Mastic seals.

The mastic seal strips between some of the body panels on my Devon are coming loose. Does anyone have this problem and if so what mastic did you use to renew those seals please.

Don't have that probelm but I was told the mastic was Hodgson Hybrid HS20.

I used sikaflex mastic which was recommended by AS when I complained to them about the mastic on my 5 year old Broadway going an unsightly black in places.  I cut out a small section to test Sikaflex and it seems to be working after a year but it is a very slow job and a known problem and I think AS have stopped this type of sealing. It is a product with good write ups so I would go for it.
By the way does anyone know of a paint which will adhere to mastic as nothing I have tried will clean off black marks ?

I had planned to reseal all the joints on our van with sikaflex this year but never got round to it, nothing wrong apart from a little staining with the old ones but like to keep the van pristine! There are several different sikaflex grades I believe didn't check which was the best on to use. Anyone know please?