Here is my advice, use the down time to polish the skills you have and build up your weak areas. Personally, as a foreman myself, pushing personal projects out on my dime wouldn't fly. Using my equipment on your time is one thing but my equipment on my clock is a no go. The benefits of using the time to improve your skills are twofold. First, it demonstrates to your current employer some initiative on your part to make yourself more valuable to them, second it opens up a wider range of future employers that will consider you should you need to move on. You can never have too many skills in this job market.
There's my .02
