Restoring Inside Sweep of Badly Pitted Gouges

[paulc]

Hello,

I know that often times pitting on old gouges can simply be ignored (once the edge is OK) or remedied with an inside bevel which brings the cutting edge below the pitting.

But is there any way to remove the pitting completely, and bring the inside sweep of a gouge back to fresh steel?

Would a coarse needle file be effective ? Or a cone shaped dremel type grinding attachment?

All efforts so far with sandpaper have made little difference.

Any advice appreciated. Thanks, Paul

 

[AndyT]

My preference would be to grind away the tip by presenting the blade end on to a coarse grinder. Shorten the gouge till you get past the pitting, then grind a new bevel.

If there's pitting all the way up and you want to rescue the tool I guess you will need to remove metal from the inside curve. In production, the maker would use shaped abrasive wheels but I don't think it's worth buying those rather than buying a new gouge.

Abrasive paper on a stick or offcut of water pipe would be what I would try first, making sure that it's some decent quality 80 grit silicon carbide, not glasspaper from a pound shop. The stick or tube doesn't have to be the exact size, and can be smaller.
Or you can round off the edge of an offcut of thin wood, wrap the paper round it and hold it in the vice. Then you can use both hands to work the gouge back and forth.

 

[Racers]

Drum sanders in a drill can be used, they tend to pull to one side and remove more metal from that side if you aren't careful.

Pete

 

[StraightOffTheArk]

I've used coarse/medium/fine slip stones to good effect, although I'm too lazy to do more than an inch or so from the cutting edge. I have also used a cheap imitation dremel initially, and found it very easy to damage the profile - the finish was a bit messy, but then sorted out with the slipstones.

Cheers,

Carl

 

[custard]

If you have pitting on the non bevelled face of any edge tool it really has to be removed before the tool will perform properly. Removing pitting is not a quick and easy job even on a flat blade like a chisel or a plane iron, read here for more,

record-stanley-laminated-plane-irons-t106851-30.html

But if you have pitting on a gouge then I'd seriously question if it's worth even trying to salvage it, given that good quality used gouges are plentiful and fairly cheap.

 

[monkeybiter]

you can round off the edge of an offcut of thin wood, wrap the paper round it and hold it in the vice. Then you can use both hands to work the gouge back and forth.

That would be my method, working up through three or four grades of wet-and-dry, but Custard is also right, and you're the only one who can judge whether it's worth your tome/effort.

 

[Bod]

My guide regarding rust pitting is, at my rate of use, how long will it take to be a problem.
I have several chisels and gouges, which are pitted, but at my rate of use, the pits will not cause concern in my life time!
A gouge could be reground in/out cannel to avoid the worst.

Bod

 

[ED65]

Would a coarse needle file be effective ?

Unlikely, the gouge is probably much too hard for the file to cut well. And if it were soft enough that a file would cut it easily it's probably not worth continuing working on it as it would be too soft to be of much practical use, unless you're happy to reharden the tip after the pits are gone.

Or a cone shaped dremel type grinding attachment?

Yes those can work, but it tends to be slow going. Many of the Dremel-type grinding wheels wear down very quickly so you might need to have more than one to complete one gouge. Sanding drums are another option and IME work much better and are cheaper in the long run.

All efforts so far with sandpaper have made little difference.

When doing this sort of thing the quality of the abrasive paper does make a big difference, so if you're not using decent wet 'n' dry or resin-coated paper it's worth switching. Also don't start too fine! You see people do this all the time, they have lots of metal to remove but start with P220 or something like that. Bulk removal calls for something like P80 to be the first grit used.

I think the easiest way to tackle this would be with abrasive paper wrapped around a dowel. The dowel + paper needs to be a slightly smaller diameter than the channel of the gouge.

Then either clamp gouge and rub the inside with the dowel or clamp the dowel and rub the gouge over it.

Last thing, just like with a chisel or plane iron just the last few mils needs to have the pits removed, any pits further back than this you don't have to concern yourself with, possibly ever as most leisure woodworkers are unlikely to hone off more than a mill or two in their lifetimes. So any pitting 3mm from an edge is of no consequence to the majority here.

 

[Phil Pascoe]

I thought carving gouges were honed on both sides anyway, in which case you'd sharpen through them?

 

[Cheshirechappie]

If the gouges are firmer type, just ignore the pitting - firmer gouges are relatively 'rough' tools compared to paring or carving gouges.

Professional tool makers use a power grinder fitted with a wheel of width close to the gouge width, profiled on its edge to the sweep of the inside curve. The amateur can do something similar with a hand-crank grinder, some interchangeable wheels and a dresser to put a profile on the wheel edge. That will do the bevels of in-cannel gouges and the irons of hollow moulding planes, and the inside of gouges. That investment of time and bother might be worth it for fun, or if there's a lot of tools to deal with; otherwise, as Custard said, the pennies might be better spent on a few decent gouges, and the hours on using them!

 

[woodbrains]

I thought carving gouges were honed on both sides anyway, in which case you'd sharpen through them?

Hello,

This is sensible. Although the bevel is on the outside, many carvers put a slight back bevel on the inside. The reason being, the outside bevel is often too steep for the user to get a comfortable carving position, when the bevel is in rubbing mode on the work. So reducing the bevel angle lowers the tool handle but makes the cutting edge too thin. Putting a back bevel thickens up the edge again. In your case, it will also negate having to remove the pitting. Two birds with one stone.

Mike.