So you are saying I should cast on a cold January or in June and July before
the humidity moves in for summer.



"Martin Eastburn" wrote in message ...

Yes I did. Depends on the water in the air - to much and more hydrogen
is brought in as it gets hot.

On 9/2/2017 1:50 PM, Terry Coombs wrote:
On 9/1/2017 11:31 PM, Martin Eastburn wrote:
Use Flux for Al. Keep Oxygen out of the hot metal. It will become
a sponge of tiny holes.

Float Al Flux over the pour and in the pour bucket as well.

Be sure to use the correct flux.

Martin


Martin , have you actually cast any aluminum ? I use sodium
hypochlorite in the melt just before casting to degas the HYDROGEN in the
melt . The H2 comes from water vapor coming from the LPG flame I use to
melt it . Depending on how much crud is in my feed stock I may also flux
for other stuff , but not always . I never float a flux on the melt while
pouring . Brass , though is a different matter . I do float a cover of
ground glass to prevent oxidation and monitor the temp closely to prevent
vaporizing the zinc out of the melt .

--

Snag