Re: Platinum deposit

From: Jeffrey D. Mathias ^lt;jeffrey.d.mathias@att.net>
Date: 12/11/04-03:45:30 PM Z
Message-id: <41BB6A7A.7000303@att.net>

Ayral wrote:
> I found some deposit at the bottom of my platinum bottle (Pot.
> Chloroplatinite )
> Should I leave it like that or is there a way to dissolve it again.
> Shaking the bottle doesn't work.

There may be a couple possibilities even for those who are careful and
clean.

a) It is K2PtCl4. Depending on the solution strength and the
temperature there may be some deposit. This is OK and normal. What
needs to be done is to warm the solution before and during use in a warm
water bath that is at the temperature to keep all the metal salt in
solution. "However it is recommended to not go warmer than 140F. It is
normal that typical Pt solutions will require a temperature greater than
the room. [Note: It is not recommended to warm the room as the coating
process in general seems to work better around 60F.]

If the deposit is present and not in solution then the coating may not
have enough Pt and the print will be weak. It is very unlikely that
this will produce black specks as this double metal salt is soluble in
water and will wash off during processing.

b) It is K2PtCl6. This is bad as this salt is only slightly soluble in
water and no amount of warming or shaking will help. Although this can
be formed at temperatures over 140F in the presence of sodium, the
likely source is contamination or an impurity of the raw double salt.
This is from the manufacturer. This can be a cause of black specks in
the print.

-- 
Jeffrey D. Mathias
http://home.att.net/~jeffrey.d.mathias/
Received on Sat Dec 11 15:45:06 2004

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