[mark20]

I think I should be able to seal the worst of mud in then, and give some room for the hold to be cleaned. Perhaps with a sacrificial drainage hole in the corner as Jon said. Thanks

[bolehillbilly]

If it helps, this worked fine on a couple of holds at The P where there was mud seeping and unstable rock.

[abarro81]

I have a hold I want to stabilize/reinforce on a project at Kilnsey - looking for some advice...
The hold is a two-hands-wide crimp rail, which seems to be a shield of rock, i.e. attached at either side but almost like a very thin thread down the back of it where you're pulling. Sounds hollow and like it would break if used extensively. I don't think I'd be able to get it off easily (it's not like it's loose, just liable to explode off). I want to try to get as much glue as possible in the back of it and was wondering about the best method, since the gap is too thin for a mixer nozzle to go in... I saw Mark R recommend using a drinking straw on the end of the mixer nozzle to get in the back of a thin crack - is this considered the best method? I had been wondering about squirting glue into syringes and then using those to get into the hold, but the drinking straw sounds like a nice flexible option... Any other beta for how best to do this? I guess it's worth using a folded over straw or similar to clean it out as much as possible first? Do people use the same glue as for glue-in bolts or something different?
Thanks for any knowledge!

[tomtom]

Would superglue work here? It can deep down really thin cracks..?

[Bonjoy]

The gaffered on drinking straw idea works well for that sort of thing.
The question with that sort of repair is what sort of surfaces are being bonded. Often flakes like this are lines with precipitated calcite. So the resin sticks to this but the bond between the calcite and the flake is weak so the repair is ineffective. Cleaning with a saw, like you say, might work. Squirting some thin superglue down first may bind the calcite. The only sure solution though is to carefully remove, clean, and stick back.

[Doylo]

I’ve removed holds that have been wobbly but hard to get off. Usually a bit of a lever with a flat head screwdriver. Like Bonjoy says always best to get it off get the surfaces spotless and stick back on if possible.

[Doylo]

Yes I use the same stuff as for bolting . Vinylester resin.

[abarro81]

Cool, I'll have another look and see if I can get it off. It's not wobbling/loose, which is why I'm not sure that I can get it off - I'd have to break the rock around it to have any chance - it just feels hollow/snappy like it will explode with repeated use.

[abarro81]

Squirting some thin superglue down first may bind the calcite.

What's the logic with this? Does the superglue penetrate the rock in a way that the resin doesn't? Is thin best just because of ease of application or is there something else about it? Sorry for all the questions and thanks for the answers!

[tomtom]

Superglue is much less viscous - and tends to seep/creep down cracks... on sandstone it seeps into the rock a bit that helps bind the surface more solidly. No idea with calcite - though presumably it can seep into any wee crooks and crannies a bit..

Bonjoy will know more I’m sure...

[Ally Smith]

I’ve removed holds that have been wobbly but hard to get off. Usually a bit of a lever with a flat head screwdriver. Like Bonjoy says always best to get it off get the surfaces spotless and stick back on if possible.

Best advice - pull it off, scrub it clean and make the fix permanent instead of it shattering at a later date because of a slap-dash repair/reinforcement.

I used this on a hold fix and it left a nasty greasy residue for a couple of months https://www.fischer.co.uk/en-gb/products/chemical-fixings/injection-mortar/injection-mortar-fis-vl-fis-vl-high-speed
Maybe consider a polyester resin instead? (I bought a tube at the weekend - will report back once I've tested)

p.s. on the weird sheets of calcite crystals at Devil's Gorge, I've had some success with stabilising large areas using a dilute PVA solution (50/50 water & commercial PVA). For more localised stuff, i've used low-viscosity super-glue, which  gets drawn into the cracks by capillary attraction and sets solid.

[abarro81]

Not sure how you'd get it off though - you'd maybe need to saw or drill through the edges to remove it cleanly. I'll have another look with more intent next time I go...

[gme]

Smash it off by hacking at it with a big hammer telling everyone present its loose bad rock. Once its the right size just glue the left over bits back and cover in sika.

Thats how most of the routes at Kilnsey were "cleaned" back in the day.

[mark20]

I’ve got quite a lot of slightly out of date polyester and vinylester resin that needs using up , will still be fine for holds, if you want it Alex (or anyone else )

[Steve R]

Not sure how you'd get it off though - you'd maybe need to saw or drill through the edges to remove it cleanly. I'll have another look with more intent next time I go...

