13 replies to this topic

[Steve]

I know there are a lot of posts on Titanium at the moment, but they are specific and so is this. I would like to discuss the relative pros and cons of sponge and swarf titanium.

I am looking into titanium with regards to personal use and resale. I quick read on the Ti section in Fireworks, principles and practice goes on to say that sponge is much prefered because of sensitivity reasons, and I have read elsewhere about the extreme friction sensitivites of Ti/Blackpowder mixes and so would need to treat such mixtures with caution. So, obviously sponge is safer. But, I have a supply of cheap Ti turning, which only need a degreasing/cleaning and meshing.

So, why am I telling you all this? My question is: Does anyone have any experiance/information about the relative safety on the use of Ti turnings over sponge, Is it worth using the turnings, or not worth the risk?

[BigBang]

I only recently started using Ti, with great results i have to say. I used the sponge type and solid type, and the sponge type gave very much better results. The sparks were much brighter, and longer lasting. I cant comment on the friction aspect, as ive not been using it that long, but ive heard the sponge type again is safer to use.

I dont think there is a definative answer to your question, as it really depends what you are going to use it for, but generally the sponge type is better IMHO.

[BrightStar]

Is there a difference in crushablility / millability of the Titanium sponge compared to the turnings / powder, that seems impossible to process without destroying your tools?

Interesting background here:
http://www.teamstorm...anium-bible.pdf

and yes, please do re-sell in either form. we will buy!

Edited by BrightStar, 15 November 2006 - 11:40 PM.

[BigBang]

I recently aquired some 3mesh Ti sponge nuggets, which are obviously way to big to use as is. I tried to crush them, without success. Ti is bloody tough!! All that happens is the sponge is crushed into smaller pieces of solid Ti, which kind of defeats the point, coz then it isnt sponge! So, ive come to the conclusion that the sponge type isnt millable.

I have now passed this on to another member with better tools than i have, to see if he can do anything with it.

[EnigmaticBiker]

I tried to crush them, without success. Ti is bloody tough!! All that happens is the sponge is crushed into smaller pieces of solid Ti, which kind of defeats the point, coz then it isnt sponge!

Just a thought, having read the Ti bible link above etc. has anyone tried cooling the Ti before crushing. Minus 25 deg C should be possible from a freezer, -50 to -70 deg C from liquid CO2.

I used this idea to help grind PVC. Although I realise it's has very different characteristics, there might be a point at which the sponge metal fractures before flattening.

[Steve]

Liquid CO2? That would require soaking the Ti in the liquid CO2 under pressure, as it is only solid or gas at room pressure. However, a mix of acetone and CO2 (called freezing mixture) may yeild better results, plus dry ice is far more obtainable.

Steve

[font=Book Antiqua]Minus 25 deg C should be possible from a freezer, -50 to -70 deg C from liquid CO2.

[EnigmaticBiker]

Liquid CO2? That would require soaking the Ti in the liquid CO2 under pressure, as it is only solid or gas at room pressure. However, a mix of acetone and CO2 (called freezing mixture) may yeild better results, plus dry ice is far more obtainable.

Steve

Yes it would be solid, I was recalling when we used to make dry ice by slowly releasing a tank of liquid CO2 into a what was effectively a cloth bag.
The acetone/dry ice mixture would provide much better heat transfer.
Then there is the problem of finding a suitable vessel and crushing media that doesn't become too brittle.

[EnigmaticBiker]

Why not go all out and get some liquid nitrogen? (Until global warming kicks in, there is a lot more nitrogen around than CO2 so it should be cheaper!?!?)

1. Dip Sponge Titanium into Liquid Nitrogen. (Using tongs and watch your fingers)
2. Remove and smash with hammer. (The Titanium not your fingers!)

Liquid N2 is nasty to deal with and I'm not sure BOC does home deliveries.

[Steve]

Why not use nitrogen?
Have you ever worked with or obtained liquid nitrogen or cardice?
Like enigmaticbiker says, Liquid N2 is a pain to get hold of, use, be safe and many other things. Unlike dry ice which you can pick up easily and can be stored in a expanded polystyrene box.

Like you say N2 is more abundant and should be cheaper.:
It doesn't work like that, it has much to do with ease of preparation, technically there is loads of aluminium and titanium (to breifly return to topic) on earth, but it isn't cheap because of processing. Likewise it is easier to make and store cardice than liquid nitrogen.

[BigBang]

Let me see if ive understood this - So....im going to obtain (heaven only knows where from) liquid nitrogen, at a cost of 4-5 times the cost of buying the correct size Ti in the first place, dip each piece of Ti in the N, risking freezing my fingers, or spilling liquid N somewhere more delicate! then whack it with a hammer, spend the next 10mins collecting all the tiny pieces, which have flown all over the place, by which time all of the nitrogen has evaporated, leaving me back at square 1.....!!

I think im missing something here or is this a joke

[Steve]

I'm almost entirely sure this turned into a theoretical discussion / Joke at some point.

Is there any more experiance from people using titanium turnings/flake?

[BrightStar]

I still think Liquid Nitrogen should be cheaper thought!

Still off topic, but this isn't quite as silly as it sounds. Liquid N2 costs about the same as ordinary milk and is much cheaper than dry ice. If you can get hold of a small dewar flask (even the cheap polystyrene ones), there are lot of labs, factories and research groups out there who will donate a litre or two - they just slosh it about like water. It will survive at least a day in your workshop before it evaporates.

Working with it safely isn't a problem either if you have half a clue. Wear goggles but NOT gloves - if you spill it on your hands (as I have done once or twice), it just rolls off and stings a bit. If you saturate your gloves with the stuff they stick and you risk loosing fingers.

I did once get hold of a small quantity of liquid helium, which costs much more - comparable to very good whisky, unfortunately it kind of escaped .. Happy days though... Now, back to Titanium...

Edited by BrightStar, 18 November 2006 - 11:21 AM.