Various coating tips sought for wheel wells, rockers

[DieselBenz]

Hello all,

I am currently in the middle of my first significant restoration/repair effort that I have been working on and off on for about a year and a half. I am hitting a point where I am getting a little discouraged so I thought I'd join here and get some inspiration from other people's projects and maybe get some advice on things I am second-guessing on my project. My car is much less "classic" than most of the projects here and only important because of personal sentimentality so I hesitate to post it in the detailed restorations thread. It is a "driver quality" restoration.

 

The question that is on my mind at the moment is about coating the welds I have done. Unfortunately I am questioning this a little late as I have completed several areas. On smaller projects I have used POR15 and it has held up very well, so I chose that to use in wheel well and other non-visible, non-UV exposed areas. The car is a 1987 Mercedes with monocoque body and is not going to be a concourse restoration, but I do want it to last as long as possible as my non-winter daily driver. On some areas there was light surface rust that I chose to clean up and paint with POR, but I also used the POR to coat the areas where I had cut out all rust and welded in clean metal. I was very meticulous with prep and used the zinc etcher prior to application. After POR, I applied seam sealer and then overtop all of it, 3M undercoating. Based on my experience and some recommendations of it online, I felt confident. But now after coming across some mixed opinions about POR I'm wondering if I made a poor choice and should have used an epoxy primer? At this point it would be quite difficult to remove what I have done, given all the crevices involved and access issues. For those with more experience than me (any experience!), do you think I will be safe with the coatings I have chosen and I'd be better to leave what's done done, or is adhesion going to be risked enough that I should considering trying to strip them and use a different choice of coatings. I will attach some photos of the areas in question; please forgive the beginner's quality ... I discovered well into this that I bit off more than I can chew but am doing the best I can. Three photos are of the front spring perch repairs (bare, with POR, and after seam sealer and undercoat) and three are the rear wheel well where I patched several areas of rust and replaced the subframe mount (bare, and with POR15 plus POR self-etching primer over it ... I was planning to undercoat it as well). I have since installed the full front suspension but the rear is far from finished.

 

My next step is going to be to weld on new rocker panels/outer sills and I have questions on this as well. This is the part that will probably see the most road grit and wear, so what do you recommend I choose as coating for the underside of that? Stick with the POR process above? Or use epoxy primer? Or chassis black? I have seen people mention using all of them and it's hard for me to decide what's right. Also, the new factory panels come with a (seemingly somewhat durable) black paint on them. Obviously I will remove it in areas to be plug welded and apply weld through primer (I use Copperweld). Should I leave the factory coating on the rest of it? I was thinking I certainly would on the inside, as I won't be able to access that to paint it. As you can see in my photos, I chose to leave the factory coat on the new spring perches ... the same question applies there, as I could still topcoat it.

 

My last question is about the inside of welds that can't be reached. Per various tips from books and internet searches, I have been painting the backs of these pieces with the weld-through primer before welding, and once the area is complete spraying cavity wax in those areas. Will his be adequate protection or should I be attempting to spray some other coating in there? My concern with the latter was that there is no way to prep the area so I could imagine very poor adhesion. Whereas the wax will creep everywhere. I already sprayed wax behind the spring perch area so I can't go back and use another coating now, but could change my approach on other areas going forward.

 

Sorry for the long post but I would appreciate any tips and/or reassurance that will make sure my hard work is protected correctly. Thanks.

[ted sweet]

you will be fine