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These are notes from the NEIYA iceboat clinic, 12/05/09, and further notes from the November 2011 clinic.
Jeff Brown gave a great tutorial on stoning runner blades. I only saw about half of it, because he kept showing folks new things for about three hours. But I did get a bunch of notes. (And Jeff has kindly pointed out some things I missed/screwed up, and I've fixed those...thanks again, Jeff!)
And Eric Anderson added a few notes to the topic, which I've attached below, slightly edited, so as to separate the two views. And since Eric also had some opinions on the matter of sharpening blades as well as stoning, I've recorded those as well. Both these guys clearly know their stuff, and as with so many things in life, there are multiple good ways to do a job.
In 2011, Eric profiled a set of blades for my daughter's new (to her) boat, and then James "T" Thieler gave her a very thorough lesson on stoning the blades.Notes on T's methods are in italics, like this.
Preparation
Preparation
You'll need a worksapce with a vise and good light, and something under it that you don't mind getting dirty -- maybe your basement floor, maybe an old sheet or something.
Get yourself a couple of stones, made by Boride Engineered Abrasives:
Keep these stones in oil, like Marvel Mystery Oil.
Use the general purpose stone for Sarns runners; the stainless stone on your stainless insert runners, and you could also get an "AM-8" stone, if you wanted, for blades made of very hard steel like tool-steel.
Alternatively, you can get yourself some 800, 1000, and 1500-grit wet-or-dry sandpaper from the body-work section of your favorite auto-part store, and cut it into strips about 1.5 x 6", labeling each strip with an indelible marker to indicate its grit. Then you also get yourself a couple of pieces of stainless steel, perhaps 1/8" x 1" x 5". You use this stainless "backing plate" to hold the sandpaper, and then use this assembly in much the same way that you use the sharpening stones.
When using the sandpaper method (or the stones), you can, instead of Marvel mystery oil, use a mix of Windex, water, and a little dishwasher detergent. My best guess is 1 cup windex, an ounce of water, and one "squirt" of detergent (about what you'd put on a sponge when you're about to do the dinner dishes)...maybe a little less detergent than that.
Setup
Setup
First, wear clothes that you don't mind getting dirty.
Get your blades to have the profile that you want by using a belt-sander or other tool. That's a whole separate discussion, and I'm not going into it here. The first step is to check the profile of the blade by placing it against a known straightedge and backlighting (see left photo below; the blade's resting on a machined piece of steel, and you can see where Eric's written some notes on it in marking pen to help him with shaping it); the second step is to remove material carefully to get the shape you want (see right photo, in which Eric Anderson has the blade in a holder that's moving over a waxed surface, and he touches the blade against a fine belt in a massive belt-sander. During the sharpening, he'll flip the blade over once or twice to be sure that the edge is centered, and he'll cool it in some ice-water as necessary when it's done.)
Get a couple of clean rags (an old T-shirt is nice). Put one in the jaws of your vise to hold the blade without damaging it, and put the other someplace clean, and a foot or two away from where you'll be working, so that no bits of steel, stone, etc., will fall on it. (If you had a hook near the vise that you could hang it on, that'd be nice).
Open up your box of stones and set it within easy reach.
If your hands have to be clean later, slip on a pair of latex or nitrile gloves.
Feel (gently) the two sides of the runner edge by running your finger across the edge (not along it, which could easily cut your finger). Assuming that you've just finished belt-sanding to get the profile right, on one side, you'll feel a "burr" of metal from the last pass of the belt-sander. If you could bend this burr back and forth and remove it, it'd leave a micro-serrated edge that can cut you really easily...but it's not the ideal blade! So set up the blade in your vise with the burr-side away from you.
If the burr is huge, you can take a light pass -- not much pressure! -- over it with a flat bastard machinist's file. That will prevent you from cutting a groove into your stone
Grab the proper stone.
Be careful about what runners you work on with what stones. When you put a stone to a runner, it picks up bits of metal, which can then be transferred to another runner. So while you could use a T-2 stone on your Sarns runners, once you do, you should never use it on a stainless runner again, because the mild steel will "pollute" the stainless. It might be worth storing stones in two separate containers -- one for stones used on steel, one for stones used only on stainless.
along-the blade view of honing set-up
An alternative setup, using a Black and Decker "Workmate" to hold the blade. Note the rag resting nearby for cleanup.
You can see a couple of bits of blue and grey sandpaper on the table near his right hand (left in photo).
