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Old 07-08-2022, 09:01 AM   #1
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Join Date: May 2022
Location: NorCal
Posts: 39
PFAS free soft top waterproofing

I wanted to redo the waterproofing on my Boxster soft top, but discovered that nearly all of the products to do this are based on PFAS per- and polyfluoroalkyl substances, e.g. 303 Fabric Guard and 3M ScotchGuard. I don't really want to create a debate over that, but there is emerging evidence that they cause a ton of health and environmental problems, and many countries and stores have begun to ban these products (see: proposed european ban, USA, Lowes). They are endocrine disruptors, and persist in the environment almost indefinitely.

So I wanted to find an alternative that will be safe and effective for the car, and safe for my family. One thing I found was this list of PFAS free consumer products:

The first thing was to identify the actual materials used in the top, to find what would be chemically compatible. Supposedly the 986 Boxster factory top is Sonnenland A5.0 fabric from Haartz. This material has 3 layers: acrylic (outside), butyl rubber (middle membrane), and polyester/dacron (interior layer). So the goal is to find something compatible with acrylic fabric. The outer layer being acrylic means it's basically the same thing as Sunbrella, as used on sailboat sun covers, and sun umbrellas.

The best candidate I found seems to be Nikwax Solarproof, a PFAS free waterproofer for synthetic fabrics that also protects from UV, so could possibly be even better at protecting the soft top vs the commonly used PFAS based waterproofers that lack UV protection. It seems to be widely regarded by outdoor gear people, especially for waterproofing things like tents, tarps, and raincoats. They also claim it doesn't really need re-application, and a single application will double the life of outdoor fabrics. I don't have any affiliation with this company or experience with their products.

Has anyone else considered this issue and have any suggestions or ideas?

Last edited by casioqv; 07-08-2022 at 10:39 AM.
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