tavert91

iTrader: (1)

I need to repaint the nose of my 91 TA and I am trying to decide whether I should sand or strip the old road rashed paint. Most strippers I have read directions for say not to use them on non-metalic surfaces. Since the nose piece on these cars is some kind of flexible plastic, I am very hesitant to strip the paint with one of these chemicals. That leaves me with sanding as the best way to go. I suppose that one of the "dustless blasting" machines would also work but I do not have access to one. Any thoughts or suggestions?

Jorlain

iTrader: (4)

No need to completely strip it. Sand\block it by hand, just to even out everything. If you can help it, don't sand through the factory primer. Most modern paints don't need flex additives anymore, so you shouldn't need to add any. Hit it with your favorite sealer and then paint\clear.

tavert91

iTrader: (1)

Thanks for sounding in on this, Jorlain. Sanding is my first choice right now and the part has no major defects, only paint dings and scrapes. Maybe someone has used an alternate method that I am not familiar with but absent that, I'll break out the sandpaper next week.

Drew

iTrader: (58)

Every circumstance is going to be different, but the front bumper on my Formula had many coats of paint on it from it's working days, and dealership touchups. It looked alright when I got it, and for a couple years it wasn't too bad, then it started shattering like glass. I mean large half dollar size chips of paint so thick you could measure them with a ruler. As I started sanding the various cracks down, I figured out pretty quickly that some (most?) of the cracks went all the way down to black plastic.

My other 91 Formula front bumper wasn't much different. It had fewer repaints, fewer layers, but still cracks in the original paint came through the later layers. I chose to sand it all down as far as reasonably possible.



I've still got another 91 Firebird front cover with some cracks to fix/strip, and a few rears that need stripped, and a Camaro front cover and spoiler that I'll have to strip eventually... There are a few flexible bumper stripping agents available, and I'm considering trying them, because while sanding works, it can take a lot of time. I can't see painting over layers of paint that didn't hold up when they left the factory, or in the 80s and 90s repaints.

tavert91

iTrader: (1)

Fortunately mine is still original paint. Still 27 years old but original. I think sanding will win in the end. What grit would you start with and then, I assume, you would progress to higher number grits. To hold the new paint, when would you stop? Maybe 500 grit or so?

tavert91

iTrader: (1)

Finished this project and I am happy with the result. I went with sanding starting with 800 grit. I then added color and clear to the surface before working through wet sanding with 1000, 1500, and finally 2000 grit. This cut through and smoothed most of my problem areas. I finished with Meguiar's Ultimate Compound and Polish followed by Griots "Best of Show" wax. Problem solved with a driveway solution!

dagwood

iTrader: (5)

I am a professional painter, so I'll chime in to help you out. If your bumper cover is wearing it's original paint, and it's still good with only minor defects, I would sand it down with 320 grit sandpaper, and when I painted it I would give it 1 coat of sealer, followed by your base color, then clearcoat. That's how I do it in the body shop, every single day.

If your factory basecoat is in super good physical condition, You CAN do a scuff and shoot without using sealer, but I would sand it with 600 grit. 600 grit sanding scratches are very good for a basecoat "bite", and will still easily be covered by the basecoat. Then shoot the basecoat and clearcoat. 800 grit is on the extreme fine line as far as getting an adequate bite for the basecoat.....ESPECIALLY on a front bumper cover that gets pelted with bugs, rocks/road debris, etc.

Just my $.02

dagwood

iTrader: (5)

Oops, I didn't see your last post saying it was already done. I hope you don't have future adhesion issues starting with the 800 grit. Be careful at the car wash trying to remove bugs!