How to Punch Ski Boots

What Is a Ski Boot Punch Used For?

A ski boot punch is used to make a controlled expansion of the plastic shell to relieve pressure caused by bony spots and unique feet. Instead of buying an oversized, poorly fitting boot, you can keep the performance fit and just add space where you need it. Dial in your perfect fit.

Common punch locations include:

• Bunion area (big-toe side): The most common pressure point, located on the inside edge of your forefoot.
• Outside forefoot (pinky-toe side): When the boot feels too narrow on the outside and causes rubbing or sharp pressure.
• Ankle bones: Pain on either the inside or outside “ankle knobs” where the shell presses against bone.
• Toe box: Not enough length or height for your toes, leading to toe bang, numbness, or crushed toenails.
• Midfoot / navicular: A firm pressure point or bump on the inside arch area, especially common in low-volume boots.
• Heel or Achilles: A hard spot digging into the back of your heel or lower Achilles tendon.

When Should You Punch Your Boots?

Punching is essential when the pain is localized and structure based. In other words:

• You have unique feet like AJ
• You need to widen your toebox

Tools You Need to Punch Ski Boots

You do not need a massive shop press to get a pro quality punch. A small, strong, and precise system actually works better for most targeted shell work.

Essential tools:

• BootForge™ Ski-Boot Punch Kit – magnetic punch heads, deep-reach frame, designed for modern plastics.
• Heat source – a quality heat gun - Wagner Heat Gun AJ Uses
• Chalk for shell marking.
• Marking Magnets (included with the kit)

The Step-by-Step: How to Punch Ski Boots

Step 1 – Mark the Pressure Point

1. Remove your liner and put your liner on to pin point your punch spots
2. Use a fingertip to press until you feel the spot
3. Mark that spot on your liner with chalk
4. Put the liner back in the shell, then remove the liner, now the punch point should be marked with chalk inside the shell
5. Use the set of magnets to transfer the punch mark from the inside to the outside of the shell (so you can see it when we punch

Step 2 – Heat the Shell

Reminder, we're not melting the shell here, the combination of heat and force from the punch clamping down on the shell creates the permanent punch.

Heating with a Heat Gun or Hair Dryer

• Keep the nozzle about 3–6 inches from the shell.
• Move in slow circles around the punch area, don't stay in one spot, we want to warm up the punch area and the area aound it
• Heat until the shell is warm to the touch, a little goes a long way, we're barely softening the shell - again not metling anything

Step 3 – Punch the spot with your BootForge™ Ski Boot Punch

1. While the shell is warm, line up your BootForge™ Ski-Boot Punch Kit with the punch spot
2. Align the punch heads directly over your mark on the shell, the clamp allows for adjusting the head angle so for different areas you may need to adjust the head or reciever so the punch will stay clamped
3. Make sure you set the tension knob on your clamp to the desired pressure, you want to be able to clamp the punch and leave it until it cools

Step 4 – Punch the Shell

1. Clamp the punch onto your shell and lock the clamp in place

Step 5 – Take a break and let it cool

Let the boot cool completely while the punch is still under load. This “freezes” the new shell shape in place, or locks in your punch

• room temperature is perfect, if you need faster leave your shell outside in the winter

Once the shell is firm and cool, remove the clamp

Step 6 – Test the Fit

1. Re-install your liner
2. Put the boot on, buckle as usual, and flex a few times.
3. if your fit is improved but still not perfect, you can repeat the process as many times as needed - to create large punches, generally better to use a series of smaller punches rather than go for one huge punch spot, we want to dial in a perfect fit, so take your time, get it right

How Big Should a Boot Punch Be?

Less is more. Start modest and sneak up on the final shape. Here are rough ranges most bootfitters work within:

• Bunion area: 4–8 mm
• Outside forefoot: 3–6 mm
• Ankle bones: 3–6 mm
• Toe box length: 2–4 mm
• Navicular / midfoot: 3–5 mm

You can always re-heat and add a little more pressure or swap heads. You cannot easily “un-punch.” a spot so this is why we want to make small tweaks until it's perfect

How Different Shell Materials Punch

Not all plastics behave the same under heat and pressure:

FAQ: Boot Punching Basics

Does punching weaken my boot?

A properly heated and localized punch does not significantly weaken the boot. You are reshaping the shell below the melting point, not melting it. Overheated plastic can cause problems just like waxing your skis - keeping the iron in one spot can damage your base - so this is why heat control matters, if you follow our guide you will never damage your boots.

How long does a punch last?

On PU and polyether shells, a good punch is essentially permanent. With some materials the punch will last a season or even more, but we recommend re-punching once a seaason which is why it's great to have the tool and not have to visit a boot fitter every season.

Can I punch both boots identically?

Yes. BootForge makes this easy: count your turns on the adjustment knob and replicate the setup on the second boot, using the same shell marks and alignment.

Can I add both length and height in the toe box?

Absolutely. You can angle the punch head or use multiple overlapping punches to create more usable toe room in both directions without losing heel hold.