Hybrid bolt removal technique when using glue-in replacements

For the TL;DR audience-  

Abstract: A proposed hybrid technique for removing any bolt from 1/2-1/4" that can save time and battery use is to simply drill a 1/4" hole along the top edge of the bolt and pull. If necessary, move on to the standard techniques and watch them work faster than expected. Bask in the glow of your hole-for-hole success.

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Longer version with video-

We removed some odd 1/2" sleeve bolts at Shelf Road this weekend. They might be earlier generation Confast or Redhead - the sleeve has 4 cutout slots in it that make it very sticky in the hole. Similar construction to a Triplex, but with no flange on the sleeve.

Got lucky on the first one and it slid out by just pulling hard. Several others in a row just broke when we tried every technique we knew. (Our core drill setup could have worked if we had 16mm bits with us, but mine currently has a 14mm that is rusted in place in the adapter...). Started chopping and patching. With two lead bolts left on the route, I got an idea: drill a 1/4" hole down one edge between the rock and the bolt to add some space and disrupt the sleeve. Worked on both.

We talked about it over burgers around the campfire and decided to try it on wedges on Sunday. We blasted thru 9 lead bolts (3/8" plated) in record time with minimal battery use. The hybrid technique looks like this:

• take off hanger, drill 1/4" hole along top edge. Bend the bit slightly as you are drilling to take out as much metal as possible.
• pull with Doodad
  •  if it fights back, either drill a second hole and pull
  • or release and rotate the bolt and drill the 1/4" hole again to just dig more metal out of the cone in a different place
  • or spin until the bolt pops out (usually pretty quickly because the additional rock channel above creates a nice edge to grind away metal as you rack it back and forth while spinning)
• Drill 1/2" hole for new bolt - the extra hole is less than 1/4" diameter semicircle - hardly noticeable. The 1/4" holes dig into the bolt a lot if you bend the flexible bit slightly. When replacing a 3/8" bolt with a 1/2" glue-in, the up-sized hole is still pretty tight. We got the Crossover bolts to engage even tho there was a tiny extra channel along the top of the 1/2" hole. 

We used this technique to quickly remove and replace 9 wedge bolts hole-for-hole. Only used one bar of battery which is much less than usual for my drill. YMMV.

Discuss.

seems like an awesome way to go (if able to powerdrill).  (for 3/8" bolts ) have you tried a 3/16" bit (then pull) followed by a 1/2" bit for a cleaner hole (and potential for mechanical replacement)?

I believe we removed similar or same bolts in White Rock, NM recently and this was our process... First, we attached the YABR and pulled the sleeve out just enough to get needle nose vice grips attached to the sleeve. Then, we tapped the cone to disengage it and used the vice grips to wiggle the sleeve back and forth while also pulling outwards. We may have tapped before attaching the YABR also. The bolts came out fairly easily with this approach. Our bolts were 3/8" with a 1/2" external sleeve.

Anna - for the first three that broke, we pulled until the bolt stretched and yet the sleeve wouldn't budge. Limestone, plus the route FA was 1990, so it had 35 years to settle in. Would have been nice to use your technique if possible. 

old5tenwrote:

seems like an awesome way to go (if able to powerdrill).  (for 3/8" bolts ) have you tried a 3/16" bit (then pull) followed by a 1/2" bit for a cleaner hole (and potential for mechanical replacement)?

I tried 3/16" bits (to pull 3/8" split-shafts) and found the bits to be very squirrelly. 1/4" bits were way easier to control. The 3/16" kept "tracking" wherever they felt like going. 

But I was also upgrading to glue-ins, so somewhat messy holes were fine. It'd be worth trying 3/16" with this method.

Mark was one route over from us and tried this method with a 5/32” rock bit. After a few bolts the bit broke off in the hole. I think he got that bolt out anyway, but that is an additional risk. 

Gregger Manwrote:

Mark was one route over from us and tried this method with a 5/32” rock bit. After a few bolts the bit broke off in the hole. I think he got that bolt out anyway, but that is an additional risk. 

Yeah I also tried 5/32", same experience, just snapped off alongside the bolts really easily.

Any value in drilling that hole on the bottom of the bolt rather than the top so it also saves some time notching? (For those bolts that instruct to notch)

Thank you for sharing this technique. That’s crazy they wouldn’t even budge! Our bolts were roughly the same era but placed in basalt. We were surprised at how easily they came out.

Tal Mwrote:

Any value in drilling that hole on the bottom of the bolt rather than the top so it also saves some time notching? (For those bolts that instruct to notch)

Sounds reasonable to me. In retrospect, I'm thinking that I could have drilled the hole at 9 or 3 o'clock instead to get tighter engagement from the Crossover bolts. -But the wedging isn't strictly necessary when the adhesive does its job.

Whenever I'm removing angle pitons in drilled holes (which are common where I climb), I drill a 3/16" hole above the bolt and one on either side, then upgrade to a larger glue in.  

I've tried just hammering and funking but it never worked, drilling at least a couple holes first makes it so easy and if you're upgrading to a glue in. Why not?

Thanks for sharing and looking forward to trying this out.  I shared the video with some other SCC folks.  Two questions:  

1. Did the bit last for all 9 bolts you removed?

2. The bit you used appears to be a standard spade bit, not a 4 point rebar bit, but wanted to confirm.

Many thanks!

Yes - standard spade bit. I used it on two bolts on Saturday and loaned it out to another party that used it on at least a couple more. Used it on 9 on Sunday and loaned it out again. The second loaner apparently broke off the carbide tip- it's gone now. Got full value for ~$1.50 tho. Looks like Zoro sells 10 Bosch 4-cutter 1/4" SDS bits for ~$36, so that might be my next purchase.