Ice boat runners

[Brian Palmer]

I am tempted to make a small iceboat for the kids, using a dinghy rig for themast and sail.

What type of metal is needed for the blades?
Could I use angle iron from the hardware store, ground to an edge, obviously?

I could use ice skates, but I don't have any and don't want to spend time scrounging some at thrift shops.

Thanks in advance,

Brian

[Mike DeHart]

I have been told that old chainsaw bars make good ice runners. They already have a good shape, good steel, and lightweight, too.

[Daniel Noyes]

Be very carefull I broke through with my ice boat a couple yrs back and was saved by the two life jackets I hapened to have along thank God, Iceboats seem a little more dangerous than skating because 1 you are traveling faster so have less time to react to a change in ice and 2 you are further removed from the ice than on skates so you are not as aware of subtle changes in the ice.
that said
ice boats are a lot of fun!
Real angle iron will work wonderfully for runners on a "for fun" Ice boat, not the bent angles but the hot formed steel ones.
or you could use plate set on edge between blocks.
skates not so well as they are designed for mainly downward force of a skater vs the side forces of a sail, also ice boat runners are sharp v on the bottom not a flat like an ice skate.
Dan
http://dansdories.googlepages.com

[Brian Palmer]

Thanks, Dan.

Yes, safety is paramount. Life jackets. Minimum 4 inches of ice.

Is there an easy way to "field check" whether the angle iron is hot formed instead of cold bent?

Brian

[johngsandusky]

I'm thinking he means the heavy cast stuff, as opposed to thin bent sheet metal bracket style. Just examine it, you'll know.

[Brian Palmer]

The stuff I've seen at the hardward store is about 3/32 to 1/8 inch thick. About the same as an ice skate blade.

Brian

[Canoez]

Thanks, Dan.

Yes, safety is paramount. Life jackets. Minimum 4 inches of ice.

Is there an easy way to "field check" whether the angle iron is hot formed instead of cold bent?

Brian

I think the reference was to hot rolled versus cold rolled steel? Hot rolled has a flaky dark grey appearance. Cold rolled is shiny and smooth.

[Todd Bradshaw]

Lots of options, although 1/8" is kind of thin (there are some pretty substantial loads on the runners of even a small iceboat). The easiest is probably just three hunks of 1/4" plate steel (maybe 4" x 15"or so) with the ends cut at an angle and the corners rounded off. People will debate for hours about what type of steel is best, but in this case, it isn't critical. That's essentially what the Lockley Skimmer uses - three parallelogram-shaped plates with a hole drilled through them to bolt them to the chocks. A lot of small homebuilts use something similar with aluminum stiffener strips along the top. They look something like the runner shown in this drawing. The blades are ground to a fairly sharp V on the bottom (sharp enough to scrape off a bit of fingergnail when dragged across the edge - otherwise, your boat side-slips, which is seriously scary).

http://webpages.charter.net/tbradshaw/!BOWRUNN.jpg

Most old-style runners had white oak bodies with a hunk of steel or cast iron bolted into them and hanging out along the edge. Flat plate inserts were used, T-iron was sometimes used and so was angle-iron. The angle-iron was usually oriented in cross-section like the letter "V" to form a "cap" along the tapered wooden bottom of the runner and ground down until the outside corner (running edge) was sharp. These days, I might be tempted to cut a slot in the wooden body and stuff a steel slab and some epoxy in there with the steel hanging out an inch or so. For a small-ish kids' boat, it certainly might also be possible to sharpen one edge of a hunk of heavy angle and bolt the other side to the bottom of a wooden body.

Runners need to be free to pivot up and down somewhat in their chocks and the pivot hole should be far enough aft that the runner is nose-heavy. Side-to-side slop should be minimal and the chocks need to be able to keep the runners on your runner plank aligned and parallel.