Particularly dirty bases on new kids' skis?

[sparty]

I've got a pair of 70cm Atomic J2s that I'm trying to prep, and even after multiple hot-scrape cycles, I'm getting what appears to be significant dark "stuff" out of the base.

I don't think I'm just getting base material in with the wax; while it's hard to tell looking at the scrapings, it looks consistent with contamination in the base, and there's also dark goop left on the iron before I wipe it off as well as small debris floating to the surface of the molten wax.

So....is it normal for kids' skis to be dirty? Should I just get some base cleaner and try that?

 

[crgildart]

Is the iron too hot and burning the p-tex? If the wax is smoking TOO HOT!

 

[Jacques]

It is quite possible to peel base plastic when hot scraping.
I use Swix Glide Wax Cleaner. Not to be confused with wax remover.
You might be running the iron too hot? Graphite or moly wax will be black too.

 

[sparty]

Is the iron too hot and burning the p-tex? If the wax is smoking TOO HOT!

Nope, no smoking. I did three pairs of skis with the same iron and BP88, iron set at 130 deg. C, and no smoking on any of them until I turned the iron up for a CH5 coat (not on the J2s). I don't have a thermometer that will accurately read a metal baseplate, so I haven't verified iron temp, but wax behavior seems consistent with getting the temp right (melting easily on a warmed-up ski, but not smoking).

I was leaning towards the possibility of peeling base material, but I would've expected that to result in less dark material after a couple of passes.

 

[raytseng]

many kids skis especially at that super small size are extruded base not sintered so.... So if this guess is right, Id suspect its not contamination in the base so much as on the base, and also as such you can't really get wax into an extruded base, so unless you know for sure these skis will accept wax, you maybe wasting your time.

 

[sparty]

many kids skis are extruded base not sintered so...Id suspect its not contamination in the base so much as on the base, and also as such you can't really get wax into an extruded base, so unless you know for sure these skis will accept wax, you maybe wasting your time.

The specs at Evo describe them as "high-density sintered bases", so I don't think that's the issue. I'd feel more confident about that if I could find another source that agreed with the Evo description, but the Atomic catalog itself doesn't say anything about the base on these.

They also seem to be behaving about as I'd expect normal bases to behave when waxed; I thought extruded bases would be more obviously different, but it's entirely possible I'm overestimating the difference (I'm pretty sure that all of my skis except for my fishscales are sintered bases).

 

[cantunamunch]

I was leaning towards the possibility of peeling base material, but I would've expected that to result in less dark material after a couple of passes.

On short skis like that I could easily suspect that the previous wax was hiding a vicious case of friction-type base burn (abrasion). Which would keep coming up in the hot scrape wax.

The other notion is that the previous wax had significant additives that are clumping together when faced with BP88, but not really floating up in the melt. When I've seen this happen, it looked like dirty soapwater was mixed with the scraped wax.

Now that you've spent a few cycles of BP88 on these bases, I would try a hot scrape with cheap denser wax -CH6 maybe- to see if the denser wax can get more stuff to float up. Going to a CH5 would then be trivial.

Sure you can do the base cleaner/Fibertex thing but then you have to start over with the waxing. If you do that, check base flatness.

 

[Jacques]

Nope, no smoking. I did three pairs of skis with the same iron and BP88, iron set at 130 deg. C, and no smoking on any of them until I turned the iron up for a CH5 coat (not on the J2s). I don't have a thermometer that will accurately read a metal baseplate, so I haven't verified iron temp, but wax behavior seems consistent with getting the temp right (melting easily on a warmed-up ski, but not smoking).

I was leaning towards the possibility of peeling base material, but I would've expected that to result in less dark material after a couple of passes.

130 c is awful hot for a soft base prep. wax. IDK about Swix. The sure recommend some super hot irons!

 

[snwbrdr]

130 c is awful hot for a soft base prep. wax. IDK about Swix. The sure recommend some super hot irons!

That's what Swix recommends for BP88.

BP77 requires even higher heat to melt the base prep, 135°c

But BP99 is where you expect it, 110°C

It is quite possible to peel base plastic when hot scraping.
I use Swix Glide Wax Cleaner. Not to be confused with wax remover.
You might be running the iron too hot? Graphite or moly wax will be black too.

The petroleum distillate that makes up the Glide Wax Cleaner DISSOLVES wax. Why else would you be wearing gloves and a mask when you use it?

 

[Jacques]

That's what Swix recommends for BP88.

BP77 requires even higher heat to melt the base prep, 135°c

But BP99 is where you expect it, 110°C

The petroleum distillate that makes up the Glide Wax Cleaner DISSOLVES wax. Why else would you be wearing gloves and a mask when you use it?

I am aware of Swix temp. recommendations. That's what I was saying. Way hot.
The Glide Wax Cleaner softens the wax, it does not remove it or "pull" it from the base.
I have not hot scraped a base in many years.