OK, I apologize in advance for not having pictures right now. I had like 5 things on my maintenance list today, and I didn't bring a camera with me (the car is 17 miles away at my parents' house, I have been biking over to prep it for a motor swap).
There has been one crack growing out of the left side of the tray area on the passenger side. I see it on a lot of E30s. Over the last year, I have been watching it creep further & further. It got about 1" out of the tray, and I decided to do something about it. There are two smaller ones, IN the tray as well. Before anything, I got some paper towels & a toothbrush out and cleaned the cracks & areas around them with rubbing alcohol to get all of the old dash conditioner off.
So I started by putting a 1/8" drill bit into a small tap handle. I then carefully put 1/8" holes in the black vinyl covering about 1/16" past the end of the visible cracking (I wanted to be sure that it wasn't going to propagate past there). OK great, now I have some fairly obvious holes in the dash!
Well, I decided to fill them with some Dow Corning black silicone RTV. I don't recommend Permatex ultra black because it is more grayish, and it has metallic flakes or something in it. Plain old black silicone RTV is black and slightly translucent, which helps it to blend into the dash.
So, I applied it liberally to the cracks & holes, really working it in as deep as possible. It tends to get all over. I then used a folded up paper towel to wipe the excess off and get it out of the texture of the dash. This isn't perfect because it will tend to scoop a little out of the holes & cracks, leaving some visible depressions. I repeated this a few times, waiting an hour in between. As of now, there is still a visible depression, but it is less conspicuous since everything is black now. The RTV is a little shinier than the dash right now, but once I put some dash conditioner ("Armor All") on there, it should even out.
I wish I could just leave it splattered on there, let it set and then scrape off the excess to get a nice flat finish. Sadly, RTV is a pain when cured, and very rubbery, and trying to remove the excess around the cracks would likely just pull it out of the cracks! I will see if I can use a soft silicone putty spreader to flatten it out better next time. The skin of my finger is soft enough to sink in to the crack when wiping, which leads to the uneven surface finish. If I use a silicone squeegee and then wipe the excess off of the surrounding areas VERY CAREFULLY with a rag, it might give me the flat finish I am after.
While getting into the car, the light was hitting the repaired spots just right and it was sort of obvious. Once I was in the car, it was less obvious than before the "fix." Once I even it out & apply some dash conditioner, I am hoping that it will blend in well. If not, then I can always search the local wreckers for clean dashboards, or may be get a nice BMW embroidered dash carpet lol. I'll see if I can get some photos tomorrow when I go help my younger syster replace her M42's expansion tank.
Topic: Fixing Dashboard Cracks - My Method (Read 5446 times)