Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Galvanised chassis

All coatings ultimately fail, fact. There are many factors why a coating may fail in service. Poor surface preparation and poor application are amongst the main ones along with the service environment. I doubt that Morgan would have done exhaustive testing on the new AP coating, rather I imagine they would rely on data from the coater and coating suppliers. As a very thin coating I'm sure it will withstand the normal flexing of the chassis however I'm not so sure about the longevity of the coating if applied poorly and had pinholes which eventually will lead to rust formation. Additionally I would be concerned how it would withstand abrasion from road debris thrown up by the wheels. Of course if you just take your new Morgan out on sunny dry days in summer it probably makes little difference but for those who use them in all weathers regularly it might.

If the chassis is coated with Dinitrol as it is 'now' I don't expect it will make any difference. It's a resilient coating and the bulk of road blasting is under the arches. The centre section remains almost untouched.

A welded Al ladder chassis would be fine. Box section for rigidity/strength, TIG welded and anodised. Cost of materials and anodising would be up t not hugely so.
The chassis would need suitable beefing up at key points..front cross brace attachment, engine mount, gearbox mount, rear axle mount etc.
Structural grade Al alloys are fine....planes are made that way!
As for an Aero style tub....repair extremely diffucult unless it were designed in sections that could be separated and a new one attached. Definitely not a job for the amareur, even most repair shops.
Modern paint systems are hugely improved over the old cellulose type from years ago, and electrophoretic dipping processes help enormously.
The biggest problems with older cars were down to poor design issues resulting in crevices to concentrate wet areas and mud pockets..remember front wing corrosion round headlights? Poor drainage of cavities...sills,doors etc.
I remember them coming into the coachbuilders my dad worked at and him showing me the rust hotspots on cars.
Dinitrol is good stuff. I particularly like the way it retains plasticity and doesn't chip.

http://www.abtproducts.com/wordpress/wp-content/uploads/2013/08/Auphoretic-Coating.pdf

I wonder if the arp4 exhaust problem is one of radiant heat effecting our new coating? If it is the 800 series autophoretic coating it has a top limit of not much over 100°C.
How hot will the chassis be next to the cat?

An interesting thought.

I have an IR oven thermometer and will check Tarka this weekend. The cats on the Plus 8 are wrapped in heat shielding, but run very close to the aluminium structure and wings. After use the wings are hot to touch, but not enough to damage the paint, or damage flesh: my guess is 50 to 60C, but I'll check.

Al has a high coefficient of thermal expansion (it expands a lot when heated) compared to steel. The knock on effect might be that coatings on it that are not as "flexible" and could crack. I doubt if a60 deg temp rise will be an issue though. If you are worried then stick on some self adhesive heat reflector to the wing inners to further reduce the temp. they get up to. Same for any chassis areas close to the cat/exhaust. Agriemach (DaveW uses them if i remember his posts) supply good stuff.

For information. A French forumer making a roadster chassis replacement due to a an accident has weighted a bare chassis: 55 kg.

The crosshead weights 9 kg.

Hi,
I am looking for a replacement car for my dad, a 1990's +4 4 seater.. So the choice is powder coated or galvanised. Post 95 galvanised was standard pre 95 was extra.

If I were to go to pre 95 car, whats the best protection? Dintrol, I have tried this but it is the brown one, what do you recommend? It doesn't seem to be that hard..

My preference is for galvanised as I think it wouldn't rust as long as it is protected, is that correct?

Thanks,
Will

Galvanising if I remember correctly has a service life of 25 years so a 1995 car would be say 20 years old.

Therefore depending on the storage conditions and if the car was driven in the winter the coating could still be great or starting to fail.

As always it has to be checked and you may well get a good one.

On an offshore platform I was involved with that was installed in 1990 ish the walkway gratings are now unsafe due to corrossion and they were galvanised but that is in a marine enviroment.

Therefore get underneath the car to convince yourself of the condition do not just assume it is galvanised so it will last years.

If my time in the lab serves me correct human flesh can touch and hold up to about 70C.Then it HURTS.