Oily paper removal undercoating.

[zachmac]

I was watching some of that wonderful oil sheet under the car drop off from being so saturated gravity overcame (got to address those pesky oil leaks) so I got under the car with a scraper and started helping out. It actually came off (I assume this was the factory stuff) very easily in big sheets and chunks. To my delight the body underneath is shiny black, slightly oily paint. The only exception of course is a small surace rust ring surrounding every rubber drain plug. Yeah undercoating holds water to the body as well as it keeps it off!

So, other than scraping and painting the small rust cirlcles, do most of you keep it painted metal or use some sort of new spray on undercoat. I know my preference is bare to aviod the aforementioned trapping of water between the undercoat and the body. The other alternative is of course to mask around any plugs and NOT cover those area. What's the concensus.

BTW, I realize where you live and how you drive the car change the answer. I live in SC and will mostly only drive the car for fun trying to avoid rain other than the unintentional times. Not a daily driver or a car that will see snow or the dreaded salt.

[zachmac]

No opinions or advice?

[amsiegel]

My suggestion is
scrape around the holes and remove what ever old undercoating that is willing to come off easily.
spray bare metal with Por-15 or someother kind of rust treatment.
then spray new undercoating

[azygoustoyou]

Hi Zachmac,
I had stripped the bottom of my 124. The were spots that came off easily and then there were places which took me forever to scrape. When I was stripping the bottom, I noticed that there was surface rust underneath the places that came off easy. The more I looked around those areas, the more the rust appeared. It took me a week just to clean up the undercoating. I'm glad I did. There was some rust in a lot of areas. Even in the well covered areas. I wouldn't just spray anything on the open areas without making sure you eliminate the rust first. At least what you see. There are products like POR15 that seals the rust as long as it's not flaking.

[bigwalt333]

Hi Zachmac: I've had good luck in the areas where undercoating was coming off(by itself or oil assisted),or any areas where rust was appearing-I applied a good quality rust converter,to make sure rust will not appear in that spot,then applied undercoating. Other areas not needing undercoating I painted over the rust converter,as it acts as a primer anyway,and seal the area that way. Hope it helps.

Tom Walters
'80 Spider