Welding Cast Alum - mid section -- New Hampshire

[race30]

Hey guys,

I have a really rare motor: yamaha 70CES short shaft
can't get mid sections for it
wanted to sell it but no one wants it because it's ugly right now...

One of the previous owners ported some 4x6" windows in the mid section.
then welded in patch panels

these patch panels weren't done well and 1 of them fell out (welds cracked)
the other patch panel is better, but still cracked on 1 weld

I had a buddy try to weld, but it immediately cracked as soon as he pulled the argon off.

Does anyone near NH, Mass, Maine weld cast aluminum successfully?
or is this just a lost cause?

[Bodhi]

Curiosity is really getting the best of me when I look at the windows that were cut?
Welding cast aluminum is very difficult due to its "crappy" composition and the need for the TIG welder to keep the part at low heat but high voltage. Any stress on a cast part such as this where it is a thin wall that has been welded will break it (even just the expansion/contraction of the part cooling).
From the pictures it looks like the mid is still structurally sound and will hold together ,it is just the appearance you are looking to fix. If thats the case I'd make an aluminum piece to fit the window and spot weld it in place (this will limit the heat input as opposed to a full 360°weld) and epoxy it in/sand it down/paint similar to how a nose cone would be installed on a lower unit.
This is just how I would go about this project based on the pics you have, I wouldn't write that motor off they are not that common. Good luck.

[LakeFever]

Look into aircraft panel adhesive. Good enough to hold jumbo jets together, might work. Welding cast anything is a major pita

[nitro_rat]

I would ask someone who shortens mid sections what they think. Ronnie on here could probably tell you if it's repairable. Maybe PM him your pics. I think it will probably crack no matter what you do...

[Dave S]

When welding In NH.....you have to set the lower wire at %15 and set the hammonick at %75 or below or you get back feed and just toast the saltwater crud....... now In FL Chazz will get it done.......He knows how.....SWFeed...... HeeHee.....Dammm Dave Again......

[Jay Smith]

I weld on tuners to form a saddle to secure the SS tubing on my dry stack system the strap is billet and the tuner is cast . I use a tig welder with pure tungsten and 100% argon ( no mixes ) I also use a low temp tig rod , bead blast all areas to weld , I find the trick for my success is heating the cast piece up with map gas torch to try and leach out the impurity’s before welding ... The influx of salt or brackish water and time ( age of the part ) will work against your welding success to ...

Good luck,
Jay

[race30]

Thanks everyone for the replies!

[Chaz]

I weld on tuners to form a saddle to secure the SS tubing on my dry stack system the strap is billet and the tuner is cast . I use a tig welder with pure tungsten and 100% argon ( no mixes ) I also use a low temp tig rod , bead blast all areas to weld , I find the trick for my success is heating the cast piece up with map gas torch to try and leach out the impurity’s before welding ... The influx of salt or brackish water and time ( age of the part ) will work against your welding success to ...

Good luck,
Jay

So if I go into the welding supply store and ask for a "low temp tig rod" what exactly am I buying ... ???

[Steve Larkin]

Unless something is really out of place I don't; see why it wouldn;t weld just out of the oven











//..,


]

[Dave S]

I j8ust nkiggink......but chedder is better......Drkn Agn......

[Jay Smith]

Hey David ,
Answering your PM :
I been using Maximum Aluminum Tig Rod :
# R-5356 1/8”
Pin # 535612570
Remember pre heat trying to leach impurity’s out , weld while hot !!

Works for me ,
good luck ,
Jay

[Chaz]

Hey , many thank fer answerin about the low temp TIG rod ya use ...

But for those interested in a response from, well ... pretty much the AWS handbook ... on welding castings and even covers castings to billet parts.

PS...
Chaz = wunderin, If tuners reach 150* F ( 65* C ) Your welcome

https://forum.millerwelds.com/forum/...d-4043-or-5356

When should I use 4043 and when should I use 5356?

4043 is designed for welding 6xxx series aluminum alloys. It may also be used to weld 3xxx series alloys or 2xxx alloys. 4043 has a lower melting point and more fluidity than the 5xxx series filler alloys, and is preferred by most welders because it "wets and flows better" and it's less sensitive to weld cracking with the 6xxx series base alloys. 4043 can also be used for welding castings. 4043 also makes brighter looking MIG welds with less smut because it doesn't contain magnesium. 4043 gives more weld penetration than 5356, but produces welds with less ductility than those made using 5356. However, 4043 is not well suited for welding Al-Mg alloys and should not be used with high Mg content alloys such as 5083, 5086 or 5456 because excessive magnesium-silicide (Mg2Si) can develop in the weld structure to decrease ductility and increase crack sensitivity. (One exception to this rule is 5052, which has a low magnesium content.)

5356 wire has become the most commonly used of all aluminum filler alloys because of its good strength and its good feed-ability when used as a MIG electrode wire. It is designed to weld 5xxx series structural alloys and 6xxx series extrusions, basically anything other than castings, because castings are high in silicon. Its one limitation is that 5356 is not suitable for service temperatures exceeding 150 degrees Fahrenheit (65 degrees Celsius). The formation of Al2Mg at elevated temperatures at the grain boundaries makes the alloys prone to stress corrosion. For components that will be anodized after welding, 5356 is recommended over 4043, which turns jet black when anodized.

________________________________________________________________

I got all kinds ... Let me look see what I can find in 1/8"



Lookie here at how nice a job this here " spool-gun" wire runs ...

[c-more]

I love ugly. Even if you can't get the weld to do right I'd be interested in the motor.

[tnelsmn]

I've never been a fan of bead blasting aluminum parts before repair welding. The material is soft enough that you will impregnate small particles of the blasting media into the part. You now have more impurities when welding. I prefer a stainless steel wire brush on a grinder. Heating the part with a torch prior to the repair to burn out impurities is a great tip! 4043 would be a good choice for a cast repair. I wouldn't even begin to think of attempting a cast repair with wire feed, TIG only. Always fill your crater, 90% of the work you see doesn't have properly filled craters on aluminum work! This won't pass a true CWI inspection and is the cause of many failed aluminum welds.

[Capt.Insane-o]

I how about having a nice freshwater 20 inch mid cut down.