Engine Bay and Wheel Arch Rust

Technical Area Body, Interior & Styling
1

Hi All

The car is new to me, one previous owner. There is more rust than I had anticipated and I am setting about getting this sorted.

I should say that I have already had the sills repaired both sides. The exhaust bracket fell apart in the first week necessitating a replacement exhaust. I have had the opportunity to view the chassis rails whilst the car was on a ramp and I have not seen anything to suggest they are at risk.

My inexperienced view is that I haven’t found anything that cannot be overcome (so far), but I would be very interested in experienced views before I embark on various ways to counter what I have found. Please see the attached images.

One image shows a wheel arch (R front) and you will notice that there is a hole at the top where the rust has completely eroded through to the engine bay. I am part way through de-rusting - I am aware this area needs more work.

With regard to the hole at the top, clearly I need to get to the otherside of it and make sure I completely clear any existing rush from both sides. Beyond that what would you suggest? Does it need a piece of steel welding in to repair it or would some other measure (which preferably I can do without needing to resort to welding).

I have a similar question relating to the large hole I found underneath the headlight cluster - as shown on the other photo. Should this be welded or are there other acceptable repair methods? Again, I know there is more work which needs doing in this area before I begin treating, but my question relates to the bigger issues.

r-front-headlight-cluster-surround-mx5
r-front-headlight-cluster-surround-mx52997×1906 716 KB
r-front-wheel-arch-mx5
r-front-wheel-arch-mx52688×4032 1.15 MB

I would really appreciate any advice from experienced restorers. I hadn’t anticipated having to do this kind of restoration, but I am eager to get it sorted - preferably myself where possible, though if it really needs a spot of welding I can arrange this too.

Many thanks for any advice offered

2

Where there are holes I would cut back to good metal and weld in fabricated plates.
Kill remaining rust with hydrate 80 or similar.
I would use metalik filler or alloy wheel filler as it’s now called to fill pitted areas and disguise weld edges.

3

I’d always agree cutting back to sound metal and welding in new panels is the way to go. However, I’d recommend using body solder to fill the joints between new and old panels to fill in and disguise the welded joints, particularly joggled joints. It has much better adhesion than ‘plastic’ fillers and is totally impervious to moisture. It was the preferred method when I did my car restoration course. PPE is very necessary when you file or sand it down, of course.

4

thanks guys, really appreciate this. Sounds like I am going to have to put the wheel back on and send it off to the garage for some welding.

I have the Dinitrol rust repair kit (https://www.frost.co.uk/dinitrol-rust-proofing-wax-underbody-coating-aerosol-kit/) which I was going to use to kill any remaining rust then treat. I was wondering what I should do about the pitting - there is some on the front wing - would this metalik filler smooth things over well enough for the outer body panels before they are primed and re-sprayed? Or would you use something else for outer panels/visible areas?

I am fully equipped with PPE, the idea of embedding rust in my cornea does not appeal! :smile:

5

Yes, use of a joggler may well make it easier to hide the welds and leave a better finish.
I’ve used Isopon Metalik or Alloy Wheel filler as the same stuff now available is called.
Used in many areas where waterproofing very important and cannot fault it. Easy to sand down too. This is nothing like the porous rubbish I used to use where a repair would last six months if lucky. .