Delaying rust?

[Pastry]

Had my first proper 'getting to know you' session with the car yesterday; A run up to Aberfoyle then a thorough wash. The drive was excellent, despite some roads being eaten by the scottish winter the suspension coped admirably though I did grimace at the sound of seemingly tons of gravel being thrown into the arches at times.

I washed it thoroughly immediately after, finding a little discoloration and very minor bubbling around the rear numberplate lamps and the left boot catch. Something to be further investigated.

Then I lookend in the sills and found damp and more surface rust. OH JOY I thought. Arent these cars galvanized? Why are my sills wet, why are they rusting?

After an evening watching the Sopranos took my mind off it I woke this morning to confirm the horrors. It had been raining overnight. I look in the sills, and thank the lord they're dry. But still rusting , its surface flake but its there, and thats only where I can see.

I think washing the arches must have allowed a bit of water to enter the sills through the sill drains just forward of the rear arch. I had a good look this morning and took some photos;

View inside sill from vent looking down (sill drain is the elongated D shape depression center of photo);

Sill drain (OS rear arch looking forward);

I'd like to delay this process ASAP, Feeling around in the cavity i can tell its been thinly waxed at some point (factory?) but coverage is inconsistent and obviously not working.

I'm thinking of using this stuff;

http://www.rejel.com/product/8546.aspx

Supposed to penetrate and arrest existing rust, and protect against further corrosion. Theres a 600mm extension for the aerosol available too.

My problem is getting to the rest of the sill I cant see. I can dangle in a webcam for a 360 look but my worry is coverage when i treat it, and as I cant get accces I cant think of any way to shift existing surface rust.

Has anyone here tried to treat this kind of thing?
Anyone used Dinitrol?
Are there other access points to the sills?

I'd appreciate any advice, and I'll document proceedings when I do the job.

 

[pauljmcnulty]

Hi Rick,

Yours looks very good, from the pictures, but you're right to want to stop any current corrosion and prevent further spread. Have a look at Peter Empson's restoration if you want to see how bad it can get! []

Bilthammer products seem to be the most popular, but serch back over the last few months and there are several threads on this subject.

 

[appletonn]

Hi, welcome to the fold!

It doesn't look to bad to me tbh, bearing in mind that these cars are all now close to 20yrs old as a minimum and galvanising doesn't last for ever! I think preventative maintenance is the key and you are definitely on the right track.

I used Dinitrol from Frost on mine and ordered two of the silicone extension tubes and joined them together so that I could feed it down through the vent hole and along the sill - I wrapped some thin wire around the tube to give it some residual stiffness so that I could more easily push it along the sill from above!

Worked well enough as I had the stuff dripping out of my drain holes for days afterwards...![8|][] I found it easy to use, as it comes in aerosol form.

That said, I had to have my lower front wings stripped and the corrosion cut out and new pieces welded in place (S2 and Turbo front wings are notorious for this, whereas the 'normal' 944 doesn't appear to have this affliction, as yet) and I had the sills stripped to metal to check that they were sound (they were, thankfully!) and then repainted with Wurth stone-chip paint and top coat etc - the sills were then 'filled' with Waxoyl but I need to get some more so that I can top it up again.

I think that ensuring the drain holes are all clear is the key too, as you want the sills to be able to 'breath' so that any moisture can escape.

Let us know how you get on and good luck! []

 

[pauly]

Did I read on here somewhere that there are holes under the carpet in the cabin ?.

 

[pauljmcnulty]

Did I read on here somewhere that there are holes under the carpet in the cabin ?.

Yep, under the thick black plastic trim that holds the carpet along the door edge.

 

[ocallen]

Having a problem locating my sill drainage holes, any help will be appreciated.

 

[edh]

ORIGINAL: pauljmcnulty

Did I read on here somewhere that there are holes under the carpet in the cabin ?.

Yep, under the thick black plastic trim that holds the carpet along the door edge.

well sort of.... []

They are under the carpet. If you remove the black plastic trim you can peel back the carpet. There are 2 rubber grommets each side, giving easy access to the sills.

Peter's resto website gives you a good pic (but is a bit scary []) - the one on this page captioned: "Above: Hole in drivers side floor"

http://myweb.tiscali.co.uk/944lux/Respray_pt1.html

 

[sawood12]

Galvanising doesn't provide protection indefinitely so after 15 - 20 yrs our cars are doing quite well considering. I think as long as you do something along the lines of using products like Waxoil or Dinitrol then you are going to be doing all you can do. Also it is worth re-applying every couple of years or so. If you apply the product into the sill cavities through the ventilation holes that run along the edge of the underneath of the sill then you should be able to get good coverage. Also thinning down the stuff will help get it into all the nooks and crannies.

Another place that seems to be suffering after all these years is the very bottom edge of the wings. It might be worth checking this out on your car and doing what you can there also.

 

[Pastry]

Invested in the bilt-hamber stuff (bet its chemically identical to Dinitrol but BH seem to get good writeups everywhere);

https://www.bilthamber.com/dynaxs50.html

bought the aerosol version

also got their detailing kit, the whole lot for the same price as a tub of zymol; trying to get the definitive answer on carnuba (warmer?, expensive) vs synthetics (longer or shorter lasting) is impossible as its about 50/50 opinion wise, with plenty swearing by one camp and dissing the other. Im going with the assumption that anything is better than nothing

 

[Pastry]

... just been looking at Mr. Empsons sills, ouch! at the condition, and respect for the dedication (madness?) at bringing that car back from the brink.

Thanks for the help guys.

 

[xenon]

Take it to Sal "Big Pussy" Bompinsero's garage and tell 'em I sent ya. Capice?

 

[Peter Empson]

ORIGINAL: Pastry

... just been looking at Mr. Empsons sills, ouch! at the condition, and respect for the dedication (madness?) at bringing that car back from the brink.

Lol! Thanks [] I think []

 

[zcacogp]

BH stuff is good. Their clay and auto-balm brings up my 944 a treat.

And I'll be going back for some of their rust-treatments as well, very soon!


Oli.

 

[Frenchy]

You can also access the sills from under the rear arch there is a rubber grommet that can be removed,bottom front wing problems are mainly due to crud and shit collecting in the plastic sill extensions, clean them out.