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filling in negative fishscales

Posted: Fri Jun 18, 2021 10:25 am
by riel
A while ago there were a whole bunch of cheap Asnes Sondre skis on eBay, some of which were nearly smooth on the bottom, and many of which had negative fishscales cut into them. I ended up with two pairs, a 210cm pair that was almost smooth on the bottom, and a 200cm pair that had fairly deep negative fishscales in the bottom.

I ended up skiing the 210cm ones a lot last winter, while the 200cm skis sat in the basement with the idea that I might turn them into skin skis at some point, or do something else with them. After this season ended, and I looked back at just how much fun I had with kick wax, I decided on something else. Fill in those negative fishscales with ptex, and make these skis waxable, too!
skiwithscales.jpg
one smooth-ish, one still with fishscales
How did I do it? Follow these simple steps:
1) Brush out and roughen up the negative fishscales.
2) Light a ptex candle, and drip ptex into the fishscales. How much ptex? TOO MUCH PTEX!
3) Wait for the ptex to cool and shrink, see that it wasn't quite enough.
4) Scrape off the excess that's already there.
5) Light another ptex candle, and melt more ptex into the remaining holes.
6) Wait for the ptex to cool and shrink, again. Maybe this time there's enough?
7) Fill in a few more last minute remaining divots.
8) Scrape the excess ptex again.
9) Some more light scraping to smooth things out.

It almost sounds like more work than it was...
smoothskis.jpg
both are nice and smooth now

Re: filling in negative fishscales

Posted: Fri Jun 18, 2021 1:20 pm
by Stephen
I was thinking the same thing for a pair I have and wondering if a base grind after all the p-Texing would be worth it?
Also, I was thinking to pass a flame over the fish scale, before the p-Tex, to improve adhesion.

Re: filling in negative fishscales

Posted: Fri Jun 18, 2021 2:05 pm
by Woodserson
Remind me, what did we say the Sondre's were like? A softer Amundsen, almost same dimensions, but stiffer than the Nansens... Was that it?

Re: filling in negative fishscales

Posted: Fri Jun 18, 2021 8:19 pm
by fisheater
Nice job Riel!

Re: filling in negative fishscales

Posted: Fri Jun 18, 2021 8:59 pm
by riel
Stephen wrote:
Fri Jun 18, 2021 1:20 pm
I was thinking the same thing for a pair I have and wondering if a base grind after all the p-Texing would be worth it?
Also, I was thinking to pass a flame over the fish scale, before the p-Tex, to improve adhesion.
Most of the fishscales are in what will be the kick zone, anyway. I plan to just iron in base binder or polar wax to smooth out the last few dimples in the base.

As for the flame, I just held the ptex candle close by the skis while it burned. Close enough that it might do what you suggest ;)

However, roughing the base of these fishscale gouges with a metal brush, and then cleaning that out with a soft brush might help more with adhesion, since that gives more surface area for the new and the old ptex to bind. Passing a flame over the base might reduce the surface area available for the two to bind, interfere with wax adhesion afterwards, and potentially reduce how well the base is bonded to the core of the ski.

Expect to use close to one and a half sticks of ptex per ski.
Woodserson wrote:
Fri Jun 18, 2021 2:05 pm
Remind me, what did we say the Sondre's were like? A softer Amundsen, almost same dimensions, but stiffer than the Nansens... Was that it?
Let me rate them with some other skis that we have both used :)

K&G speed: Traverse 78 < Ingstad < Sondre < Gamme < MT51
Turning: MT51 < Sondre < Gamme < T78 / Ingstad (depending on conditions & terrain)
Stability at speed: MT51 < T78 (chatter) < Sondre / Gamme < ingstad (depending on conditions)
Edge hold in hard/icy conditions: MT51 < T78 < Ingstad < Sondre / Gamme (Sondre maybe better?)
Flotation: MT51 < Sondre / Gamme / T78 < Ingstad (don't know how the middle ones rate against each other, Gamme may be better than Sondre & T78)

I hope these ratings also make it clear why I'm thinking of getting Gamme skis for the coming season, since those are a step up from the Sondre skis in many ways, without ever really being worse at anything (except price).

Whether I get a pair of Otto Sverdrup skis as well will depend on where they fit into the quiver compared to the other skis. If they provide better K&G speed, stability at speed, edge hold, and turning than the Ingstad and the T78, they might become a ski of choice for when I need more turning and float than Gamme can offer, but want more efficiency than Ingstad and T78 can offer...

Re: filling in negative fishscales

Posted: Tue Jun 29, 2021 5:29 pm
by fgd135
That's a lot of work; I saw those cheap skis on fleabay and decided to pass, seems an interesting project at least.
Some ski shops will completely replace bases, or do the repairs needed on butchered bases like on those Sondres, using a full base extruder followed by a base grind. It's really something to watch! Automatic feed, coat, grind.
Ski rental shops are the big customers for that kind of work, as it keeps their (alpine) rental fleets usable for more than one season.
The extruded material adheres much better than the ptex candle method, as there's no carbon from burning, which can prevent long term adhesion.
It's probably expensive to have done for just a single pair of skis even if you can locate a shop that has the machinery...and the skill to do it correctly.