195 replies to this topic

[DomCr250]

^{I guess I am going to be shot down here but I really don't see the problem with cover sills. I accept that they are not original but if the inner sill has been repaired or replaced professionally by that I mean all the corrosion removed and then spayed with weld through zinc primer and then cover sills fitted, and the cavity filled with a wax type corrosion protector, then I really don't see the problem. But at the end of the day its up to the individual and there preference and as long as they are not fitted to hide anything nasty.. maybe that's is the only problem, if you buy a car with them how do you know... See I can even argue with myself sometimes !}

 
Ignoring the fact that they trap moisture witch has nothing to do with being left out in the rain. As you will always get condensation inside a steel box section, hence why the sills are vented. And oversills don't offer the same structural strength as proper sills do. I once drove a mini with oversills fitted both sides and before a pair of popper sills were weed on, when pushed (hard not to with so many roundabouts and mg metro 1275) the doors used to creek on their hinges as the shell flexed.

 
That's interesting. My Mini has oversills, and I intend to sort them this summer.
 
However when I go into my garage, I have to go up a small ramp. If I open the door whilst the car is halfway up it (front wheel up the slope, back wheel on flat ground) then the door latch rubs on the striker plate. If the car is level that doesn't happen. Sounds like the shell on mine could be flexing as well.

Shells flex if you subject them to enough movement from new. I had a 309 GTI brand new in 1989 and you could not even close the back doors if you parked the front on a decent curb.

[DUF2]

Just read all the pros & cons re Oversills.
A standard sill it attached at the flange where it sill meets the door step, the bottom of the sill is spotted welded to the floor section approx half way up the section of floor at the 45 degree slope
An oversill attaches the the flange where it meets the door step (same as the proper sill) the bottom of the sill is welded to the horizontal section of floor, quite some distance to the top fixing.
Now I shall ask for opinions on this.
Use an oversill, but before fixing cut out the bottom of the vent "bumps" to allow ventilation, then run a line of spot or plug welds where the standard sill would be fixed, also the oversill would be welded to the floor, so in this case there are three lines of weld, ( the top flange, the middle of the oversill and the bottom of the oversill.
This method should provide even mor e strength than the standard sill fitment as there is a section of floor that is now double skinned. Obviously all sections to be painted before hand and Waxoyl injected into the cavities.
What are you thoughts on this?

[Cooperman]

Sounds like a disaster of rust waiting to happen.

Just fit as-original sills and there will be no problems.

[sonikk4]

Sounds like a disaster of rust waiting to happen.

Just fit as-original sills and there will be no problems.

 

Yup agree whole heartedly here. You are building in a rust trap along the bottom no matter what. A standard short sill as designed is what should be installed nothing else.

[1984mini25]

 

 

 

^{I guess I am going to be shot down here but I really don't see the problem with cover sills. I accept that they are not original but if the inner sill has been repaired or replaced professionally by that I mean all the corrosion removed and then spayed with weld through zinc primer and then cover sills fitted, and the cavity filled with a wax type corrosion protector, then I really don't see the problem. But at the end of the day its up to the individual and there preference and as long as they are not fitted to hide anything nasty.. maybe that's is the only problem, if you buy a car with them how do you know... See I can even argue with myself sometimes !}

 
Ignoring the fact that they trap moisture witch has nothing to do with being left out in the rain. As you will always get condensation inside a steel box section, hence why the sills are vented. And oversills don't offer the same structural strength as proper sills do. I once drove a mini with oversills fitted both sides and before a pair of popper sills were weed on, when pushed (hard not to with so many roundabouts and mg metro 1275) the doors used to creek on their hinges as the shell flexed.

 
That's interesting. My Mini has oversills, and I intend to sort them this summer.
 
However when I go into my garage, I have to go up a small ramp. If I open the door whilst the car is halfway up it (front wheel up the slope, back wheel on flat ground) then the door latch rubs on the striker plate. If the car is level that doesn't happen. Sounds like the shell on mine could be flexing as well.

Shells flex if you subject them to enough movement from new. I had a 309 GTI brand new in 1989 and you could not even close the back doors if you parked the front on a decent curb.

 

 

Shells do flex, But the mini I was on about with the shell flexing and creaking doors. The last garage to have worked on it and mot it (was bough after it had been mot'ed and then parked up for 8 months) had chopped the original sills off both sides and fitted oversills held on with nothing more than tack welds along there perimeter, covered over with sealant/underseal. The remains of the inner sills were stuck to the carpets when they were later removed. So I'm not surprised the shell flexed, but more surprised that the shell don't fold in half or at least would have done in a impact.

[Retroman]

Oversills should never be fitted, its just a cheap nasty rust disaster to scrape through an MOT. they are a nightmare.

 

   Early Mk1 sill were foam filled, which adds strength and as its a closed cell foam it stops rot too....its a shock when you first weld one though...fire watch is the phrase...hahah

 

Doing a '72 van that has had oversills...only way is to chop the lot out and start again.

 

This is a '72 van (upside down) with the oversill peeled back...tin-worm unlimited

[minimissions]

This all looks familiar to what my sidewalk was like, its a bloody mess and they shouldn't be sold as a panel.

 

Like you say only was is chop it all out see what is left and rebuild it all.

[JakesTe]

Is it possible to modify oversills by shortening them width wise and adding vents?

Hope this question wasn't already answered. 

[Marco1972]

Is it possible to modify oversills by shortening them width wise and adding vents?
Hope this question wasn't already answered. 

You can cut them down and yes it’s been done before
But unless you already have them just buy the proper ones in the first place save yourself all the hassle

[JakesTe]

 

Is it possible to modify oversills by shortening them width wise and adding vents?
Hope this question wasn't already answered. 

You can cut them down and yes it’s been done before
But unless you already have them just buy the proper ones in the first place save yourself all the hassle

 

Yes I have already bought them, that's why i asked.   Thanks

[CityEPete]

I can't understand why the reputable suppliers still sell them or even after all the pictures of what happens people are still trying to justify fitting them.

[Ben_O]

I don't just fit Heritage sills because they are not coversills, I fit them because they fit perfectly, look original have lovely clean edges and give no problems.

 

They aren't expensive either so no reason not to

[Marco1972]

Is it possible to modify oversills by shortening them width wise and adding vents?
Hope this question wasn't already answered. 

You can cut them down and yes its been done before
But unless you already have them just buy the proper ones in the first place save yourself all the hassle

Yes I have already bought them, that's why i asked.   Thanks

If you still have the receipt take them Back and get the proper ones 👍🏻

[first_mini_chris]

Thanks OP, really handy post, something I'll look out for when buying

[minimissions]

Hi all thought I would share some pics of our experience with oversills on our mini sidewalk the original sills were still in place.

inner sill repaired.

These were then stone chipped and painted to match the body..