Setting permanent survey stations

[Aaron Addison]

Does anyone have ideas (or experience) on what the best way to set permanent survey stations in sandstone might be?

AA

[gillip]

Initially I thought of a MAG or PK nail in a drilled hole, but on second thought, a magnetic nail and a magnetic compass would not get along. Also, hammering a metal object into place often creates a magnetic charge when there was not one before. Many land surveyors used to use lead (melted) with a tack set in it to mark corners in rocky areas. A small butane soldering torch could melt a small puddle of lead (or tin) solder to hold a small tack in place. Using a tin tack should avoid any possible magnetic interferance.
If you are a carbide caver and the ceiling or some place on the wall is suitable, you could make a small soot mark. If you are not a carbide caver, a plumbers candle can be used to make a soot mark and the waxy soot is long lasting.
You could also set a bolt in some inconspicous place.
I know that these kinds of permanant control are frowned on in a cave, but I think it is a good ideal on long survey to set some very permanant and easily recoverable control points. Every one doesn't need to be this permanant, but two consecutive permanant control points set periodically along a long or complicated survey could save a lot of time.
This opinion is influenced by my past work surveying above ground, but I am sure it would apply underground as well.

[mabercrombie]

what about Nail polish?

[hunter]

How permanent? Nail polish and flagging will be around a little while but can easily get disturbed by traffic. For really permanent stations I think a stainless steel bolt is good. I've also used stainless deck nails with aluminum tags. Some stainless is non-magnetic so I'd check before buying a specific type.
I'd avoid using lead (due to contamination) and melting it without good ventilation is a VERY bad idea.

I know that these kinds of permanant control are frowned on in a cave, but I think it is a good ideal on long survey to set some very permanant and easily recoverable control points.

Totally, especially since non-recoverable survey points often leads to a resurvey which is more impact.

James

[Aaron Addison]

Thanks to everyone for the ideas. I was leaning toward some sort of anchor or metal tag, but I have 100s of these to set and it needs to happen relatively quickly (per station that is.).

My main concerns are:

1. getting something to stay in sandstone

2. Setting a station that will be around in several years (no recreational traffic)


AA

[George Dasher]

Carbide lamp.

It is still the best.