Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Traditional Chassis Finishing

Thinking of ordering new trad but notice chassis are no longer galvanized, does any one have experience of new coating? Very concerned it will start peeling after a few years similar to old TVR chassis.

I have a coated chassis on my Morgan, admittedly it's not an MMC original but a Terry Foxen (GEE) replacement. It's 7 years old now and holding up very well, I keep it sprayed with Dynax S50. Terry doesn't recommend galvanising, and there's not much he doesn't know about Morgan chassis.

Most Morgans don't get used in foul weather much, and especially not when there's salt about on the roads, so an electrophoretic coating should stand up pretty well. The old enamel-painted chassis were ok even if not particularly cosseted, mine was 25 years old when I replaced it, and it wasn't completely knackered.

Which is a rather rambling way of saying that I wouldn't see it as a deal breaker. There are lots of other reasons not to buy a Morgan

It's certainly not a deal breaker, but realistically if you want the chassis to outlast you, then TLC is necessary. Each and every drilled hole will rust around the cut. So where the cross head fits the chassis, it's worth dribbling ACF50 down between the flanges.

I asked for clear underseal for aesthetic reasons but this allows easy inspection of the chassis.

Mine is coming up for two years old and is in good shape, despite getting wet 'a lot'........

electrophoretic coating is painting by a more complex process than simply spraying but its paint nevertheless. The elecrtic part of the process ensures that the piant gets into every nook and cranny but if MMC then drill holes in the chassis they have breached the coating.The bond between paint and metal is a mechanical one so corrosion can travel down the interface once started.

Hot dip galv is different firstly because the zinc forms an alloy with the iron in the steel so there isnt an interface in the same way. Its almost as if the zinc was welded to the steel - it isnt but thats the best way I can think of describing it. The second difference is that the zinc coating is sacrificial ie if a hole is drilled in the chassis, rather than the steel round the hole corroding as with a paint, the zinc itself is eroded slowly away and the steel remains intact. In effect a little battery is formed with the zinc as the anode. Obviously this wont last forever - there comes a point when the remaining zinc is too far away from the steel being attacked and the steel corrodes as a result.

There is a reason that fabrications like motorway crash barrier are galvanised rather than painted - the reason is that they last far longer that way. Trouble is, hot dip galv is a polluting process and keeping it clean makes it expensive. MMC chassis are now painted not because its better but because its cheaper. But then, most cars on the market are painted and they dont dissolve in days do they.

So paint is amply good enough for a reasonable life of many years but its isnt quite as good as galv. Are you worried about what happens to your painted chassis in 20 years of summer time use?

Especially given that if you look after it, it will last a whole lot longer than 20 years. And if you don't, then a chassis replacement is always an option. By modern car standards it's not even that expensive. £1000 for a chassis, and a full week or so in the workshop.

I am in the process of removing the body tub from My '61 DHC. For a inspection of the chassis. I am hoping all I need is to refinish the chassis. I will wirebush it, coat it with OSPHO, marine grade primer and a finish coat of marine grade Gloss Black.

If I must source a new chassis. I will probably follow My Friend in Southern Oregon and have Terry Foxen ship a chassis unwelded and then follow Terry's advice for coating. Finding a Welder that could do the job would have been easy for Me 35 years ago when I worked at a Local Shipyard. But today it might be a challenge. I am hoping I can set it up in my garage and have a Mobile Welder put it together. Not sure if the cost of welding in Seattle would save Me enough to be worthwhile. There are other sources in the U.S. but I know what I am getting from Terry, not sure about the U.S.

[quote=howard MMC chassis are now painted not because its better but because its cheaper.
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They spend less time fixing warped galvanising, too.. Price is little different I believe, but it's also more environmentally friendly I was told.

The M3W has had this coating on the chassis since they were introduced, although to be fair, rusting of the chassis isn't high on M3W owners agenda...but they don't peel their coating...unless it's to weld it...

They spend less time fixing warped galvanising, too.. Price is little different I believe, but it's also more environmentally friendly I was told.

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Galvanizing and Chromium plating are both very harsh for the environment.

Both the new chassis (Plus 4 and 4/4) I got from Terry came powder coated but I sprayed them with two heavy coats of 2K Gloss Black for a little extra protection.

The 4/4 project I bought a couple of years ago, came with a new chassis which was supplied powder coated but subsequently got galvanised (not by Terry but by a third party firm), sadly, they failed to drill one of the box sections and its blown. Not affected the alignment of the chassis or to render it scrap but just looks unsightly!

Arwyn

Gallanach,

Don't forget the factory underseal all the trads after the road test & snagging sign-off - they now have a dedicated bay for this and it looked a proper job, it took about 2hrs just to mask up all the 'do not coat' parts