964 Inner Wheelarches - Correct factory finish?

[Spenny_b]

Hi Guys,

This weekend, with the eventual break in the foul wet weather, I rolled the car out to start cleaning up the chassis in preparation for putting the engine/gbox back in.

First job was to clean up the rear inner arches. I got all the grime off, no problem, however, what I was expecting to see was the body coloured stonechip paint finish on the inner arch (ie the tub). What I actually got was a black "top coat"and it seems to extend beyond the plastic inner arch liners. Where I've been scrubbing (mainly using Bilberry wheel cleaner until I ran out...) it has removed some of the black coating to reveal the original body coloured paint stone resistant paint underneath.

So....for a MY 1992 964 Turbo, does anyone know what the factory finish should be? From what I've seen on other 964 & 993 build threads I'm sure it shouldn't be black....but you never know.

Or has a previous owner had this applied quite diligently, ie they went to the trouble of removing the plastic inner arches....

And what would you guys do next? I'm not at all confident that I can get it all off satisfactorily, to make it look good. Should I just buy some good quality protective paint like this Dinitrol and re-apply to both protect and smarten up?

Apologies for posting in this forum versus the 964 one....just a bit tumbleweedy over there!

Thanks in advance folks
Spencer.

[Porshaah]

I believe the factory used a tintable Wurth rubberized coating, but I'm not sure how well it will stick to a previous cured surface of itself, let alone the black top coat. Usually the top coats are petroleum based so a petroleum based solvent should remove it with a little elbow grease otherwise scuff it up a bit so whatever you apply has something to grab on to.

[RSTarga]

the tub should be body color, inside of fenders just satin black paint.

[Spenny_b]

Originally Posted by Porshaah

I believe the factory used a tintable Wurth rubberized coating, but I'm not sure how well it will stick to a previous cured surface of itself, let alone the black top coat. Usually the top coats are petroleum based so a petroleum based solvent should remove it with a little elbow grease otherwise scuff it up a bit so whatever you apply has something to grab on to.

Thanks, good thinking, I grabbed some petrol earlier and carefully scrubbed some onto the black surface - it does lift it a little, and I'm sure with enough persistence you could get most of it off, but it's ingrained into the divots of the anti-stonechip surface.

There's a hell of a lot of it to get off, and I have to wonder that with the damp UK climate, a good re-application of black Dinitrol to protect the tub may be a better (albeit not factory original) option.

First job - get everything thoroughly cleaned and degreased. Coming along nicely, but going to ache like a ***** tomorrow, all sorts of strange upside down contorted angles going on!

Cheers
Spencer

[Porshaah]

Originally Posted by Spenny_b

Thanks, good thinking, I grabbed some petrol earlier and carefully scrubbed some onto the black surface - it does lift it a little, and I'm sure with enough persistence you could get most of it off, but it's ingrained into the divots of the anti-stonechip surface.

There's a hell of a lot of it to get off, and I have to wonder that with the damp UK climate, a good re-application of black Dinitrol to protect the tub may be a better (albeit not factory original) option.

I was going to suggest gas and a scrub brush to get into the divots, but it appears that's what you're using. Definitely not for the faint of heart. Would be nice if there was a way to gel gas so it hangs on to the brush. Not a fan of black under coating, while it looks good at first, years down the road it just looks dirty, whereas if you colour match, it will turn black through neglect and when you clean it you feel like you have a brand new car.

[Spenny_b]

Originally Posted by Porshaah

I was going to suggest gas and a scrub brush to get into the divots, but it appears that's what you're using. Definitely not for the faint of heart. Would be nice if there was a way to gel gas so it hangs on to the brush. Not a fan of black under coating, while it looks good at first, years down the road it just looks dirty, whereas if you colour match, it will turn black through neglect and when you clean it you feel like you have a brand new car.

I've just been out to the garage and hoisted the car up on the lift to get a better view now it's dried off. Hmmm. There's blooming tonnes of the stuff on there, particularly the front wheel arches, where it extend right around the front to underneath the aluminium structural bumper/behind the oil cooler assembly.



It does look very much like a factory application; no runs and once washed it's a high gloss finish. If it has been applied after the car was built, then somebody has done a proper job and removed all the ancilliaries and rubber grommets first. Even the access hatch on the RH side footwell is bright and plated, no overspray; I stripped the oil cooler and pipes out over a year ago for the engine project, and there weren't any signs of waxy overspray. On the other hand, if it was a factory coating, then surely the underside of the floorpan would also be black? It's not, it's the standard dusty beige colour.



Here's the rear arches, showing what I managed to clean off over the weekend -->





So, although I agree, a factory stock colour would be nice to see under there, unless I can buy the solvent that is specifically meant to remove this (I'll speak to Rejel tomorrow, who re-sell the Dinitrol range), I don't think it's possible to get it cleaned up well enough to look "stock"....that'll happen in "X" years time when a full strip, dip and respray will inevitably need doing!

Anyway, this car's so far from being stock it's not funny....what's one more item that's custom, eh?

[charge]

Funnily enough, I cleaned my arches a few weeks ago, and came upon the same black paint, which came off with vigourous cleaning with brake cleaner, to leave the blue paint over the shutz. A clean up i could manage, but not stripping off the paint everywhere. Once clean puffed a bit of Wurth satin black back over the bits I went mad on!