With the patch at the front complete it is time to fit the 'castle rail' (bottom piece) and the inner sill. These are the two main structural components of the bottom side of the car and will support the outside edge of the floor. Fortunately there are some excellent reference points to get the inner sill aligned. At the back it has to mate with the piece of the rear frame component that comes over the wheel arch and at the front there is a small indent in the B post that aligns with - this is why you have to be careful taking the old sill out so you do not lose the reference.

I was fortunate because the cross-member was in very good condition and so was the jacking point so when it came to fitting the castle rail and having reference pints I had a slot that it went straight into. Then there was some fiddling to fold it up at the front fit it to the back wheel arch. There is some messing about to get it to capture part of the front so that there is a tight seal on the front outside edge.

I plug welded the panels into place then because I could get the the inside I seam welded them the entire length which should make them stronger than the original.

Note::
The distance between the top of the inner sill and the bottom outside edge of the castle rail should be exactly 5.5 inches because that is the width of the close plate that goes in next. It is also the width of the outer sill that is going to be seen so getting the width right all the way along is important.

The picture shows the inner parts of the structure in place and the seam welded join. (Taught myself to weld so it is not great but it should be strong)

Now the door gap is reinforced and the floor is out it is time to start sorting out the problems. In the case of this car the first problem was the fact that the front part of fire wall that supports the floor had rotted away so there was nothing to attach the new Castle rail and inner Sill to. So I had to make a patch to cover what had rotted away. I don't have a background in metal fabrication so the patch is not great but it will not be seen so as long as the material is solid all should go well.

The picture shows the patch I put together. You can also see the holes along the side where I had to drill out the spot welds holding the 'outer sill', close plate and Inner Sill to the box section which supports the wing. You can see the holes where the wing bolts go through from the inside but are hidden inside the wing.

The main support rail which under the passenger side floor can also be seen. These were in reasonably good condition on this car so one less job to do.

I will update the next stage tomorrow. Hope this is useful to someone??

As you can see from the previous post the passenger side was in a very bad way (apparently it is the side always against the curb so it is often being driven through water?) The floor was shot (it had been patched and then filled with bondo) and water had been trapped against the sill and rotted it all out i.e. outer sill, center close plate, castle rail and inner sill. This meant that I had to cut out almost the whole side of the car then work my way out again. I did not take a lot of early shots of this side so what I have posted is a shot of the 'driver side' before I got started.

If you look hard at the shot you can see the key bits of the structure i.e.
- the floor with it patch.
- the outer sill (the white bit on the right. It is the step into the car)
- the inner sill which is what is badly rusted because of the rubber mat holding water.
- if you look through the hole in the inner sill you can see the castle rail which forms the bottom. You can also see that the lip of the castle rail supports the floor.

The steps I followed were as follows:
- cut the floor out using a hammer and cold chisel + some work with a drill. That meant I could clean up the primary supports and patch anything that needed.
- brace the door gap using two pieces of 1/2" square steel section tack welded to each side about a foot apart.
- Then start removing the sill components from the outside in being careful not to ruin the edges I was going to have to go back and work with.

I will update with the next stage tomorrow.

I have been trying to bring this 1969 MGB back to life for about four years but it has been a difficult road. I brought the car with the intention of updating may of it pieces with bits from my previous car which was written off in an accident. However, once I started working on the car I realised that it was in a very, very bad way and what started out as a 'cosmetic' update has ended up being a total reconstruction.

This shot shows the state of the sill on the passenger side (LHS in Australia). As you can see under the two layers of rubber matting there was very little steel left ..... and the PO drove it every day!!!

I am ready to get the car painted but will upload some of the more interesting bits of work I have undertaken so that others might benefit from what I learnt.

The whole history is at my web site http://members.westnet.com.au/des.thornton/