Ski Builders Forum

I found out the mystery glue that is used by some companies to glue the edges to the base, as seen in a few layup videos. It is a neoprene contact adhesive.

I ordered some 3M Scotch Weld neoprene contact adhesive from mcmaster, and a squeeze bottle to apply it. I did a simple test last night with some scrap ptex and scrap edges, and it seems to have worked ok, but it's hard to tell.

I applied it by putting a constant bead along the edge of the ptex, and then a bead along the teeth of the edges, let them dry slightly, then clamped them together. That's the best I could get from the videos.

My worry is that all that contact cement will block epoxy from squeezing in between the edge tines. I put some clear top sheet on my test piece so I could see, but it's hard to tell if it really blocked the epoxy or not.

I'm laying up some skis this weekend and I'm debating using this new glue, or sticking with CA. I'd hate to ruin a pair of skis over something so simple...

Has anybody used something similar for edges? Is my application method right? Should I be clamping the edges wet, or let them dry completely, or...?

Go to 1:35 in this video to see what I'm on about.

Your following the video tutorial : ) and they just roll it together (@1.46)

As it's a medium viscosity adhesive, I would have thought it was going to spread out and cover all the inner face of the edge set. In the absence of a cassette to force a seal, I would think this is the ideal.

The only issues from my perspective is the colour when dry - clear bases etc and inter facial bond (neoprene glue and epoxy). Assuming the glue is as good as the specs, then why do you need to worry? It has the +/- temperature range and the suggestion appear to be that the bond is formed slowly over time.

Maybe you can use a pre-mold? You just need a few strips of wood, 3-4mm thick. Create the bond and then allow expansion of the base material within the cassette to force the seal.

Great find ... PLEASE update your findings

I've never had any issues with using CA for edges, this is just me wanting to be more like the "pros".

The stuff I got is 3M Scotch Weld Neoprene Contact Adhesive #10, part number 75425A67 on McMaster (for a quart).

I'm not doing clear bases, but if you did you would definitely see a mess of the glue. It's bright yellow in color. I've never really paid attention to it, but now I'd like to look at one of K2's clear-based skis up close to see what it looks like, and how it ends up between the tines, etc. I can't find any good pictures online

When I did my test last night I allowed the glue to dry slightly - but this kind of glue is normally applied in a thin film and you let it dry completely. By laying down a bead, it sort of forms a dry outer shell. Then when I clamped the edge on it popped in a few places and oozed wet glue out, like a bunch of zits. Maybe I just need to use less glue.

The specifications say you can apply using a roller. You could apply a thin film and control the width/amount used. Apply a thin bead to the edge set using one of those micro tips available for CA. Avoid the tines completely.

Personally, I would be tempted to use a roller on both materials and bond the tines using this adhesive. Pushes the next bond line further away from the joint between the edge and base.

In reality CA's aren't the adhesive of choice - according to what the tech guy. Arguably it does not adhere to the PE, it forms a sort of micro vacuum, even with pre-treatment.

True, but the way we use CA, it's job is only to hold the edge in place long enough for the epoxy to squeeze in there during the layup, it's not actually holding the edge in the ski. The way I'd be using this glue, it really becomes the primary edge holder (for lack of a better term).

Twizz - Why not use the neoprene glue in the same manner as you would CA glue? Then you won't have the worries of the epoxy not seeping in. In the video they use it on the entire edge and all along the edge of the base. They must not be worried about epoxy. Looks like the neoprene glue does the work. Only 1 way to find out.

Well I just went at the edges with some pliers, and although it did take a lot of force, I was able to pull the edge (about 8 inches long) completely out clean.

Needless to say I will not be using this glue on the skis this weekend, I have high hopes for these skis turning out amazing (bamboo veneer top sheet), so I don't want to risk anything. I'll have to do more experimentation before I trust this neoprene glue.

