It’s been a fairly slow week in terms of progress, partly due to work interrupting a couple of days, partly due to some annoying paint reactions.
In the last post I had the wing all ready for the primer. So on Tuesday I went ahead and sprayed the bumper with U-Pol P88 primer. This was an old tin of primer which I opened about 2 years ago to do another project, but it’s cheaper than the Zinc 182 which I have recently bought, so I went ahead and used it anyway.
Having done the first coat, I left it to cure for the recommended time. Unfortunately, the primer did not take at all well to the wing. Firstly, I thought this was down to the thin layer of primer I sprayed when I removed the old paint (with the aim of preventing rust whilst I did other projects). However, having removed all old paint and resprayed the primer, it was still lifting/cracking.
This was really annoying, as I had prepped the wing well, sanded the whole thing down with the recommended 120 grit sandpaper and degreased before spraying. Having racked my brain, I really couldn’t come to a conclusion why it was cracking everywhere, so I called it day and came back with a fresh approach on Thursday (at work on Wednesday).
I had to leave for work at 2pm on Thursday, so I didn’t have all that much time. The first thing I did was strip the failed P88 primer with an angle grinder and a preparation wheel. I still hadn’t come to any firm conclusions as to why the P88 hadn’t taken to the metal, but I knew the Zinc 182 worked on the bumper plinth, so I decided to use that instead.
Lo! and behold, it went on nicely with absolutely no issues. I couldn’t believe that I had wasted a whole day due to the type of paint. Now, whether the P88 had gone off (do paints have a shelf life?!) or some other reason, I honestly don’t know.
A small bone of contention; I do realise that a self-etch or epoxy primer would’ve been a decent way to go when laying down the first layer as it eats into the metal, forming a great bond. However, I just purchased 5 litres of Zinc 182 and it needs to be used up – I’m also happy with the way it comes out of the gun, so I’m sticking to it. This may well cause some issues later on down the line, but I just want to get this panel finished now…!
The primer went on in 3 coats and it’s now ready for the black. Check out the finished article in the next post.
In the meantime, I had to give the taxi a good clean as it was just sitting there in an unhappy state!