After I get all the paint off is there a good temporary primer I can lay down to prevent rust and then use the NCP 271 over that when I think I have the panel straight?

Reading the arcives I see a some people like the PPG NCP 217 over bare metal. I was told at the paint shop I won't sand thru it. That said I need to make sure my panel is straight. Well I am not sure I will have a straight panel until I get all the paint off.

When we switched from S-W to PPG we tried out a few gallons of NCP271. The stuff does sand good with 180 dry but wetsanding with 500 is a nightmare. The stuff eats sandpaper, I recall one decklid off a 01 dodge stratus, it took me 2 full pieces of 9x11 sandpaper to sand that thing graemlins/angry.gif

Also we noticed when not sealed just topcoated with basecoat we did experience dieback problems.

As for using on a FULL bare metal panel I wouldnt use it. From what I got out of the PPG rep was the reason they label it a RUST RESIST primer surfacer is because they added some expoy like resins to make NCP 271 stick better. Which why it sands tough also.

Am a BIG fan of etch primer then urethane primer. Say coating the metal first with dx1791 or dpx171 then coating that with K36 or K38 or even ncp271. Etch primer fights corrosion on a molecular level were expoy based primers just form a seal over the metal. Etch is the best method for fighting rust hands down.
This link is right out of the PPG site on how to fix rust.
http://www.ppg.com/cr-refinish/phase1/frmShowDefect.asp?LanguageId=4&IntDialCode=44&ProcessStage=0&ShowPicture=0&DefectId=88


As for a primer surfacer PPG's stand by or standard primer is K36. K36 is a great product, also its a 3in1 product. Depending on how you mix it, it can be a sealer, primer or tinted primer, not all products can do that. But in my opinion PPG's best primer surfacer is k38, fills better then k36, but it cant be mixed as a sealer or tinted.

Just remembered in the tech sheets of ncp271 it stats that for max performance of adhesion and corrosion a two step metal treatment or wash primer(dx1791) should be used. If used on galvanized steel the metal treatment or etch is a MUST...Eric

Thanks. I tried that link and it only took me to the main home page. I can't seem to find the rust tech tip there. Should I have gotten a tech sheet for that NCP271?

Jim,
I copied and pasted this right from the link.
If you want a tech sheet I can email you anysheet from PPG...Eric

Corrosion, Rust Under Film, Rusting

Description
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Loose paint, bubbling and discolouration of the paint film, especially around body fittings, panel edges and seams.



Cause
Corrosion of the metal substrate, resulting in loss of adhesion of the paint. This is frequently caused by:

a) Exposure of bare metal surfaces by accidental damage, or by leaving drilled holes untreated.

b) Exposure of bare metal surfaces due to destruction of the paint film by contamination.


Prevention
a) Ensure that all metal surfaces are treated with the correct metal treatment fluids and etch primer prior to painting.

b) Repair any damage to the paint film as soon as possible. Always treat any newly exposed metal edges immediately.


Rectification
Strip the paint from the affected area down to the bare metal, remove all existing corrosion, treat the surface with the correct metal treatment fluids and etch primer, and repaint.