Hi,
I have a pin prick leak on the visible edge of the radiator head. It is so small that even at running temperature with the system pressurised it just drips. Its very accessible and about an inch to the right (looking forward) of the main pipe that runs from the radiator to the stainless steel pipe that is along the top of the engine.
See photo.

I have tried RAC permanent rad sealer but it has not worked. The leak is so small I believe a putty might work.
Can any one suggest a good product.
Also bearing in mind I am in Witney (OX29 6PZ) can any body recommend someone who could braze the hole insitu without having to remove radiator from car?
Any help appreciated
Ian