Isn't that the vid from the shop you worked in? Arn't they just rapid prototyping? Not really a long lasting product perhaps?
The neo glue is fast and easy it appears.
Like rich says I think we are perhaps missing a press and or casette and cook maybe? Not sure.
The ca is weak also but the epoxy is strong. Just use less perhaps if it works better than ca? The ca sets super fast for tacking. Never summer is using what looks like a rapid set 2 part ca.
Wagner looks like they use a 2 part maybe ca or epoxy.

Thanks for the info MM.

I worked at K2 when they were still on vashon, but most of what I did was break skis after they were made, I never did any layups so I didn't really learn their techniques.

And yeah maybe they only use it for prototypes, and not in actual production... Never thought about that. In the video from the dynastar factory in the How It's Made show they don't do anything, they just place the edges dry onto the base in the mold. But they obviously have legit cnc'd molds/cassettes to hold it all in place.

I reckon those dynastar molds are magnetic twizz, which holds the edges in place.
One video from Moment talks about "snap in" cassettes, which I take to mean a tight tolerance cassette so you roll the edges in next to the base material and they are effectively wedged in there (I think that's what it looks like he does on the swell panik vids too).

But it's a contact adhesive that need to be given time to cure at ambient temperature - the suggestion being around 2 weeks for maximum yield (I'm assuming the press accelerates the cure?)

http://multimedia.3m.com/mws/mediawebse ... 098823.pdf

Our problem is that PE is difficult to bond, so it's a bit distracting to think of CA as being weak (not being critical MM). While I'm not against CA, spot welding or anything like that ... I just think the door is open for a better choice.

The epoxy we use is a compromise between the different characteristics, I'm find it difficult to believe that epoxy is the adhesive of choice and 430 psi is a big number!

How about this twizz, bond on a small section of edge, place it within the press, cycle the heat and test. It might need to be a low pressure test, otherwise you'll mark the cassette. I'm happy to do the epoxy equivalent if you want to compare, just let me know what length of edge you are processing and thickness of material.

Btw, how do you know this is the adhesive being used, I mean, you appear doubtful of it potential?

I made my test piece exactly as you described. It was a piece of base, with two sections of 8" long edge glued onto either side with the contact adhesive, then a layer of triax fiberglass over it, and then some clear topsheet, using super sap epoxy, 180 deg F in the press at 60psi for an hour.

When I pulled the edge out, the contact adhesive looked like gum stuck to the bottom of your shoe, it stretched as the edge pulled out.

As to how I finally found out what the glue was - I asked an old colleague at my former winter sports equipment manufacturing employer Now the information I got was "3M contact adhesive, neoprene type", and there are a few others different from the #10 that I got, but the specs are similar, and this stuff is yellow so I figure chances are good it's the same (or equivalent). I'm going to see if I can squeeze any more information out of my contact, I just have to be careful that I'm not fishing for proprietary information, because that is not my intent.

Unrelated to this thread - I picked up my bamboo veneer yesterday for my new skis, this stuff is AWESOME! I'm pumped to make the new skis, got everything ready to go for lay up tomorrow.

I have a contact in the snow spots biz also. I asked him about it and he said typically it is used with lower temps and with CNC cassettes with magnets and CNC bent edges. He did not mention which specific adhesive though.

Knowing this do you think the high temps needed
For super sap are the issue? Or could
There be other epoxies that are more
Compatible?

I never doubted you for a moment

You could ask 3M what the consistency should be once it has been left to cure for 2 weeks. If it is sandable, then you know bubble gum wasn't a full cure. Alternatively, it may be a matter of putting it to one side, letting it cure and then relying on its service temp range of 100 degrees.

On the plus side - bubble gum suggests it actually adheres to both surfaces!

It's a bit late here in the UK and sunny for that matter (early finish for everyone).

Working around the absence of a CNC cassette is no great shakes, but lets say you find the right epoxy ... and lay up within 24hrs, do you get the chemical bond? The suggestion appears to be 'yes' from the Wagner video.