Been a while since the last update.. I have spent way more hours than I wanted on doing this but here goes.
I was trying to find a knocking noise from the front end of the car after installing the BC Racing coilovers and had changed virtually everything and still couldn't get rid of it. I reached out to BC Racing to see if they could inspect them for any dampening issues or faults. While BC agreed to look into the issue I had a great idea of fixing any rust on the sills/arch areas of the car. I had a few small rust bubbles on the lower door shuts and I had abit of surface rust behind the drivers wheel arch liner at the front end of the sill. I knew there would be more to find when taking off the side skirts from all the rust posts I have seen in the past. I was quoted 3 weeks for BC to have a response and for me to get them back so I could use the car again.
So firstly I started to strip the front bumper off and wheel arch liners. My old bumper had a crack and wasn't in good condition so I managed to pick up another bumper that was in decent condition. I then took off the side skirts which revealed rust at the back of the sills and the lower inner arch area. The original underseal had started to crack and was holding alot of water and dirt. Once I started peeling some of it off it was apparent that it had to be completely removed and start from scratch. There was lots of areas that had 0 signs of rust or water but as soon as you poked the underseal with a pick tool you could see the water starting to drip out in places.
I ended up cutting out all of the rust which was both rear sills and lower inner arch panels, and the front of the drivers sill. Once I had all the rust cut out I found there to be two bags full of foam that sits between the rear quarter and the rear metal behind the door cards. While the foam was in a sealed plastic bag it was soaking wet and meant that any water that got in the sill would be stuck at the back end of the car. I know car manufacturers do this alot but not really sure why? My 1992 Mr2 Turbo has a similar issue.
Once all the rust was cut out I was able to get an inspection camera along the full outer side of the sills which let me determine if I was going to have to replace the entire sills (which I have done on another mk5 and wasn't fun). Most of the areas were easy enough to get into and clean the metal inside with sanding discs or a wire wheel. I used zinc weld through primer within the sills to make sure they weren't bare metal that would end up rusting again.
I bought 1 full sill panel from eBay which gave me enough to work with when replacing the 3 parts I cut out. The sill shape on a mk5 is pretty easy to work with and match upto. The repair panels were slightly warped and took some panel beating to make them look like the original shape. The back lower arch areas I used spare metal I had lying around and manipulated it to match the original shape. Once all the welding work was done I had to panel beat the rear arch lip areas as the panel never came pre bent.
At this point I then got some torx screw plastic inserts from VW so I could refit the lower arch liner rubber splash guards. I ended up chopping these up as the design doesn't allow water or mud to escape and will lead to more build up and eventually rust.
I filled the whole length of the sills, inner arch, jacking points and inspection panel with BiltHamber Dynax S50 cavity wax. Also used some of this to coat the arch lip areas as it dry's like a hard wax and will repel water really well.
Now to the frustrating part.. I wanted to learn how to paint and have been doing so for the past few months, I thought this would be perfect time to attempt painting/blending. First off I sanded and painted the new bumper I got. Turned out ok but could have been better. Next up was the grill and the Edition 30 lower lip, both of these turned out great. I also wanted to smooth and colour code the side skirts as the front/rear lower bumpers were no longer black textured plastic. After watching many youtube videos I finally committed to painting both rear quarters. At this point I was ******* myself as I was about to take sandpaper to my car and possibly have an epic fail of trying to paint it. The passenger side I managed to sand the lower half of the quarter, door shut and blend the new paint into the original paint. The door shut turned out great but the rear quarter you could see a haze line between the original paint and the new paint. I tried wet sanding again and polishing which did blend the colour to the point it is barely noticeable.
For the drivers side I had to sand upto the plastic bump strip that runs along to meet the door, this made it very difficult to paint and not see a difference in the finish/colour. First attempt was ok but I ended up sanding too much when wet sanding and went through the clear coat. Had to sand the whole area and start again. Second attempt.. I had ran out of paint and ordered a new batch, this one looked very slightly lighter than the paint I was using on the rest of the car. I ended up mixing it with the little amount I had before and started painting again. On the second attempt it turned out even worse because I didn't sand the primer back enough you could tell a height difference between the new paint and the original paint. At this point I was close to giving up as I couldn't achieve the finish/match I was aiming for, so I called around a few places to paint the rear quarter but was being told I would have to wait 6 weeks minimum bearing in mind the car had been off the road for 4 weeks at this point. I then spoke to a few painters for advise on blending and achieving a good finish, they recommended I changed my technique and purchase some good quality paint guns.
I could either wait and spend the money on getting someone else to do it £600 or buy a good set of guns and try again £400. I had planned on painting another project car I was working on so I decided to end up buying the new guns and getting as much advise as I could. I sanded the lower half back to bare metal and scuffed up the whole quarter, door jam and sill area and attempted it again. This time it turned out great and the new guns made a massive difference. Paint match is really good and the finish is night and day different to the results I was seeing before. I think I spent a good 20+ hours this time masking off the whole area, sanding, wet sanding, painting, polishing etc. Finally achieved the result I wanted and gave me much more confidence in painting other projects in the future.
Some pictures of the before, during and after.
