Sealant/Glue for Bindings... and other mounting secrets.

[GrimSurfer]

Aren't these "inserts", as Altai calls them, heli-coils? ballahok.jpg

Hard to tell at that resolution. A Heli-Coil (using the proper trade name) is literally a coil of wire that relies on a tapped hole to work. See bottom image.

I think what people have in mind is something called an E-Z Lok, which would be my choice for what’s being discussed here. These are self boring and used in composite wood products, like IKEA furniture. All they need is a proper hole size to work. See top image.

The challenge here is the shoulder of the E-Z Lok, which is going to sit proud of the top sheet unless chamfering is done. At that point, you’re further breaking into the top sheet, where a portion of the ski’s strength lies.

Lots of things to consider but a helicoil is either the incorrect term or incorrect fastener for the application being discussed.

[Jurassien]

In the EU there is an industrial standard, BS EN 204, for non-structural wood glues. The glues are rated in 4 categories from D1 to D4, where D1 is mildly moisture resistant and D4 is weatherproof:

D3 = Interior areas, with frequent short-term exposure to running or condensed water and/or heavy exposure to high humidity. Exterior areas not exposed to weather
D4 = Interior areas with frequent long-term exposure to running or condensed water. Exterior areas exposed to weather

I don’t know if this standard is recognised in the USA or elsewhere, but if so, then any D4-rated wood glue should be appropriate for ski binding montage.

Cascol, as recommended by Åsnes, is rated D4 – but so are several non-PU glues. I think Åsnes are doing their customers a disservice by not explaining why a PU glue should be superior, or more desirable, in their skis than any other D4-rated glue. They refer to “regular white wood glue” rather than referring to the industrial standard.

Quote from Åsnes:
THE BASIS FOR OUR RECOMMENDATION
Extensive testing, traditions and long experience gained from all the skis we have provided for expeditions, harsh mountain environments, and military NATO Forces prove that PU-adhesives work much better than ordinary glue made for wood. PU adhesives have been found to have on average 20% better properties related to the holding of the screws in the ski and in strength. Since PU adhesives also cure in contact with moisture, it has actually been shown that the strength and hold can be even stronger if the adhesives are lightly sprayed with water before mounting of the bindings. This can also be done with a moist cloth to be sure one does not use excessive glue and to avoid too much moisture.
Most importantly, the PU adhesive has better properties than regular white wood glue to seal the screw holes, because the PU-glue expands and has a more flexible and water-resistant composition.


I’ve been told (= I don’t know) that PU glues have a short shelf-life once opened – so you would use a very small amount for your skis and, if you didn’t need the stuff for anything else, you’d be taking the rest to Hazardous Disposal in a year’s time. Perhaps someone who knows better can comment on this.

[wabene]

Aren't these "inserts", as Altai calls them, heli-coils? ballahok.jpg

Hard to tell at that resolution. A Heli-Coil (using the proper trade name) is literally a coil of wire that relies on a tapped hole to work. See bottom image.

I think what people have in mind is something called an E-Z Lok, which would be my choice for what’s being discussed here. These are self boring and used in composite wood products, like IKEA furniture. All they need is a proper hole size to work. See top image.

The challenge here is the shoulder of the E-Z Lok, which is going to sit proud of the top sheet unless chamfering is done. At that point, you’re further breaking into the top sheet, where a portion of the ski’s strength lies.

Lots of things to consider but a helicoil is either the incorrect term or incorrect fastener for the application being discussed.

Altai calls them inserts not heli-coils so it is me who is creating the confusion .
I edited my original post because I think you are correct with your distinction, my local shop is using threaded inserts and calling the them heli-coils and I don't want to create any confusion. Thanks for pointing this out, these little details are important.

[GrimSurfer]

In the EU there is an industrial standard, BS EN 204, for non-structural wood glues. The glues are rated in 4 categories from D1 to D4, where D1 is mildly moisture resistant and D4 is weatherproof:

D3 = Interior areas, with frequent short-term exposure to running or condensed water and/or heavy exposure to high humidity. Exterior areas not exposed to weather
D4 = Interior areas with frequent long-term exposure to running or condensed water. Exterior areas exposed to weather

I don’t know if this standard is recognised in the USA or elsewhere, but if so, then any D4-rated wood glue should be appropriate for ski binding montage.

Cascol, as recommended by Åsnes, is rated D4 – but so are several non-PU glues. I think Åsnes are doing their customers a disservice by not explaining why a PU glue should be superior, or more desirable, in their skis than any other D4-rated glue. They refer to “regular white wood glue” rather than referring to the industrial standard.

Quote from Åsnes:
THE BASIS FOR OUR RECOMMENDATION
Extensive testing, traditions and long experience gained from all the skis we have provided for expeditions, harsh mountain environments, and military NATO Forces prove that PU-adhesives work much better than ordinary glue made for wood. PU adhesives have been found to have on average 20% better properties related to the holding of the screws in the ski and in strength. Since PU adhesives also cure in contact with moisture, it has actually been shown that the strength and hold can be even stronger if the adhesives are lightly sprayed with water before mounting of the bindings. This can also be done with a moist cloth to be sure one does not use excessive glue and to avoid too much moisture.
Most importantly, the PU adhesive has better properties than regular white wood glue to seal the screw holes, because the PU-glue expands and has a more flexible and water-resistant composition.


I’ve been told (= I don’t know) that PU glues have a short shelf-life once opened – so you would use a very small amount for your skis and, if you didn’t need the stuff for anything else, you’d be taking the rest to Hazardous Disposal in a year’s time. Perhaps someone who knows better can comment on this.

