A stationary belt sander (aka
edge sander) is really the best tool for sharpening runners.
For example, at the "
Nordhaus Boatwerks", we have got together and bought an 89x6" sander a couple of years ago:
Unfortunately, such machines aren't cheap, although you can sometimes find (relatively) inexpensive used machines for sale (that's how we got ours).
You can build your own around existing sander systems, or buy the parts for each end of the sander (ex. rollers and drive) and mount them on a custom base. I know many people who've done that; hopefully a few of them will post photos.
IMHO the Sarns jig is not very useful. Hopefully there will be some adherents who can post some tips and suggestions about using it. So far as I know it will only work with plate runners.
Independent of your sharpener, inexpensive Alumina belts (the brown ones) work well sharpening runners. They do wear out, but the cost is small.
For hand-stoning runners, I prefer the narrow abrasive stones (about 1/2"x1/4"x6") from
Boride; Ron Sherry sells them in
sells a nice kit of stones.
For more aggressive hand sharpening, I'm a fan of "super sandpaper". It's simply two sheets of sandpaper glued back-to-back and cut into small pieces. Ron Sherry stiffens his with a layer of Mylar sheet in between. I use a spare stone to back up my sheet and keep it flat.
Hand stoning and sharpening is an art. It is very easy to "roll" the stone/paper over the top of the edge and do more harm than good. With practice it's a very effective tool for minor tune-ups at regattas and such.
For holding runners during hand-sharpening/stoning, most people like the
table-top "Workmate" style units, but they are hard to come by. Wolfcraft used to sell one, and Sears/Craftsman also had one in their product line.
You'll need two 0.008" feeler gauges. Many people use shim stock (esp. soft materials like brass and plastic that won't damage the runner edge). I've found the standard rosin-paper (used for laying floors) is almost exactly 0.008" thick (so at least here's one item that won't cost much!).
Steel straightedges and granite surface plates work well; you can also have a piece of steel I-beam ground flat in a machine-shop. It's important to remember that flatness to
at least 0.001" is crucial; flatter is better.
We have both a stone and a rule at the shop. Our steel-rule is a bit flatter, so I use it for critical crown measurements, but the stone is way more convenient because we have it mounted at eye height with a light behind (you can see it above the sharpener in the photo above) so gravity holds the runner down while you look at the edge as you rock the runner back and forth. I have a very flat stone in my home shop, so that's all I use there.
For length, all you need is something as long as the edge part of your longest runner. For DNs 36" should be enough. I forget if our rule and stones are 36" or 48" long.
I hope this helps.
Cheers,
Geoff S.
US-5156