Sharpening molding planes???

Re: Sharpening molding planes???

Bob Hackett


>Most of these old irons can be cut by a sharp file(I like chainsaw files for inside curves)and then honed by your slipstones.

If you don`t have the right size slipstone then sandpaper over an appropriately shaped bit of wood works just as well.

Slippery slope indeed.How much extra shelf space do you have?

Mainely,Bob

Few tips

jim reed @ tallahassee


>My first step is to grind the profile at 90 degrees. The next step is to apply the bevel. You can watch the bevel sneak up on the edge. As far as how to grind, you can dress your wheel to an appropriate shape, you can use a narrow wheel (1/4), you can use a cutoff wheel, you can use a Dremel. Takes lots of patience. Good luck.

Re: Few tips

William Duffield, on the Cohansey


>But, if these are old irons, they should still be close to the desired profile. Grinding to 90� first would remove a lot of otherwise useful tool steel and take a lot longer than just making subtle changes with slip stones.

I usually use medium and hard Arkansas slips, the same as I use for carving chisels. Of course, India slips, water slips and diamond slips would work too, depending on which medium you are used to using for your other sharpening tasks.

Re: Sharpening molding planes???

ThomD


>First thing is to decide whether the plane profile is useful or needs freshening. But lets assume you have a perfect profile to the plane body and all you want is a template for the iron.

Start with a copy of the body profile, the shape you will be creating on the resulting molding, plus any alignment surfaces for the plane. You can copy this by digital camera or by using other devices like, say plasticine, to get a good crisp profile. Idealy you want to scan or digital this to your cad program, or draw it to scale on some paper.

If you get the profile in JPG form into your CAD, you can copy it with simple lines and curves, align it to the 0/90 grid, and then stretch it.

There is a similar manual process which consists of drawing the profile on paper and extending the lines for the significant chnge points horizontaly through a 45 degree or 50 degree angle that represents the aditional length of each of these points. You use that to draw the stretched out iron profile. You could do the same thing by calculator. Imagine a plane that cuts dovetails and over it's width has a rise on the slope of 1/10". You could put the profile on your paper, and then stretch difference of the two change points (start and end of the slope), by 1.44 or whatever the factor is. So in this case the blade needs to have a difference of .144" to catch up with the 1/10" slope gain, at a 45 degree pitch.

When it comes to actual sharpening you need to read the edge that is already there, or look at similar planes. You need to ensure that there is a positive clearance angle in all directions which will give some of the elements a reamed look at the bevel.

My home computer still has modem trouble so I can only get back on this stuff while I am visiting, and after tommorow i'm gone again. So i'm not being rude if I can't follow up.

Re: Sharpening molding planes???

Dave Mount


>I don't remember where I saw it, but someone, I think from this board, had a webpage showing the grinding of a new molding plane iron as a replacement for an existing plane body. They used a thin (like 1/4") white grinding wheel that they had reshaped to a round edge using a diamond wheel dressing tool. Around that they built a small platform to provide work surface (maybe 8"x8") that was canted so that the tangent of the wheel was 30 degrees to the work surface. With this arrangement, they could swing the iron back and forth to grind complex profiles, including reasonably small concavities. It might be a lot of setup fuss for just an iron or two (as opposed to sandpaper on a dowel and some patience), but it was a pretty slick rig if you have any substantial amount of metal to remove.

I just can't find the bookmark. I think it might have been Scott Post's page -- my old bookmarks for Scott's pages indicate that his host site is gasphincto.

Good luck,

Dave

Dave Mount

NE Minnesota

sharpening inside curve

bill tindall


>Mount aluminium, or something else, cylinder in drill press. Charge it with diamond powder, about 30 micron. Make an angle block to rest tool upon so it precents itself to cylinder at correct angle. Grind away, and quickly I might add.

To clarify

Jim Reed @ Tallahassee


>By grinding to 90 degrees, I did not mean the whole blade. Mark the profile with a sharpie on the flat side. Grind at 90 to that profile. Then bevel up to the properly ground cutting edge. Sorry for the confusion.

Re: To clarify

William Duffield, on the Cohansey


>Yes, of course, your recommended method makes perfect sense now. It might even save metal vs. trying to reshape it by trial and error, and should be a lot quicker, too.

Re: To clarify

Larry Williams


>It is the quickest and most accurate method to match the profile but I suggest a metal scribe and layout fluid on the iron. I prefer red layout fluid which I then use on the flat from the 90� ground flat. Lapping the layout fluid off the face after the 90� grind makes the red flat area much easier to see and work to. A flex shaft grinder with well dressed grinding points followed by rubberized abrasive points makes for quick work ending in a sharp edge.

Thanks to all of you for the info.

Angus Barclay, in New Zealand


>Thanks for all the info about how to sharpen the molding plane irons.

I figure I'll start by trying Bob Hacket's suggestion of a sharp file followed by slipstones. I have these items in my shop already, so that's the obvious place to start. I won't be too surprised if the file just skates across the iron though. I don't have a Dremel or similar but this could end up being an excuse to get one.

If the sharpie that I have turns out not to be accurate enough for marking, then I'll follow Larry Williams' sugestion of a metal scribe and layout fluid. Given the business he's in, I figure he probably knows a thing or two about sharpening molding planes!

I don't have CAD (I'm more of a pencil and paper type person) or a drill press, but those suggestions were helpful anyway. They got me thinking that I could turn a tapered spindle on the lathe and maybe use that as the basis for grinding all sorts of different curves. That could be really usefull for making or modifying plow blades into double and triple beads. Any suggestions as to what material to make such a spindle from? Maple and stick sandpaper to it? Aluminum and use diamonds?

regards

Angus Barclay

Re: Sharpening molding planes???

Jake Darvall


>Hi Angus.... here's a link to a thread I did a while back on it. A step by step process of how I sharpen the buggers with grinder and buffing wheel. Pictures etc.

might help some. Maybe give you some ideas.

http://www.woodworkforums.ubeaut.com.au/showthread.php?t=19928&highlight=sharpening+moulding+planes

Goodluck....there not easy. Have to be prepared to practise a fair bit.

Re: Sharpening molding planes???

Angus Barclay, in New Zealand


>Hello Jake,

thanks for that. I've added it to my bookmarks as a definite keeper.

regards

Angus Barclay

Re: Sharpening molding planes???

Jake Darvall


>No problem. Have a good week Angus.