repair concrete block for fixing

[ladwey]

I was drilling into the wall (1930s concrete blocks) to install some heavy shelves and the SDS hit a chunk of something and made a ridiculously massive hole -- 50mm across maybe. The fixing's got to be exactly there, so I can't patch it and try again 3 inches to the left. What's the best practice for filling it so I can redrill? I've got a tube of resin left over from doing the resin anchors for an extension roof, and I wondered if I could do something with that ... Cheers, J

 

[Wayners]

Take block out and put in a new one an option?
That's my first thought

 

[ladwey]

Take block out and put in a new one an option?
That's my first thought

Sadly not possible!

 

[Wayners]

You thinking of using a threaded bar and resin?

Wood block with hole in taped so its secure over hole to guide bar which would cover hole to keep the resin in.
Let rip and fill. Push bar in.
Would that work?

I think it would

 

[ladwey]

I was kind of hoping that might work! It's a pretty big bracket that's getting attached, so it will hide whatever's behind it -- just has to be a strong fixing. So on reflection I could actually skip the wood block and just use the bracket itself -- screw through the top hole in the bracket, fill with resin, threaded rod through the bottom bracket hole. Unless I'm overthinking it and could just fill with resin and then screw directly into that?

 

[Wayners]

Resin is hard you won't be able to drill it so threaded bar is the way to do it.
The resin is a bit runny so you need something to stop it running out hole like your bracket.
I also am thinking two nuts sandwiching a washer may help hold resin at the back end

 

[ladwey]

Thanks mate, I'll let you know how it turns out. Unless I get crushed by a shelf