Welding Tips and Tricks

As a general rule, are all cast aluminum alloys weldable? I have an old and quite handy CM chain hand winch. It is a much older version of this:
https://www.cmworks.com/Hoists/ManualHo ... LeverHoist

The body and handle are cast Aluminum of some sort. Somewhere in its past life, something heavy was dropped on the end of the handle and it fractured right where the part you grab with you hand is. It otherwise works just fine and I have been using it like this for years, But then I figured, "why should I do that? I have a welder and "almost" know how to use it!..."

I do not have the broken off piece, but was thinking that I could fashion an replacement out of something I know that I can weld, and attach it. Is that a bad theory?

I have a Lincoln SW TIG200 and an SP250 MIG machine that I can feed Al filler with, along with some 4043 rod I was given a while back though nothing says I have to use that. Any suggestions?

Is there any way to know if the cast stuff is weldable beyond just trying it?

Try it. It's already broken so you're not gonna hurt it.

Running welding current through any lifting device is big no no.

Poland308 wrote:Running welding current through any lifting device is big no no.

Well it will be through only the handle, with the handle removed from the unit.

That's probably ok but beware if anything ever gets damaged or someone gets hurt you will be accepting a huge liability. Even if the welded part isn't the cause.

Josh has a point. My overhead crane inspector certification covers this... chainfalls and come-alongs If you were using this in a work setting, I would be forced to reject it out-of-hand. I could not force you to stop using it, but I would be on record that it was out of spec and unsafe, which would haunt you in an accident/incident.
If this is for your personal use only, and you assume all the risk, then I agree you have little to lose by giving it a try, since the issue is solely in the handle.

Steve S

Appreciate the replies, and I do understand the message. This is not in a work environment (I know better and work around hazardous stuff of various sorts in my "real" job) and is only for my own use. The most I have used it for is dragging the occasional log across the yard and similar non-critical personal tasks.

I just did some cast Al that won't experience any heat but requires good strength and the job turned out really well. I fixed two break points. This will never truly be used but for testing purposes with human body weight and jumping on it, it holds. I used 5356 for one side of a weld and 4943 on the other side for both breaks. This was for testing mainly.
The 5356 seemed to cook out more stuff or the filler might have had some contamination. The 4943 had almost no contamination at all.

One interesting thing about the filler rods by themselves is you can bend 5356 to a 90 degree and it can still bend but 4943 breaks at about the 90 degree bend or just before. 5356 is strong by design but this also suggests to me that in a serious impact it will be more prone to stretching/bending than sheering vs. the 4943 which will likely take a hit but sheer more than it would stretch. I've broken off several 4943 welds and the story is the same too.

The 4943 did weld much nicer and easier than the 5356 as well. The 5356 stays fluid and flexible longer as well which is easily observable at the filler rod near the arc. All in all I'm happy with both results but in the end I believe the 5356 would have been the best option over the 4943 for the entire job considering the part's purpose (motorcycle rear set/foot peg requiring heavy weight load and heavy shock with low operating temperature).

There is another thread where multiple suggestions with very valid reasons for someone doing a cast water pump that was very old and in service doing high pressure water pump with fresh water for fire truck. There's also some suggestions like peening which you may benefit from.
http://forum.weldingtipsandtricks.com/v ... =5&t=10170

Thank you very much for the very informative post. Lots of good info there and in the post you linked as well. I do have some 5356 in the form or MIG wire around here I think, I may try that on some scrap to see how it works for me. I have not had time to give any of this a try, but hope to get to it next week. This "working for a living" nonsense really messes with my hobby projects. Gotta be a better way.

Thanks again all, for taking the time to reply. When I do give this a try I'll report back if the results are not too embarrassing.

I don't know if this applies since your application is not automotive, but I almost always use 4043 filler wire on my cast aluminum work. even when welding aluminum extrusions to cast (difficult) I havent seen any cracking or problems doing this with this filler wire.

Good info and nice looking stuff. Thanks for taking the time to reply. much appreciated.

weldit321@gmail.com wrote:I don't know if this applies since your application is not automotive, but I almost always use 4043 filler wire on my cast aluminum work. even when welding aluminum extrusions to cast (difficult) I havent seen any cracking or problems doing this with this filler wire.

I meant to ask the other day, did you want to cry when some one asked you to put nitrous outlets in a Shaun's manifold? That dude does killer work.

Sent from my VS995 using Tapatalk

GreinTime wrote:

weldit321@gmail.com wrote:I don't know if this applies since your application is not automotive, but I almost always use 4043 filler wire on my cast aluminum work. even when welding aluminum extrusions to cast (difficult) I havent seen any cracking or problems doing this with this filler wire.

I meant to ask the other day, did you want to cry when some one asked you to put nitrous outlets in a Shaun's manifold? That dude does killer work.

Sent from my VS995 using Tapatalk

Yes sir, those intakes are fantastic looking intakes for sure. Welding anything into a $5k+ intake is a bit stressful :p especially knowing it will be sitting in some dude's garage with 60 car guys saying they "could have done it better with their ac225". I've been at it a while but still get that pause before I dive in and start going.

So after much time has passed, I finally got back to this and thought I would post a follow up. I squared off the broken end of the handle and used a short length of 6061 1/8" wall rectangular tube and welded that to it. I made the new handle part from a 6061 solid square machined to fit inside the rectangular piece and welded them together. The part was removed from the hoist during all of this work to avoid any welding current passing through critical parts, etc.

Though my welds had my awesome signature "blob of melted dimes" look to them, I opted to sort of blend them with a file and a flap disk to what you see here. I held the end of the handle in my vice and hung my (ahem....) near 200 pounds off of the other end, so an reasonably confident in the integrity of things.

So not quite a showpiece, not threatening any of you guys jobs, but strong and functional. This will mark the first actual useful thing I have done with my new TIG welder, so that was somewhat satisfying.




Appreciate all of the input.