POR-15 When It Is Pouring Out...Not A Good Idea

posted Jun 18, 2014, 8:26 AM by Jonathan Imberi
I started Monday with the intention of getting the subframe connectors and the Panhard/track bar coated with POR-15. It was raining when I got out to the garage, but since the car was inside and I could still crack the door open without getting water in the garage, I figured I would be fine. We have applied POR-15 a few times already when it was raining outside and never had a problem, so I proceeded as planned.

https://lh4.googleusercontent.com/-sYE7Eqvmzq4/U5-phA7pIBI/AAAAAAAAl10/Zkww4iTwNP0/w1504-h846-no/IMG_20140616_113200939.jpg

I got POR-15 and supplies out and was ready to get started.

https://lh6.googleusercontent.com/-bZxoqZxF02g/U5-phM2T6gI/AAAAAAAAl10/qP0eGkXl5tA/w1504-h846-no/IMG_20140616_105725912.jpg

Here is the driver side subframe connector.

https://lh3.googleusercontent.com/-C3iFbZDOA6Y/U5-phHbs13I/AAAAAAAAl10/ZUg4YdvfDeg/w1504-h846-no/IMG_20140616_105744147.jpg

https://lh5.googleusercontent.com/-m5b02ht_cnI/U5-phBPee9I/AAAAAAAAl10/z-iTqObbwQE/w1504-h846-no/IMG_20140616_105755899.jpg

Here is the passenger side subframe connector.

https://lh4.googleusercontent.com/-kgYFH_HNGvw/U5-phCGjHoI/AAAAAAAAl10/ymbxkdnWrjE/w1504-h846-no/IMG_20140616_105818099.jpg

https://lh5.googleusercontent.com/-M1YDbbtJHbI/U5-phKmSBtI/AAAAAAAAl10/BDwwZzcDXyc/w1504-h846-no/IMG_20140616_105806481.jpg

The first coat went on extremely easy and in relatively no time I had the first coat on both subframe connectors.

https://lh4.googleusercontent.com/-LtmTBJGeP7I/U5-phHWLuKI/AAAAAAAAl10/7XGUZfzuvIA/w1504-h846-no/IMG_20140616_112820063.jpg

https://lh6.googleusercontent.com/-3Og3R70WKZY/U5-phKNdXlI/AAAAAAAAl10/yH51L8LSbgo/w1504-h846-no/IMG_20140616_112830594.jpg

https://lh5.googleusercontent.com/-qkSRASIBPj8/U5-phF-uk1I/AAAAAAAAl10/vzoGExYXMTk/w1504-h846-no/IMG_20140616_113233749.jpg

https://lh4.googleusercontent.com/-KgYGSq12NSc/U5-phHkxVCI/AAAAAAAAl10/U6b5lRIyOFM/w1504-h846-no/IMG_20140616_113246184.jpg

https://lh5.googleusercontent.com/-ZqAokbB8NTQ/U5-phPLgckI/AAAAAAAAl10/jelYRlCDlrs/w1504-h846-no/IMG_20140616_113258163.jpg

Now that the first coat was on the subframe connectors, I started on the Panhard/track bar. The first thing I did was hang it from the painting hooks in the ceiling. I used 30 pound Spiderwire fishing line to hold it up.

https://lh4.googleusercontent.com/--YM0nxKxYvU/U5-phG0f5EI/AAAAAAAAl10/GTPIEttJGyU/w1504-h846-no/IMG_20140616_125343887.jpg

I masked off each of the grease Zerks with painter's tape.

https://lh3.googleusercontent.com/-RHB3UBOewwQ/U5-phMmGkkI/AAAAAAAAl10/SoVzdnVa6p0/w1504-h846-no/IMG_20140616_125648176.jpg

https://lh6.googleusercontent.com/-2ho93UQrPVc/U5-phO-viRI/AAAAAAAAl10/7MQPwoT6lC0/w1504-h846-no/IMG_20140616_125731838.jpg

The first coat went on the Panhard/track bar just as nicely as it did on the subframe connectors.

https://lh6.googleusercontent.com/-3yQFJkQwTFE/U5-phOeRRMI/AAAAAAAAl10/K8pv6MNPLqk/w1504-h846-no/IMG_20140616_131548942.jpg

I had to let the first coat dry until just a slight finger drag was present before the second coat could be applied. Sara had just got home, so we went in to have lunch.

After lunch I went out to check on them. I did not expect them to be ready yet, but with the higher humidity I just wanted to see how they were doing. What I found really surprised me. The POR-15 had hundreds of little bubbles in the finish. In all of our experience with applying POR-15 we have never seen it do this.

I called POR-15 to see what they could tell me. The POR-15 rep said that high humidity is usually not a problem, however, if it is above 71% it can sometimes bubble because the POR-15 dries too fast and forms a skin before the gas caused by the molecular bonding can escape. It is the trapped gas that causes the bubbles. 

https://lh5.googleusercontent.com/-acVyFLgSDqQ/U5-phJAAbmI/AAAAAAAAl10/58vF4zxFLR0/w1504-h846-no/IMG_20140616_132753711.jpg

https://lh5.googleusercontent.com/--1UJGswOQRA/U5-phI2--2I/AAAAAAAAl10/eV_IcXN2UCc/w1504-h846-no/IMG_20140616_132805321.jpg

The POR-15 rep told me this will not affect the POR-15's protection of the metal surface. It just does not look good. He recommended sanding with 320 grit sandpaper to remove the bubbles and then reapplying. 

I am going to have to wait for a day when there is less humidity though and rain is not in the forecast. I was hoping that would be today, however it is 97% humidity outside right now with a 80% chance of thunderstorms. I am hoping to finish Friday afternoon instead.