Ski Builders Forum

today i stopped by the plastics store (Tap Plastics in Seattle) to pick up some thin 3/32" white ABS material to be used as tip-spacers. while talking to the sales person, i discovered that ABS is available in very thin sheets. the sales person showed me some of the stock. after glancing at the black colored 0.040" thick ABS material, i came up with the idea of using the stuff for topsheet material. the last time Kelvin and i were there we bought a thin sheet of clear polycarbonate material to use as a topsheet. we used the polycarbonate on the Kung Paoders, but it didn't stick too well to the epoxy, and as a result, delaminated rather quickly. but since the ABS material worked well as tip-spacers, i decided to purchase the very thin (0.040") ABS for topsheet. and so i bought a 4'x8' sheet. the cost was $27 for the sheet, which works out to be ~$12.11/m^2, which is cheaper than the standard topsheet material used by the snowboard industry, e.g., $16.70/m^2. anyway, i'm going to give the black ABS a try. my guess is that i'll have to rough up the surface that will be exposed to the epoxy to ensure that it sticks, but i have a feeling that it might work out pretty well. i'm working on building a new pair of skis this weekend using the ABS, so afterwards i'll talk about how it went.

Let us know how that goes. A bench test comparing adhesion between abrading the surface and use of a PVC primer would be interesting and possibly save you some time.

welcome jrad!

well, i'm not sure if the ABS topsheet is going to work that well. looking at the left-over scraps (after trimming our new skis), i noticed that the black ABS topsheet material peeled off rather easily. this is a concern. Kelvin and i sanded the material to abrade it before we pressed the skis. my guess is that the skis will delam quickly. anyway, i'll take the new Ahma BC's into the backcountry this weekend and see how they performance, and, of course, i'll keep an eye on the topsheet. i'll report back in a few days.

so, tell me more about the PVC primer. i'm interested....

kam

the asymmetrical sidecut looks dank, im sure youll get some comments and looks on the slopes
i did notice that the amha BCs are not as wide as the originals, please explain

Madriverglen: i wanted to make the Ahma BCs narrow to make the skis lighter for touring, but they didn't end up that way because they are almost as wide as the original Ahmas. but using maple and poplar mix sure helped.

btw, i took the Ahma BCs out this weekend for a tour in the North Cascades. they worked great!! i'll write up a report soon.

In order to get ABS and other thermo plastics to bond you have to flame treat them with for example a cheep micro torch you kan buy in any hardware store. Best is if the gas mix in it contains as much propan as possible. Don´t burn the plastic but give it a light yellow color, if its white. Otherwise you have to go by instinct.

Lennart: thanks for the info about flame treatment. so why does the flame treatment work? we flame treated some ABS topsheet material, but it caused excessive warping of the material. the topsheet was pretty thin, i think .040". we didn't try epoxying it, so don't know if the warping would have been a problem.

after putting some days on the Ahma BCs, here's what happens: the ABS topsheet chips easily and if not properly abraded for epoxying, the topsheet peels off, see (the notch cut in the tail of the ski is for skin clips)



the material also scuffs easy too. it's too bad that the ABS is too thin to flame treat to help it stick better to epoxy, otherwise it would be a decent topsheet material, if you don't mind the occasional chipping and scratching. personally, i'd use either p-tex (which has been abraded) as a topsheet material because it is fairly tough, or a special topsheet material such as the stuff that is sold through snowboardmaterials.com.

Why couldn't you flametreat the ABS? Did it melt?
I just ask because Isotop is flametreated ABS. And quite thin. Maby you can cool it from the other side while you torch it?

yeah, it's was a bit thin for flame treatment. it warped considerably. but that's not the major problem. ABS chips pretty easily, as you can see in the above photo. so it wasn't that great for topsheet material. the p-tex we've been using is much, much better. very durable.

Yes I can see that looks like chocolate.

I am a new ski builder, and am having trouble finding ski materials comapnies (ie: edges, P-tex, etc.). Can someone refer me to a company that might supply these types of materials?
Thanks,
Jake Quigley
Breckenridge, CO

hey jake, you can find some suppliers here: http://www.skibuilders.com/links.shtml

snowboardmaterials.com is a good option for beginners.