Thread: Mounted My Own Skis for First Time - Possible Fuck Up Question on Screw Tightness

So I just mounted a pair of small dukes to a 4frnt YLE, and everything went smooth for Boot center position/mount line, and side to side straightness of the mount.

I may have fucked up the tightening of the screws;

The screws were damn tight! I thought they felt solid, and I didn't want to push my luck and strip the screws out by tightening them more...so I left them where there were. Then later I was admiring my handywork and noticed there is at most 1/2 millimeter gap between the mounting plates for the dukes and the ski. Some areas have no gaps, some just barely.

Total fuckup or no?

No worries. Take a soldering iron and rest it on the screw heads (I am assuming you used epoxy and this is why you are asking) for a bit to heat up the screw and then the epoxy. Then just finish seating the screw.

Did you chamfer the holes before you tapped and screwed the binders on?

When you drill the hole in a ski many times(not always) there will be a raised edge around the hole. Some folks call this a volcano.

You can use a tool to round off the edge or cut it down with a razor blade scraper. If you did not do this it can cause the binding to not sit flush on the ski. You can unmount the skis and redo or leave it and ski it. On Dukes it would not matter, on Dfits you be fucked.

Not the end of the world but a job worth doing....

I've had that happen, even noticed it on some shop mounts. It didn't pull out or loosen. You should probably see what others say though, I don't know anything.

Scotty, I never get volcanoes when drilling, they are only there after the binding comes off again. You might be able to countersink to keep them from forming but I'm not really sure that's the best thing to be doing.

Good point Scotty, forgot about that. The bit on the drill can wind out the top sheet causing the surrounding of the hole to be a bit higher at the hole - "volcano"

I have gotten slight volcanoes from the drill bit, but nothing like after pulling the binder off. I just take a razor blade to the holes after I drill them to make them flush. No need to chamfer or countersink IME.

First time I ever did a mount though, I thought the screws were tight but then I noticed maybe 30 minutes later that they really weren't (saw a gap similar to what you described). I was so worried about not stripping the screws that I just didn't tighten them all the way down. After you feel the screw stop, it's pretty obvious when it's fully tight. On foam cores, I've found that I actually need to use a wrench on top of the screwdriver handle. Even with the lever arm, it's pretty obvious when it's finished.

The Duke/Baron plates are not truly flat. When you take the plates out of the box and rest them on the ski without screws, it will not rest flat and you will be able to see light.

Mounting and tightening the screws properly will make the plate sit flat, but not always.

Without seeing your handy work, I couldn't say if the gap is fine or not.

As others have noted, usually when there's a gap between binding and ski and the screws feel tight, it's because the topsheet material has volcanoed up and it's holding the binding off the ski surface. Usually it's from forcing the screw in, not drilling. I'm with scottyb on the countersinking, I hit the holes with a 45 degree countersink very lightly (just the plastic topsheet), then tap with a 12AB before putting the screws in.

In your case, just take them off, shave the high spots with a razor blade, and put the bindings back on. The screws don't have to be super tight, just firmly snug.

Originally Posted by TwinTipFlip

Then later I was admiring my handywork and noticed there is at most 1/2 millimeter gap between the mounting plates for the dukes and the ski. Some areas have no gaps, some just barely.

Total fuckup or no?

1-2-mm gaps? Not sure I'd be comfortable with that. Like Mtskier said...hard to say for certain w/o a picture.

IMHO leaving a gap of more than a cunt hair is a lazy mans handy work, shop or not. Do this...

In your case, just take them off, shave the high spots with a razor blade, and put the bindings back on. The screws don't have to be super tight, just firmly snug

You should be able to hand tighten a binding totally flat with a pozi screwdriver without stripping the threads. I've really wrenched on them without it stripping.
The fact that the plate isn't even smooth, even and kinda flat on Marker Dukes is just more disappointment about them.

Pick up a tiny thumb plane from a home depot type store and just knock off the volcano. Quick and easy.

Probably the volcano was created before the binding was snugged down to the ski top, I would take it off, countersink the hole in the ski, make sure the screw doesn't bind in the bindings hole and try it again

I don't have a real mounting bit so I twirl a large bit by hand to put a slight countersink on the top of screw holes

I've had this happen in the past for a couple reasons:
1) I didn't drill the full depth of the bit
2) I didn't get all the shavings out of the screw holes
3) screws were a little long (you can usually tell by whether or not you had bumps on your bases where the screws are)
4) forgetting to tap a metal top sheet.

In all cases, no big deal. I just backed them out, made sure I was drilled to full depth, cleaned out the holes, tapped if necessary, and reinstalled. I use glue as well - never been an epoxy fan. I'm using Marine Goop these days as it has a little elasticity give, which has been helpful with the screws on my NTN bindings.

Originally Posted by cat in january

No worries. Take a soldering iron and rest it on the screw heads (I am assuming you used epoxy and this is why you are asking) for a bit to heat up the screw and then the epoxy. Then just finish seating the screw.

