Thermoforming hockey skates

Baking for width, custom skate press, custom insoles

In previous articles I've written how I widened my first ice skates and some beginner tips, along with first experiences thermoforming (heat molding) the True TF7 skates. It's been a while and a lot has happened since I wrote those, so this time it's going to be a bit deeper (or rather, wider) stuff.

About thermoforming (baking) the skates

When searching around the Internet, most people are very wary of thermoforming their skates more than once or twice. There's a good reason - in theory. If there's plenty of pieces glued together, heating up the joints several times might decrease the integrity of the skates. However, for example the TF7 features a single piece boot. In total I've thermoformed them already seven or eight times (I already lost count along the way). I see and feel absolutely no adverse effects - although, I'm not a pro, so the forces I apply aren't pro-level either. But this is from a recreational skater's perspective. The fiberglass composite doesn't necessarily like being heated and cooled down several times, so it is good to try to keep the number of baking times to a minimum. But the more important factors are the used temperature and time when baking. The first few times I tried baking the skates, I was giving them too little time to go through the resin's glass transition range - that is when the material becomes truly moldable. The change is rather sudden.

You need to give the skates a good amount of heat. This also would decrease the number of needed baking rounds. In my experience, hockey shops basically give you lukewarm skates, at least here in Finland. The True TF7 really soften up once they are warm enough. However, it is critical that the temperature is not too much - for the True skates, a temperature of about 95 ℃ (200 ℉) is good, but the skates need around 10-12 minutes of it to really start softening up. Also the oven fan is a critical requirement to avoid hot spots and get the boot soften evenly. See in the video how soft the skates are when they are actually moldable. I'm pressing with thumbs and the skate gives immediately. Remember that the thermoformability of the skates depends on the materials and construction of the boots - mine are of good quality, with one piece fiberglass composite shell. Cheap skates often do not feature thermoformable materials.

A heat gun isn't that useful, mainly only as additional heat source for tougher spots, or for bending the edges around the ankle area. Especially if you'd like to modify the toe cup, you need not only heat but also a lot of force. For that, I built a custom skate press. To my knowledge, perhaps it's the world's first such device.

The shrink wrap is useful in keeping the skates tight and the correct shape during the process. Another useful trick is if you know you have some spots that require extra care (such as a bone or otherwise tender spot), for the duration of shaping the boot, put some extra padding over the spot. I used this technique to get extra width in the middle, and to push some room for my navicular bone. It hurts a lot during the molding process, but it pays off when skating.

The custom skate press

So my problem was as follows: the skates were still too narrow, but they had plenty of space in depth (height). I figured if I could make their profile a little flatter, I would eliminate pain and also some extra space. This is all just bro science, but mathematically, the cross section of the skate can be roughly thought of as a rectangle. Let's further approximate it as a square with a side length of X. The volume would then be X*X times the length of the boot. Since the perimeter of the square 4*X is constant as the boot isn't stretching, if I make the boot a bit wider - say, by an amount of Y - it'll lose the extra width from its height. So, the new width would be X+Y, the new height would be X-Y, and also the volume would hence be smaller as the cross sectional area would be smaller: (X+Y)*(X-Y) = X*X-(Y*Y) < X*X. Hence, by widening the skates, I'm actually making them smaller in overall volume, so a better, tighter fit. At least this is my hypothesis.

To make the skates that much flatter I built a custom skate press. It was important to have something I could brace the boot against, so as not to accidentally twist the bottom of the boot. I also needed a lot of force, which the nuts and bolts of the wrenching system provides.

The skate press turned out to be an excellent tool. I was able to widen and flatten the toe cup and make the skates a much better fit. Without the press the toe cup would try to return the fiberglass shell to its original shape.

Eliminating even more space

I was really aiming for a tight fit, and I've seen some commercial products that would fill up the extra space at the front of the boot. I believe they are basically some kind of pieces of memory foam or something similar. The idea is that crunching your toes would not cause your feet to move upwards that much, but instead at least some of the pressure from the big toe would transfer to the ice. I wanted something durable and bought sheets of ABS plastic and some self-adhesive EVA foam.

I heated the ABS plastic and pressed it against my foot to create a custom shape. The original idea was to have the feet locked in place very tightly, but I realized very quickly this would not work. It would just hurt way too much and I think the feet eventually need at least some space for example for the tendons to be able to move. So eventually I ended up with just gluing small pieces to the underside of the tongues, cushioned with the EVA foam and drilled with holes around bony areas for comfort and ventilation.

I can't say if these have had much effect in the end, but at least the skate feels quite tight and doesn't hurt.

Custom insoles

When widening the skates so much, new insoles are needed. My original insoles were already starting to fall apart so I decided to create strong custom ones. I was aiming for a shape that would flatten out the bottom of the skate for maximum width. This was a tradeoff of going as thin as possible for maximum power transfer and skating feel, and maximum width and comfort. I bought the CCM Orthomove insoles and some dense EVA foam meant for shoe midsoles.

Since I had already thermoformed the skates for my ankles using the original insoles, I needed the new insoles to match their height so that my ankle is locked correctly. I used a tool to grind away some extra material, and then a heat gun to fold down the rising edges of the insoles to make room for my feet. Then it was a matter of trial and error for the height and shape of the arch support. Drilling a lot of ventilation holes for moisture was a must. That became clear very quickly, both during and after skating.

A note about laces

I've seen and heard people struggle with lacing their skates if they're tightly formed around their ankles. This is true especially for True skates, at least back when the TF7 was released. The laces have to be almost ridiculously long to get them all open when putting the skates on. For this reason I have put a small elastic loop on the laces. I use it to hold the long lace ends away safely when skating.

When putting on the laces, you'd obviously do it before putting the skates on. However, the tongue might still be in the way. Don't try to press the tongue backwards, but downwards. It's then easy to put the laces through the top eyelets. This might seem trivial, but even the hockey shop I bought the skates from didn't know this trick.

How the skates have been working

During the beginning of the 2024-2025 season I baked my skates a couple of last times and used the skate press to eliminate any hurting spots. After that it was simply a matter of just skating the whole season. The skates aren't perfect, but the difference is night and day compared to where I started from. During the season I started to learn backwards crossovers. And the first time ever, I actually found my feet hurting because of the muscles used during the backwards skating, not just because of a painful skate fit. That was certainly a win.

For the 2025-2026 season, I only tweaked one of the insoles a bit to prevent one of my toes from grinding against some seam. This was after a few times on the ice. After that, I just skated, and I probably won't be doing anything to the skates anymore. Some new things I tried to learn this season was the grapevine, a freestyle skating technique. I figured it's a good way to learn more about using the outer edges and balance with safe speeds. To some extent, it has worked. Progress has been slow as I've mostly been to the ice rink only once a week, but I have progressed. The funniest thing this season was when I once dreamed of being able to brake using just a single foot and the outer edge - something I definitely couldn't do before. A few days later I still remembered from the dream how it felt like and tried it at the rink - and I actually managed to do it a bit. You just need that mental model of how it should feel like.

Conclusion

Having skates that you are able to use for hours with just little (or better yet, zero) pain and no damage to your feet is essential in being able to progress. It keeps the activity fun and healthy. You also shouldn't be afraid to try crazy and radical approaches to solve the problems with fit: any positive outcome is still better than nothing. I still don't know if the skates are a perfect fit or not, as I wouldn't know where to find someone with analytical enough skills and knowledge to discuss the thing through. But as long as I'm progressing and my feet are fine, the results say I've been going to the right direction.