Removing spits

Joe Duxbury

Joe Duxbury

Member
How easy is it to pull out old Petzl spits? If they'll still take a bolt, can the bolt be used to crowbar them out? Otherwise, I guess they'll have to be drilled out.
 
Brains

Brains

Well-known member
A slide hammer screwed in to the spit sometimes works, but when I was installing the P bolts, the easiest wat was to drill the keyway for the shank of the new P just below the spit, then chisel down the old fixing, very similar to the link from Ian above. Main difference being using the same drill bit as for the main P placement, and only one hole to be drilled below the spit. Both versions then require a hole to be drilled in the old placement to take the new bolt.
It was quite worrying to see the state of the removed spits in some cases, with the sleeves being split and broken, or the cones being ineffective at flaring the inner end of the anchor. Corrosion was present but not the worst thing, and yet some of these were used and trusted regularly :O
 
P

PaulW

Member
diamond hole saw, drills out neatly around the spit for removal, cant remember what size is needed
www.screwfix.com

Diamond Holesaw 17mm x 35mm - Screwfix

Order online at Screwfix.com. Industrial-grade diamond holesaw for clean cutting in ceramic tiles. FREE next day delivery available, free collection in 1 minute.
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pwhole

pwhole

Well-known member
Interesting. Would it need water-cooling to cut rock? And I guess the chuck would have to be really tight to stop it slipping on a cylindrical shank.

Upscaling this, has anyone ever used a core drill bit to put larger holes in limestone - approx 40mm or even 50mm dia by 200mm depth? I've got some 35mm stainless rebar that would work well for a variety of applications when resined in, but making the holes is the tricky part. If it does work, is it possible to easily break off the core at the bottom end, given it's not coming out of the 'other side'? Presumably using a long wedge of some sort.

https://www.screwfix.com/p/erbauer-diamond-core-drill-bit-38mm/57772
 
cavemanmike

cavemanmike

Well-known member
I’ve used a core drill for putting scaf bars in.a bit like a scaf stemple works a treat as long as you cut the scaf really tight
 
G

georgenorth

Active member
pwhole said:
Interesting. Would it need water-cooling to cut rock? And I guess the chuck would have to be really tight to stop it slipping on a cylindrical shank.

Upscaling this, has anyone ever used a core drill bit to put larger holes in limestone - approx 40mm or even 50mm dia by 200mm depth? I've got some 35mm stainless rebar that would work well for a variety of applications when resined in, but making the holes is the tricky part. If it does work, is it possible to easily break off the core at the bottom end, given it's not coming out of the 'other side'? Presumably using a long wedge of some sort.

https://www.screwfix.com/p/erbauer-diamond-core-drill-bit-38mm/57772
Click to expand...
I’m intrigued about what you’d be using 35mm rebar for underground?!
Generally you use a chisel to remove the core - ease of removal depends very much on the rock.
Assuming you’ve got an electric supply then an sds max drill is probably the easier option for a hole this size.
 
pwhole

pwhole

Well-known member
Possibly as permanent stemples, and possibly as belay stakes into mixed mineral where regular bolts may not work. I don't have access to a SDS MAX drill, and there'd be no chance of a supply where I'm thinking - Odin.
 
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