It should never be “necessary” to refrigerate brazing pastes prior to their use. The need for any refrigeration of pastes is a carry-over from the "old days" when brazing was being done in hot heat-treat shops where the ambient temperatures were hot enough to cause breakdown of the brazing-paste binders, and the binders could no longer suspend the brazing powder. In such shops the brazing paste was stored in "cool places" such as refrigerators.
that there is absolutely nothing inherent in the chemistry of the binders used
in making brazing pastes (by any manufacturer) that is enhanced, or
made better, by refrigeration. Refrigeration is
only needed to prevent the breakdown of binder systems from excessive heat in
the brazing shop.
In most brazing
shops that I visit today, the rooms where the brazing filler-metal (BFM) pastes
are stored are actually quite comfortable and often air-conditioned. Thus,
storing the brazing-paste containers in the cabinets in the room is perfectly
satisfactory, and any "refrigeration" warnings can be very safely
Having said that,
please note that if the brazing paste is stored in very warm room conditions, it
is possible that the excessive heat could cause the binder systems in the
brazing pastes to lose their suspending capabilities, and the paste will be said
to "break down," (i.e. the brazing powder will sink to the bottom of the
cartridge or container, and the liquid binder will rise to the top).
not mean that the brazing paste is bad! It merely means that the binder
system can no longer suspend the brazing powder. So, stir the brazing paste
thoroughly prior to use, and then use it immediately before it begins to
settle out once again. Continue this procedure until all the paste is finally
Is Refrigeration of Brazing Paste Needed?
By Dan Kay
KEYWORDS: Brazing Paste
Dan Kay operates his own brazing consulting practice in Connecticut (since 1996) and has been involved in brazing for almost 45 years. He received his BS in Metallurgical Engineering from Rensselaer Polytechnic Institute in 1966 and his MBA from Michigan State University in 1982.
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