Advanced Angles on the Lee Valley Honing Guide Mk II
It occurred to me that building templates is quite straight forward, and I'd like to offer a guideline here.
Building a template for the Stanley #140
I have built a #140 template (below) as an example of the process. The steps involved are:
• Measure the mouth angle of the skew (see picture at left).
• The other relevant measurement is the distance between the start and stop on the blade registration jig. The setting for a 25° bevel is #2 (yellow) on the Honing Guide…
…and Green 17° (or Red 35°) on the Registration Jig.
• Transfer the dimensions to a durable material (I have used a cutting board), and cut this out.
• Place the template on the Registration Jig and set up blade.
• Reverse it for the other hand (my Stanley is used here for illustration).
It is important to do your own measurements as sometimes these will differ between planes. For example, although I have above used 70°s for the Stanley #140, mine is in fact 69°s (which is why I had to regrind the brand new LN blade I got for it–damn!).
The measurements for the #79:
Making a template for the #79 is exactly the same. I have not made one yet (i.e. is untested), but took a few pictures and measurements.
• Settings for a 25° bevel are: Green (#3) on the Honing Guide, and Red 45° on the Registration Jig.
• The template is calculated as above.
• See picture at left for angles involved.
The rest is up to you.
A cambered scrub plane blade
The new Lee Valley Honing Guide Mk II excels at honing square bevels on blades. One of the areas in which a modification or accessory is being evaluated is that of honing a camber on a blade. Below I am offering my strategy for honing the camber on scrub plane blades using this guide. I have no idea if LV will take this seriously–you are more likely to laugh when you first read my description–but it is a serious recommendation. I have used it successfully on a number of occasions, and will demonstrate this below.
I might add that there might be potential here for adding other forms of camber, such as to jack or smoother blades, but this is not its intended use at present since I am still evaluating it in that regard.
For scrub blade use, the only modification to the Honing Guide is the addition of a washer under the Blade Carrier Locking Knob. This is to raise the height of the knob.
Set the Registration Jig for a 30° bevel angle, lock it to the Guide…
…and then insert the blade upside down (i.e. as if you were going to hone the back of the blade).
I hone on waterstones, and depicted here is my King 8000. The scrub blade has already been ground to 30° (in this case on my belt sander jig, but alternately you could either use the existing factory grind if using the LV Scrub plane, or you could first hone a camber on a blade on lower grit waterstones).
Onto the waterstone I place a steel card scraper, and then onto this I place the Honing Guide upside-down so that it is riding on the Blade Carrier Locking Knob. This scraper blade raises the angle enough to hone a 1° micro bevel .
I pull the blade towards myself since pushing it is likely to cause it to dig in. It requires only a few strokes to create a full micro-beveled edge (you can see the glint of the micro-bevel).
Stroke off the wire edge (or use David Charlesworth's Ruler Trick to do so), and you are ready to go.