Warming Blades Up

[LordShout]

"However, I think it's just superstition. I've never broken a cold blade by bending, and I've never felt a warm blade was any easier to shape." Eroo

Now I swear by warming blades, I wont fence with a cold blade ever since I snapped one of my LP blades fencing with it cold. I'll try and look up the actual physics behind it but how many people warm their blades up before fencing and do you think it makes any difference?

For me, well I live in Michigan and the blade I snapped was probably somewhere around -2 +/-5 degrees Celsius, certainly enough to make a noticable difference in my opinon but that wasn't a usual circumstance. I know members of the LP production team browse these boards, any data on blade durability as related to temperature?

And yet another question, FIE tests, are they administered at a constant temperature, pressure and humidity, if so what TPH?

[MyrddinsPrecint]

ok, so, i understand the feasibility of warming a blade before canting it, but before fencing with it???? How do you do that? I have a hard enough time warming up my jacket and knickers............

[erooMynohtnA]

The theory goes thusly:

Cold things are brittle. Brittle things break easier. Ergo, warm blades are more durable.

Another variant (more for the old timings when people flicked a lot more):

Cold things are stiff. Cold things move more slowly. Ergo, warm blades are more flexible and faster.

As to the feasibility of heating the blade, most people rub it vigorously with a towel, some people run it underfoot, and a few just flex it a bunch. You're pretty much limited by the temperature at which metal will feel like it's burning bare skin, 117 F.

But, here's the thing; steel is not a good insulator. Your blade does not wear a coat. The air isn't that warm. There is no sunlight to heat it up. There is not that much mass, but there is a lot of surface area. You could heat up a foil blade to red hot and grab it five minutes later. No matter what you do, your blade will reach the ambient temperature by the halfway point of an average bout. A cold blade will warm up, too. Unless you're fencing in a room that is actually at the point of freezing, the blade will quickly acclimate.

Also, for the FIE test, I think there's no need to specify pressure or humidity beyond average atmospheric, because neither of those are a factor in the fracture toughness or shear modulus. I know steel can exhibit a great reduction in fracture resistance in aqueous environments, but that's not the same thing.

Also, I will note that one of the Paul brothers has already agreed that heating a blade is superstition.

[LordShout]

The only thing I wanted to know humidity for was the rate at which the blade will reach the ambient surrondings temperature is related to the humidity of the air.

I usually just try and warm mine up to body temperature by placing them in various areas and squeezing for a few minutes, I don't want them hot I just don't want them freezing. Room temperature is fine, its when they come out of my trunk at freezing that it worries me.

I did see that Mr. Barry Paul had replied that he doesn't believe it to have any effect, but he didn't say if that was supported by testing or merely a feeling.

[Fencergrl]

I was taught to warm my blades if my blades have been outside (in your trunk) and it's cold out.

One of the clubs I train at is really cold most of the year. It's like a large walk-in cooler, often it's warmer outside. When it isn't, I warm my blades. Otherwise I don't worry about it.

I'm on my 3rd year with my FIE blade.... I don't know if warming my blade has helped or not.

[twisterfencing]

LordShout:

Sorry, I have never heard of this in any form. When I get a blade handed to me, its most likely to have something wrong with it. I know I do nothing to it to warm it up to work on it!

Gary Spruill

Originally Posted by LordShout

"However, I think it's just superstition. I've never broken a cold blade by bending, and I've never felt a warm blade was any easier to shape." Eroo

Now I swear by warming blades, I wont fence with a cold blade ever since I snapped one of my LP blades fencing with it cold. I'll try and look up the actual physics behind it but how many people warm their blades up before fencing and do you think it makes any difference?

For me, well I live in Michigan and the blade I snapped was probably somewhere around -2 +/-5 degrees Celsius, certainly enough to make a noticable difference in my opinon but that wasn't a usual circumstance. I know members of the LP production team browse these boards, any data on blade durability as related to temperature?

And yet another question, FIE tests, are they administered at a constant temperature, pressure and humidity, if so what TPH?

[Cookeit]

Well,

My captain on my HS fencing team told me to use a towel and warm-up my blades (our season is during the winter mind you) and I have done it since.

[MyrddinsPrecint]

Y'know, the towel thing is a good plan in at least sabre, since no one likes to get rust or other weird stuff on their lames..... But I've never heard about it prior to this thread..........

[erooMynohtnA]

Originally Posted by MyrddinsPrecint

Y'know, the towel thing is a good plan in at least sabre, since no one likes to get rust or other weird stuff on their lames..... But I've never heard about it prior to this thread..........

I think that's how it started.

A polite fencer would rub his blades with a towel to clean them (as I do, prior to every competition), and he pulled a newbies leg. And it spread from there.

I approve of it, whatever the reason. It keeps stuff off me.

[SJCFU#2]

There may actually be a kernal of truth to this. I do know that some of the more unusual breaks I have seen over the years have occured in blades that had just been brought inside after spending the day out in the unheated trunk of a car on a cold winter's day (like the epee blade that split down it's length, with both sides still more or less intact).

The fracture toughness of some steels decreases significantly at temperatures near freezing (samples of hull plating recovered from the wreck of the TITANTIC suggest that this may have played a role in her sinking - that particular grade of steel would never even be allowed in a ship's hull these days).

Also, as the blade begins to warm the outer surface will warm faster then the core so there will be a certain amount of internal stress due thermal expansion. A cold blade is a fairly significant heat sink so it will take a little while for the core of the blade to reach room temperature, and it will take even longer if it is sitting in a bag filled with other items that are also warming up.

[griffindm]

I've been doing the towel warm-up for cold blades for over thirty years now. Never really thought much of it. Either it works, or not. If it doesn't, like MyrddinsPrecint says above, at least it helps keep the corrosion off.

[Alex_Paul]

We have never done tests at different temperatures, we dont have a big enough fridge!

I would be very suprised if it made a significant difference however why risk it... I would alow a weapon to warm to room temp before use but this probably only takes a minute or so but I wouldnt try to get it to above ambient.

[oso97]

I suspect that the main issue is actually the differential expansion due to warming, and subsequent stress, as SJCFU#2 alludes to.