after several helpful replies on the topic of Magnesium,
my questions have shifted a bit, and am reposting under a new
topic.

recent experience:
pair of brake calipers showed up from a gokart... really light,
i figured they were cast aluminum. i've welded cast alum before,
so i fired up the MIG and had at them. the mig wire blew RIGHT
THROUGH the calipers. it did a better job that my drill press!

fast forward a few weeks:
bought a Lincoln Invertec TIG welder (205T AC/DC)
i'm having trouble selecting filler metals for TIG welding aluminum.
-- because i dont know what type of aluminum i'm trying to weld.

i do this as a hobby.. but enjoy it enough to want to learn more.

most of what shows up here at home are castings...
brake calipers, guides (fences?) for woodworking equip,
oil pans, pulleys, etc..

any good way of identifying what type of aluminum these are
made of (if its aluminum at all)? and if they are weldable?

the books i have are very broad on aluminum classification
(ie, all castings are the same species of aluminum).. either that,
or they presume outright that i have a spec sheet telling me
what type of aluminum it is.

are there general purpose aluminum filler rods that i can use
blindly? an old standby? or is aluminum too sensitive?

thanks again,
-tony

tony wrote:

are there general purpose aluminum filler rods that i can use
blindly? an old standby? or is aluminum too sensitive?

The most universal Al filler is probably 4043. While there are better
for some jobs, that's the "do anything reasonably well" alloy. Ernie
says 4047 is better for castings. I plan to get some to try but I have
had success with 4043 even if it isn't the best.

Ted

In article , Ted Edwards
wrote:

tony wrote:

are there general purpose aluminum filler rods that i can use
blindly? an old standby? or is aluminum too sensitive?

The most universal Al filler is probably 4043. While there are better
for some jobs, that's the "do anything reasonably well" alloy. Ernie
says 4047 is better for castings. I plan to get some to try but I have
had success with 4043 even if it isn't the best.

Ted




4047 has twice the silicon content of 4043, so it has better wetting, a
lower melting point and less weld shrinkage.

are there general purpose aluminum filler rods that i can use
blindly? an old standby? or is aluminum too sensitive?

The most universal Al filler is probably 4043. While there are
better
for some jobs, that's the "do anything reasonably well" alloy.
Ernie
says 4047 is better for castings. I plan to get some to try but I
have
had success with 4043 even if it isn't the best.

Ted




4047 has twice the silicon content of 4043, so it has better wetting,
a
lower melting point and less weld shrinkage.

How about welding plate to cast? I want to take a V6 cast aluminum
intake manifold, machine off the original plenum and runners leaving the
water passages, valley cover, and about an inch of the intake runners
coming off each flange, and then make my own plenum and runners from
something like 6061 sheet about 1/8-3/16" thick for the runners and 3/16
or 1/4" for the plenum to handle 30 psi boost, and then weld my runners
to the cast stubs. Sort of a cheap way to get a short runner large
plenum single plane sheet metal intake manifold without spending $2500
or making up all my own flanges and jigs. I am guessing the manifold is
something like A356, because I've read it's most common for automotive
head and manifold castings. Is this weldable? What alloys would y'all
recommend?

--
Regards,
Carl Ijames

In article , Carl Ijames
wrote:

are there general purpose aluminum filler rods that i can use
blindly? an old standby? or is aluminum too sensitive?

The most universal Al filler is probably 4043. While there are
better
for some jobs, that's the "do anything reasonably well" alloy.
Ernie
says 4047 is better for castings. I plan to get some to try but I
have
had success with 4043 even if it isn't the best.

Ted




4047 has twice the silicon content of 4043, so it has better wetting,
a
lower melting point and less weld shrinkage.

How about welding plate to cast? I want to take a V6 cast aluminum
intake manifold, machine off the original plenum and runners leaving the
water passages, valley cover, and about an inch of the intake runners
coming off each flange, and then make my own plenum and runners from
something like 6061 sheet about 1/8-3/16" thick for the runners and 3/16
or 1/4" for the plenum to handle 30 psi boost, and then weld my runners
to the cast stubs. Sort of a cheap way to get a short runner large
plenum single plane sheet metal intake manifold without spending $2500
or making up all my own flanges and jigs. I am guessing the manifold is
something like A356, because I've read it's most common for automotive
head and manifold castings. Is this weldable? What alloys would y'all
recommend?

--
Regards,
Carl Ijames



The absolute perfect filler would be 4010, but that is gonna be a bit
expensive.
4010 is the wrought version of A356.
Same chemistry.

4047 should work fine for that and will definitely work better than
4043.

You can find 4047 if you ask every welding supplier in your area to
check their company inventory.
Every chain seems to have a 10 lb. box hiding somewhere.

I searched the Seattle area and got 10 lbs of 3/32" from Cascade Airgas
and 10 lbs or 1/16" from Central Welding.
I still haven't found 1/8", but I haven't really needed it yet.

For aluminm alloy filler metals data check out

http://www.alcotec.com/

They have lots of downloadable PDFs of aluminum info.

4047 should work fine for that and will definitely work better than
4043.

Thanks yet again, Ernie.

--
Regards,
Carl Ijames