Talk Morgan Forums Morgan Sports Cars Morgan Aero 8, 2012< Plus 8, SuperSports, Coupe & Aeromax Aero 8 Quality

No sign of rust on my 2009 grill welds I have to say.

Thats not corrosion around the welds.

The grills are resistance spot welded together, stainless steel when heated and exposed to "air" will oxidise slightly and change colour. Depending on how hot and how much air determines the colour. Generally from straw yellow at the colder end to purple/blue at the hot end. If the weld is a dull grey then it means all the chromium has precipitated out of the weld. Not only is this a weak weld but but will corrode faster.



This was a Ginetta G27 Fuel tank I made a couple of years ago, as it was to be a Christmas Present, I made the welds Christmas coloured...

Simon @ Mulfab

Correct SimonH.
It is the natural discolouration from heating.
Stainless exhausts do it on bikes and M3W.
It can be polished out.
The colours used to be referred to as "temper colours" by blacksmiths etc. who would heat items to the desired colour before quenching to attain the required final metal hardness/temper state.
It is also used creatively to form coloured surfaces.
Titanium is often heated to generate colours for cosmetic use. The Pagani has such a purple coloured resonator box to tune the exhaust note....baked to attain a specific colour.
To leave such discolouration visible on a premium car is not good presentation or image.
Also, the filler metal used needs to be correctly chosen...."weld decay" is a term used where a filler of stainless that has too high a carbon content is used. The carbon combines with chromium to form carbides which weaken the weld.
Use of low carbon and titanium stabilised filler metal combats it.

Yes, but it's not like the grille welds are actually visible when it's on the car, though is it? The top of the grille is hidden under the cowl and the reverse is up against the lower cowl box.

If somebody presented you with an options list that included an extra GBP 500 to have all the invisible welds polished out, would you really tick that box?

That's where "visible" comes into it.
If not normally visible then no problem.
However, someone seeing it may think it is a problem. It may be thought to be rust and not natural discolouration by someone who is not aware of the heating effects. It doesn't worry me if it is not visible and cosmetically not good but to the layman it can be wrongly interpreted as rust.
The discolouration on the tank shown above wouldn't worry me if the tank was hidden. If on display as a feature then yes it would.

You think many Aero owners take parts off their car?

No...I don't!
I also don't expect "hidden" areas to be lavishly finished.
Where visible then the finish must be good.
Where not it should be indicative of a decent standard showing care and thought in build quality without overdoing it for the sake of it.
The welds are hidden so no real issues.
The mesh not fully finished with cut bits left ....
No need to be OCD but come on.....does this match the claims of "hand built craftsmanship"?
This implies a degree of design and care.
For those who do get hands on with their cars it becomes irksome, but accepted as It's a Morgan.

It is perfectly possible to build cars with exquisite attention to detail, each car absorbing many hundreds of man-hours of work to create a really high quality result.

The problem is that the resulting cost of such vehicles places them in the range solely of the significantly wealthy (only 1% of taxpayers earn over £150k).

Personally, I am very happy that MMC cut a few corners here and there. It places their cars, maybe not into the realms of affordability, but certainly in the realm of possibility for me.

There are many 'hand assembled' cars, all of which are considerably more expensive than a Morgan - which is 'hand built'. A subtle difference.

True. There are also some hand-built cars (I'm thinking of stuff like Bob Petersen's Dartmoor Coupe etc), the price of which make even the most expensive Morgans look like small change.