Repairing parts with welds.....

[Heavy Hand]

Hi,

Just a random question...hoping people with experience will give their view!

Got a couple of little projects where I could weld up a worn spigot (Mig or Tig) and then lathe back to size. Got no idea of the grade of steel, and the bearing surface will be under pressure but not turning fast. (not safety related). Given that idea.....In practice, will the heat just anneal the part and it will wear ridiculously quickly?......MIG harder than TIG etc?.......Better to just find a replacement?

TIA

 

[zzr1200]

Pictures of part, more info on part, what machine does it fit into, what does the spigot support???

Mind readers we aren't......

Helpful we try to be.....

 

[frank horton]

Mr Hand,
if u wanna see what can be welded up n repaired take a look at this lot....
100's of vids.....
def some not recomended but it is the 3'rd world....

 

[Agroshield]

As above, specifics of the part and application will help.

In general, it is a reasonable technique.

A refinement is to turn down the worn part first, then weld, then turn to finished size.

The interface between old material and new weld material can have strange metallurgical properties because it is a mixture, and may not turn well. You want that interface to be below the eventual finished surface, so you are only turning new material, that from which your welding filler material is made.

 

[premmington]

Hi,

Just a random question...hoping people with experience will give their view!

Got a couple of little projects where I could weld up a worn spigot (Mig or Tig) and then lathe back to size. Got no idea of the grade of steel, and the bearing surface will be under pressure but not turning fast. (not safety related). Given that idea.....In practice, will the heat just anneal the part and it will wear ridiculously quickly?......MIG harder than TIG etc?.......Better to just find a replacement?

TIA

This is what most of welding is...

Blowing pins out of diggers - building things up - line boring - repairing stuff - bolt extraction.

Hardly ever get any new metal and fabricate anything.

 

[Domdom]

If you want to see an example of how an Aussie engineering firm does this, have a watch. This isn't 3rd world stuff among the dirt, they have the machinery and the skill.

 

[Morrisman]

Norman Hyde used to weld up the cranks of Triumph Tridents and re grind them with a longer stroke.

Almost anything is possible if you use the correct techniques.

 

[zzr1200]

It's generally not the job that's the problem.

It's all the associated (homemade sometimes) tools/specialised equipment or workarounds that cost the time/money...

Often at times the cost of a new part is cheaper, than the time, effort, investment in equipment costs to repair the old one.

 

[Gareth J]

Without details it's hard to say but, with access to a lathe and welder, I would first rule out turning up a new spigot and pressing in/welding that on.

 

[Heavy Hand]

I was purposely vague about the specifics.....I was trying to stop the thread decending into a discussion about post treatments and whether or not it needed to be quenched in unicorn tears!

One of the jobs was a spigot used as the pivot for the belt tensioner on an old lawn tractor.
(assumed it was softer so sacrificial to the main plate.....brought new £7!!.....but could have repaired!!)

The other job is the bearing forks on a portable english wheel set.......not done yet....but wondering if I should mod to fit bearing sleeves!

Just wanted to know if it was a good thing to do, or if rapid wear means things fail quickly!

 

[Morris]

Also consider turning down the spigot and the fitting an interference fit sleeve. I have repaired a lot of shafts using that method.

 

[selectedgrub]

....quenched in unicorn tears!

Desert sand and baby furseal oil.

 

[zzr1200]

1. One of the jobs was a spigot used as the pivot for the belt tensioner on an old lawn tractor.
(assumed it was softer so sacrificial to the main plate.....brought new £7!!.....but could have repaired!!)

2. The other job is the bearing forks on a portable english wheel set.......not done yet....but wondering if I should mod to fit bearing sleeves!

1. Not exactly high tech, either repair/replace or modify with a bolt, depends on spare availability or if the shops are open??

2. Pictures would help here, but weld up n turn down/bearing sleeves or braze up then turn down.

An English Wheels (bottom?) Roller Holder isn't really high pressure, so I'd personally try the braze/machine route first.

 

[Heavy Hand]

I really worry about myself sometimes........ dug the box out of the garage!... I would appear the welding fairy has already visited the wheel saddles!!. Guess I thought MIG welds would be harder?!.

I still need to do something with the pivots of the wheels.... tending towards the sleeve route, only dragged my heels coz it was a 1930's tool (Denterazer) .....didn't want to kill it's soul, but maybe better that it is usable!?

 

[zzr1200]

The roller, either make a new one (4140) or bore out the middle and fit a new shaft (press fit/loctite the roller to the shaft), then skim/polish the roller surface.

The yokes don't appear to fit that roller (not wide enough), so either repair or replace.

Having a totally original machine is nice (even with some worn parts), but having one that works even better with new homemade parts, is even nicer.....

 

[fizzy]

Mr Hand,
if u wanna see what can be welded up n repaired take a look at this lot....
100's of vids.....
def some not recomended but it is the 3'rd world....

Often their work is very serviceable. Especially their lathe work. The really know their stuff.

They must do to keep these old Bedfords running in very harsh climates

 

[Heavy Hand]

The roller, either make a new one (4140) or bore out the middle and fit a new shaft (press fit/loctite the roller to the shaft), then skim/polish the roller surface.

The yokes don't appear to fit that roller (not wide enough), so either repair or replace.

Having a totally original machine is nice (even with some worn parts), but having one that works even better with new homemade parts, is even nicer.....

The slots were completely welded up and not yet machined out again - originally very little meat either side of the slot!

 

[zzr1200]

Often their work is very serviceable. Especially their lathe work. The really know their stuff.

They must do to keep these old Bedfords running in very harsh climates

View attachment 490677

They certainly don't have many low bridges, or head winds...

Mine you they like their curries so it might be wind power...

 

[premmington]

I really worry about myself sometimes........ dug the box out of the garage!... I would appear the welding fairy has already visited the wheel saddles!!. Guess I thought MIG welds would be harder?!.

I still need to do something with the pivots of the wheels.... tending towards the sleeve route, only dragged my heels coz it was a 1930's tool (Denterazer) .....didn't want to kill it's soul, but maybe better that it is usable!?

There is whole other world of what you can use. 312 309L - you can weld harder more tensile stuff to anything - but it is the machining that gets hard work.

For line boring digger arms - I lay in 6013 - as it is "buttery to cut out".

I thinking about making or buying a "bore welder" to lay down A18 wire with a mig nozzle.