Cross-Country Ski Hot Box Wax (XC Ski Base Prep)

A hot box allows soft wax to slowly absorb into your ski bases. It is a great way to prepare your skis prior to applying the wax of the day. You can bring your skis into a local ski shop, or you can make a hot box yourself. This post includes notes, pictures, and specifications of the hot box I built. I also describe the process of waxing skis in a hot box.

Hot Box Process

Step 1: Prepare the ski

Brush out the skis with a fine steel brush to remove any surface debris.

A ski base prior to brusing.

Step 2: Soft wax cleaning

Melt in a soft wax (I use Fast Wax Base Prep, but any warm-weather wax should work), let it cool, then scrape the skis. This further cleans the base. The skis need to be as clean as possible before beginning the hot box process.

Step 3: Hot box wax

Next, melt a heavy layer of Fast Wax Hot Box Wax on the skis. Do not cool or scrape. Place the skis in a hot box set to 55 degrees Celsius for 2-4 hours. Remove the skis from the hot box, allow to cool, then scrape. At this point, the ski bases are cleaned and conditioned, but they’re very soft and are not ready for skiing.

Step 4: Harden the base

Melt in a layer of a mid-temperature blue wax (such as Rex Blue), allow to cool, and then scrape.

At this point, the skis are ready for the wax of the day, but I wont apply that until a day or two before use when the forecast is more certain and I can select the best wax for the race conditions. Note, even if a blue wax is the race wax I will use, I still apply a 2nd layer to the hardened base.

Cross country ski hot box set-up

Hot Box Specifications

Cost

About $250 for Materials

Materials List

2 Sheets 1/4" 4' x 8' Plywood & 2 Sheets 3/8" 4' x 8' Plywood

(Each sheet can be cut to make a top/side/front or bottom/side/back)

2 Sheets 3/4" Foam

1x2 Pine - Enough to frame each piece (front, back, top, bottom, sides)

2x4 Pine - Support on left, right, and bottom

(3) 2x8 Planks - To form work surface

(1) 2x8 Optional - Ski Wax Support

Hinges

750 watt electric heater

Dowels - For racking to accommodate 2 pairs of skis, or add more if you like.

Johnson Controls Thermostat

This Johnson Controls thermostat keeps the temperature in the box within a few degrees of set temp.

Dimensions

Inside Dimensions: 12" x 24" x 79"

Construction

See Pictures and Video

Make top/bottom/back/front/sides. Sandwich 3/4" Foam between two sheets of plywood (1/4" inside and 3/8" outside). Use 1x2 frame around the edge. Glue and nail. Screw top, sides, back, and bottom together to form an open box. Cut 2 x 4 to make a frame around the bottom and sides. Hold out to allow for front to close flush. Mount hinges to bottom 2x4. Make catch. Line top with 2x8 to create work surface. Leave inside unfinished. Apply a coat of poly to the outside.

Other waxing technique notes:

-- While you can just use a clothes iron to melt your wax, it really is easier and more precise to use a specialized waxing iron. I personally use the Star digital waxing iron, and it has worked well for me.

-- The recommended iron temperature for melting is always listed on the wax box. If you can't set a temp, aim an easy melt with minimal smoking.

--If you don't have a hot box, you can still deep clean and prep your skis by simply applying three layers of a soft wax (cooling and scraping between each application).

--In my opinion, a hot box should not be used to melt in your race waxes, as to do so would require a higher temperature that potentially can damage the epoxy in the skis. Using a temp that is low enough to be safe for the skis will not melt racing wax so serves no purpose.