Great post. The Europeans have always been ahead on standards… starting with the British Standard (BS) in the early part of the 20th Century and moving to EN (European Norm), German DIN etc.

I’m inclined to agree with Asnes on this one. PUs seem to do everything needed. They expand to fill voids, they harden up very well, and they are impervious to water when hardened.

Wood glues are great for carpentry. They take their time to bond (which assists in positioning), absorb into wood (bond well) and are water soluble/non marring. They also shrink over time, which isn’t very good.

Epoxies have other properties, like fast curing, water resistance, and heat resistance. Some even resist oil and solvents, which PU and wood glues either don’t do at all or do t do very well.

I can say from experience that PU glue doesn’t store well. Left uncapped, it turns into a big foam ball in the presence of any moisture. It doesn’t tolerate freezing very well until it cures. It doesn’t expand or harden properly when left to cure in the cold. It’s messy AF, which explains the permanent stains on almost all of my trousers.

I think the reason why manufacturers don’t explain a lot of this stuff is because people don’t want to take the time to read/understand. They’d use a glue stick (collagen) if it suited them and wouldn’t want to spend the money on something better.

Companies like Asnes cater to a higher crowd. While I don’t ski Asnes, I do appreciate their attention to detail, as do their users.

[GrimSurfer]

Aren't these "inserts", as Altai calls them, heli-coils? ballahok.jpg

Hard to tell at that resolution. A Heli-Coil (using the proper trade name) is literally a coil of wire that relies on a tapped hole to work. See bottom image.

I think what people have in mind is something called an E-Z Lok, which would be my choice for what’s being discussed here. These are self boring and used in composite wood products, like IKEA furniture. All they need is a proper hole size to work. See top image.

The challenge here is the shoulder of the E-Z Lok, which is going to sit proud of the top sheet unless chamfering is done. At that point, you’re further breaking into the top sheet, where a portion of the ski’s strength lies.

Lots of things to consider but a helicoil is either the incorrect term or incorrect fastener for the application being discussed.

Altai calls them inserts not heli-coils so it is me who is creating the confusion .
I edited my original post because I think you are correct with your distinction, my local shop is using threaded inserts and calling the them heli-coils and I don't want to create any confusion. Thanks for pointing this out, these little details are important.

Reminds me of a structural engineer I knew who would lose it every time somebody used “cement” in place of “concrete”. Ha ha. Sometimes I’d do it for the reaction.

Maybe this is what Steve Martin was talking about when he said “I love the French, they have a word for everything”. LOL

[Jurassien]

It’s messy AF, which explains the permanent stains on almost all of my trousers.

That’s your excuse!..........I’ll think of that one when someone asks me to explain the stains in my pants after a hairy descent on skinny skis.

[GrimSurfer]

Ha ha. If a skier from Switzerland says it’s steep, I take the cable car or wear a balaclava (acts as a restrictor plate to save the back of my pants from blowing out).

[Stephen]

I should really know better than to go down this rabbit hole…
I’m limiting myself to one post.

I can’t speak for all epoxy adhesives, but the West System G/Flex Epoxy adhesive I use has virtually solvents.
For example, looking at SDS sheets for G/Flex and Gorilla Glue, I see that VOC (solvents) info listed as:
G/Flex: …………… VOC Content Resin/Hardener … (g/L) = 8.6
Gorilla Glue: …… VOC Content …………………………… (g/L) = 12

For example, surfboards made with EPS foam have to use epoxy resin because polyester resins will dissolve EPS foam — but not polyurethane foam, where polyester resins are used.

One nice thing about epoxy glues is shelf life — many years, maybe decades, because the reactive agents are seperate, whereas the reactive agent (H2O) for polyurethane glue is in the air.

All that said, polyurethane glue for bindings is rock solid and easier than messing around with epoxy.
Titebond III is fine, too.
Stop thinking about it and just use one or the other…

Asnes just wants you to not use crappy white Elmers glue, which is fine for crafts, or whatever.
If Asnes tell you the one thing to use and you use something else, and have a problem, well, their butt is covered.
And besides, they want you to NOT have a problem and enjoy using their product.

Binding inserts are a mature technology & product. They’ve been around for over 10 years — no conjecture needed.

[GrimSurfer]

VOC is a pretty broad term. There are VOCs in antifreeze (ethylene glycol) and solvents (MEK). How they interact with materials (and bodies) varies greatly. About the only things they have in common is that they off gas at normal atmospheric pressure (volatile), are based on some form of organic chemistry (carbon chained), and include other elements bonded to carbon (compound).

Solvent is a broad term too. What’s the world’s most commonly used industrial and domestic solvent? Water. Yup. It’s a solvent because it can dissolve all kinds of substances, from inks and wood glue to mud.

Lots of rabbit holes to be sure. And I agree that some of them aren’t worth going down. But Einstein once said that it’s important to think simply… but not too simply.

The truth is that some people take stuff written on the internet with a grain of salt or very literally. The latter is a land mine waiting to explode. Like rushing off to the hardware store to buy some helicoils for your skis… or using any fastener (like an EZ Lok) not designed for a particular application. Neither of these are binding inserts, btw, but EZ Loks come a lot closer in terms of general design and use-case.

Glue? Same deal.

The goal should be to go down the rabbit hole deep enough to explain why things are the way they are.

[wabene]

An EZ Lok without a "shoulder", jazzy.

I like calling them "heli-coils" just for fun