Master Series – What NOT to do! – 1966 VW Beetle Project

I was so happy with the Master Series Mastercoat Silver Permanent Rust Sealer/Surfacer Primer and their AG111 top coat, that I decided to put it on the top of the pan too.  There was a coating of a Wurth undercoat type product already on the top of the pan (installed by the previous owner) prior to me attempting this.  It looked good, but I really liked the durability and the look of the Master Series product.  I had done a test to see if the Master Series product would lay down nicely over the Wurth product, and my test seemed successful.  I cleaned the top of the pan, leaving the Wurth undercoat in place, and then started with the Mastercoat Silver and then the AG111.  It looked AWESOME!!!!  UNTIL it started to bubble up on me.  It ends up the Wurth product is *petroleum* based and the Master Series products are *not*compatible with petroleum based products.  Basically, the Master Series product started disintegrating the Wurth undercoat that it was covering.  I had no choice but to completely remove the MasterSeries products, and the Wurth undercoat product. Please don’t make the same rookie mistake I made.  It’ll save you a lot of time and hard work! Stay tuned for another blog post highlighting my progress and my second attempt at laying down the Master Series product.  Here are some pictures from this part of the project:


The top of the pan, prior to starting


Here it is after the primer


The final top coat…  Looks awesome (just before bubbling up on me)! 


I was unable to capture the bubbles in an image, but here’s a picture showing the beginning of my efforts to strip it all off…


75% of it came up in sheets like this while using a putty knife and a heat gun…  The other 25% is what took the longest to get off.

2 thoughts on “Master Series – What NOT to do! – 1966 VW Beetle Project

  1. Randy

    Sweet pan. Great effort and fantastic insider info. THANK YOU for passing it along. I’m sure that compatibility issue would have not entered my mind… until “it” happened. Our projects demand blood, sweat, tears with the possibility of limitless joy :o) I would love to have your quality OEM pan under any sedan I owned. Keep up the good work. Thanks for sharing. It helps with all our projects.
    R. Long Beach, Ca.


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