1995 chassis corrosion...

[polainm]

...a well documented topic before Arch improved their surface blasting process...

...however I find myself with a 1995 car that I would like to keep using as an 'every day car' (except for salty road weather) for a few years before I do a chassis strip and refurb at Arch.

I've all the RustBuster kit from other time-consuming madness (Chlor-X DTS, SP10, Fe-123 and Epoxy Mastic EM121 etc).

Question for the Blatchat experts on this: Where chassis paint has flaked off up to the alloy panel, how much further (if at all) does the steel oxidisation usually go beyond? Should I drill out rivets and pry back the alloy sheet to scrape a little more chassis paint away, or will it be in most cases, 'protected' by the oxidising alloy sheet? Obviously some rolled sheet I can't do this to, only the flat.

Cavities and grot-traps another issue. Just doing the worst, to slow the steel oxidisation and avoid structural damage. 80C Dinitrol 3125 or MIL-SPEC at 50psi+ has worked pretty well on my other vehicle restorations, where I can get to see the external surfaces or cavity access. Chassis hidden by alloy skin is new to me.

Thanks!

Matt

[Paul McKenzie]

I did my '96 chassis around the Millenium when I found a lot of powder coat flaking off in the areas exposed to rain.  I drill wire-brushed off loose powder coat, then passivated the steel with phosphoric acid, then brush painted with Hammerite no 1 primer, followed by 'Hammerite underbody seal with Waxoyl'  It's been fine ever since except for the 'bubbling spot' that everyone gets.

Your chassis has gone a lot longer without treatment, so If I were you, I'd just do the obvious exposed tubes and rails if you're going to do the full strip later, and leave the later complete refurb job to the experts.

[Tony P]

Matt said:
>> ...before Arch improved their surface blasting process... <<

To be fair to Arch: from what I remember, the impression at the time was that that situation was not so much to with what Arch were equipped or prepared to do, but what they were asked to do (or not do), and paid to do by their customers...

When, after 17 or so years of all-weathers use, when my late-'91 spec car was stripped for refurb, the powdercoating was in remarkably good nick - even in the 'grot traps' (it was the rear 'basket' that had suffered the most, but even then nothing rusted through).

There seemed to be an intervening period after that when a number of owners were disgruntled with the durability of the coating, but I don't think I would lay that problem at Arch's door.  :-)

[Tony P]

Matt - I hope that didn't sound like I was "having a go" - not my intention; just hoped to add my tuppence-worth to the somewhat flakey history of powdercoating...!

[Paul McKenzie]

Tony,

It's OK to say that now, they're under new management

[Tony P]

Actually, I was concerned that Matt might have thought I was having a snipe at him and his opening comment...nothing else!

[Golf Juliet Tango]

My chassis is Arch stamped '95 and the car is registered '96. (Scholarship car)

After 18 years and 120,000+ miles, I treated it to a chassis-up rebuild and the difference between repair and replacement of chassis was minimal.

[polainm]

Thanks for useful comments. No offence taken!