75/25 or 90/10 for welding loader arm?

[Steve Bowman]

Well, my impatience and ADD has kept me busy while waiting on the 71M wire.

As I mentioned, I am also building a quick attach for this loader. I think have the pieces I need mocked up with wood. They will be cut from 3/8 plate with the exception of the main crossmember shown. It will be two 2" sq tubes side by side.




Thoughts? Go back to solid wire, or stick with the 71M? The plates for the quick attach brackets are about .300.

 

[Jonas302]

Looks amazing but that wood is not going to weld very well Honestly though once you get the dual shield wire tuned in you will be amazed how well it works on a project like that

 

[Steve Bowman]

Thanks.

I do have bosses made already that will weld onto the outside of the plates where the pins go. Not just relying on the plate for pin support.

One thing I don't really like is the locking levers pull up to lock. Things just didn't work out with them pulling up to unlock, like most machines. The substantial cross-member required for my single tilt cylinder was necessary.

 

[Junkyard]

Dual shield is hard to beat. We use it a lot at work building our own tooling etc. You can lay down a nice bead and really put some heat down too.

 

[Steve Bowman]

Dual shield is hard to beat. We use it a lot at work building our own tooling etc. You can lay down a nice bead and really put some heat down too.

At the risk of irritating the experts, wonder where will I be able to use up the 10lbs 71T-GS I was given? Surely it has some value too. But, on the other hand, 25lbs of 71M will likely last a while around my place.


Also, with the gussets I have planned to strengthen my crossmember assy, I am wondering about wall thickness on the 2x2 tubes. 1/4 should be fine, I suppose. Or, possibly just one rectangle 4x2

 

[StanRUS]

Steve,
I would stay with 75/25% as you have that already. CO2 requires higher voltage setting to maintain arch transfer compared to 75/25% gas mix, i.e. will lower your duty cycle with the Millermatic 210. NOT BROKE, DON'T FIX IT.

Pre-machined pin bushings: If you have two bores in alignment requires using a alignment mandrel 0.005" smaller inside diameter than the machined bore diameter. Cat manufactured thousands of buckets (up 980 sized loaders and excavator buckets) using pre-machined bushings.

Welding the bushings is referred to as 'pre-set' welding. You follow a circular weld sequence pattern and continuously turn the mandrel and slide the mandrel back and forth to determine by hand-feel weld shrinkage caused miss alignment.

Alignment and Repair of your loader's arms will require using a similar approach, IMO.

 

[Welder Dave]

The loader arms will require close attention to detail while being welded and most likely need some tweaking with a hyd. jack, come-a-long and/or heat to get the pins to go in smoothly after completion. Weld pulls one way, line up pin is tight, cools off pin is tight the other way. I'd be more worried about getting the loader arms fixed so they work before I spent a bunch of money on a quick attach.

The roll of GS flux core could be used for anything that just sits there and doesn't take a lot of loading. If you wanted to build a table or some shelves or something light duty it would work.

 

[StanRUS]

I'd be more worried about getting the loader arms fixed so they work before I spent a bunch of money on a quick attach.

Yep...Steve thinks a bit about the arms, IMO...job done onto fab-ing a attachment.

The roll of GS flux core could be used for anything that just sits there and doesn't take a lot of loading.

No loading, HA, HA...Cat (and Komatsu) products fab'd with L50, no impact loading specified, buckets, quick attachments, grippers, shears, ripper frames, dozer blades etc. Manufacturing uses the most economical weld filler material as per engineering design specifications.
Couple of example photos.

Mig spray arch, L50-CO2 downhand Cat Work Tools-Wamego
Robot Welded, L50-CO2 horizontal downhand


FOLLOWING INSTRUCTIONS BLINDLY equals Standard ISO, ANSI shop floor procedures worldwide; shop prints with symbols-control boxes, sometimes short written descriptions by engineering. Raw materials to finish products...employees' job description IS to follow instructions that are not > BLINDLY sent to the shop floor, LOL Robots don't have opinions, pi$$ed girlfriends or wives, disappointing childhoods; programming, maintenance and repeat welding...

Ebay welding wires: 71M is packaged in cardboard box and warped with plastic bag. In pi$$ poor storage condition for 12 months soaking up moisture. Good deal gone bad, LOL

@ Steve, Airgas Ohio dose not stock 71M; hard to believe your nose did not hit your keyboard typing that statement

 

[Steve Bowman]

They said they did have a roll of Bohler 71M in .045, but the .035 I saw on the shelf was all -11. My next choice vendor also did not have any 71M stocked in .035. They also discouraged the 100% co2, said it would be colder. Anyway, learned a little.

