Like waxing a ski, you're going to get more "expert opinions" on this subject than you know what to do with. So, for what it's worth, here's what we do and why we do it that way.
As you've all seen, many shops still use those cute little colored plastic plugs that try to match the color of the ski. Who cares about the match as another set of bindings will be going on anyway. The big rub is what kind of glue is used and in almost all cases, I'll bet you that it's not the right glue/adhesive as those little plugs are usually a polyethylene type of plastic which is difficult at best to bond.
Over the years, we have tried to use those plugs but only after prepping them with a bonding promoter. Available at your local hardware store? Not a chance! And, if it was, you wouldn't want to even open the bottle at home.
So as we say in aerospace, we write a "repair procedure" and here it is:
1- Remove the binding screws and determine if there is any moisture in the core. If there is call me.
2- Take a utility knife blade and cut off any loose or deformed top material around the screw hole. It is important that this be done to ensure a flat surface for the next set of bindings. Make sure that there is no debris in the hole. A little shot of compressed air, even one of those cans for dusting off your computer will work.
3- Now to fill the hole and let's not plan on doing it in a big hurry, please! Done properly the ski will be as good as new, screwed up and the hole can leak or the new binding screws can be compromised with potentially disastrous results.
I always use a good grade of structural epoxy adhesive to do the job. Here it's always 3M DP-420 or DP-460. Both are the same basic stuff but different curing times. Now make sure that the ski and adhesive are both warm. For two reasons of which the first is that warm epoxy is thinner and will flow better into the holes thus filling them with no voids and penetrating into the adjacent core or composite material. The second reason is that as the ski and adhesive cool down the adhesive will shrink very slightly and leave a little concave surface. You don't want to trap air so always get the epoxy to the bottom of the hole first and then let it fill to the top. Come back with a second spot of the same adhesive and fill in the top. After that, use the utility knife blade to shave the top flat. If your concerned about the cosmetics then go to the store and buy the Sharpie of your choice it'll probably match the color better than those cute little plugs.
I get all kinds of questions on this subject. Here are a few:
1- If I can't get the 3M adhesive then what do I use? Well if you can't get it then call us because we do. It's expensive but it's the best. Or go to your local hardware store and look for the little side by side tubes. A recommendation is to first look for a "toughened" structural epoxy. "Toughened" meaning the epoxy has component added to it to make it less brittle. Second is to look for a product that has that little static mix tube with it. The "static mix tube" is a dispensing tube with a spiral insert to mix the two parts of the epoxy as it flows through. I like the mix tube because I'm lazy and can get the epoxy to the bottom of the hole more efficiently.
2- Can I re-drill into the same holes or close to them? A good question! If you use those cute little plugs then you are taking a big risk! When we use the 3M adhesives we can either re-drill the hole or drill as close as we want. Should you do it? I'm not going to guarantee your workmanship and I'll leave it at that.
3- Will the holes leak? Not if done properly and as I always say, if you're uncertain or have a question then give us a call.
John Carpenter
President
Snowshark Monoskis
Division of RMD Composites, Inc.
john@snowshark.com
Telephone: 360.387.4976