reprocessed UHMWPE for sidewall?

[vinman]

I was looking around the interweb for some UHMW for sidewall and came across some reprocessed black UHMW rectangular bar stock. Price for a bar of this material is super cheap (~50%) in comparison to what we normally pay retail for. .5x5x65 inch bar for about $23 + shipping from what I could tell. 12.7mm x 127mm x 165cm. That is enough for about 8-10 sidewalls if you use 1cm sidewall.

I've emailed the company to see if they think it would bond with epoxy if abraded and flamed and I'm waiting to hear back from the.

What is the sense from you guys on this type of material do you think it would bond? It is basically recycled material from ground up UHMWPE and has a sort of marbled look to it.

Thoughts? It is cheap enough I might buy some and test its ability to bond. I'll at least wait until I hear back from the company before doing this.

[falls]

Sounds good
Some commercial companies are using recycled UHMWPE in their tip fill and sidewalls.
It should bond if abraded and flamed CORRECTLY.
Emphasis on correctly - as I think many have tried and failed to get this to work (although some people seem to have worked it out).
I'd say get some and do some experiments, or better still if they can abrade it and flame it get them to!

[MontuckyMadman]

the funny thing about diy flaming is that it can be done a bunch of different ways and speeds and heats and it works for different people at different times.
The method that was tested on here with a dyn pen is totally different than the way dbs did it in his factory for years. It seems it can take a bit of heat before that water sheets the way its supposed to in some cases. Doing right before layup seems to be key too.

POst the company?

[SHIF]

I've used this reprocessed UHMW as sidewall material with mixed results. I abraded the hell out or it with my belt sander, and cleaned it with solvent followed by flame treatment with a torch. The stuff is still difficult to bond to and it eventually had some delamination between the ski edges and sidewalls. These cracks did not diminish the performance of the skis however.

I only use hardwoods for sidewalls these days. It bonds very well and is just a tough as plastic. Plus it adds to the structural properties of the core, UHMW is just dead weight.

-S

[vinman]

here's the link

http://www.interstateplastics.com/Black ... +%3E%A0%A0

could the solvent have caused your delam instead of the material?

[SHIF]

The solvent did not cause the delam. I think the shearing forces created by flexing the ski made it delam. These skis did not have VDS above the edges. That's probably the root cause. It is interesting that on my skis having hardwood sidewalls and no VDS, there are no delams or cracks, even after considerable abuse on the mountain.

I still don't like the dead weight aspect of it.

-S

[vinman]

right on, thanks SHIF. I think I'll order a sample and test it out. I have 3 pair in the works and the skibuilders store is currently out of black SW, white just won't cut it with the current color of the veneer tops I'm using.

[MontuckyMadman]

but that dead weight can transfer to dampening effects as I understand.

[Brazen]

Right. Less vibration, better sidewall compressive life and abundant repeatable flex with plastic, wood be damned. Use full wood? That's one way haha I happen to like uhmw...you have zero maintenance for better protection and you build your cores accordingly. Sheesh.

I'm just sayin'.

[Damon]

Theoretically, the only difference is that reprocessed UHMW should have a lower molecular weight compared to virgin material. There should be no difference provided the surface is properly prepared.

[vinman]

one of the suppliers I contacted is sending me a sample. SO once I get it I'll abrade and flame it and try to bond it to some wood and fiber glass with QCM epoxy, heat and compression. If It works I may order some. I actually like the marbled/speckled stone look.