I used wood glue…

Originally Posted by scottyb

Did you chamfer the holes before you tapped and screwed the binders on?

When you drill the hole in a ski many times(not always) there will be a raised edge around the hole. Some folks call this a volcano.

You can use a tool to round off the edge or cut it down with a razor blade scraper. If you did not do this it can cause the binding to not sit flush on the ski. You can unmount the skis and redo or leave it and ski it. On Dukes it would not matter, on Dfits you be fucked.

I used a wood chisel to remove a very small volcano that developed from the drilling. Is it safe to remove screws anchored with wood glue?

Originally Posted by auvgeek

After you feel the screw stop, it's pretty obvious when it's fully tight. On foam cores, I've found that I actually need to use a wrench on top of the screwdriver handle. Even with the lever arm, it's pretty obvious when it's finished.

They were damn tight, my hands were white!

Originally Posted by mtskier

The Duke/Baron plates are not truly flat. When you take the plates out of the box and rest them on the ski without screws, it will not rest flat and you will be able to see light.

Mounting and tightening the screws properly will make the plate sit flat, but not always.

Without seeing your handy work, I couldn't say if the gap is fine or not.

Please see pictures!

Originally Posted by Bandit Man

1-2-mm gaps? Not sure I'd be comfortable with that. Like Mtskier said...hard to say for certain w/o a picture.

½ mm gap, not 1 to 2mm.

Originally Posted by axebiker

I've had this happen in the past for a couple reasons:
1) I didn't drill the full depth of the bit
2) I didn't get all the shavings out of the screw holes
3) screws were a little long (you can usually tell by whether or not you had bumps on your bases where the screws are)

I think if anything its the depth of the drillbit was set a little on the short side, with a combination of a small volcano from screwing (not drilling) that casued the gap. Screws were not too long, and no metal in ski.

used a wood chisel to remove a very small volcano that developed from the drilling. Is it safe to remove screws anchored with wood glue?

I use a the same to knock them down when needed also. I've pulled bindings off and remounted where I had epoxy holding them in. Wood glue shouldn't be a problem.

Originally Posted by auvgeek
After you feel the screw stop, it's pretty obvious when it's fully tight. On foam cores, I've found that I actually need to use a wrench on top of the screwdriver handle. Even with the lever arm, it's pretty obvious when it's finished.
They were damn tight, my hands were white!

Careful not to crank the shit out of the screws when screwing them in after it stops, you might end up with spinners.

Another point to remember with srews. Apply firm downward pressure on the screwdriver when cutting threads (fresh hole) and no downward pressure when reusing threads (boring old hole). Fairly versatile advice really

I had that issue before, my problem was didn't drill the holes deep enough. Got scared that I'd punch through.

Originally Posted by time2clmb

Careful not to crank the shit out of the screws when screwing them in after it stops, you might end up with spinners.

X2, once the binding is pulled down to the ski, making the screws tighter doesn't increase the attachment strength at all. You've got all of the thread in the ski you're going to get. As long as they don't vibrate loose, snug is enough for maximum pullout strength.

Originally Posted by Winkler

Another point to remember with srews. Apply firm downward pressure on the screwdriver when cutting threads (fresh hole) and no downward pressure when reusing threads (*following old threads*).

Push real hard on the screws when first starting them (unless you tapped the holes), otherwise the screws can lift the topsheet away from the core and you'll get extra bad volcanoes without the screws even getting started. (Bad volcanoes can be lightly hammered back down, then try starting the screws again with firm pressure.) Even when done properly you'll get some volcano effect, which I slice off with a razor blade. I drill, put some silicone on the screw threads (for lube & sealing), drive the screws most of the way into the ski (through the binding), pull them all back out, slice off the volcanoes, put a dab more silicone on the screw threads, and then do the final binding attachment.

If you're reusing old holes with good threads in the ski, lightly turn the screws counter-clockwise with VERY light downward pressure until you feel the screw drop down into the thread start. The reverse direction and thread in the screws. This will help prevent cross-threading and help preserve the threads in the ski.

Originally Posted by 1000-oaks

Cranking the screws just adds to upward loading you'll put on the ski core/topsheet/retention plate when skiing.

Interestingly enough, no. It's completely against logic, but it's not the case. The force of the tightened screw is not added to the force of the binding trying to pull out when talking about screw pullout force.

Long version:
For simplicity's sake, let's talk about two metal plates, bolted together, and the plates are being pulled apart. You torque the bolt such that there is 100 N of force (or pounds force, or whatever you're comfortable with) bringing the plates together. Now if you pull the plates apart using 200 N of force, the force on the bolt (the forces which will strip the threads or snap the bolt if high enough) is actually 200 N. You'd think it would be 300 N, the two forces added together, but it's not. When there's 20 N pulling the plates apart, the bolts are holding 100 N. So, the bolts experience exactly the load of whatever it's torqued to, until the applied load exceeds the force value you got by tightening the bolts.

^^^ That makes sense, I stand corrected.