Honing
Honing
Dampen your stone with a little oil (or windex-mix, for the alternative approach), and place it on the beveled edge on the far side of the blade (the one with the burr on it) so that the long axis of the stone (the 6" part) is fore-and-aft on the blade. Rock it back and forth a little until you're sure it's resting flat on the bevel. If the burr is not too big, surface tension will want to hold the stone in place: rocking away from or towards you will let you feel a kind of "stickiness" at the "stone-is-flat-on-the-bevel" point. This stickiness is increased as the layer of oil gets thinner, so if you apply some pressure to squeeze out the oil, you'll be even more certain that it's flat.
Setting up stone on bevel of blade
Now apply some pressure--enough to make the tips of your fingernails turn from pink to white, and maybe a little more, using both hands on the stone.
You get get a good sense of the pressure needed by picking up a 10-lb stack of books with the fingertips of both hands. That's about the amount of force you want your fingers to be applying to the stone, maybe more as you get better at it.
Slide the stone along the blade-bevel from end to end in one smooth motion. You'll feel the burr making the stone's motion a little scratchy and irregular. Work back and forth, from end to end, 4 or 5 passes in each direction. ("T" suggested 25 passes in each direction with each weight of sandpaper. Do both sides with 800; then both sides with 1000; then both sides with 1200.)
Maybe you feel a little scratchiness at one spot after you've taken a few passes. It's tempting to work that area a little to get rid of that last bit. Don't do it. Instead, take a few more passes over the whole blade.
Concentrate. If you lose concentration and rock the stone towards you as you're sliding it along, you'll put a big long "flat" in your runner, and have to start over again.
Sliding the stone along the runner: go end to end to ensure even honing!
Now flip the blade around in your vise, and hone the other bevel, always working end-to-end.
Repeat the process, re-stoning both sides for a few more passes. At this point, the stone should slide along the bevel without any rough feeling at all, and the surface should be fairly shiny. The actual edge will now be a 90-degree angle that's an almost perfect line, rather than a ragged, serrated edge that can cut you.
Examine the edge you've made:
Wipe the edge clean with your rag, and hang up the rag again.
Shine a bright light on the blade from above, and see whether the edge (not the bevels!) reflects any light at all. Any reflection from the edge indicates a flat spot, and a need for further honing.
Re-hone as necessary.
Continue with the other blades in your set.
Never drop your clean-up rag on the floor, or set it on your work-table, or any place else it could pick up nasty grit.
Finishing up
Finishing up
When you're all done stoning, use some 600-weight sandpaper to "bullnose" the sharp edge for about 1" at the tail end of the runner, and for about 2-3 inches of "lead in"
Pack your stones away in their oil bath, put away the file and the sandpaper, make sure that your blades are otherwise free of rust or other corrosion that will make them stick to snowy patches, and perhaps even give them a light coat of oil or silicone to help keep them from corroding.
Care of Stones
Care of Stones
Stones get worn over the course of a season; they may get grooves in them, which means that you can end up stoning the wrong thing -- the blade-edge. When this happens, you need to make the stone surface flat again ("dress it").
To dress your stone:
Wipe off all the oil from the stone.
Place a piece of 60- or 80-weight paper on a wooden block.
Take a few passes over this paper in multiple directions to get rid of any grooves in the stone.
Wipe the stone clean with a rag that you can throw away, being sure to remove any sanding grit.
Alternative method, quick and dirty, but it works in a pinch.
Rub two stones together against each other to flatten both of them.
It gets hard to read the lettering on stones after a while. You can use a file to make a small notch or two in the edge of the stone (perhaps 1 notch for a general purpose stone, two notches for a stainless stone).
Keep your stones immersed in oil.
Marvel Mystery Oil works well. You can get it from McMaster and probably from your local hardware store
Oil-bath setup. The tray is from Chinese take-out. There's a layer of window-screen at the bottom to hold any grit that falls from the stones. There's a bent coathanger holding a stone up out of the oil. (Note: this picture shows the setup without any oil so that you can see the general idea; the oil would be filled up to the level where it covers the stones at least halfway.)
You can see a similar tray in the stoning photo above, but filled with "T"'s mix of windex, water, and detergent, and with a toothbrush for spreading the mix and cleaning off grit. "T" is working the sandpaper end-to-end in one smooth motion.
Eric Anderson's comments on stoning
Eric Anderson's comments on stoning
Stoning and neatness: the right tools for the job
Stoning is messy, Eric says, and while it may be OK to make a mess in your basement, it's not OK to do so in that motel room before the race, and if you make a mess in your car or truck, you'll regret it. So what's an iceboater to do? I'll let Eric speak for himself:
"First you need a vise that is portable. Black and Decker used to make a small tabletop vise like a workmate. Wolfcraft makes them also (Ed: although these are not available in North America...buy some the next time you go to the Worlds!) If you can find them buy one or a few. You can clamp any runner in it and put it on the desk at your hotel to stone runners on.
