You've just run your expensive new skis over a sharp rock. Are they ruined? Not at all. Experienced skiers know this is inevitable. Become skilled at this repair, and you'll be in demand at ski cabins everywhere. This repair is best performed in a garage or basement with a cement floor, because hot P-Tex drippings can damage floors and carpets and cause fires.
Bring the damaged ski inside, where it can get warm. Dry it off. Allow it to warm up to room temperature.
Place the ski upside down across two sawhorses or chairs in a garage or basement. The more stable you can make the ski, the better. Try aligning the ski so that the tail end rests against a wall.
Inspect the gouge. Remove any embedded rocks or dirt. Using a sharp knife, trim any rough edges off the gouge until a smooth hole remains.
Ignite the end of a P-Tex candle. This can be done with a match but is much easier with a lighter. As the candle heats up, molten P-Tex will drip from the end of the candle. Take care not to drip it onto yourself.
Take the candle to the ski and drip P-Tex into the gouge. Don't worry about getting drips onto other parts of the ski. They can be easily scraped off later. You can control the drip rate by rotating the candle. For a deep gouge, dab the candle directly against the ski.
Continue filling the gouge until the repair material is slightly higher than the original ski base. Blow out the candle.
When the repair area is cool enough to touch, use a metal ski scraper to shave down the repair until it's level with the original ski base. Work slowly with the scraper; aggressive scraping can damage the ski bottom.
Hold the scraper in both hands and draw it toward you across the repair. Angle the scraper so that you are pulling the blade across the repair. When the repair is nearly level, you can push the blade across the repair.
Remove any stray P-Tex drips.
Some gouges may not fill completely the first time. Repeat if necessary.
Show off your work to your friends around the fire.