Throwback Thursday! I’m always working on our binding mount DIY content. Funny how it never remains static. We refine our processes here at WildSnow HQ, and I’m always learning new things from readers and industry folks. I published this post a while back but figured it should get a later date so it’s better indexed. Did some edits and re-writing as well. Your feedback appreciated.
A WildSnow website reader took me to task on our Dynafit binding homebrew mount instructions. Getting feedback on our backcountry skiing articles is always a gift, so M.J. gets our sincere thanks! For example, due to reader comments I periodically work on our Dynafit mounting how-to guide, thus clarifying a things and simplifying what I’ll admit is sometimes confusing due to my edits.
One of M.J.’s gripes was my recommendation of using a 5/32 inch (3.9 mm) drill bit for most backcountry skiing binding mounts, and not tapping (threading) the subsequent holes. While it’s true that using special binding mounting bits of 3.6 mm diameter (for non metallic skis) to drill binding holes always a good idea (available from companies such as SlideWright), I’ve used the 5/32 drill bit on numerous skis and never had a problem with it (though going out of gamut like this is not recommended for some of the lighter carbon skis without beefy binding mount plates).
Note, in the case of skis with minimal mounting reinforcement and soft cores, you can also use a 9/64 inch (3.5 mm) twist drill bit, but in my experience this hole is slightly too small for threading standard ski mounting screws and can be difficult to tap without damage due to the tap not threading smoothly.
The key is that the 5/32 bit results in a slightly oversized hole. Thus, the screws have to be placed with care and not over-tightened, and they must be inserted with epoxy or a strong urethane glue. Tapping isn’t necessary because the slightly oversized hole allows the screw to self-tap.
Speaking of homebrew backcountry skiing binding mounts, the biggest issue in my mind is what glue to use for the screws. With most skis a touch of 1-hour epoxy yields a strongly placed screw that never loosens. To remove, briefly heat screws with soldering iron (or flame with a butane lighter in an emergency), or spin a reverse mounted small drill bit on top of the screw to heat with friction.
We used to use 5-minute epoxy for all this. I subsequently learned that 5-minute is too brittle for a long-term mount so we use 1-hour if we’re doing a “permanent” install and 5-minute for test bindings we know we’ll be removing sooner than later. If a ski is strong and the mount temporary, I’m not adverse to using waterproof wood glue, but I’m not a fan of such glue for long-term mounts. I’ve seen too many of such mounts with water damage.
Perhaps MJ’s best point was that a competent shop might be a better alternative than DIY homebrew mounting of Dynafit and other backcountry skiing bindings. I somewhat agree with that, but the fact remains that not all ski shops have more than passing experience with ski touring bindings, and many people are located in areas where there is simply no ski shop that even comes close. Horror stories abound of trying to get clueless shops to mount backcountry skiing bindings correctly — thus we’ll continue to recommend DIY for anyone with moderate hand skills and a few tools. (Of course, if a specialty shop cares to advertise here on WildSnow.com and tout their incredible experience with backcountry binding mounts and maintenance, as well as their willingness to do affordable mail-order mounts, we’re always looking for new sponsors!)
To that end, it’s worth saying that WildSnow.com makes an effort to provide DIY how-to mounting instructions for all the main players in the backcountry ski touring binding market, and those instructions are linked in the main navigation menu above.