Punching a Nordica Strider and other ?'s

[Lord Thomas]

Do these require infrared to punch or can I use a regular heat gun, hot water, or steam instead? Nothing major, just a simple navicular. Also, what about grinding; do they grind worth a shit? And lastly, will a cochise alpine sole work on these?

[mntlion]

to punch a boot you need both heat and pressure. Any heat (infrared, heat gun, water, etc) and any pressure (leaver punch, internal, broom handle, persons foot, etc)

If you can 100% find the spot, and its thin/shallow grind. If you are not sure, punch (mostly reversible)

I assume it wont fit

[Lord Thomas]

As for pressure I have access to a scott press and a brand new hydraulic punch (can't remember the brand). So, it sounds like there is nothing magical about that plastic that requires infrared, traditional methods will suffice. That's good. Need to get these ready to go in the next couple of weeks.

[mntlion]

As for pressure I have access to a scott press and a brand new hydraulic punch (can't remember the brand). So, it sounds like there is nothing magical about that plastic that requires infrared, traditional methods will suffice. That's good. Need to get these ready to go in the next couple of weeks.

yup, Neither the boot, not infared is magic. its just heat and plastic

[gregL]

Do these require infrared to punch or can I use a regular heat gun, hot water, or steam instead? Nothing major, just a simple navicular. Also, what about grinding; do they grind worth a shit? And lastly, will a cochise alpine sole work on these?

Nordica would like you to think that you need the infrared system they sell, but you can heat the boot with anything. I would opt not to use water, as it can hydrolyze the plastic making it permanently softer (water also boils @ 210 F. and point at which most TPU compounds move and stay there is somewhere in the 260-290 F. range). I tend to get the best results with a heatgun held very close and used intermittently; heat only the spot you need to punch so the rest of the shell doesn't distort from the ring.

The navicular punch is about as straightforward as it gets, you just need to get the position right. People who used to grind for most any issue seldom do now, as the shells are much thinner.

[gregL]

PS The same is true if you have the 130 flex version; the shell is Grilamid but I'd still use a heat gun. The Scott press may be a bit short to reach the navicular region with the cuff on, depending on where your issue is.

[Lord Thomas]

most TPU compounds move and stay there is somewhere in the 260-290 F. range

Good to know. My heat gun is adjustable in 20deg increments so, with the help of an IR thermometer, should be able to hit the temp range just right.

if you have the 130 flex version; the shell is Grilamid but I'd still use a heat gun

They are the 130 version, so is the temp range a little lower for the grilamid?

[XavierD]

The infared boots are pretty thin in the marked ‘zones.’ I wouldn’t grind them. In general the modern Nordic’s boots take less heat to move, and stay there, than older boots.

The required plastic temperature is a bit lower for grilimid but the plastic also passes heat slower. Be a little more deliberate and methodical with it. Use a finger on the inside of the boot to asses heat transfer. Heat the outside for 30 sec, remove the heat source, wait until you feel the heat come through, repeat. If you just keep the heat gun on the boot you’ll ‘burn’ the outside before the inside wall is warm enough to give a lasting stretch. Also let it sit on the press until the entire boot is room temperature.

[gregL]

They are the 130 version, so is the temp range a little lower for the grilamid?

The actual melting point of most Grilamid compounds is higher but the transition from solid to a gooey mass is quite fast. The real issue is that a Grilamid shell is much thinner than a comparable TPU shell so you need to be more careful when heating it. I don't trust IR thermometers much, though I advise our new bootfitters to start with one - they only measure surface temperature, not interior temperature, and the reading can vary enormously when you move it only a centimeter or so. Hold your finger inside the shell under the area you're heating, hold the gun close but go slowly (i.e. a few seconds on, a few seconds off, etc.) until you can't hold your finger on the spot for a full second - usually half a second means its heated all the way through and ready to punch.

The gun we (and most other shops) use is the Eddy Pro 500-750 F. version, not sure what your gun is capable of.

[gregL]

Heat the outside for 30 sec, remove the heat source, wait until you feel the heat come through, repeat.

Depends how close your gun is to the shell; if I heated a Grilamid shell for 30 seconds at a distance of 1" I'd melt a hold through it. Go slower and see how it responds; you can always heat it more but you can't fix it once you overheat it and blister the surface.

[Lord Thomas]

My gun goes from 120 to 1,200 in 20 deg increments and 5 fan speed settings. Pretty handy to have that kind of control for welding the various fly line materials I use to mix and match for designing spey lines. Suppose I could start it off at low temp and hold it there for a while as it warmed through, and then turn it up to get to the final temp. Good to know that the hot finger test is still valid on Grilamid. Thanks for the info.

[turnfarmer]

Pretty well covered by all. The nice thing about the infrared is that it heats the shell more evenly through the plastic. You can still damage the plastic if you leave it on too long.

[gregL]

The nice thing about the infrared heaters is that they are pretty much idiot-proof if you start cold with the 6 minute default setting and only use it on conventional alpine shells.

However, they are relatively slow, and the pattern being heated is confined to the shape and size of the lamp housing, and the correct duration varies a lot depending on whether it has been pre-heated. Also the suction cup apparatus that comes with the heaters is worthless.