of what you're working with... you should have used sandpaper to take that stuff off, and it might still be fixable with sandpaper, but we NEED to see what you've got!


I tried sanding it, but the weird stuff that was on it (that prevented the primer from sticking) was very thick, it would have taken a huge amount of time to sand off. (This is the side-rear fairing i'm talking about.

I worked around it by putting a layer of bondo over the affected areas (just enough to fill in the grooves) and then sanding it down until it was smooth.
(To add to this I'm still learning how bondo stuff works.. ( which is a whole other experience in itself :biggrin: )

Yeah I know it's all trial and error, but that's part of the fun in learning how to do these body-fix'n things and figuring it as i go.

[image: View Post]roman, on 28 June 2010 - 12:38 AM, said:

[image: View Post]SEBSPEED, on 26 June 2010 - 11:44 AM, said:

A wire wheel?? Really??? [image: Posted Image]

I'm sorry if this sounds mean, but if you thought that was a good idea at the time, you're going to want to enlist someone to help you with the fix. I'm not sure I can type enough to give you the help you need.

Let's start with some pictures of what you're working with... you should have used sandpaper to take that stuff off, and it might still be fixable with sandpaper, but we NEED to see what you've got!


I tried sanding it, but the weird stuff that was on it (that prevented the primer from sticking) was very thick, it would have taken a huge amount of time to sand off. (This is the side-rear fairing i'm talking about.

I worked around it by putting a layer of bondo over the affected areas (just enough to fill in the grooves) and then sanding it down until it was smooth.
(To add to this I'm still learning how bondo stuff works.. ( which is a whole other experience in itself :biggrin: )

Yeah I know it's all trial and error, but that's part of the fun in learning how to do these body-fix'n things and figuring it as i go.


You could have used the sandpaper in conjunction with an air or electric d/a sander, or a tool with 3M Roloc wheels. Also, for filling areas less than 1/8" in depth, use glaze instead of Bondo. Like Icing from Urethane Supply Company.

Check out the forums at www.autobody101.com before you venture too much further, you'll be happy you did!