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What tool for grinding out a weld in a corner...
jps - 9/5/14 at 07:38 AM

As per title really. Imagine you've got a box with no lid on it. What tool would you use to grind out a weld that went right into the inside corner of the box?

Obviously an angle grinder won't get in there - and a drill will just slip about all over the place.

Wasn't sure if I needed something like this: http://www.diy.com/nav/fix/power-tool-accessories/grinding-discs/grinding_stones/Bosch-Grinding-Stones-Set-2609256549-9286509?ecamp=SEAPLA9296209& ef_id=Uz539AAABaEkouA4:20140509073311:s

But am not sure how well they will fare against MIG weld on 3mm steel...?!


designer - 9/5/14 at 07:44 AM

A small grindstone will take forever to cut a weld in 3mm plate.

Depending on it's position, can you cut down it with a hacksaw?


Slimy38 - 9/5/14 at 07:51 AM

I'm currently using a black and decker powerfile to tidy up some inside corner welds, problem is it's got a fixed radius on the end so it can't go past a certain point.


nick205 - 9/5/14 at 07:53 AM

You'll be there for ever with a Dremel type tool and as you say it will wander about all over the place.

You could use a power file like this...



...but it still won't get right into the corner.

Question - why do you need to get the weld out of the internal corner? Most people just live with it there or design around it if necessary. e.g. cut a chamfer on mating parts to clear the weld bead.

...Beat me to it Slimy

[Edited on 9/5/14 by nick205]


NigeEss - 9/5/14 at 07:54 AM

A good quality carbide burr in something like a Dremmel. Don't waste your time with stones or HSS burrs.
If it's a MIG weld then bear in mind this will be a bit harder than the mild steel plate and choose a burr
accordingly.
(MIG wire is harder than mild steel so that it stays straight during the feed process)

[Edited on 9/5/14 by NigeEss]


jossey - 9/5/14 at 09:04 AM

Dremel


DW100 - 9/5/14 at 09:14 AM

Die grinder with a carbide burr.


teegray19 - 9/5/14 at 10:21 AM

A good quality big carbide but single cut


jps - 9/5/14 at 11:24 AM

Thanks for the feedback - I have used a (cheap) Dremel type grinding stone in the past with little success (when trying to cut out for mounting of a master cylinder in the back plate of my pedal box) so did suspect 3mm mild - or MIG weld - would be too much for them...

quote:
Originally posted by nick205
Question - why do you need to get the weld out of the internal corner? Most people just live with it there or design around it if necessary. e.g. cut a chamfer on mating parts to clear the weld bead.
[Edited on 9/5/14 by nick205]


I'm probably being over cautious about having nice clean welds in anticipation of IVA. It's a weld which holds a gusset to a plate which the roll bar stays will mount to. It's been welded (not by myself - but a professional welder) properly on one side - but I wanted to finish the job off by running a bead of weld down the other side. But I made a mess of it.... I had intended to clean it out and try again (once I'd perfected my welding technique) so it all looks neat and tidy...

I think i'll see how far I can get with a handfile before I invest in a powerfile....


FuryRebuild - 9/5/14 at 11:39 AM

+1 for the Carbide Burr in a die-grinder.

That's the right tool for the job, and will shift anything.

Can you get a flap-disk in there on an angle-grinder - that's surprising in what it will shift.


jps - 9/5/14 at 12:33 PM

quote:
Originally posted by FuryRebuild
+1 for the Carbide Burr in a die-grinder.

That's the right tool for the job, and will shift anything.

Can you get a flap-disk in there on an angle-grinder - that's surprising in what it will shift.


Can't get in with an angle grider - had a Google of 'Carbide Burr'. Any reason I can't use one in the chuck of a decent drill?


MikeR - 9/5/14 at 12:43 PM

Drills aren't designed for sideways loading so you'll knacker it, eventually.


jps - 9/5/14 at 12:46 PM

quote:
Originally posted by MikeR
Drills aren't designed for sideways loading so you'll knacker it, eventually.


Cheers - I hadn't considered that!


NigeEss - 9/5/14 at 05:10 PM

quote:
Originally posted by MikeR
Drills aren't designed for sideways loading so you'll knacker it, eventually.


Also the drill is far, far too slow. Burrs are designed to run in the 10-20000 rpm range, use a dril
and you'll simply take chunks out of your expensive burr.


Eltel - 9/5/14 at 05:21 PM

Die grinder from machine mart