I am repairing an old Howard 350 rotavator. It's basically sound but
the previous user/owner had allowed the tine bearings to completely
disintegrate and one of the consqequences is that the chain drive has
made some holes and cracks in the chaincase.

Now the chaincase is pretty sturdy, 16swg or maybe even thicker
mild steel, say 1.5 or 2mm. Thus I have been able to weld the cracks
successfully with my old ClarkeWeld arc welder using 1.6mm rods. In
fact I've made quite a reasonable job of it! :-)

However the holes present more of a problem because the metal around
them is quite thin as it's been ground away. Will a MIG welder make
fixing these easier or will I need to fix patches in place somehow
anyway? Can any sort of welder allow me to build up across gaps
easily? The biggest holes are, say, 1/8" diameter, and I have some
longish holes which are maybe 1/16" across and 1/2" or so long.
What's the best way of dealing with these?

--
Chris Green )

wrote:
I am repairing an old Howard 350 rotavator. It's basically sound but
the previous user/owner had allowed the tine bearings to completely
disintegrate and one of the consqequences is that the chain drive has
made some holes and cracks in the chaincase.

Now the chaincase is pretty sturdy, 16swg or maybe even thicker
mild steel, say 1.5 or 2mm. Thus I have been able to weld the cracks
successfully with my old ClarkeWeld arc welder using 1.6mm rods. In
fact I've made quite a reasonable job of it! :-)

However the holes present more of a problem because the metal around
them is quite thin as it's been ground away. Will a MIG welder make
fixing these easier or will I need to fix patches in place somehow
anyway? Can any sort of welder allow me to build up across gaps
easily? The biggest holes are, say, 1/8" diameter, and I have some
longish holes which are maybe 1/16" across and 1/2" or so long.
What's the best way of dealing with these?

Depends how thin the metal is around the holes. With a lot of
patience and a bit of luck you can use a mig to bridge holes in
0.7mm sheet. Any thinner and you'll just blow holes in it.

Personally, I'd patch it. Get some sheet, cut it to size, and
weld all the way round.

--
Grunff

wrote:

However the holes present more of a problem because the metal around
them is quite thin as it's been ground away. Will a MIG welder make
fixing these easier or will I need to fix patches in place somehow
anyway? Can any sort of welder allow me to build up across gaps
easily? The biggest holes are, say, 1/8" diameter, and I have some
longish holes which are maybe 1/16" across and 1/2" or so long.
What's the best way of dealing with these?

Mig will work fine on small holes like that.

Steve

wrote:

I am repairing an old Howard 350 rotavator. It's basically sound but
the previous user/owner had allowed the tine bearings to completely
disintegrate and one of the consqequences is that the chain drive has
made some holes and cracks in the chaincase.

Now the chaincase is pretty sturdy, 16swg or maybe even thicker
mild steel, say 1.5 or 2mm. Thus I have been able to weld the cracks
successfully with my old ClarkeWeld arc welder using 1.6mm rods. In
fact I've made quite a reasonable job of it! :-)

However the holes present more of a problem because the metal around
them is quite thin as it's been ground away. Will a MIG welder make
fixing these easier or will I need to fix patches in place somehow
anyway? Can any sort of welder allow me to build up across gaps
easily? The biggest holes are, say, 1/8" diameter, and I have some
longish holes which are maybe 1/16" across and 1/2" or so long.
What's the best way of dealing with these?


MIG should work fine for this. I've just patched a sump that was like a sieve
on a Metro using a MIG welder.

You have to get bead of weld all the way round to start with. You may have to
chase after it if its burning away or leave to cool a bit and go back again
later. Then just weave back and forth filling the hole in the middle. You can
grind down flat if your bothered about appearence and fill any holes again until
your'e happy.

Good luck

Jimmy

Jimmy Gibson wrote:


wrote:

I am repairing an old Howard 350 rotavator. It's basically sound but
the previous user/owner had allowed the tine bearings to completely
disintegrate and one of the consqequences is that the chain drive has
made some holes and cracks in the chaincase.

