Stalactite repair from scratch

[Pitlamp]

There's plenty of information available about repairing speleothems when the various parts are still available, But suppose there is a stalactite with the end completely missing. Is there any way that a "prosthesis" can be made which will eventually calcite over and then not look any different?
I've done a lot of stal repairs over the years but never when a large section is lost. Does any forum member have any experience of this situation, or suggestions as to how it might be attempted?

 

[mrodoc]

A hi tech solution would, if you had a photo of the original, becto create a 3D model then print it out before attaching it. Calcite would then cover it with time and it would look much the same as it ever did.

 

[Pitlamp]

Sorry mrodoc; I'm the wrong generation for such complicated things!

I was thinking more about how some sort of frame might be fashioned, then covered with something, for new calcite to grow on. Best I can envisage is galvanised chicken wire smeared with plaster. This could be sensitively sculpted before drying to look stalactite shaped. It might be expected to become covered within a few years and then appear reasonably natural.

I'm still pondering on the best way to attach it to the end of a damaged stalactite.

If anyone has better ideas; great!

 

[Lankyman]

Maybe these folks can help (if they're still employed after the US government shutdown ends). They've invented a 'stalactijack' and various other useful tools

The Cave Formation Repair Project - Repairing Cave Formation on the Lincoln National Forest, New Mexico | US Forest Service

By Michael Mansur

www.fs.usda.gov

 

[Mr Mike]

I would guess that there a fair few on UK Caving that are 3D printing savvy. If you know how to do it, it's really easy and a great solution. Can't help thinking plaster / chicken wire would end up blowing in the end. Poss better with white cement, fibre glass rods as re-enforcement etc... if doing it that way.

 

[mrodoc]

Maybe these folks can help (if they're still employed after the US government shutdown ends). They've invented a 'stalactijack' and various other useful tools

The Cave Formation Repair Project - Repairing Cave Formation on the Lincoln National Forest, New Mexico | US Forest Service

By Michael Mansur

www.fs.usda.gov

I have always thought something like that would work but beyond my capabilities to construct. However it means you avoid all that pinning etc etc and getting a direct connection.

 

[Lankyman]

I have always thought something like that would work but beyond my capabilities to construct. However it means you avoid all that pinning etc etc and getting a direct connection.

If I was making (bodging together more like) a 'Stalactijack' it would probably employ old tent poles, rubber bands and a bit of cutlery? Without government funding needs must.

 

[dougle89]

Sorry mrodoc; I'm the wrong generation for such complicated things!

I was thinking more about how some sort of frame might be fashioned, then covered with something, for new calcite to grow on. Best I can envisage is galvanised chicken wire smeared with plaster. This could be sensitively sculpted before drying to look stalactite shaped. It might be expected to become covered within a few years and then appear reasonably natural.

I'm still pondering on the best way to attach it to the end of a damaged stalactite.

If anyone has better ideas; great!

Could quite easily knock up a model on CAD for you from dimensions given, there’s plenty of companies that could print them from file for you if no members have a printer

 

[ChrisB]

I'm still pondering on the best way to attach it to the end of a damaged stalactite.

I would use one of the various epoxies or construction glues (eg, CT1) that work in damp conditions. No chance of damaging the stal and if it doesn't work you can try a different one.

 

[andrewmcleod]

I'm sure I've heard of people laser scanning stals that have been collected for sampling and 3D printing a replacement.

 

[Cantclimbtom]

Hmm there was me thinking someone was going to suggest papier mâché with car body filler compound (2 part, so sets in damp conditions) depending on it being a small repair, and just let it calcify over, hiding any pinkness left by the hardener or hopefully all evidence in a year or five. I'd drill a tiny hole in the top of the stal and jam in a match stick to half depth, if it's only needed to hold it during the repair.

 

[Digit]

I'm sure I've heard of people laser scanning stals that have been collected for sampling and 3D printing a replacement.

In the far distant future there may be some very misled archaeologists who come up with very misled ideas about what went on underground in their past.

 

[Pitlamp]

Just a quick update - I'm now in discussion with Mike Mansur, who has been extremely helpful.
We've kicked a few ideas back and forth about the best way to achieve this particular objective.
Looking to do the job early in the new year.

 

[Jopo]

I would use one of the various epoxies or construction glues (eg, CT1) that work in damp conditions. No chance of damaging the stal and if it doesn't work you can try a different

In 1970 the Trident in OFDll was broken by someone wanting to photograph The Judge. It was repaired by a Roger Smith using the then new Araldite. The end was dried with a meths lamp and then supported by tape. It was broken a second time in the late 70's by someone again passing to see The Judge and re-repaired again with Araldite. The new break was along the bonded join. This time we used the new "rapid setting" Araldite.
The repair has lasted until now and a layer of calcite has since formed over the break.

 

[Tony_B]

In 1970 the Trident in OFDll was broken by someone wanting to photograph The Judge. It was repaired by a Roger Smith using the then new Araldite. The end was dried with a meths lamp and then supported by tape. It was broken a second time in the late 70's by someone again passing to see The Judge and re-repaired again with Araldite. The new break was along the bonded join. This time we used the new "rapid setting" Araldite.
The repair has lasted until now and a layer of calcite has since formed over the break.

It has been repaired in my time as well, so that would be the third repair? I remember it well and I joined SWCC in 1986. I think it might have been Pete Dobson who spotted that the bottom of the longest stal was missing, and the bits were found in the pool. The suspicion was that someone had been arsing around, possibly swinging on it. Elsie co-ordinated the repair effort but I'm not sure she did the underground work. I seem to recall that a ring of plasticine or something was wrapped around the stal above the break to divert the water and keep the repair dry while it set.

 

[Jopo]

It has been repaired in my time as well, so that would be the third repair? I remember it well and I joined SWCC in 1986. I think it might have been Pete Dobson who spotted that the bottom of the longest stal was missing, and the bits were found in the pool. The suspicion was that someone had been arsing around, possibly swinging on it. Elsie co-ordinated the repair effort but I'm not sure she did the underground work. I seem to recall that a ring of plasticine or something was wrapped around the stal above the break to divert the water and keep the repair dry while it set.

You have jogged my memory Tony. I think that may have been the repair I was referring to so maybe only two repairs but still dammed good advert for Araldite.

 

[Rhys]

I recall Elsie and Malcolm Herbert being involved in doing some fixing. It would've been in the late eighties or very early nineties.

 

[Pitlamp]

But did they make a replaement part or did they have all the pieces?

 

[Rhys]

They had the bits.

 

[Pitlamp]

Thanks; that was fortunate.

But as the OP I was more interested in a possible repair where part of the stal was missing.

I do have a plan now for the stal in question but don't let that stop other folk from making suggestions as the method of choice is partly experimental and there's no point reinventing the wheel if someone else has developed a successful technique.