Broken screw is stuck like cast

[Boolean]

Happy continuation, what do you think about this?

Environment basement with perfect temperature for beer, etc.
Ventilation duct a few meters with a vent cover where the integrated screw has broken off almost perfectly at the height of the threaded wall section's surface.
Possibly the previous owner managed to paint the screw in place.

Can't reach to pinch with pliers or other tools. Tried rust remover.
Tried inserting a new screw to pull it out but it doesn't grip.
Attempted to create a slot for a screwdriver, but there's not much to take from.

The plan is now to drill a hole through about 15 mm of screw material and try to find something I can get through (possibly conical) to try to get some leverage. However, I think it will slip.
Possibly crack it, but the material is thin.

I can of course remove everything and replace it, but I think old is appealing and would rather put in some effort.

Anyone with good input?

 

[Violina]

Weld on a nut or bolt and unscrew it when the material is hot.

 

[InsidersUnited]

Drill out and rethread. If the above doesn't work.

 

[Boolean]

Weld on a nut or bolt and unscrew it when the material is hot.

Good idea, but I don't have a welder and the space is limited. Also unsure about the material - seems to be light metal.

 

[InsidersUnited]

You can put on two nuts that you tighten against each other with a washer in between, then you tighten everything.

 

[Violina]

Good thought, but I don't have a welder and the space is limited.
Also unsure about the material - seems to be lightweight metal

Cut a slot with the angle grinder?

Drill a hole and insert a Torx?

 

[Violina]

How much sticks out on the back?

 

[Boolean]

Cut a track with the angle grinder?

Drill a hole and insert a torx?

I think the angle grinder's disc is too coarse.

 

[Violina]

Buy a thinner disc?

 

[Boolean]

How much sticks out at the back?

Only a few mm and it's hard to get a hand in.

 

[InsidersUnited]

I thought there was a bit of the broken bolt sticking out on the back?

 

[cpalm]

Drill a moderately sized hole and tap out using a Torx bit that is pressed in. Usually works ridiculously well.

 

[Dan_Johansson]

It looks like someone has already drilled a hole...

If you heat it up well with the heat gun, you should be able to remove it with a grispitt...

 

[Violina]

You have at least received my three best tips, in roughly the order I usually try to apply them..

I hope someone else has a better idea then..

 

[Violina]

I thought there was a piece of the broken bolt sticking out on the back?

I think that picture (which I assume you're thinking of) is of the cover