The Old Ruminator
Well-known member
Usually we use steel poles but are aluminium poles stable in the long term in a cave environment ? I know they oxidise but that is suppose to add a protective coating. Tried the web but not convinced either way.
Aluminium Scaffold Poles. OK ?
- Thread starter The Old Ruminator
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cavermark
New member
A friend of mine advocates doing good walling if you are thinking really long term - this will never corrode! (concrete is similar but less aesthetically or environmentally pleasing).
Is it because you have a location that is hard to get to with steel tube, or just that you have a load of free alu tube?
(you could sell the alu tube and buy lots of steel.....)
Is it because you have a location that is hard to get to with steel tube, or just that you have a load of free alu tube?
(you could sell the alu tube and buy lots of steel.....)
The Old Ruminator
Well-known member
Its a platform 20m above the floor so walling is out plus steel poles make the job a lot harder. I have read further that pure aluminium is rarely used as its mixed to make an alloy. Our pole is from a tower scaffold so I guess that might make it OK but take the point about steel clamps.
cavermark
New member
Alloy will suffer in the same way.
How about building a temporary frame to work off with the aluminium, then building the steel frame from this. Is it the head of a the "down pitch" in reservoir hole? surely if you can access this from above building it with steel shouldn't be too tricky (put bolts in, clip yourselves in, measure stuff up and cut it outside the cave (or somewhere comfortable up the passage), use ropes through pulleys to take the weight of long tubes and swing them into place, etc...)
Or is it that someone has a piece of scaffold tower platform that they think "looks like it should be useful somewhere"..?
Bograt - the stainless bolts won't corrode, but they will cause the alloy they are in contact with to corrode faster.
It's to do with different electropotentials of the materials.
How about building a temporary frame to work off with the aluminium, then building the steel frame from this. Is it the head of a the "down pitch" in reservoir hole? surely if you can access this from above building it with steel shouldn't be too tricky (put bolts in, clip yourselves in, measure stuff up and cut it outside the cave (or somewhere comfortable up the passage), use ropes through pulleys to take the weight of long tubes and swing them into place, etc...)
Or is it that someone has a piece of scaffold tower platform that they think "looks like it should be useful somewhere"..?
Bograt - the stainless bolts won't corrode, but they will cause the alloy they are in contact with to corrode faster.
It's to do with different electropotentials of the materials.
nickwilliams
Well-known member
The tube used for pre-fabricated section aluminium tower scaffold is very significantly thinner and weaker than that used for tube-and-clip scaffolding and is not designed to withstand the clamping forces from a scaffold clip. It also relies heavily on its shape for its strength so it won't stand being bent like a steel scaffold tube will.
If you are sure that the tubes you have will stand the kind of load you need then they will be fine so long as they are supported in the same way as in the original pre-fab scaffold tower, but I would not advise modifying them or using them in the way you would 'normal' scaffold tube.
Nick.
If you are sure that the tubes you have will stand the kind of load you need then they will be fine so long as they are supported in the same way as in the original pre-fab scaffold tower, but I would not advise modifying them or using them in the way you would 'normal' scaffold tube.
Nick.
Les W
Active member
bograt said:
Even stainless corodes in farm yards in contact with farm slurry. Reallistically all metals will corode to lesser or greater degree (apart from Gold and Platinum...). The best advice is to use something that takes a long time, try to be in a dry environment and keep all the metal used the same.
The Old Ruminator
Well-known member
Thanks all. Actually its for an up platform and not a down one. The one tube I have is the larger diameter support bar with built in clamps either end. It only has to support a limited weight so I think we will give it a go. Incidentally the main cross support is an acro prop with the foot cut off. A steel scaffold pole with a clip used as a stop fits the internal diameter perfectly. The two ends then then sit on galvanized steel pins across the rift. Here is a very poor photo as I was hanging on by my teeth at the time. There is a 20m sheer drop below the platform and the boulders you see are very loose.
TheBitterEnd
Well-known member
Electrically isolating dissimilar metals will help, e.g. if you use a steel clip on a ali tube you could wrap the tube in electrical tape (or paint it).
The Old Ruminator
Well-known member
Spot on Caver Mark. Also its a staging post for the next ladder higher up.
I suppose you could have rigged a traverse line there but that does not sort the boulder problem out as the whole lot could go at any time. Perhaps the SRT climbing specialist would sniff but in the longer term for everyone I think a platform suits best. Better photos may appear on 17th if I can take any tomorrow.
I suppose you could have rigged a traverse line there but that does not sort the boulder problem out as the whole lot could go at any time. Perhaps the SRT climbing specialist would sniff but in the longer term for everyone I think a platform suits best. Better photos may appear on 17th if I can take any tomorrow.
cavermark
New member
Nowt wrong with some platforms and ladders (even rigid builders ladders etc. if you can get them in there) to make things easy during exploration/digging/surveying.
Perhaps this means your platform could be seen as temporary - if the dig at the top doesn't go it can be dismantled, or if it becomes a trade route it could be rebuilt (or replaced by eco bolts for SRT once exploration is finished...).
Of course "temporary" anything in a dig usually ends up permanent (until it breaks unexpectedly), so it can often be worth taking a little extra time to do it well, do it right from the word go....
Perhaps this means your platform could be seen as temporary - if the dig at the top doesn't go it can be dismantled, or if it becomes a trade route it could be rebuilt (or replaced by eco bolts for SRT once exploration is finished...).
Of course "temporary" anything in a dig usually ends up permanent (until it breaks unexpectedly), so it can often be worth taking a little extra time to do it well, do it right from the word go....
ttolyaj
New member
We used alloy scaffold to build a platform in Box's Cave about 35 years ago, and its still there, proper alloy scaffold tube not thin walled, I think its still fine have a chat with the Thrupe diggers they have been down last so should know its condition if I remember rightly it did have alloy clips as well.