Quick sill question

Not a resto per say but nonetheless a question about repairing a Mk1.

My Mk1 failed it's MOT on a small section of the sill to the rear (along with a couple of easy fixes, horn, arb bracket loose, exhaust leak and a buckled wheel, not bad for a year off the road! (whilst I was fitting a 16v engine)).

This is the area which failed:


You can only really see it if you get down low to the ground and then look up at the sill, just so you know what bit we're looking at.

I will be getting out a welder bloke to see what he thinks. I have 2 new sills (from Hadrians Panels/ perfectpanels.co.uk), as the other side was given an advisory (yet it still looks good… on the surface…).

The general condition of the rest of both sills are pretty much like this:



Small patches and spots of surface rust.


So the question really is, should I replace both sills, full length, or simply just repair the area that has caused it to fail, then sand and repaint the sills? :dontknow:

If the consensus is to do both sills, should the rear arches be done as well, or would this require the car to go into a bodyshop for proper repair?

Cheers,
James.

Personally I would patch up the end and treat the rest. Probably get away with painting that area with a spray can too…

Mine is going in the same place, but not that bad yet. Don't really want to tackle a whole sill, so may end up patching mine soon.

Personally I would patch up the end and treat the rest

Yes i have to agree with Big Al !

Get some rust proofer fluid [waxoyl] etc and when its repaired flood the inner box sections and sills to hold the rust back .  Then do the whole of the car underneath . Might save having to weld her every year,

Cheers………

hi wouldn't use waxoil this months practical classic tested it, there are better new products avaliable now, the test were between an acclaimed swedish cavity wax, poor.
uk's leading cavity wax, complete failure.
and a brand called dynax s50 which was in exceptional condition, made by bilt hamber laboratories. this test was in the march edition where treated metal was exposed to 2000 hours hot salt water testing.
i've not used it yet but have some ordered.
hope it helps

Hey i am a panel beater. Its all depends on how long you are keeping the car. You can use rust fluids and spot it in. But wonce rust is there it will always be there. The only way to get rid of rust is to cut it out. If you just touch it up i garantee you it will be back within 6 months. So best thing is to replace them but its to you what you would want done to it and if you have the cash.

Cheers

I agree with that, if you patch it up you will be putting of a much bigger bill next time. Also flooding the sill in waxoyl now is not the greastes idea as it is highly flammable and a real pain to work around when welding and cutting. If you have sills and can afford it get them on there and then treat with cavity filler etc into fresh metal.

volkswarren said

hi wouldn't use waxoil this months practical classic tested it, there are better new products avaliable now, the test were between an acclaimed swedish cavity wax, poor.
uk's leading cavity wax, complete failure.
and a brand called dynax s50 which was in exceptional condition, made by bilt hamber laboratories. this test was in the march edition where treated metal was exposed to 2000 hours hot salt water testing.
i've not used it yet but have some ordered.
hope it helps

That "article" in Practical Classics is an advert for Bilt Hamber Labs who make Dynax S50… so they could be kinda biased.

not to side track guys, but do you have to brace the door opening when replacing the sills, to prevent the door opening sagging? :dontknow:

I'd say it depends on the condition of the inner sill once you've cut the affected area out, if it's in decent condition, then you'll get away with a loaclised repair and it'll last a few years. If the inner sill has gone too, then cut all the rot out of the inner sill whilst you're there. To do a repair that'll last longer, it'll involve replacing the whole sill and probably the whole inner sill too.

To answer dojodubber, yes, if you're cutting the whole sill away, brace and make sure it's braced well. You do not want to weld the sill back in, drop the car down and find it looks like a bannana. If you are just doing the bit at the front of the rear wheel arch mind you, you shouldn't have to brace the door.

I had rust in the same place, and cut it all out and welded a patch in, i did'nt do the whole sill as it was sound.
On yours, it depends on the rest of the sill's condition, if it's ok i would just cut all the rot out of that one area,

Although you might start cutting and find more  as many here will tell you :wink:

Remove the door…

Thanks for the info and suggestions guys, I'm going for a localised repair on this one after my welder bloke had a look at it and commented on how solid the rest of the sill was.

I'm having the work done tomorrow, so it should be looking good for passing it's MOT second tme around with ease.

Hmm, localised repair?  you do realise you'll be doing this again in two years time!

The iceberg rule applies with corrosion, 10% is all you see.  Once you cut the sill off you'll be horrified, I guarantee it.  Think about it, if the sills been open to the elements, all the mud/rain/muck/dirt will be sitting in the enclosed section rotting it out from the inside.

Given you already have the replacement panels, my attitude is - take the time and effort to do the complete repair.  My moto is "Do it right, do it once, forget about it."

Furthermore, I'd not enjoy crashing a car with rotten/patched/mend and make do sills - plus I bet you have chassis flex.

I'm not saying there is a ight and a wrong way to do it.  If all you want to do is get an MOT on the car to sell it on - patch it up.  But if it's a car you acutally plan on keeping/using - do a full repair.

Don't economise when it comes to the structural strength of your car - if you have an accident - you might not live to regret it!

:clap:  :clap:  :clap:

The iceberg rule applies with corrosion, 10% is all you see. Once you cut the sill off you'll be horrified, I guarantee it. Think about it, if the sills been open to the elements, all the mud/rain/muck/dirt will be sitting in the enclosed section rotting it out from the inside.

Totally agree there Steve. The hole in the sill is bang next to the N/S rear axle mounting point and there are a number of cavities in this area that could be rusting due to water getting in. This is all structual and you want to rid the area totally of rust rather just patch it up. The inner part of the O/S rear axle mount area looks a bit dodgy to. to do a proper job in this area, it is best to take the axle off (for access) and the fuel tank off (for safety 8O ).