Mondial sill rust

I've started the light restoration on my 1984 QV, and so far I've not found too much of the dreaded rust. The sills are the only areas where I've found a significant problem, with the driver's side being much worse.
It looks as if the stainless sill covers have trapped water under them at each end, which has led to the rust. There's localised surface rust around each of the screw holes as well. I've got a cheap Ebay borescope and had a look inside, and it looks ok, with just a small area of surface rust in 2 places (where the big holes are).

I'm planning on sanding the rust down as far as I can, filling the screw holes (I'll use tape to secure the sill plates, and glue the stainless screw heads in place) then applying rust killer, before priming and painting. I'm also going to apply a liberal amount of cavity wax. I know the gold standard would to be replace the entire sill, and I've seen the very good thread on this, but for now I localised repair will have to do.

Looking for a bit of advice about what to do with the 2 bad arears at each end (see photos). I'm thinking of cutting out a playing card sized section and replacing the metal, having seen some posts it seems the metal is very thin and non-structural. Do I go with welding, or can it be bonded?

Finally, if bonding, any product recommendations, or if welding - has anyone had any experience of the cheap stick welders that are on Ebay for £50. I did a bit of MIG welding a few years back and am thinking of trying one of these as the low power is sufficient for my needs.

Cheers
Paul
Image Unavailable, Please Login Image Unavailable, Please Login

 

Thanks for the advice - the seats are coming out for a good clean and conditioning treatment, and so are the carpets - so I don't set fire to them!
I'll have a good look round for any further sigs of corrosion then.

 

Great idea about the AVK inserts - I never thought as them to secure the sill plate, and as you say a better option in respect of drainage.

I've opened up the holes a little more, poked around with borescope again and am relived to see it the deep rust is fairly localised, I've got a MIG welder being delivered next week, so the dremel will be out to cut and clean up the affected metal, before welding in a couple of patches.

I was thinking of using Waxoyl underbody spray under the sill plates, in the hope that any trapped water in future won't get to the metal.

How do you get at the internal sill cavity (so I can get some Wayoyl in)? Easy on the rusty side - there's a couple of holes to go at, but the passenger side is solid.