I'm starting the work on my 91 si now. Doing a budget respray.


I've got new oem front and rear bumpers.

I've been told that you have to clean them very thoroughly to remove the oils and greases from the manufacturing process. Is this true? If so what is the exact process?


Also I've been told that all plastic molding and bumpers should be painted with a flex agent or additive in the paint. Is this true as well?

I'm using PPG Omni line BC/CC if that makes any difference.

Thanks

 

Yes you want to clean the bumper to remove the molding oils. You can either bake the bumper in a booth (if you have access) or buy special prepping paste that removes the oils while scuffing the raw plastic. If the bumpers are already primed there is no need to bake or try to clean them, just scuff and start spraying.

DuPont has a plastic prep scuffing paste called 2310S, use a gray 3M scuff pad wet and the paste to prep the bumper if you can't bake the bumper. Here are some steps to help you out a bit.

1. Bake the Bumper (if you have access to release the oils) or Prep with Plastic Sanding Paste DuPont 2310S and a gray 3M scuff pad http://www.performancecoatings...S.pdf (if you use the plastic prep, skip step 2 and 3)
2. Wash the Bumper
3. Scuff the Bumper (3M gray scuff pad)
4. Wash the Bumper
5. Dry with Air Gun
6. Go Over Bumper with a Raw Plastic Cleaner DuPont 2319S http://www.performancecoatings...S.pdf
7. Spray Bumper with an Adhesion Promoter, DuPont 2330S http://www.performancecoatings...S.pdf
8. Spray Bumper with 2 Coats of Primer Sealer
9. Spray Bumper with 3 Medium Coats of Base (tack between every coat)
10. Spray bumper with 2-3 Wet Coats of Clear

I've said it before, this is just my method, everyone does it a bit different. Other companies make the prep products for plastic prep and painting, I just know DuPont a little better. If you are using a flex additive don't forget to mix it into your base and clear, DuPont suggests using the flex additive in both.



Modified by WihaSi at 9:44 AM 9/5/2007

 

You can also use Bulldog adhesion promoter. I use it at work at haven't seend any problems yet.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SneezinCD5 &raquo;</TD></TR><TR><TD CLASS="quote">You can also use Bulldog adhesion promoter. I use it at work at haven't seend any problems yet.</TD></TR></TABLE>

Yeah, but I usually stick with the same brand I'm painting with...I'm **** like that.

 

so you are saying use an adhesion promoter and also to add flex agent to both BC/CC?

Do I just spray the entire car with the paint with flex agent then? How does that additive affect the paint flow and difficulty of laying down a smooth coat?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bambbrose &raquo;</TD></TR><TR><TD CLASS="quote">so you are saying use an adhesion promoter and also to add flex agent to both BC/CC?

Do I just spray the entire car with the paint with flex agent then? How does that additive affect the paint flow and difficulty of laying down a smooth coat?</TD></TR></TABLE>

Yes, you always want an adhesion promoter. DuPont reps. also told me that you "can" add flex additive to your base coat, and they actually suggest it (all surfaces, plastic, steel, etc...) Flex additive won't affect how the paint lays down, just paint like normal. You only add maybe 1 oz. per 10 oz. of paint (not exact but something along those lines). I could be wrong though...I forgot to add flex additive many times

 

ok thanks for the advice.

another question while I have you here.

My car has had some filler work done, just small areas to fix door dings. They were done when I purchased the car already, but have been exposed to the elements for over 6 months.

Should I grind it all out and redo it or just clean, sand and prime? Its straight but I'm worried about adhesion issues. I've heard the filler can absorb water and cause trouble later on.

 

if the bodywork on the car had been exposed to elements such as rain without a primer for protection, there may be possibility for rust. Although there may not be any signs of rust on the surface, there possibly may be some underneath. even trace amounts of rust spread overtime. If I were you, i'd redo the bodywork if adhesion, or rust is a concern. and remember, 50 percent overlaps!