17 replies to this topic

[OllieTheWelder]

Hi, I have a 88 and was wondering if it would be worth removing the outer sills? I don't want to leave it to late and find out I'll need a new floor. What do you think, should I leave them or take them off? Also what's the best way of removing them without cutting straight into the under sills?



Thanks, Ollie.

[myredmini]

By your name I take it you can weld. Get them off asap, you should be able to save the inner sills and get some 4.5" original sills on it, theres no doubt, it WILL eat into the sills and floor pans, I am replacing front and rear floor pans on my project because of over sills..

Dan..

[Carlos W]

there's some interesting looking holes, and the jacking point looks a bit sus!

[BeardedMidget]

Cover sills is what you have there. They are'nt brilliant because they dont let your inner sills breath but they are'nt the end of the world like some believe. If the inside area's were properly protected when they were fitted then there should'nt be a problem. Take up your carpets-the inside of the inner sills are visible under your door apeteure and down at the bottom of the door pocket If no rust is visble you are ok. Drill some holes into the enclosed areas and get busy with the waxoyl! If there are holes in your inner sills hidden by the covers then i'm afraid they need to come off and be repaired properly. The inner sills are structural and although a cover sill will get it through an MOT the shell is'nt as strong and might be unsafe in an accident.

[sonikk4]

As per Dan get them off asap, i have just done this on Project Paddy, cut along the top lip with a 1mm stainless steel cutting disc then do the same at the front and just fwd of the the rear heel board. Once you have done these three cuts pull the sill down (you may have to cut around the jacking point if its been attached) this should allow you to see exactly where its been welded along the bottom.

Although you may not see rust under your carpet inside the car this does not mean the inner sills are good.
As in the above picture there is rust but not too bad and remember this car is over 36 years old so the inner sills are really good for their age however if i was restoring the car now i would replace the inner sills as they will not last for much longer. I have treated these areas and protected them for the time being and then in a couple of years they will be replaced.

Cut as close as possible to the welds then carefully grind back the welds until the sill splits off. If you are really lucky like us the old sills would have been cut off, if not and the old rotted sills were left on then i think you will find some nasties hiding i'm afraid.

Edited by sonikk4, 29 May 2011 - 07:50 PM.

[OllieTheWelder]

Thanks for the quick reply I'll have a look for some 4.5" then

Ollie.

[OllieTheWelder]

Cover sills is what you have there. They are'nt brilliant because they dont let your inner sills breath but they are'nt the end of the world like some believe. If the inside area's were properly protected when they were fitted then there should'nt be a problem. Take up your carpets-the inside of the inner sills are visible under your door apeteure and down at the bottom of the door pocket If no rust is visble you are ok. Drill some holes into the enclosed areas and get busy with the waxoyl! If there are holes in your inner sills hidden by the covers then i'm afraid they need to come off and be repaired properly. The inner sills are structural and although a cover sill will get it through an MOT the shell is'nt as strong and might be unsafe in an accident.

I've just looked under the carpets at the inner sills and they have a bit of surface rust but nothing too bad. Where should I drill the holes? Do I drill through just the over sills?

[sonikk4]

To be honest with you why bother, there are holes already in the top of the sill which will need sorting. Also looking at the jacking point that appears to be suffering.

Yes you could pump waxoyl in but over sills are weaker by design plus the one in your picture is rusting so will be even weaker and an MOT failure.

Take it off and find out what is going on underneath it, the longer you leave it the worse it could get. If over sills were good then they would be on all mini's, they are a repair panel not a replacement panel.

[BeardedMidget]

Cover sills is what you have there. They are'nt brilliant because they dont let your inner sills breath but they are'nt the end of the world like some believe. If the inside area's were properly protected when they were fitted then there should'nt be a problem. Take up your carpets-the inside of the inner sills are visible under your door apeteure and down at the bottom of the door pocket If no rust is visble you are ok. Drill some holes into the enclosed areas and get busy with the waxoyl! If there are holes in your inner sills hidden by the covers then i'm afraid they need to come off and be repaired properly. The inner sills are structural and although a cover sill will get it through an MOT the shell is'nt as strong and might be unsafe in an accident.

I've just looked under the carpets at the inner sills and they have a bit of surface rust but nothing too bad. Where should I drill the holes? Do I drill through just the over sills?