Thanks for the fabrication tips. I won't bother with the co2. Sounds like more trouble than it's worth.

I do hope I have good results with the ends of my loader arms.

 

[Welder Dave]

Yep...Steve thinks a bit about the arms, IMO...job done onto fab-ing a attachment.


No loading, HA, HA...Cat (and Komatsu) products fab'd with L50, no impact loading specified, buckets, quick attachments, grippers, shears, ripper frames, dozer blades etc. Manufacturing uses the most economical weld filler material as per engineering design specifications.
Couple of example photos.
View attachment 191172 View attachment 191174
Mig spray arch, L50-CO2 downhand Cat Work Tools-Wamego
Robot Welded, L50-CO2 horizontal downhand
View attachment 191175

FOLLOWING INSTRUCTIONS BLINDLY equals Standard ISO, ANSI shop floor procedures worldwide; shop prints with symbols-control boxes, sometimes short written descriptions by engineering. Raw materials to finish products...employees' job description IS to follow instructions that are not > BLINDLY sent to the shop floor, LOL Robots don't have opinions, pi$$ed girlfriends or wives, disappointing childhoods; programming, maintenance and repeat welding...

Ebay welding wires: 71M is packaged in cardboard box and warped with plastic bag. In pi$$ poor storage condition for 12 months soaking up moisture. Good deal gone bad, LOL

@ Steve, Airgas Ohio dose not stock 71M; hard to believe your nose did not hit your keyboard typing that statement

If it's Lincoln L-50 Mig wire it has impact values at O deg's. F with CO2. Still better than t-11 flux-core. Lincoln has or used to have a special L-56 with impact values at -40 or -50.

 

[StanRUS]

Dave,
L50/CO2 spec -0deg CVN = not specified.

CO2-solid wire vertical up is difficult to use compared to 71M.

 

[Steve Bowman]

Wow!

Thank you, thank you. Just running some tests to get settings close and this wire just runs so smoothe.

I spent most of the morning installing a fume extraction fan i have wanted to do for quite some time. And after you mentioning the additional smoje from the flux core, i figured no time like right now.

I have some other stuff to do today(genset) and dont think i will have time to finish. So, rather than preheat twice, i will start early tomorrow with that.

Thanks again for the advice.

 

[Steve Bowman]

Oh, on my Millermatic 210 running the .035 70M vertical. I am running wire on setting 65 which is about 440 in/min and volts on 6, which is about 25 volts loaded - 32v open. 35 cfm 75/25. 3/4 stickout.

 

[StanRUS]

Oh, on my Millermatic 210 running the .035 70M vertical. I am running wire on setting 65 which is about 440 in/min and volts on 6, which is about 25 volts loaded - 32v open. 35 cfm 75/25. 3/4 stickout.

Try 23.5-24 volts, 75/25% should run 1-1.5 volts lower than straight CO2. Mig contact tip should be recessed 1/8", not flush with edge of the nozzle. Use that distance for stickout.

If you're not in a air draft try lowering gas flow to 30Cfm.
I use a flow meter that attaches to the mig gun's nozzle to measure cfm delivered. Pricey $70.00 calibrated plastic tube and rubber cup, but eliminates all of the variables like different flow meter model orifices, wire feeders etc.

If you start getting worm-gas marks refer to this Lincoln article:
https://www.lincolnelectric.com/en-...ns/Pages/gas-marks-on-fcaw-process-welds.aspx

@ sweet spot, you'll hear a 'hiss', low smoke, sparks and the flux will self peel or just require a tiny tap.

Have fun

PS, Lincoln's Welding Solutions / handy reference
https://www.lincolnelectric.com/en-us/support/welding-solutions/Pages/welding-solutions.aspx

 

[Welder Dave]

Stan, this is where I saw impact values of 27ft./lbs. at O deg's. F with CO2. No rating for mix gas though.

https://www.lincolnelectric.com/ass..._MIGGMAWWires-SuperArc-SuperArcL-50/c4103.pdf

Gas flow 20-25 and is CFH not CFM. Sorry, I'm in tech. support and hear this all time or how much PSI should the shielding gas be?

Here's the suggested parameters for 71M wire.

https://www.lincolnelectric.com/ass...Shielded-Outershield-Outershield71M/c3101.pdf

 

[StanRUS]

Gas flow 20-25 and is CFH not CFM. Sorry, I'm in tech. support and hear this all time or how much PSI should the shielding gas be?

Yep, CFH; my brain was thinking D8N engine-torque overheating radiator issues on another thread...OP or myself haven't asked how much PSI should the shielding gas be?

