Does anyone know what kind of material this is??

Date 05-09-2015 13:55 Edited 05-09-2015 14:23

My father wants me to weld up a cracked part on his boat. It's part of the cooling system and its' been leaking for the past few years and he finally got the time to pull it off for me to weld. I've ground the crack out completely so it wont return from the vibration. Now I wanted to tig weld it back up but the arc is erratic and the weld pool is just bubbling and popping. adding filler metal helps but I get porosity. I've welded cast iron before in the past but am curious if this is that unweldable stuff that I've heard of.

Now I've got a large void where the crack used to be in. I'm thinking of stick welding it with a "Brutus AAA" rod (weld supplier I have told me that the equivalent would be "Super Missile Rod". This rod leaves a gold-ish colored weld and it can weld dissimilar metals together.

My question is, what type of material do you think this is and how would you go about welding it?

Weld settings are:

Amps: 120
Gas: 100% Argon @ 15 cfh
Filler: ER70S-2 (3/32)
Tungsten: 3/32 (E3/ the purple stuff)
using a gas lens with a number 6 cup

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By 803056

Date 05-09-2015 17:06

Have you thought about brazing welding the component?

I've tried the rod you mentioned on Unobtainium with similar results to what you observed.

Best regards - Al

By Lewis87 (*)

Date 05-09-2015 19:54

I haven't. I'm not very good at it. If I were to braze it would I have to braze a patch on the area that I ground out? I don't think I can fill a gap that size with brazing, can I? The gap is about 3/16".

By welderbrent (*****)

Date 05-09-2015 22:52 Edited 05-09-2015 22:54

Andy,

(Good one Al, here with go with the unobtainium again :lol:

)

First, what kind of sparks did you get when you ground into that? I ask because you caught me off guard with your thoughts on type of material. My first guess without having the part in my own hands would have been aluminum.

Now for a list of things:
1) ER70S-2? That would not even be a starting place for alum nor cast iron of any grade. If it is a cast and not alum I would suggest 309 stainless. A little bit at a time, keep the heat down. Do a search here for using stainless on cast iron. There have been several threads with great ideas.
2) Don't mess with the trick electrodes. Many will work after much practice but they are way too expensive and can usually be replaced with regularly available consumables. And look at their base, usually nickel and or chromium, basically, stainless steel.
3) CLEANING!! Regardless of material, Alum or Cast, it will need good cleaning by several options maybe even mixed together. If it is a years old cooling system the material has absorbed a lot of contaminants. You will need to use either a Muriatic acid, acetone, heat, or many other options to get the base clean before trying to weld it. And a stainless steel brush.

Just my two tin pennies worth.

He Is In Control, Have a Great Day, Brent

By 803056

Date 05-10-2015 01:38 Edited 05-10-2015 01:48

If it is cast, it is probably cast iron. It looks like you ground everything to "bright" metal which is a good start.

I would stay with braze welding if it is cast iron and you insist of repairing it. Lay in bead after bead until the voids (groove) is filled. My first choice would be oxy-acetylene welding with a cast iron rod (assuming it is cast iron). I've repaired several cast iron parts using oxy-acetylene there were previously welded using SMAW and GTAW with nickel rod. When all else fails, oxy-acetylene always came through. The secret is to use plenty of preheat (300 to 400) and then slow cooling. I usually light up a 20 pound bag of charcoal and let burn while I do the repair. Once the welding done, toss the part into the charcoal and cover it. It will be cool by the next morning.

As an alternative, entertain the idea of fabricating a new component. Since this goes on a boat, you will have to consider the potential for galvanic corrosion. Use a coupling through the housing and use a zinc plug to serve as a sacrificial component to "save" the rest of the engine.

Best regards - Al

By Milton Gravitt (***)

Date 05-10-2015 12:51

Al could it be cast aluminum.
M.G.

By 803056

Date 05-10-2015 14:30

You could be right, but the "tack welds" in the photographs are not what I would expect to see if one used carbon steel filler metal on aluminum.

A cut with a file on the arc strikes will provide a clue as to the hardness. If it is very hard, i.e., the file doesn't cut the arc strike you have evidence of the hardness. Very hard - cast iron, soft - cast steel (lower carbon).

I'm still waiting to hear what the sparks looked like when the casting was prepared. That will also give a clue as to what the material is.

No one has mentioned checking the casting with a magnet. Is it iron based?

Without knowing the material, it is a crap shoot.

Best regards - Al

By Lewis87 (*)

Date 05-10-2015 17:47

Thanks for all the replies!

The sparks where similar to what you would see grinding on steel. I wasn't paying attention to the sparks really. I'm positive that it's not aluminium.

I'll clean the heck out of it with a stainless wire wheel and some acetone. I have some stainless rod I'll try, worst case I'll have to grind it out again.

I'll post some pictures that may help you guys with answers. With some luck, and the help you've all given me already, I'll post some pics of the fixed part.

By Lewis87 (*)

Date 05-10-2015 23:45

Got Her!! I through it in a trash can full of ash from the wood stove in the shop. Hopefully there wont be any cracks when I pull it out tomorrow.

Here are some pics. The tack and the small weld that I did on the side(top) next to the toe of the weld was done before the finished weld. I did that to see how the stainless rod would lay in there.

Glad I had an amp control foot pedal! there was definitely a fine line of too much amperage and too little amperage. The filler didn't want to stick if I had too much or too little amperage.

The start was a bit rough but I did a little better on the technique as I went along. Again, Thanks for all of your input!

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By kcd616

Date 05-11-2015 00:57

good job
for future info
inconol welds almost all iron based metals
sincerely,
Kent