Binding Screw Glue

[fgd135]

True for polyester resin (probably due to MEK catalyst); not true for epoxy. Have applied a lot of epoxy to a lot of foam.

Edit to add: Biggest con of all for epoxy mounts, IMO:

Epoxies are certainly able to be loosened, with heat, but that is of little comfort if a binding breaks and needs replacement while you're in the field instead of the home workshop.

Not sure what you mean by all this, but it has been my personal experience both as a nordic ski tech, a binding manufacturer, and an active ski patroller, starting about 1980 with all this--I've seen plenty of foam core XC skis trashed by epoxy use, and have had more than one personal experience attempting to repair broken 3 pins way back in the woods that were installed by the owner with epoxy glues...and in a repair shop situation as well.

Perhaps different types of foam cores, and laminated XC honeycomb cores have different requirements, hence my statement about following manufacturer's recommendations,
Thanks.

[Whiteout]

Not sure what you mean by all this,

Guessing a confusion might be over "con." Should have said "negative," to prevent imagining I meant "con-job." I am agreeing with you (as to the problems epoxy-set screws can cause away from the shop). I am a long time proponent on the old Telemarktips that epoxy is unnecessary overkill. And individual ski constructions can cause special considerations (like dumping excess glue into a screw hole that breached an air channel.) I won't question the damage you saw from binding pull out, but it sounds like epoxy doing too good a job: screw/ski interface weaker than ski around it.

I ONLY weigh in here to counter a long-cited myth that epoxy resin melts or weakens foam. It doesn't.
Cheers

[zonca]

I agree with Whiteout "a long-cited myth that epoxy resin melts or weakens foam" with an additional note.

Some epoxy does incorporate some solvent to thin the resin and maybe to save costs. If using epoxy on skis (recommended for inserts for instance) make sure the epoxy is 100% solids.Label should say.

When a screw pulls out a chunk of ski it sort of indicates that the glue penetrated the foam around the hole. Solvent free epoxy shouldn't do that. A little bit of cell breakage around the hole and screw insertion pushes some a very little way into the foam so screw ought to pull out with minimal core.

full disclosure- I learned this stuff from boat building not skis.

[Stephen]

Thanks for all the input. I have used literally 100s of gallons of epoxy in boat building and have sort of a soft spot for epoxy. Also, I have it around and it lasts for a long time, unlike some glues.
Usually, when there is a rule or specification, it is there because something bad happened, so I was wondering what negative outcome Asnes wanted to avoid when they specified a particular type of glue for binding screws.
Since most (all?) Asnes skis are wood core, foam core degradation is not the issue. It could be that a solvent based glue could damage the plastic top sheet.
I would not think Asnes would be concerned with screw removal, since that is beyond their sphere of responsibility. If I have a problem removing screws at a later date because I used epoxy, that’s my problem, not theirs.

Bottom line, I think I’m overdoing it with epoxy and trying to solve a problem that doesn’t exist.
As has been said, the main (maybe only) purpose of the glue is to seal the wood core to keep water out. It’s not to strengthen the screw’s holding power (although it does), because that’s not needed.
I can imagine that on high-tech bindings, with stiff boots, and resulting higher forces, possibly epoxy would make for a more bulletproof mount, but not needed on relatively narrow skis with NNN, NNN BC, 75mm, etc. bindings.
But, I’ll probably keep using it, since I don’t anticipate needing to do field repairs (I’m not carrying spare bindings), and also don’t anticipate removing the bindings. The apply-heat tip is helpful, if I ever do want to remove the screws.
Peace

[lilcliffy]

Need I say more?

[Stephen]

You set the binding screws in ...beer?
Oh, wait, now I see the glue...
Say no more.

[athabascae]

My main issue with polyurethane glues, like Gorilla glue, is that the shelf life of the unused product is about a year after it is opened.

I have used wood glue (PVA-based) in the past, but I am really thinking I should use polyurethane-based glue given Asnes advice.

Anyone use Gorilla glue (the original version) for new mounts? I can also get the LePage version that Gareth uses.

I have no interest in epoxy for a new mount.

The shops I called recommended regular wood glue (not even Type II or Type III PVA) or nothing at all (dry mount).

This decision is making my head hurt.

[lilcliffy]

I am not an expert here-

My understanding is that the polyurethane glue will completely seal the hole- preventing any moisture from getting into that precious wood core.

Yes? No?

[Smitty]

My main issue with polyurethane glues, like Gorilla glue, is that the shelf life of the unused product is about a year after it is opened.

I have used wood glue (PVA-based) in the past, but I am really thinking I should use polyurethane-based glue given Asnes advice.

Anyone use Gorilla glue (the original version) for new mounts? I can also get the LePage version that Gareth uses.

I have no interest in epoxy for a new mount.

The shops I called recommended regular wood glue (not even Type II or Type III PVA) or nothing at all (dry mount).

This decision is making my head hurt.

I don't think you can go wrong either way, but I was in the same boat and decided to use polyurethane to mount my new Nansens at the beginning of the season. I used Gorilla Glue brand, had used it in the shop for a few projects previously, it was fine. I think quality is solid. If you haven't worked with PU before, note that you need to moisten the surfaces prior to applying the glue, and this does make the glue foam / expand a decent amount as it sets. So you probably don't want to go overkill with volume. All my mounts before that were Weldbond brand PVA wood glue, including my Gammes. No issues there either.

I've never removed bindings mounted with PU before, so I found Woods' comment interesting about gummed up threads and making it a pain to re-use the screws. I will be keeping that in mind going forward. Will likely avoid if mounting a ski that I may pass along down the road. Wood glue is just easy to deal with during removal / re-use.

Funny side note, if you Google "Gorilla Glue" there are just as many results regarding a weed strain that apparently has the same name as there are about the adhesive.

[athabascae]

Thanks folks. I went with what I know - wood glue, Type I waterproof.