Shimizu about coating Mg with potassium dichromate - why drying the Mg first?

[Potassiumchlorate]

Despite potassium dichromate being a very nasty chemical, I'm considering the use of it to protect my Mg. I have been considering the use of MgAl as well, but since it's inferior in performance I'd like to avoid it.

 

The process seems pretty easy. 1000 grams of magnesium, 50 grams of potassium dichromate and 300ml of distilled water.

 

I'm just wondering about one thing: why does Dr. Shimizu say that the Mg should first be heated in an oven at 100^oC for one hour? It's going to be put into a solution anyway. Might water somehow get trapped between the Mg and the magnesium dichromated formed? It doesn't sound likely. Should it be this warm to properly react with the potassium dichromate? Nothing in the text suggests that the Mg should be put into the solution this hot.

 

Is there any risk whatsoever that the Mg might ignite during heating?

Edited September 19, 2012 by Potassiumchlorate

[pyrojig]

The heat I believe , will aid in the metals pores being more receptive to the absorption of the dichromate , and allowing the material to infuse to the metal better . 100* is nothing to worry, Your mag cant ignite at those temps. It would take well over 900* to have a prob. It is toxic, but a necessary evil. Avoid breathing the vapors or getting the stuff in cuts , eyes, etc.

[Potassiumchlorate]

I have a military protection mask that can withstand nerve gas, so I guess that will take care of that.

 

I know that 100^oC is a "low" temperature in pyro, it just feels a bit uneasy to heat a kilo of Mg in the oven

[Algenco]

I was of the understanding that the reason for "preheating" the Mg was so to keep temps up after applying the dichromate solution.

The idea is to have it as warm as possible to speed drying

[Potassiumchlorate]

Aha! Seems logical