On Tue, 31 Aug 2004 10:37:36 GMT Ross Herbert
wrote:

You seem to accept that the aluminium tip has an oxide layer which
prevents proper "wetting" contact with the solder at a joint but you
seem to be saying that you still get good heat transfer. It is a fact
that the efficiency of heat transfer is dependant upon the surface
area at the tip where it is in contact with the joint. If you have a
needle point tip the surface area at point of contact will be very
small and therefore the heat transfer efficiency will be very poor.

I guess what you're saying is that a wetted tip gives you a "positive"
meniscus while a non-wetted tip produces a "negative" meniscus. The
"positive" meniscus obviously produces a much larger surface area
across which heat can be transferred from the iron to the solder.

I never thought of it quite this way before, but it makes sense.

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Jim Adney
Madison, WI 53711 USA
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