Is This a Cover Sill?

[cobolman]

Car is a 1960 Mk 1 Mini. I've attached a couple of images below. Is this a cover sill?

2024-01-22_13-16-24.jpg

[Alex]

Early cars aren't my speciality, but I think home-made may be a closer description.
Without pulling it off or drilling though it there's no way of knowing if it's a single skin or slapped over the top of the grot.

[Peter Laidler]

Same as above. No vents that we can see....., looks like home made on a simple sheet metal bending machine. Of itself, probably OK but what metallurgical nightmare is it hiding.........?

[cobolman]

Of itself, probably OK but what metallurgical nightmare is it hiding.........?

Exactly my concern. I've spent absolutely ages removing Tetroseal and the more I remove, the more challenges I find. Now, it looks like I have cover sills to remove and I'm dreading what this might reveal.

I'm off on a car welding course tomorrow. I'm not sure I'm going to be learning enough!

[coopersean]

The very early cars had a flat sill, so it ma be original. Example can be seen on the 1959 mini register page - https://1959miniregister.com/variations-shell/

[cobolman]

The very early cars had a flat sill, so it ma be original. Example can be seen on the 1959 mini register page - https://1959miniregister.com/variations-shell/

That's a great catch, coopersean! Thanks for the link. That does look like mine and there's no discernible weld on mine either, which I found confusing. But maybe you've hit the nail on the head here. Fingers crossed. My depression is lifting a little ...

[mab01uk]

If you have the early flat outer sills the inner sills will be separate/joined to the floor with a seam (red sill photo).


If you have the later vented outer sills the inner sills are part of the floor (green sill photo).

[cobolman]

If you have the early flat outer sills the inner sills will be separate/joined to the floor with a seam (red sill photo).

Thanks - that helps to confirm what I had hoped. This is the inside of my car:

2024-01-22_17-05-44.jpg

So it seems that I do have the early, flat outer sill. What a relief! Then again, I need to take the Tetroseal off the outer sill and see what state it's in. I know there's at least one patch in it.

It's astonishing to think that this may be the original sill as fitted in 1960. The car did in excess of 70,000 miles in the twenty years it was on the road before being dry stored for over 40 years.

[mab01uk]

The flat sill cars do tend to survive rust better but the original design was changed to lap the sill joint the other way to stop water leaks under the carpet. It was said early prototype testing was done in dry climates....so the Mini was in production when the owners complained of wet carpets!
Many flat sills are also foam filled to cure the leaks which also seems to slow any rust but causes problems when welding repairs have to be made...

[mab01uk]

More info on the foam filled sills here:-
http://mk1-forum.net/viewtopic.php?f=3&t=36946

[harrymini]

Be careful welding near or around foam filled early sills

[cobolman]

More info on the foam filled sills here:-
http://mk1-forum.net/viewtopic.php?f=3&t=36946

Thanks!