On Fri, 11 Nov 2005 22:51:24 -0000, John McCoy
wrote:

I have an aluminum casting which has broken. Does anyone have any
experiences or recommendations on the likelyhood of success, glueing
it back together with epoxy? I have West System on hand, and can
fairly easily get other products (e.g. Aluminax). Any tips,
techniques, or pitfalls I should be aware of?

thanks,

John

If the casting is ornamental, there is no reason why an epoxy glueup
would not work for you.
But if the casting takes a knock, or sustains any load at all really,
you should be wary.

Think about the numbers:
epoxy 2 part glue - tensile 2500 to 5000 lb/sq in
Aluminum alloy casting 10 - 30 thousand psi

If the casting in question has fairly thick wallls - say 1/2 inch or
more - but not more than 1 inch thick at the break - and you don't
need to maintain an anodized colored surface, you should tote it to a
weld shop with aluminum MIG or TIG expertise.

Brian Whatcott Altus OK

Brian Whatcott wrote in
:

If the casting is ornamental, there is no reason why an epoxy glueup
would not work for you.
But if the casting takes a knock, or sustains any load at all really,
you should be wary.

It takes no significant load, so I'm not too worried about that.

If the casting in question has fairly thick wallls - say 1/2 inch or
more - but not more than 1 inch thick at the break - and you don't
need to maintain an anodized colored surface, you should tote it to a
weld shop with aluminum MIG or TIG expertise.

It would be tedious to remove the one part, which is why I'm
hoping to be able to re-attach the broken part w/ some sort
of adhesive. My experience with welding castings (as opposed
to sheet/plate stock) is that the chance of success is highly
dependant on the skill of the welder, and welders who've worked
with castings aren't overly common. So if I was to remove both
parts, I'd probably go ahead & replace with new (even tho that's
a considerable cost).

I beleive I will try glueing it w/ the West System that's on
hand, and see how it goes.

Thanks to all who offered advice & suggestions.

John

you're dead right in your views about welding cast parts... its
tricky, as noted by one other poster noted due to the manganese and
silicone content. I've done a fair bit of work repairing cast exhaust
manifolds, some with tig, but mostly with a torch. The tig can be made
to do it, but you usually need to have at least 3-5 layers of weld to
get a satisfactory result. exhausts are complicated a lot by the
deposits on the inside of then though, so other casts are not as
difficult. I've had good success with lawn mowers. If you are going
into a shop, call around and see who will do it with gas. its true
that using the flame is harder, but in general i think you'll find that
only a few shops will have anyone who can braze at all, and those you
find will be old school old timers who know their stuff. Just finding
someone like this is a worhtwhile experience. You'll want to keep
their number as they will build up old parts with wear bronze, can
usually operate a lathe and mill and often undercharge for their time.
craftsment are disapearing