Small Hollows and Rounds Iron Profile

[OtakiriLad]

I am going through the investigation stages before making my own Hollows and Rounds. So far so good but when it comes to the smaller sizes I am confused.
Usually the irons have a tang width of about 3/8" which is greater than the plane profile for #1 - #5 being 1/16" - 5/16". Should the hollow/round profile be cut from the centre of the iron or from one edge?

[markharrison]

I haven't done it yet so I am interested in your experiences. There is a DVD available called Making Traditional Side Escapement Planes by Larry Williams. It's available from Lie-Nielsen (http://www.lie-nielsen.com.au/catalog.php?grp=1320), and many other fine vendors I'm sure.

To answer your specific question, you might be able to work it out from the information at Lie-Nielsen on this webpage (http://www.lie-nielsen.com.au/catalog.php?cat=548). They sell ready made tapered irons for moulding planes.

From what I can deduce from this is that there wasn't a single standard tang size. The tang seems somewhat proportional to the cutting edge width.

What I don't know is how you cut a the mortise for all the odd sizes of tangs. I've never seen a 3/32" mortise chisel ever!

[lwilliams]

The tang width is smaller than the width of the mortise. The tang should be somewhere around 2/3 to 3/4 the width of the mortise and irons should be selected by tang width rather than over-all blade width. Over-all blade width may look to be 1/8" oversize for even numbered planes to 3/16" oversize for odd numbered planes. You'll need 1/16" of that to accommodate a leaning wedge and the remainder gives a little leeway plus some steel to work with if one chooses hack saw off the remainder.

Even with the tang width being smaller than the mortise you'll find you have to slightly bend the tang to get it through the mortise when working with some of the smallest of the sizes.

The profile of hollows and rounds needs to begin at the blind side of the escapement and extend for the full width of the sole. The width of the sole is the same as the radius of the profile so the plane cuts a 60º arc.

[OtakiriLad]

Many thanks for that - I will work on that basis and now look for material for irons that is cheaper than the $85 for 25 x 3 x 200 I was quoted today!

[Clinton1]

old files or leaf springs work well.

[markharrison]

You can buy O1 tool steel, shape away with a file and harden. There are a number of places to get O1 tool steel both here and abroad.

One thing to consider is that traditional irons were tapered. They were thicker at the cutting edge than the end of the tang. The taper with the wedge secures the iron.

You don't have to do that but if you intend to go hardcore, but that's how they were made. On the other hand, there is more fun to be had in this world than hand tapering plane irons with a file!