Porsche Enthusiasts Club Forum

You see the small step at the bottom off the inner sill, that's actually part off the face sill. Most DIY pannles don't include that part

Hi, you're right, this is not too bad at all. Couple of things though...you did have some advice earlier in the thread regards cutting both sills at the same time, it is not a good idea as the shell structure is compromised and opening the doors can cause the chassis to distort a bit. So, watch out for that..basically don't go jumping around in it with both doors open!

The inner sills (as T3rra says), are repairable in places, your welder should be able to assist here. At this point you can get a bit aggressive with the screwdriver and have a good poke at the rusty bits. If they give, then they need plating, if not - you're good...

You don't need to 'sand lightly', what you do need to do is get back to good metal. So, firstly..dry the entire area using hot air. Make sure the rusty bits are as dry as you can get them. Then a rotary wire brush along with a 4in grinder fitted with a abrasive emery cloth wheel (not a grinding wheel) should do the trick. If you don't have a grinder, get a cheapo one on eBay along with a selection of abrasive discs as you tend to get through them easily. Once you have taken the rust down as far as you can, treat the metal with a good quality rust convertor (plenty available in Halfords, motor factors, etc.), ask around for recommendations. I used Kurust (or something?) but I have heard good reports for POR15, etc. Always use rubber gloves when using any of this stuff, really...don't apply it without them on.

Then, once the convertor is completely dry, apply a good coat of a zinc-based primer. If possible, get hold of a weld-through mixture as it doesn't catch fire as easily as others! Once that has dried, use a good quality enamel (Hammerite type) paint and spray liberally on the face as well as into all the cavities, etc. Always leave this to dry before attempting any welding as it easily catches fire due to the localised heat applied. I would suggest you don't apply the wax (waxoyl or similar) until the welding is complete as this stuff is very flammable. You can apply some behind the inner sill panel, but be careful that it doesn't run out where the weld seam is going to be.

Treat the inside surface of the outer sills with zinc primer, enamel, etc. prior to fitting.

Once the welding has been done and you are all 'buttoned up', then apply a good coat of waxoyl inside the sill. You can get pump sprays with long nozzles that should do the trick. Otherwise, find someone local who could wax treat the area for you...'cos it's bl**dy messy!

Treat the outside metal with zinc, then apply a good quality overpaintable anti-stone chip coating. Always check that it is overpaintable as many aren't.

T3rra's comment about the small step at the bottom of the sill belonging to the outer sill is very important. If you cut this away, then the drain holes also disappear. When cleaning up the metal, leave this in place and test it for corrosion damage. If it is OK, then try to leave it and treat it. It makes welding easier too as the lower seam is a pig to work on if the car is not lifted high. Leaving it also ensures the original profile remains intact too.

I can see from the photos that there is quite a bit of rust along it, but you might be OK for most of it and just patch up where necessary? However, if it is rotten it will have to go, but ensure you cut some drainage holes in the new ones along the lowest point. You don't want to have to do this again in a few years time!

Good to see you making progress and feeling better about it.

Very well put rhett

Rhett, thanks for the post! Now I have a good idea of what I need to do!

Was too curious about the nearside sill! I thought someone said earlier that only the inner sill was structural?? I will keep the other door closed whilst I'm working on the offside!

This step you both mentioned, it's this right? (black marked)



Whilst cutting out the outer sill, I cut along the red line mark as I placed the porkapart sill to see where it comes up to, before cuting. Hope this is fine?



I'm enjoying working on it, although I wish I had more spare time and that I had another car to keep me on the road!

Yep, the step mentioned is the bit you have highlighted in black. A nice clean cut along the red line should do it. Your welder should be able to seam along there nicely, just ensure he doesn't weld up the drainage holes!

It's always a pain when you have to do this sort of major work on your daily driver... Been there, done that !

Keep the photos coming as the work progresses and don't hesitate to ask about any aspect of the job either, as a lot of forum members have been in exactly the same situation as you and have completed the work very satisfactorily, safely and with a good finish, their advice/help is always welcome. Let's face it, we all want to keep as many of these cars on-the-road..

My mot's due in 8 weeks and I'm expecting a fail on the n/s sill, I held back hoping OPC would stock them again which they now do. The mot guy is going to have a look at the sills for me in the week so I can plan ahead and get that sorted before the mot.

I'm confused by the mot requirements, this looks a failure it's way worse than mine but it's got 11 months mot and no advisories!

http://www.ebay.co.uk/itm/Porsche-944-S ... 43c51e90b9

^^^ I saw that eBay listing too and wondered exactly the same thing...that really does look like a fail! Whoever buys that car will have to get those sorted quite quickly I would think.