Sill repair advise

[iandromiskin]

In removing the kickplates to gain access to the box section on my car to fit front seat belts I discovered a bit of flakey rust inside the box section. For the most part the sill and floor is very good but there are some small holes in three places in the inner sill and some where the inner sill meets the floor pan, though I suspect this is just poor welding.


Image from below looking up at the inner floor section on the near side showing two of the small rust penetrations.


Seen through the box plate with a light shining up from below. It looks worse than it is, but is is holey.


Same as above but better image.

Solutions please ? ?? At the very least I assume I have to cut out the small rotton portion and weld in new metal ? I don't think it needs a whole new half sill as the holes appear to be isolated (not that I'm capable of major surgery such as that) and the remainder of the sill/section appears to be sound. However I am open to correction.

[les]

Looks like you've got quite a bit of rust in those areas, so if you patch what you see, there may well be more about to appear, plus you need solid metal to weld on. I'd want to remove the cill and see what's going on, which would mean at least another cill.
I suppose you've nothing to loose by attempting to patch it but you might have to bite the bullet in the end.

[iandromiskin]

I have to get back to clean it up yet. There was certainly a lot of rust flakes in the box section to clean up with the hoover and get a grinder/wheel on the bottom to clean up the underneath to see what it looks like. There is one more hole at the very front of the inner sill near the base ot the A-post.

Not sure what a new panel looks but I presume I have to cut out the whole/part of the inner sill and replace with a new one to the inner floor edge and outer sill ? Will have to do it while car is on axle stands.

[bmcecosse]

Sorry to say it looks like it's all paper thin...........you won't be able to weld anything to it. It's going to be a new sills job....

[kennatt]

if you can cut it back to sound metal (If your lucky) it could be patched .but you are chasing the inevitable,it will very soon need a full sill repair,if its just the inner under sill,and the outer and boxing panel are sound,then its quite a difficult job to replace just the inner because you are bound to damage the boxing panel and outer sill because they are welded to the inner under sill.So its less time consuming to have the three sections replaced as one job because you can just rip the whole lot off and start from scratch. Then you know its done for another 20 years.Depends what you want bodge up or rebuild.

[alexandermclaren]

Sorry to say it looks like it's all paper thin...........you won't be able to weld anything to it. It's going to be a new sills job....

Sound advise
bite the bullet

[iandromiskin]

Managed to take off the off-side kick plates and get a grinding wheel to clean up the sills and loo and behold LOTS of holes appeared . (Pictures to follow). So it's inner sill/floor replacement time all round

Not sure I'm capable of doing big structural work like this but if anyone has any links to previous threads or images to sill replacement I'd appriciate it.

[taupe]

Type ' morris minor sill ' into google images ....lots of info there.

Also I recommend getting the replacement sill sections before cutting too much out as you can then see how far you might need to cut.

Dont forget if the metal is sound you can trim the repair panel size down to join with sound original metal

Taupe

[kennatt]

the first question is can you weld to a reasonable standard,if not then its going to be an expensive job, to pay a pro, is the other side the same,may as well have a look.The work itself is straight forwards just a methodical approach.Its easy to see where the new panels fit once you have them on the floor.I personally wouldn't cut and shut the sill ,the panels you get are full, not repair sections,do it right and forget for another 20 years. DO NOT cut anything out untill you weld a solid brace from a to b and c post if four door,the car WILL sag if you dont brace it up. GOOD luck.

[iandromiskin]

Got the wire brush out the other day and cleaned up the front and rear inner sill on both sides as well as removing the drivers/off side kick plates. From what I can see the boxing plate and outer sill on both sides appear to be good with no rust or holes that I can see. The rot appears to be isolated to the floor and side walls of the inner sill.


The car in question (complete with Orb, if you belive such things).


Decay on floor of rear inner sill.


Decay on floor of the front inner sill and seen from inside the box section.

I presume it is not or at the very least very hard to replace just the inner sill ? I presume the parts I need, with the exception of the boxing plate and outer sill, are RP134L/R and RP135L/R ?


Sill section of drivers side showing decay in floor of inner sill from the outside and inside the box section.


Rear sill section on driver side showing the decay from the inside of the box section (sorry I thought I had taken a picture from below).

[chickenjohn]

Best thing to do here is bite the bullet and replace the whole sill structure (hopefully using the existing inner sill step). One side of the car at a time.

You will need front and rear floor edge sill panels, the long 4- door outer sill panel and the long 4- door boxing panel.

Expect to make a few repairs to the inner sill step at the rear as well and while you are at it, remove front and rear wings to gauge the condition of the A and C pillars, these may need work as well and some work to the inner wings that close the sill structure.

Don't be tempted to overlap weld in patches as this will only last a few years before the rust breaks out again. At the very least you can fabricate repair sections and butt weld these in, but then if you could do this already you would not be asking these questions!

Please post more pics!

And show us some pics of your Mig welding.

[kennatt]

As I mentioned before ,the problem is cutting out the inner under sill from the side step panel and edg e of the boxing panel and outer undersill,and then making good the edges of these to weld the inner back in,these egdes will get damaged its impossible to do it without some damage,you may salvage the boxing section by remaking the bottom edge meaning no welding to the top joint.So I suppose you could cut the whole bottom,inner and outer off and use the boxing panel as a guide.I would redo the whole lot thats what a pro would advise. This is why you see lots of minors with a bodge up plate welded over the rotted section,because its hard to do as a single replaced section,then all the rot is hidden inside the sill. And they then weld on the cover plate so you can't easily see inside.And again can you weld to a competant standard.

[Trickydicky]

I would bite the bullet too, if you cant weld to a reasonable standard then you may end up doing more damage than good.
I was faced with the same problem you have and decided that while I could weld and do patch repairs I felt I didnt have the confidence to take on a big job like replacing the sills,boxing plate both sides and crossmember. I took mine to a local restorer and he did a the job for me.
To keep the costs down I stripped out the interior carpets and seats and the cover plates and left the car where he only had to replace the sills and boxing plate and cross member.
This helped keep the cost down as his hourly rate is far mor than mine!!!