Magnesium Carbonate

[Malice]

I'm just wondering
Has anyone has ever used magnesium carbonate (the white talc or chalk climbers and gymnasts use to keep their hands dry) instead of magnesium silicate ( your usual talcum powder ) for repairs ?

And what was the effect ?

[mhosea]

I don't know, but you might want to expose a latex sac to it for awhile to see what happens. I've been using graphite. Why I haven't bought a bag of talc yet, I don't know. I think it's because I have this crazy idea that I'm not going to be doing many more restorations, but I probably first had that thought a dozen restorations ago, so maybe it is time.

[OcalaFlGuy]

Most of us don't feel the need to fix something that isn't broken.

 

 

Bruce in Ocala, FL

[inkstainedruth]

It could be that the OP has a ready access to the material?

That being said, I have no idea of whether there would be any issues. But the usual stuff is pretty inexpensive -- I think I paid about $3 for a container of talc from Pendemonium (no affliliation other than being a satisfied customer).

Ruth Morrisson aka inkstainedruth

[Malice]

I'm not saying it's broken, I'm just very curious to find out more and try new ways to do things.

That said, I do have ready access to the material, since I do rock climbing.
My interest in this is mainly because even though they are similar, to my experience,
magnesium carbonate keeps things dryer for longer.
Magnesium carbonate is also available in a finer powder and those mesh application balls are pretty handy.
Plus I've read in a couple of publications that it's used to amplify the tensile strength of latex, so safety should not be an issue.

But then there's the friction component and the dry lubrication component that talc offers, and I wonder how it will compare.

Anyhow, it seems a good idea to re-sac two of my cheap 'let's try this before we try it on the expensive one's' fountain pens and run a little experiment.
One resacced with talc and one with magnesium carbonate and then compare the two.

greetings,

M.

[JonSzanto]

I have to wonder, though: if you do a comparison of these two compounds, I'd think that it would take an awfully long while for differences in performance and function to show up. My assumption is that the talc aids in reducing friction, especially in the filling mechanism, and there isn't going to be a lot of repetition in standard pen use.

 

How would you propose to judge the merits of the two compounds (save for a catastrophic failure as an indicator)?

[Malice]

Time is going to be an important factor, no doubt about that.

The way I'm thinking of setting up the experiment:

I have two almost identical cheap lever fill pens, resac them both using sacs from the same supplier, use the lever 300 times on each,
fill with ink, leave filled for a month, employ the lever another 300 times.
Disassembly of pens, so pliability of sacs can be manually tested + a visual inspection checking for defects in the latex.

[Richard]

I don't recommend using magnesium carbonate. The properties of magnesium silicate that make it desirable are that it is the softest known mineral; it is rarely found in crystalline form and therefore powders extremely finely; it is water repellent; and it is a glidant (a natural dry lubricant).

 

Magnesium carbonate shares magnesium silicate's water repellency, but its other properties make it unsuitable for use in pens: its greater hardness and its normal crystalline structure make it abrasive; and it is not a glidant.

[Malice]

Thanks Richard !

That answers my question, not to mention saving me an experiment.

M.