You want to get wax in between the two layers of metal but you dont want any holes visible on the outside of the car. I would drill a few holes along your door step then plug them with rubber grommets after your done. Pump the wax in with a flexible probe and make sure the probe goes all the way to the end of the sill on both sides. Make sure the wax is as hot as possible too otherwise it will be viscous as hell and wont find its way into all the little nooks and crannys. Just make sure you are happy there is no rust first though because any wax will have to be removed before you will be able to do any welding.

[OllieTheWelder]

Ok, Thanks for the help guys. I'll have a think about it.

Ollie.

[valve bounce]

if you want to see the inside condition i would just cut one of the squares of sill off to see inside

[MigliaMayhem]

Over sills are as nasty as people make out for one simple reason, the flutes on a genuine sill are there to allow water to drain off out of the sill cavity, now minis with over sills on are classed as a repair panel and require seam welding for the MOT. Any water that gets in there including condensation will quickly rot the car out as it has no where else to go.

I am yet to see a decent inner floor/over sill that has stood the test of time and I'm sure many of the lads who restore the cars will back this up. People who like these sills are either too lazy to carry out the correct repair to the floor prior to fitting genuine spec and use these to cover up what should be a seperate panel or don't know any better and accept it as a sound repair by garages that should know better.

A pattern sill costs only a few quid and are a canny fit, genuine can be had for less than £30.00 so it is false economy to go ahead and fit these cover sills, they look horrible and hide a whole load of misery for future owners.

I would never accept the word of a restorer if I seen a pair on his finished article but believe me there are plenty who do, the only model that should have no sill is the early mk1 as this was part of the floor and for some funny reason it was quickly changed..

[Cooperman]

Over sills are as nasty as people make out for one simple reason, the flutes on a genuine sill are there to allow water to drain off out of the sill cavity, now minis with over sills on are classed as a repair panel and require seam welding for the MOT. Any water that gets in there including condensation will quickly rot the car out as it has no where else to go.

I am yet to see a decent inner floor/over sill that has stood the test of time and I'm sure many of the lads who restore the cars will back this up. People who like these sills are either too lazy to carry out the correct repair to the floor prior to fitting genuine spec and use these to cover up what should be a seperate panel or don't know any better and accept it as a sound repair by garages that should know better.

A pattern sill costs only a few quid and are a canny fit, genuine can be had for less than £30.00 so it is false economy to go ahead and fit these cover sills, they look horrible and hide a whole load of misery for future owners.

I would never accept the word of a restorer if I seen a pair on his finished article but believe me there are plenty who do, the only model that should have no sill is the early mk1 as this was part of the floor and for some funny reason it was quickly changed..

The reason the Mk.1 sill was changed is because the early cars had foam-filled sills, so no water could get in. However, after someone nearly died from toxic fumes when trying to weld an early car caused a re-think about foam filling and then the need for drain holes was required.

Edited by Cooperman, 30 May 2011 - 06:52 PM.

[lrostoke]

You see a lot of comments about water drainage being a problem with oversills. But even though I have fitted proper vented sills on the last 3 sill and floor jobs Ive done I do struggle with this water explanation.

Surely water and damp getting up into an open cavity including road salt is as much of an issue.

The sill is basically the equivalant of a chassis rail with are basically box sections, so I would think with all the rust cut out and regular waxoiling the risks of rot are as much as an open sill ???

I think the big killer with oversills is the lazy &^**^%% who just weld them over rotten old sills.

Edited by lrostoke, 30 May 2011 - 08:09 PM.

[sonikk4]

If there is sufficient treatment in each sill ie paint and waxoyl then being open to the elements would not be an issue as the water/moisture could drain out.

With an oversill even with treatment moisture will still build up and over time will start the corrosion process. But like you say if the old sill has been cut out, any damage treated correctly then there is no reason why an oversill would not do the job apart from the lack of strength issue that has been discussed in several other threads. By drilling holes at the bottom of each sill would suffice to let any moisture out.

As you can see from the pictures i posted of Paddy the old sill were removed but there was no treatment applied inside the inner sill and the oversill so a waste of time apart from making the car look good. Within a year of being used on the road i would put money on the sill rusting through plus doing damage to the floor and of course the untreated rust on the inner sills would have perforated.