Best options for the rust arch/sill problem

[Leozack]

Hi all - I'm wondering what the best options are for longevity when your car has suffered with the arch/sill rust problem. Mine is an IS300 2003.

I've had mine welded for a couple of years to pass the MOT, but I'd prefer to find a way to get it done in a bigger job to stop it needing it every year getting worse.

Is it possible?  Or is it just going to die if it lives in a rainy country and has no garage?  Being my daily driver it can't live in hiding, either.

Currently it looks like this

 

[steve2006]

The problem with rust is that it needs to be fully removed back to good metal and it is all the internal structures as well.

The sills are multilayered so all the metal here needs to be cut out and reconstructed, the inner and wheel arches are the same.

To do the job properly is days/weeks of cutting out, fabrication of new parts, welding, preparation and painting.

I seem to remember a member doing this job a few years ago and he did a comprehensive series of posts.

[Bluemarlin]

The trouble with rust is that what you can see if often only a small part of it.

I had similar with a previous car, where I was having the sills cut and welded, but the rust kept reappearing. In the end the only cure was to replace the sills entirely. It may be worth doing that now,  rather than periodically patching things up.

Whichever way you go, I will say that it makes sense to apply some kind rust proofing on a regular basis once you've got it fixed. Bilt Hamber do a  couple of spray wax products (Dynax) that are easy to apply,  and come with a lance attachment to get into places like sills and other crevices. Alternatively, or as well as, a good spraying of ACF 50 on the underside, arches and sills, with a pump garden sprayer once a year, will help keep further rust at bay.

[Leozack]

I'm no opposed to paying for the bigger job to be done *if* it is going to save the car and keep it going another 10y or whatever.  The car itself will probably keep going beyond what this poor body can handle with the rain/mud. But I currently have no idea on how much would need doing or therefore the cost, so it's not ideal.
Hindsight is beautiful and of course I wish I could roll the car back in time and clean the arches out regularly and apply some kind of product underneath and/or on these painted to stop the rust in the first place.
I guess the reality is I can't afford any kind of car to rival this one if I had to replace it, it's just too good. I also value the time/money I've spent on it.

[J Henderson]

Since it's a 300, it's arguably worth the expense and could prove to be money well-spent. Even if it'll be a 4-figure sum to put right.

These cars are probably just going to become harder (and more expensive) to acquire in the future...

My old IS200 LE suffered the same fate and I had the sills patched a couple of times to get through MOTs. Then some of the bodywork got damaged in a car park, so decided just to sell it on to a friend, as-is, rather than spend a fortune putting it right again. Had it been a 300 (or an Altezza) I might not have parted with it so easily.

BTW, my friend ran around in it for about 3 years, then sold it to a guy from Ireland, who subsequently put the time and money into restoring it. This is how it looked a couple of years ago.

So, yes it is indeed possible to "save" your one.

[Leozack]

That does look nice!  Yeah if the sils were a swapout I'd have already done it definitely.  I'm just not sure how much is going to be needed to properly get it out and then protect it from returning. Mine doesn't have any skirts or anything on it and since it's my daily it doesn't get to sit clean in a garage and come out for show, it's usually dirty and the bloody brake dust is real. Then again I think there's always at least 1 caliper seized, usually front o/s, making more dust. Doesn't help my work carpark is gravel by a river too 😅
I've struggled to find recommended IS or bodywork people or preferably a combo.  I've ended up recommended to a guy by Chippenham who then doesn't do the rust/bodywork either but knows someone else who does - and that's 20+ miles from me so can't just pop over.  Don't you wish you lived next door to a mechanic who was an expert with your car 😁