Tech support...where did you come up with 20-25 CFH for 71M per OP's post #71 references? Per Lincoln's pdf spec is: Flow Rate is 40-50CFH

Hobart's Excel-Arc 71 flow rate is 35-50CFH
https://www.hobartbrothers.com/uploads/pdf/datasheets/FabCO_Excel_Arc71.pdf

EASB's 7100 Ultra no flow rate given
https://mam.esab.com:8443/assets/1/...E98A512E1F1D4/237-en_US-FactSheet_Main-01.pdf

I cross reference different manufactures' procedure spec's for similar wires. Carry 71M, Excel-Arc71 spools in the service truck for different wire feeders and jobs.

40-50CFM @ max recommend gas flow. Using lower gas flow rate helps prevent sucking atmospheric nitrogen into the molten weld puddle AND simply wasting gas to increase jobbers', retailers' profits.

71M coupons pass x-ray (Miller Electric, Rancho Cucamonga, Calif) using 25-35CFH 75/25%...i received structural engineering's prints that did not spec ASW or ASME codes, just 1/4" leg on fillet welds. Shop fab was easy and certified. Field erection, the cert welding inspector was okay with changing from 1/8"-5/32" 7018 but wanted certs for using 71M to cover his a$$. Easy to increase weld strength by 100% by running one pass on the ID's of column connectors. Owner-engineering always spec 'as built'; allows on the fly design changes-adjustments.

 

[Steve Bowman]

Yep, CFH; my brain was thinking D8N engine-torque overheating radiator issues on another thread...OP or myself haven't asked how much PSI should the shielding gas be?

True, but aren't most of them fixed psi? I will say that the flowmeter regulators I have do not have low pressure gages, and appear to not be adjustable. I believe they state 50 psi on the side. However, I do have a more traditional regulator with the LP gage, but no flow meter. I think it is the one that actually came with my welder.

As you suggested Stan, i dropped my voltage back a notch and tried some passes. Spatter/noise increased. I tried more/less wire with no improvement, so back to the higher setting (6) for me. My dad was there sharpening some knives and commented on how quiet it was.
I did get a little worm hole defect in there somewhere, but it was at the very top of my test and close to my fume pickup, so perhaps it was effecting the shield gas a little. I also dropped my flow down a little - so about 30 now, and i pulled my nozzle off just a little - tip is flush with the nozzle fully seated.

Breakfast finished, now off to start the preheat.

 

[Welder Dave]

My bad on the gas flow. Was thinking of a different wire where too a high a gas flow can cause turbulence. A lot of shops are starting to use the gas flow meters right at the nozzle because some wires are real finnicky with gas flow. Steve, make sure you have the wire running properly before you jump right in on your repair. Don't have the fume extractor so close it sucks your shielding gas away. Did you get some line up pins made and have bracing in place to keep the holes as close as possible? Flowmeters have preset pressure, 50 PSI is common but the outlet should be CFH.

 

[Welder Dave]

Just wondering how your repair is going?

 

[Steve Bowman]

Thanks for asking.

Before I started welding, I could freely rotate and remove the pin on the arm I was welding on. The other pin was not quite so free. As I was welding up the boom, I kept my eye on it. In the end, it was tighter, but I could still move it around with a 12 oz hammer. I also started with a run out tab.

I kept my eye on the preheat with a little water - just to where it sizzled. I would weld 1 or 2 passes on one side, then the other. Then hit both with the needle scaler. And then repeat. Grinding occasionally between the welds to keep a constant grove. I put some extra passes on to allow me to grind it smooth before I finished.
The clamps here are just for me to rest my arm on, and to support the blanket during preheat. Hard to see, but the come along is still there holding the "twist" alignment.




After all of that, I did one last preheat and wrapped the boom with the blanket to allow it to cool slowly.



So, after that, I leveled the frame of the loader with screw jacks and went to work on the lower boom. Placing a level across the bosses in the arms(on the right side of this photo), The boom was also level as I expected. So, I held the bushings in place on the bucket using a piece of shaft. I moved that assembly into position and checked the bucket for level 1st. It was out a little, so I raised one side a little. I put a bungee strap on to hold everything tight to the loader boom and started measuring. I centered the bucket from the dog bone bosses. Then I centered the boom bushings in those bosses. Not that I wanted to do anything about it, I did check the shaft for level and it was within the lines. Lastly, I checked from the front of the rear end housing at each wheel unit back to the center line of the lower pins. They where within 1/4", which was very surprising to me, and good enough. So I put some tacks on it and removed the bucket.