What to TIG filler for cast aluminum???

[scapegoat]

I am going to be doing some work to my 351 ci. yates manifold, and to the timing chain cover. I was wondering what is the best for tig, also tungsten, and gas, I have welded aluminum before but never cast, so thought I would ask before attempting, and what about migging it to, I was looking at getting a mig gun for my lincoln, any ideas, and suggestions would be appreciated. Andrew

[hotrodder]

you're gonna get many different opinions on this one regarding tungsten and filler

pure argon for the gas (argon/helium mixs will work too but un-necessary if the machine is powerful enough)

personally i would use a zirconiated tungsten for this

cast aluminium can weld quite nicely or be a PITA depending on quality, age and whether it's been soaked in oil for years. i would expect the manifold to weld quite nicely (i've modified/repaired several edelbrocks- they all welded pretty cleanly), timing chain cover might take a few attempts (the welding heat can pull all the contaminates out of the Al. stop, grind it clean and try again)

cast Al can be various alloys but many are silicon based (silicon helps with the casting process) so 4043 would be a good bet if the alloy is unknown

a gentle preheat (don't cook it, just get it warm) will help as will a slow cool. if i suspect a castings gone porous/is contaminated i'll make an initial run with just the torch (not welding, just getting the joint good and hot) to see if any crap gets pulled out. remove any contaminates with a cutting burr in a die grinder and you should be good to go- very dirty castings (old oil pans etc) sometimes take a few attempts

[LMG]

I have done a couple, as stated some weld great some not so great. I did however with one of them that was giving me trouble degrease, hose off with brake cleaner, then baked it in the oven 450 or 500. You would be surprised how much more oil came out. I think I let it cool a bit and then hit it with brake cleaner or acetone where I was welding it and it came out good.

*Caution you aren't gonna wanna put it in a oven inside your house, it will give off some fumes...

[zapster]

4043 is for billett material..
5356 is for castings...
I have done millions of repairs on each type material..
And thats what you use..

Tungestion..Red End 3/32"
Straight argon will work but I have a gas mixer and run it @38% argon..

...zap!

[Go1lum]

Originally Posted by zapster

4043 is for billett material..
5356 is for castings...
I have done millions of repairs on each type material..
And thats what you use..

Tungestion..Red End 3/32"
Straight argon will work but I have a gas mixer and run it @38% argon..

...zap!

5356 is not designated just for castings, 4043 is not designated just for billet. Like hotroder said most casings are silicon and since the major elements of 4xxx are aluminum and silicon i would reccamend 4043 or a 4047 as a filler choice. 5356 would work also. For that type of repair also it doesn't sound like your going for the best base to filler match as possible. Your welds are not going to be loaded under a lot of stress. So I would go with 4043

[hotrodder]

Originally Posted by zapster

4043 is for billett material..
5356 is for castings...
I have done millions of repairs on each type material..
And thats what you use..

Tungestion..Red End 3/32"
Straight argon will work but I have a gas mixer and run it @38% argon..

...zap!

replies like this are a big reason why you 'attract' so much negative attention, attacks and baiting

filler selection is not as simple as 'x' for cast and 'y' for billet (wrought would be a more accurate description- covers extrusions, rolled products etc)

if scapegoat had asked about repairing a cast wheel i would have suggested a magnesium based filler as Mg is commonly the major alloying element in wheels

FACT. many different alloys are used in castings, sometimes it won't make a huge difference which filler is used sometimes it does in the long term and some times it'll crack almost immediately. a simple rule does not cut it for every situation


a little experiment for you...

fillet weld a couple of 6061 coupons. use 5356 for one and 4043 for the other and then do a simple destruction test.

the 5356 weld will be stronger AND more ductile. the 4043 will suffer a brittle failure in comparison to the amount of elongation exhibited by 5356

despite this 5356 would be poor choice if the part were to see elevated temps in service. as you know 4043 is no good if the part is to be anodised. before anyone mentions it, i know that 6061 is a wrought alloy- just illustrating a point that things aren't as simple as they can appear

[zapster]

Whatever...
I've only been doing this for 30 yrs..

If you don't want my opinion don't ask for it then..

...zap!

[Go1lum]

Originally Posted by zapster

Whatever...
I've only been doing this for 30 yrs..

If you don't want my opinion don't ask for it then..

...zap!

Zap i don't think we have a problem with your opinion, i just think what your said was too broad of an answer.
Hotrodder i also believe there is just some things you should never weld and a rim is one of them.

[zapster]

I look at it this way..

When I did defence work the prints specified what alloy for each job..

Every Billett job was with 4043 (unless it was being sent out for annodizing then 5356 was spec)
If you were welding a cast piece to a billett piece then 5356 was spec..

Every casting job spec. 5356..

This is all Military specs..


I have repaired many many blown to bits cylinder heads all with 5356..
No failures yet..

Use what you want..
But if it came to ME for fixing then thats what I would use..

J.M.H.O.

...zap!

[hotrodder]

Originally Posted by zapster

Whatever...
I've only been doing this for 30 yrs..

If you don't want my opinion don't ask for it then..

...zap!

quit whinning i didn't ask for your opinion- scapegoat was asking the questions.

i answered with my opinion and backed it up with reasoning. you answered with incomplete and inaccurate information stated as fact

for an inlet and timing cover it really doesn't matter much- not exactly structural, just needs to be a solid leak free weld

my point is this,...profit aside, the whole point of a forum like this is education- a resource/database of information. bad info is bad info- i'll quite happily listen to almost anyones opinion as long it's reasoned. experience alone doesn't mean squat to me i'm afraid

[zapster]

Read my LAST post..
Thats where my info comes from..

...zap!

[hotrodder]

i already have. because i was told to is not a reasoned argument in my view.

the people that wrote those specs have far more experience and (more importantly) knowledge than either of us. unfortunatly without knowing the alloys and service environments of those weldments the info doesn't mean much

[zapster]

Fine and Dandy then..

You do it your way..
I'll do it mine..


...zap!