Hi,
I have probably asked this before !
I have these cracks in the indent that goes from the top of the windscreen to the canvas of the roof.
I have had them repaired before but it only lasted a month or two. If i was to have them repaired again, does anyone have advice on what i should have done to prevent it happening again.
Does anyone else have this problem and could someone post photos of their own so i can compare.

My 500 hasn't got that joint, I'm guessing the cracking is due to two pieces flexing independently of each other.

Surely thats not a crack; is it not the manufacturing joint that the early cars have? What year is yours?

I believe it is the manufacturing joint ! Just thinking should it be filled in as much as it is ?

dk500 said:

I believe it is the manufacturing joint ! Just thinking should it be filled in as much as it is ?

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I'm with you now..Doh!
I've had a small area with the similar joint at the front wing showing faint signs of that. That's despite using quality sealant and taking great care on preparation. It has to be, as said previously, slight body flexing and I don't know a solution. If it has just been filled with ordinary bodyfiller, gouging that out and using PU might help?

some guys I know who ran a body-shop doing high end cars....
Used to braze these type of joints and re-cut the line with a fine cutting disk so the line remained but the joint didn't flex and crack the paint

You can clean out the joint and lead load, this is the old school method. I found lots of lead loading around the joint in my Gamine when I restored it a few years ago.

Ralph

Well you learning something everyday as they say. I never realised D's had that joint up there. I assume it disappeared when they swapped the doors round they right way! no the wrong way!!!!!!

As stated before a brazed joint looks the way forward to cure it long term, as per the front wings.

Thank you, food for thought !
Could i trouble someone for a photo of their joints !

Sounds a little odd !

dk500 said:

Could i trouble someone for a photo of their joints !

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Here you go. Excuse the bad clarity, with electric light the iPad had trouble focusing for some strange reason.

Hope that helps.

dk500 said:

Sounds a little odd !

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Better than asking us for a photo of our cracks!!

It looks like you may have some corrosion in the gap causing it to split.
Also they may have used either filler or a hard sealer. These will also crack.
The best was is to clean the joint, treat it for corrosion then you have a choice:
Weld it to stop it from flexing open, grind a line back in and recreate it with filler.
Braze the joint, I used to do this on BMW's year ago, if you flow the braze into the joint nicely you can clean it up with a 3m clean'n'strip wheel and need no/little filler. This gives it a sturdy joint that wont crack. However you can cause more problems due to damage from the heat causing internal corrosion process so plenty of wax oil inside required.
Last option, make sure it is welded at both ends of the joint, then use a Polyurethane sealer in the joint. Remember this is a 50 yr old car, corrosion is always going to come back unless you get rid of it for ever.
Wait to see my joints on my D, I have some serious repairs to be carried out.

Thank you all ! Franko, i already feel better looking at your joints !