skim coat over primer

[chall7074]

new to sight, I need a little help. I am only able to work on my car on weekends. I need to seal metal work with primer I need to know do I have to remove all the primer before I skim coat or can I rough it up and apply filler to primed surface. I have been told yes and no. I would really appreciate any help and comments

[inot2old]

I'm sorry I can't help you with your question, I am sure someone here can. 
I just want to welcome you to the site.  You should go to the new member section and introduce yourself.

[EvilTwinATX]

in short... yes you can. PPG actually recommends that you do it this way, but you should rough up the area with 80 grit first....
Unless of course you are using fiberglass, then you should go down to bare metal with something rough to give the glass something to "bite" into.

[torredcuda]

Yes and no    the old way was to grind to clean metal and spread the plastic filler onto bare steel but the with better primers and fillers the new way is to use an epoxy primer,rough it up and skim coat over that which keeps the metal protected and still adheres well.

[chall7074]

Thanks for the help I will go to the new member and introduce. I will be asking a lot more questions in the future. Will need alot more help.

[Steve]

Note that the PPG DP family of primers has a very narrow work window. They recommend you apply whatever you are going to apply within 7 days...this includes high-builds, fillers, etc. If you don't apply within 7 days, you must scuff and lay a fresh coat of DP epoxy. DP is a great product but it really makes the timing of your project difficult. Sign up for the forums at www.paintucation.com....there's a lot of information out there about using various products.