QC LAB: Remounting previously drilled skisWednesday, September 7, 2016
[Photo: Grant Gunderson}
We get two main questions when it comes to mounting bindings on skis:
- Which method should I use—glue, epoxy, no glue?
- Can I re-use holes in skis to re-mount and/or how close to previous holes in my skis is it ok to drill?
We decided to tackle number 2 today, and we'll leave the first for another day (for the record, BD recommends using a slow-set 2 part epoxy to mount your bindings).
A lot of seasoned ski techs have their own rules of thumb when it comes to re-using pre-existing holes (not recommended) or how close to drill. So we had our tele-charging, QA Engineering wizard, Andy Rosenberg, perform our standard, not-overly-scientific-limited-data-point study to see what kind of differences we got when drilling holes and mounting screws varying distances from pre-existing holes.
Once again, this is not comprehensive, just some info—do with it what you will.
- 3.6x9.0 drill
- Standard penetration depth
- Pre-existing holes had a screw run in and out (no actual binding mounted)
- BD O3 screws
- No glue or epoxy used
- All tests performed on one BD ski
- Distances measured center to center
- Each distance had its own baseline data point taken
Comments and Conclusions
As usual, this is super limited data - there is much more that could be done to get a more conclusive look at the situation:
- Use pre-existing holes that have actually had bindings mounted and have been skied hard
- Use many different types of skis (wood only, with metal, sidewalls, etc) Note: the BD ski we used is known as being particularly burly
- Try different type of screws; different screw pitch in pre-existing holes
- Do the tests with wood glue, or epoxy in the pre-existing, or new, or both holes
However, given this test, it looks like you may want to stay 7mm away or greater in order to attain maximum strength when drilling next to pre-existing holes.
There you have it. Pray for snow.