Morris Minor Owners Club

I hope someone out there can help me.
I'm trying to work out how to replace the sills on my converted saloon. I've taken the outer kick steo off and it is clear that the boxing plate and the outer under sill will need replacing. Looking through the holes in the boxing plate the inner sill looks sound with just a little surface rust where it joins the floor. Inside the car it is covered by what I guess is a sill strengthener which also looks OK although there is one patch on the floor adjacent to it which covers a small hole.
Do I need to cut the inner sill strengthener out or should I just leave it and take the boxing panel out first?
Also are there any ways of replacing the sills without cutting off the rear 1/4 panel?

Thanks for any suggestions...or if you are in Cornwall maybe you'd like to come and have a look at it (there's a cup of tea or a can of beer in it!!)

I'd suggest you get some specialist advice before starting. Even on a saloon it is quite easy to distrot the whole car when replacing sills so on a Convertible it's almost a guarantee!
Certain places like Canterbury Convertibles have done dozens if not hundreds of converted saloons so they should be able to give good advice on how to repair them properly.

The convertibles(and Travellers) are originally fitted with an
additional 16 swg 'U' section beam inside each sill assembly.
Mine had rotted badly and I was advised not to attempt to renew
them but to leave the remains in situ and fit the inner oversill
assemblies which are supplied in the conversion kits to turn a
saloon into a convertible. I am perfectly satisfied with the rigidity
of my car and would recommend this method. You say that you
have an additional oversill strengthener fitted already? So it had
been rebuilt before? You CANNOT properly rebuild the whole
sill assembly without cutting away the bottom section of the
rear quarter panels. On my car the rot in that part was worse
than in the 'under door' section. Be prepared to have to make
up some repair sections. When you reweld the repair sections
on these rear quarter panels beware of heat distortion.

I see that yours is a converted saloon so that explains the
extra oversill. Do make sure that you have the 'B' post
reinforcing uprights and the curved sections added to the
right and left dashboard corners. I have seen cars without
them!

also you need a flat floor, and do any welding with the doors fitted and closed,( inc pin), as much as possible. check opening closing as you go.

thanks for the advice...I'll try and contact canterbury convertibles after the bank holiday weekend.
The conversion does seem to have been done with all the right panels. Will I need to remove the B post strengthener to get to the sill structure behind it? I was planning to brace the door gap with some lengths of angle iron (like in the Jim Tyler Book) and I should be able to keep the doors closeable if I weld the angle iron inside the door shut flanges.
I'm just wondering if it might be better to pay someone to do it for me as I have little experience in restoring cars.
Any thoughts...?

Well it is a job which needs handling in the proper manner.
It is advisable to do the sills with the doors on if possible as it
is too easy to finish up with a poorly fitting door opening. If this
is not possible in your case then bracing the opening with angle
etc is ok ,plus careful jacking of the chassis, before you actually
cut the boxing plates away. Do one side at a time!!!

spot, if you're asking these questions you should hand it over to someone. any convertible is very difficult to deal with, start a with 2 door saloon and learn the structure from that. remember its not a joke at 90 on the motorway, especially with no roof. if you remove sills and boxing plate (one with holes), then the only strength between front and back is the flat metal floor. which becomes very flexible, do you really want to go there?
ps make sure the people you give it to know what they're doing.

Last week I had a look at a convertible with very similar rust problems. My local specialist (Chertsey Minors) are restoring it. To avoid distortion they had removed the seats, carpets and gear box cover then welded two square section bars across the top of the box sections on both sides These were square section bars and about 4.5 feet long to bridge the gap. They also braced the scuttle / dashboard with more bar sections. When they were confident that the bracing made the car rigid, they started to cut away the rusty boxing plate.

did they support the dashboard, it goes on and on.

if you're asking these questions you should hand it over to someone. any convertible is very difficult to deal with, start a with 2 door saloon and learn the structure from that.

having rebuilt a couple of cars myself I would agree.

I've scrapped 2 Minors (which I don't brag about) but one of which was a 4 door saloon where I'd removed complete floor, sills, inner step ond one side and the complete crossmember and was part way through fitting new metal. It was more than 10 years ago and being younger my enthusiasm was bigger than my ability. It was more work than I wanted to do but when I realised the mistakes I'd made due to lack of knowledge + expertise (skill) and the fact that if the car ever went back together the doors wouldn't fit correctly etc.. I had to cut my losses.

I'm not saying it's impossible but DIY comes with no guarantee, and for a convertible it's best not to learn by your mistakes (that's what saloons are for ).