How to rebuild the front fenders?

[BMW3.0CSi]

[FONT=&quot]Hi all,

I have a question about my front fenders. I want to try to rebuild the upperpart of the front fenders, because new ones are so extremely expensive. The gutter/drain and the sheet metal on the upside of the fender has to be replaced, because they are rusted. (See the pics) Does anyone of you have experience with this? Or does someone have tips or trics to get this job done?

I have looked at a lot of restorations topics, but there are not many topics who discuss the front fenders. Neither do they give an anwser about the question if the fenders were still in good shape or that the bought themselves new ones.

I have an idea to fix this, but I'm interested in any suggestions from your side.

Regards, Rinke

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[John Buchtenkirch]

I'm thinking the reason no one has answered your question is because most people realize that once the top of the fender rusts out the top of the strut tower, the top of the fender skirts and the part of the firewall that is behind the front tires is going to need rust repairs too. Basically, you really have to remove the front fenders to assess those areas for repair work. Also if you weld the patches shown in your photos into the fenders the metal is going to shrink along the weld seam and curve the top corner of the fender inward. You could minimize the curving problem by putting you weld dead center in the approximately 2 inch wide area that is the top of the fender, in other words don't use the whole patch panel as shown in the photos. This would have the added advantage of being able to tap the weld down if it's a little high. Personally I would recommend you go for the fenders unless you already have a lot of body work and welding experience. ~ John Buchtenkirch

 

[BMW3.0CSi]

Hi John,

First of all my appologies for the very late reply and thank you for your feedback. I've tried to repair the front fenders and almost managed to fix it. Almost, because after a thermal paint removal treatment it turned out that there was to much rust on the places where the A-post starts and the rubber of the nose section hits the front fender.

I have added some pictures to show you how I made the new top piece of the front fender.

It all fitted very well, but at the end I bought myself some new ones..

 

[BMW3.0CSi]

Some extra pictures.

The proces was as follows:

-. First I cut out the rotten parts of the fender.
-. After that I had made a piece of sheet metal and made it fit into the fender.
-. Then I spot welded the outer side of the sheet metal to the front fender as shown on the picture
-. Then the most difficult part of the proces came across, welding the gutter to the front fender and maintain the right shape in reffer to the hood. I placed the front fender on the car in it's normal position. I installed the hood to have a reference for getting the sheet metal piece into the right shape.
The gutter was cutted into three pieces to get enough strength in the construction, I also did this to keep it as original as possible.
When I had everything in place I pushed the sheet metal upwards from underneath to get the right line of shape and welded it to the gutter.

After all, for an amateur I was satisfied with the result. Especially with the smoothness of the shape of the fenders. Of course my painter had to do some final finishing.

Regards

 

[John Buchtenkirch]

Any patch work I do at my business is all cut to size and then butt welded into the part on the entire seam, that eliminates problematic lapped seams where capillary action draws in water and causes future corrosion. I think you made the wise choice when you bought the new fenders :smile:. ~ John Buchtenkirch

 

[tmason]

Hi John
What is a Fusion Welder,I did a Google search and they look like spot welders?
And how much are they?
Thanks

 

[John Buchtenkirch]

Hi John
What is a Fusion Welder,I did a Google search and they look like spot welders?
And how much are they?
Thanks

Fusion welding is just a style of welding where you melt metal together without adding any welding rod, it can be done with gas welding or tig welding. The advantages are minimal or no grinding (just hammer the weld flat) and minimal metal distortion but it does require nearly perfect fit-up of panels and a lot of practice and experience. I still make mistakes and have to add rod but after 40 plus years of experience and not the greatest eye sight anymore :-( I can still do okay :smile: on some days. ~ John Buchtenkirch