Tr7 rust showing between rear wing and deck joint

[Colin Cutts]

Had my 7 resprayed earlier this year and noticed a couple of weeks ago that the paint has cracked in the joint between wing and rear deck and is now showing signs of rust , what's the best cure for this ? Before the respray the small amount of rust in this area was treated to a localised blasting with a portable blasting gun and then primed . What's the solution if any 

[Velocita Rosso]

If it was done by a professional than it would not have surfaced so early. If it was ,then take it back 

[mikeyb]

Seams are notouriously difficult to de-rust.  The problems arise when the original factory paint/sealer cracks and moisture gets between the spot welds.  The trouble with blasting is that it would not have got deep in between the two flat spot welded sections.  A phospheric acid neutraliser would have helped as this would potentially find itself between the plates via gravity, however is not without problem in itself as if you do that, it is near impossible to clean all the chemical back off again with the result of possible paint reaction. 

As VR said, if you paid good money to have it done, then talk to whomever did it.  Are you sure that it is rust coming back again or is it paint reaction?

If it were mine, I would be tempted to first of all blast as you have done, then phospheric, then wash out with something like Bilt Hamber Atom Mac

https://bilthamber.com/product/atom-mac/

Please note that I have not yet tried painting over that combo, so would experiment before doing it for real!

[Colin Cutts]

Thanks for your comments it was in fact done by a very competent body work company who have had articles in sports car magazines . The owner is a hands on guy and is going to have a look at it in the spring I have every confidence he will sorte it 

[mikeyb]

Keep us posted, will be interesting to hear the cause and the cure!

Edited December 27, 2021 by mikeyb