Welder Capacity - Axle Repairs

[Retroanaconda]

Folks,

Quick query - I have a Murex Miget MIG welder, pretty old thing by all accounts but seems to work well. It is rated with a 30-170A output range and is a single-phase machine which I have wired up through a decent 16A supply circuit. Running argon/CO2 mix gas and is fitted with 0.8mm mild steel wire.

Is it likely to be up to the job of welding replacement spring seats or other brackets onto a Land Rover axle, or am I hoping for too much from it? The brackets tend to be 4-5mm thick.

I'll give it a go in due course but if consensus is that I'm wasting my time I won't bother and will farm it out to someone with a big welder.

[SPendrey]

Plugged your numbers in here and although at the top end of the welder's capability, it would seem possible.  Its a PITA getting the inside edges done, but get as much on both sides as you can.

[Bowie69]

I often weld up to 6mm with my Clarke 151TE, you just have to be mindful of preparing things properly.

V-notch and welding from both sides helps lots, but thinking about it when you come to do it you should see a way in every case I would imagine.

Remember there's nothing to stop you running a second or third bead while the first weld is still hot to build up the throat.

 

[steve b]

It should be fine , providing good prep. and technique is applied - as said above vee prep fillet edges to gain full thickness penetration with a good hot root (spray deposition ) then a dip transfer cap , weaving as required .

Don't forget the rule of thumb for fillet welds - a 10mm run of 6mm fillet will take a 1t tensile load , so if  done well it will be plenty strong

cheers

Steve b

[Ex Member]

He won't get spray transfer with that machine, wire and gas.  The machine will be fine.  The question is down to the operator.  Making nice looking MIG welds is easy.  Making strong MIG welds is hard.

But, as stated above, you will have so much more weld than needed, it does not really matter what you do.  I would suggest running a flux core wire and the gas.  It will eliminate a lot of the possible problems.  And try to avoid position welding as much as practical.

[steve b]

I can achieve spray or dip transfer on my 160a snap on single phase in the home workshop - it's just a question of balancing wire speed and amps in one direction or another . Agreed it's easy at work on the end of 500a of Kemppi loveliness on 20mm plate but with a bit of practice it should be possible in a home workshop .

What mix is your Ar/CO2 ? somewhere around 5% CO2 should be optimal .

 

cheers

Steve b

[FridgeFreezer]

LR axles aren't very thick, I'd think with good prep and a bit of practice beforehand to get the settings dialled in it'd be up to the job. Can always run a 2nd bead over the top with a bit of figure-8 weaving.

[Retroanaconda]

Thanks all, think I'll give it a go. Will let you know how I get on.

Have never used the welder at its higher settings as I've never had need to or had a proper power supply for it but it dealt with chassis repairs and such on a 13A supply easily enough. Not sure what mix the gas is, will have a look at the weekend.

On the front axle I only need to replace the spring seats, so they'll be the first ones to get attention.

[Ex Member]

Don't worry about the spray.  You really don't want to spray for a few different reasons.

A more normal higher CO2 mix is better for this application in short circuit mode.  Like I said, I would personally suggest picking up some flux core wire and run it with the Ar/CO2 gas..  It will avoid the need to be surgically clean.  If you can avoid vertical position welds, do it, as it requires a lot of practice to not mess up.

[ballcock]

4 hours ago, Red90 said:

He won't get spray transfer with that machine, wire and gas.  The machine will be fine.  The question is down to the operator.  Making nice looking MIG welds is easy.  Making strong MIG welds is hard.

But, as stated above, you will have so much more weld than needed, it does not really matter what you do.  I would suggest running a flux core wire and the gas.  It will eliminate a lot of the possible problems.  And try to avoid position welding as much as practical.

Hi Red90 I have never heard this done before. Do you need to reverse the polarity as well, or is it alright using it as normal?

[Ex Member]

40 minutes ago, ballcock said:

Hi Red90 I have never heard this done before. Do you need to reverse the polarity as well, or is it alright using it as normal?

Flux core?  It should be electrode negative.  Solid wire is electrode positive.  Always read over the data sheet for the consumable to understand setting limits.

[pete3000]

Could always gas preheat/warm the tube, to raise the temp a bit for better penetration, give it a quick tickle with the grinder brush then give it a mig on full power.

[UdderlyOffroad]

16 hours ago, Red90 said:

Flux core?  It should be electrode negative.  Solid wire is electrode positive.  Always read over the data sheet for the consumable to understand setting limits.

The 'flux core' we get over this side of the pond is meant for gasless application, rather than what's generally available  in North America.  This appears to be intended to supplement the shielding gas (at least according to some of the Youtube channels I subscribe to).

I would guess it comes down to a difference in what's acceptable according to ASME/AWS and the EN stds, which therefore drives what consumables are available.

I am not a welder or materials engineer however, so am happy to be corrected.

As for spray transfer, yes it is do-able with DIY kit, but I would personally stick to the old motto of 'the key to good penetration is good preparation' using conventional MIG...

[FridgeFreezer]

Some of these suggestions sound overcomplicated to me: clean it to death, prep the edges, whack the amps up & wire speed down and burn it in well.

[Ex Member]

Gas shielded - Flux-core is available everywhere.  It is, though, only sold in large diameters and thus not suitable for this use.  Using self shielded flux core with gas will produce a better weld than without.

http://www.esab.co.uk/gb/en/products/index.cfm?fuseaction=home.productsbycategory&catId=56

 

 

[steve b]

I've visited a couple of places nearby that use it on large pipework - butt joints around 50mm wide at the top , never had the chance to watch it live though . Do you work in the welding field then Red90 ?

It's of endless interest once you get involved

 

Steve b  

[discomikey]

Hi, have you done this yet? 

I'd like to offer my 2p.

Your welder is capable of this work. Whack it up to full power and just make sure it's prepped well and keep to the front of the puddle. Watch It dig! There's no need to overcomplicate this. If you are at all unsure then take it to a professional welders. An axle falling off is far from ideal but you know that.

Happy welding. 

[Retroanaconda]

When I stripped it properly I found a few more of the brackets were rotten and the diff was suspect so in the end I just got a newer axle for less than it would have cost me for new brackets and a decent diff. And no need to repair anything.

I did this before making the call though, and it seemed to penetrate quite well:

I have kept the casing, it's got an HD diff pan on it so I might get the brackets in the future and have a bash at repairing it so it can go on the 90 instead.

[discomikey]

even if you repair it as practise, you wont really waste anything other than a bit of time and a small amount of cash!