"Ross Herbert" bravely wrote to "All" (31 Aug 04 10:37:36)
--- on the heady topic of " how do you clean your tip?"

RH From: Ross Herbert

RH You seem to accept that the aluminium tip has an oxide layer which
RH prevents proper "wetting" contact with the solder at a joint but you
RH seem to be saying that you still get good heat transfer.

Yes, I specifically mentioned the good heat transfer. The most
plausible explanation is, because the oxide layer on the Al surface is
extremely thin (only 1 or 2 molecules thick), and is easily broken.
One reason for this thin layer is due to Al's high oxidation state.
A peculiar thing I noticed was the solder clung to the Al edges in
tiny clumps appearing a bit like thick cold butter.


RH It is a fact
RH that the efficiency of heat transfer is dependant upon the surface
RH area at the tip where it is in contact with the joint. If you have a
RH needle point tip the surface area at point of contact will be very
RH small and therefore the heat transfer efficiency will be very poor.
RH That is the very reason why "wetting" is essential for efficient and
RH reliable soldering and desoldering. The "wetting" action actually
RH increases the surface area in contact with the solder and therefore
RH heat transfer is at a maximum, even when using a needle point tip.
RH There can be absolutely no argument about this fact.

I'm not arguing against wetting in the usual method but since it
doesn't happen with Al then its good heat transfer might be key.
Well, I'll just have to try it for myself and see, won't I?
I just recalled where I might have a length of #12 Al wire...

A*s*i*m*o*v

.... Bad Beer Rots Our Young Guts But Vodka Goes Well.