"Jeff uses oil as the cutting fluid for his stones. I agree that this is the best for stoning, but I never use oil for iceboat runners. The reason is that I often will give myself small cuts on my fingers stoning and the oil really aggravates this. Since you need to stone runners every night, often multiple sets, your fingers get beat up after a week or two. Also it is very easy to screw up the furniture which makes the hotels not like iceboaters. I use Bori-lube stoning fluid. http://www.borideabrasives.com/category.php?cat=107. This is a water based cutting fluid made specifically for the stones we use. Be careful if you leave it in your trailer because it freezes when it is below zero. If I only stoned in my shop, I would use oil, but I have made a royal mess of my car and hotel with the oil. The boride stoning fluid wipes up easily. In a pinch, water with a squirt of dish soap works. You can't go back and forth between oil and water based fluid with the stones because it screws up the stones.(Ed note: If you're feeling flush, you might consider getting two sets of stones --- one for oil-use at home, one for Bori-lube use on the road.)"
Why to stone
The folks with the fastest boats all do it, and that's provided a good deal of evidence that it produces a fast running in most situations.
When to stone
Eric suggests "After each and every day of sailing." If you do this really conscientiously, you can keep your blades sharp with stoning alone. "If I am careful and don't run over a bunch of crap on the ice or sail back through the launch area, which tends to have lots of grit on the ice from people's boots, etc., I can get away with using a belt-sander on my runners only once every year or two."
Alternatives to stoning
"When you belt-sand, you can use grits that range from 40 (super coarse) to 60,80,100,120, 180, 220 and trizac belts up to about 600 grit. If you are not going to stone, using progressively finer belts and finishing with trizac belts works well. If you follow this process and then look at the blade surface, you'll see alternating light and dark areas, indicating that the surface has shallows waves in it from the sanding process. If you stone your runners carefully, you can get rid of these waves and make the runner more uniform."
Stoning process
"I wipe the runner edge with lubricant before each set of passes over the blade. I do 20 passes per side, then do the other side. I stone the whole length of the runner with each pass. If I feel it start to scratch like there is a big piece of grit on the stone I stop and clean the blade and the stone and start again.
"If the runner is really bad because of grit on the ice or the runner is dull, I use strips of 100 grit wet or dry sandpaper backed by the stone and do 20 passes on each side and then start with the stone. (I picked this trick up from John Harper.)
"I start with 150 grit T2 stones (blue ones). I go in series: 150, 220, 320, 400, 600, taking 20 passes on each side. After a while it gets to be kind of a zen thing.
"After stoning, I use 600 grit sandpaper to dull back the lead in and exhaust. Afterwards, I clean the runner and use either finishline wet lubricant (bicycle lube) for short time, i.e. between uses, or use grease for summer storage. Silicone spray works well also."
Variations
"If the runner was used lightly and it is still sharp and there are no nicks I will use 320, 400, and 600 only. [Editor's note: at the NEIYA clinic, we were stoning blades that had just been belt-sanded. For those, we used only 600-grit stones. Maybe Eric would have started with 320 or 400...I'm not certain.]
"If you pick up a nick in one spot and you can't stone it out, the runner needs to go back to the belt sander. In a pinch in the pits at a race you can stone a very small section --- perhaps about ~1/2" long --- with the stone directly on the edge of the blade. This dulls a small section, but also eliminates the protrusion formed by the nick. I hate having it to this. (I learned this trick by watching Matt Struble stone runners)."
Helpful tips
Dressing stones. To dress(flatten) the stone you can rub 2 stones of similar grit together [Ed note: only use stones that have been used on the same kind of metal -- don't rub your stainless-only stone against your mild-steel-only stone!] . I like to use a piece if ¼" plate glass with 80 grit wet sandpaper glued to it, and rub the stone on that.
Care of runners.
One of the easiest ways to keep runners in good shape is not to sail all the way to the launch area. People always carry grit onto the ice from their shoes, so assemble your boat a ways out on the ice.
Bird crap contains hard stuff that you don't want to run over.
Dry your runners as soon as you take them off the boat and coat them with some sort of lubricant.
Lastly, invest in a good box or padded bag to carry your runners. Runners are expensive and they are easy to damage in transport.
Editor's note: Thanks again to Jeff Brown and Eric Anderson and "T" Thieler for these instructions.
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