Heat molding ovens - Celcuis or Fahrenheit, where convects?

[Query]

High end skate shops have special heat molding convection ovens.

A boot maker might tell skate techs, for a given model, to preheat the oven to a specified temperature, and bake it for a specified number of minutes. If you do everything right, it may heat mold as well as it can. If not, you may destroy the boot, and leave yourself with a few burnt ashes surrounding a lovely melted puddle of goo. 

1. Are the temperatures calibrated in Celcius or Fahrenheit? Does that depend on the brand or the country in which the oven is sold?

2. Does the fan significantly blow into the interior of the boot, or is most of the convection (and heating) around the outside of the boot?

3. I would also love it if any of you could provide what other boot makers provided you.

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Background:

I want to optimally heat mold GRAF Edmonton Special skates.

Delayne Brian, from Customer Service at GRAF Canada Ltd. just told me:

We do not suggest baking your skates at home, since all ovens are different and we cannot predict how each one will work.

That being said, retailer heating instructions are as follows:

Preheat the oven to 180 degrees

-Place boots in oven, allow boots to be heated for 3 minutes (less if they are JR 9035's) -Remove boots from oven and check that the boots have reached proper molding temperature -To ensure proper molding temperature, check the heel counter pliability. This is done by squeezing the outside of the heel counter. It should be soft and flexible, not stiff.

-Once the boot is hot enough to mold, place on the athlete's foot. Make sure the athlete kicks the heel back hard into the heel counter.

-Tie the skate snug, but do not over tighten.

-Keep skates on for approximately 15 minutes, or until they no longer feel warm.

-Untie the skates. The skates are now game ready once they have been cooled off to room temperature.

-It is very important that at no time the athlete stands or applies any pressure to the heated boot so that the skate can take shape to the foot in lock position.

-Any pressure points that remain after heat fitting can be pressed out using a ball and ring press.

-You can bake your skates more than once if need be.

(I have emailed GRAF again to find out if 180 degrees is Celcius or Fahrenheit; Also whether those instructions were meant only for hockey boots, because of the use of "JR 9035" and "game ready".)

In comparison, GAM told me 4 minutes at 500 degrees (Fahrenheit?) for their top end freestyle boots.

Don Klingbeil told me that Klingbeil boots fit perfectly and don't need heat molding, but 180 or 185 degrees (I forget which; time unspecified, Celcius? Fahrenheit?) was what SP Teri (who learned at Klingbeil) used for SP Teri boots, so might be safe.

Thanks!

[fsk8r]

180C is cake baking temperature to give you a reference point.
So that's going to be 180F unless you really want to eat your boots!

[jlspink22]

The special oven I saw was just a box that convection heats, not much more than a glorified convection oven. If you see this video, he gets the leather soft and on her foot fast and correctly. I've done it at home with second hand skates in my convection oven.

https://www.youtube.com/watch?v=XhZLOEw7o5Q

[Query]

I called up GRAF again - 180 deg Fahrenheit.

I called up GAM again. This time they said 300 deg Fahrenheit. They say that GAM boots heat mold at higher temperatures because they are all leather, so there isn't anything that can melt at that high a temperature.

I directed the blast from a couple hand held hair driers onto the temperature sensing element of an oven thermometer. One, at about 1/4" distance, could reach 180 deg Fahrenheit. One went around 125 deg Fahrenheit. I also tried a cheap Radio Shack heat gun designed for 428-500 deg F; it made a fairly week breeze, but there was a distance where it could have managed 300 deg F; there would have been very little breeze at a distance that would do 180.

So it looks like an appropriately chosen and calibrated-for-distance hair drier is the better way to go for the GRAFs (which is what I am using), and similar for the heat gun for the GAMs. (Note that some heat guns are rated to up to 1200 deg.)

I think two things are very clear - start by calling the boot company, to get the info. Then, if you are going to use a hair drier or heat gun, calibrate the distance from it to the boot to match. There is too much variety among different boot brands, and among different hair driers and heat guns to use them without careful calibration!

But at only a 1/4" distance to the hair drier, I would have to mold one little piece of each boot at a time...

A lot of people on the web heat mold by pre-heating a cooking oven, again calibrated with an oven thermometer (because cooking ovens are not very precise), turning off the heat, and putting the boots on a cookie sheet for the specified time. That idea sounds plausible, but without convection, it won't get quite as hot in the same time - but I don't want to leave it in long enough that the inside gets too hot to put against my foot.

I need to think this over a bit to get things optimal.

[jlspink22]

When I did it at home, I put them at the lowest setting in the convection oven part and checked the skates every 2-3 minutes. It took about 8-10 minutes before they were soft/warm but not too hot.