Grinding molding plane irons

[LuptonM]

Just wondering how do people grind/ hollow molding plane irons as they would be easier to sharpen with a hollow if they've been abused in the past?

 

[AndyT]

If you need to do some reshaping, the simplest way in my experience is to wrap coarse abrasive paper round an offcut of dowel, or copper or plastic pipe. You need something of smaller diameter than the curve so you can adjust the side to side angle to reach all the curve on the iron. I prefer to clamp the iron on a bevelled block and hold the abrasive horizontal, as if it was a file.

Most moulding plane irons are not fantastically hard and don't need powered grinding wheels.

Pretty sure I learned this from Alf at the Cornish Workshop.

 

[Racers]

I use the cheap diamond needle files from Aldi/Lidl etc, they come in lots of profiles and work well to reshape the blades.

You would have to have a very narrow wheel and very good had eye coordination to use any form of powered grinder, plus eye and ear protection.

Pete

 

[Cheshirechappie]

For anybody with a hand-crank grinder, search out a supplier of replacement wheels of different thicknesses. Dress the periphery of each 'new' wheel to a curved profile, and you can reshape and in-curved cutting irons quite easily - not just moulding plane irons, but in-cannel gouges, chairmaker's spokeshaves and chair devils, and anything else that might crop up.

The hand-crank is a far more controllable tool than a powered bench grinder, slower to cut but far more civilised. A 6" model is much easier to find replacement wheels for than a 4", though, which is worth bearing in mind should you go looking for one.

Mostly, though, for the amount of reshaping most people will need to do on in-curve tools, Andy's and Pete's methods, whilst slower, will be more than adequate.

 

[G S Haydon]

I've never tried a Dremel, but I guess they could work. I would revert to the advice of Andy though, hollow grinding moulding plane irons is not something I'd worry about.

 

[LuptonM]

Thanks for the replies.

I know in america you can get thin grinding wheels from Norton? Any idea where to obtain some in the UK?

I think a hand grinder is probably best if using thin wheels otherwise could cut through your hand if you slip up!

 

[woodbrains]

Hello,

TBH how much do these cutters actually need to be reshaped. Unless someone has been trying to plane shrapnel, they are usually just dull or with slight nicks and chips. I have never seen them so far off, they need grinding. It is surprising how quickly they can be reformed with just hand power and some Norton slipstones. Failing that, some abrasive stuck to dowel. They are small cutters and don't take long with low tech methods. Just go for it.

Mike.

 

[AndyT]

As above. I assumed you were asking about hollows as in hollows and rounds but see that you actually wrote grind/hollow. There is no need to get anything like a hollow grind on the edges of these irons and I have never seen a hollow grind on any old moulding plane. (I do have a fairly wide selection of moulding planes.) You just need to get some sort of bevel, generally a pretty shallow one, all along the edge, then hone the edge at a slightly steeper angle.

If you are making a new iron from scratch, the old method would still work - heat the steel to soften it, shape it with files, then re-harden it.

 

[Droogs]

What I do for my Record 405 irons and my moulding planes is to true the flat the face initially, just so i know I have a sharpish edge and then cut 200mm x width of the iron strips of dense hardwood, which i then plane with the iron to create the profile of the iron. Then I (vigourisly) mix a little mineral oil and shavings from rouge block and load the result on to the block. The I just hold the iron at around 30Deg and draw the iron backwards across the block until I feel the smallest hint of a burr, then clean off the iron and use it. Has worked well for me so far.

i find that I have to then give the finished moulding a sanding with 240/320 abranet/autonet just so that i then give any dye or stain a chance to penetrate.

 

[D_W]

Hello,

TBH how much do these cutters actually need to be reshaped. Unless someone has been trying to plane shrapnel, they are usually just dull or with slight nicks and chips. I have never seen them so far off, they need grinding. It is surprising how quickly they can be reformed with just hand power and some Norton slipstones. Failing that, some abrasive stuck to dowel. They are small cutters and don't take long with low tech methods. Just go for it.

Mike.

This. We try to minimize the work that they do because they're a pain in the ding to sharpen compared to rabbet and plow planes. If a used plane is so far off that major work is necessary, sometimes it's easier to just draw the temper out of an iron, file it, and then reharden it and finish it off with slips.

That should only be necessary with irons that can't be ground, like small hollows and complex profiles, and it should only be done once.

All irons should be maintainable with slips once they're corrected.