Cast iron downpipe access hatch repair

[rkj47]

Hi,

I've got a cast iron downpipe which has a section with an access hatch. The bolts on the hatch door have been corroded over time and have broken off, so it leaks quite a bit in the rain. I've tied it back on for the moment with some string, but looking for a better fix without having to replace the whole section ideally. Any ideas?

Cheers!

 

[Wayners]

Sand back to metal best you can
Clean with meths
Black polymer mastic to stick cover on

 

[datarebal]

Drill and re thread the holes , then new bolts . Pretty straightforward