Small angle grinder with thin cutting disc to neatly score/cut edges where it's still attached? Would then tend to break along the cut lines rather than exploding when trying to prize off.  Can fill cuts back in with resin as you're glueing hold back on.

[dunnyg]

I know you probably aren't daft, but as an occasional angle-grinder user whilst abseiling (and not a rope access worker), be careful as fuck if you do this.

[Bonjoy]

Squirting some thin superglue down first may bind the calcite.

What's the logic with this? Does the superglue penetrate the rock in a way that the resin doesn't? Is thin best just because of ease of application or is there something else about it? Sorry for all the questions and thanks for the answers!

Yes, low viscosity sg is thinner than water and wicks into porous rock very well. Resin doesn't wick in much at all. For very short bonds sg is strong I.e. between grains in a porous matrix, so is decent for hardening and bonding a soft layer. It's poor at filling voids though, unless used with a granular material (for cosmetic repairs I've used sg mixed with sand for instance).
All resins I've used leave a nasty chemical film when they dry. This weathers away after a while though. Ragging and brushing is effective enough in the short term.

[Bonjoy]

If you go for low viscosity sg make sure you get a quality product. I ordered some cheap stuff the other day and the glue that arrived was, if anything, more viscous than standard sg.

[m.cooke.1421]

Any advice on how to stabilise this flake? It is the top hold to a few problems and whilst I don't think it currently moves, it does look and feel pretty insecure. It does look like someone has had a go at fixing it in place previously along with some other holds at the crag. I'm not sure on when this was done but it was definitely over ten years ago and doesn't look the smartest job.


I appreciate the best thing to do would be to prize it off, clean it up and then stick it back on but it is quite large and might be hard work to hold it in place whilst the glue sets.

Would pumping the back of it full of resin work at all?

If it did come off it is of a size and at a height that it could seriously injure someone if it landed on them. It would probably leave behind something useable and wouldn't make the problems any harder but it would leave a less satisfying finishing hold.

[remus]

Looks like it could do with a couple of pins to hold it in place while the glue sets.

You could drill it before pulling it off so all the holes line up, then pull it off, clean it up, stick the pins I'm and then smash a load of glue on to hold it on properly.

[Bonjoy]

One options short of removal would be to stick on a support block to fill in the 90 angle on the underside. This could be well fixed and would greatly reduce the load and leverage on the existing bonds. I'd still reglue the hold as much as possible as well. Obviously it will look less discrete then a hidden repair like pins, but might not look so bad if you picked a well matched  triangular wedge of rock.

[Wood FT]

Any advice on how to stabilise this flake? It is the top hold to a few problems and whilst I don't think it currently moves, it does look and feel pretty insecure. It does look like someone has had a go at fixing it in place previously along with some other holds at the crag. I'm not sure on when this was done but it was definitely over ten years ago and doesn't look the smartest job.


I appreciate the best thing to do would be to prize it off, clean it up and then stick it back on but it is quite large and might be hard work to hold it in place whilst the glue sets.

Would pumping the back of it full of resin work at all?

If it did come off it is of a size and at a height that it could seriously injure someone if it landed on them. It would probably leave behind something useable and wouldn't make the problems any harder but it would leave a less satisfying finishing hold.

Let me know if you want any help. I can’t offer any specific skills but I can hold a ladder etc.

Guy

[m.cooke.1421]

Thanks for the suggestions and the offer of help. I think I'll have a good look at the back of it from a rope before deciding what to do but I like the idea of a supporting block.

[mrjonathanr]

Hi all, any advice would be welcome. Looked at a new grit route which has a sizeable flake on it. The horizontal top of the flake is about 1m wide. The left edge is about 20cm long and the right edge about 1m long. The cavity behind is about 3cm so the volume of space behind the flake is large. Unfortunately the flake makes a disconcerting bong sound when tapped. It is okay to pull on but provides the only gear on the route. It would be disastrous if it came off in a fall.

Might it be possible to stabilise it by pouring loads of resin down the back? There’s no way to access the space and pulling the flake off is a no-no.

Thanks.

[Bonjoy]

Ready mix mortar might be an option for that kind of volume. You can get ones with resin additives for extra strength. Why is removal and refix not an option? Done properly it gives the best fix and the neatest visual result.