Now the chaincase is pretty sturdy, 16swg or maybe even thicker
mild steel, say 1.5 or 2mm. Thus I have been able to weld the cracks
successfully with my old ClarkeWeld arc welder using 1.6mm rods. In
fact I've made quite a reasonable job of it! :-)

However the holes present more of a problem because the metal around
them is quite thin as it's been ground away. Will a MIG welder make
fixing these easier or will I need to fix patches in place somehow
anyway? Can any sort of welder allow me to build up across gaps
easily? The biggest holes are, say, 1/8" diameter, and I have some
longish holes which are maybe 1/16" across and 1/2" or so long.
What's the best way of dealing with these?


MIG should work fine for this. I've just patched a sump that was like a sieve
on a Metro using a MIG welder.

That sounds encourageing, thanks, I've been half looking for an excuse
to buy a MIG welder and now I seem to have one! :-)

You have to get bead of weld all the way round to start with. You may have to
chase after it if its burning away or leave to cool a bit and go back again
later. Then just weave back and forth filling the hole in the middle. You can
grind down flat if your bothered about appearence and fill any holes again until
your'e happy.

.... a bit as one would with an ordinary welder on thicker metal I
guess.

--
Chris Green )

wrote:

Jimmy Gibson wrote:


wrote:

I am repairing an old Howard 350 rotavator. It's basically sound but
the previous user/owner had allowed the tine bearings to completely
disintegrate and one of the consqequences is that the chain drive has
made some holes and cracks in the chaincase.

Now the chaincase is pretty sturdy, 16swg or maybe even thicker
mild steel, say 1.5 or 2mm. Thus I have been able to weld the cracks
successfully with my old ClarkeWeld arc welder using 1.6mm rods. In
fact I've made quite a reasonable job of it! :-)

However the holes present more of a problem because the metal around
them is quite thin as it's been ground away. Will a MIG welder make
fixing these easier or will I need to fix patches in place somehow
anyway? Can any sort of welder allow me to build up across gaps
easily? The biggest holes are, say, 1/8" diameter, and I have some
longish holes which are maybe 1/16" across and 1/2" or so long.
What's the best way of dealing with these?


MIG should work fine for this. I've just patched a sump that was like a sieve
on a Metro using a MIG welder.

That sounds encourageing, thanks, I've been half looking for an excuse
to buy a MIG welder and now I seem to have one! :-)

They are great little machines, you'll probably find yourself using the MIG in
favour of your Arc welder. I've welded 1/4" plate with mine without any problmes
and got much better results. You need a little practice to get the wire feed
rate and gas settings right, when welding correctly you should hear a continuous
hiss like frying bacon. If it's spitting you need a little more gas.
You should have the wire feed set so that there is about 1/8" to 1/4" of wire
sticking out as you weld. Too fast and the gun gets pushed away from the work
piece. Too slow and you end up running out of wire and welding the end into the
tip, you can get the wire out again with a bit of poking round but you sometimes
have to sacrifice a tip if it's too bad. Keep a pair of wire cutters handy as
you have to cut the wire back to size when you miss the workpiece, more so when
patching holes and you're chasing a burnaway.

Don't go for the cheaper gasless only welders, they are no way near as good.
You get lots of fumes and slag buildup as with arc welding so you have to do a
bit of guesswork as to whether you've got it right. You can use the gasless
wire in a gas mig if you're in a fix with no gas left, just make sure the welder
can take 0.8mm wire.

The small disposable bottles don't last long, try to get a refillable one if you
can. If not Machine Mart and probably others do a higher capacity disposable
bottle which works out a bit cheaper, can't remember the size and my catalogue
is at home! The CO2/Argon mix is best but C02 is OK and a bit cheaper.

You have to get bead of weld all the way round to start with. You may have to
chase after it if its burning away or leave to cool a bit and go back again
later. Then just weave back and forth filling the hole in the middle. You can
grind down flat if your bothered about appearence and fill any holes again until
your'e happy.

... a bit as one would with an ordinary welder on thicker metal I
guess.

I suppose so, I've never tried patching holes in thicker metal with an ordinary
welder. Try with the lowest power setting first and work up if needed.

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