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Sanding Ski Bases

post #1 of 46
Thread Starter 

Here's how I'm prepping my daughter's brand new skis (Blizzard Viva Jr.).  Clearly, this isn't the textbook approach, but I'd like to hear some constructive criticism from experienced folks.  I'm not so much interested in the what and how as I am in the why.

 

1. Wipe down with base cleaner (Tognar citric/naptha blend)

 

2. Flat file with SkiVisions File Base Flattener, tip to tail

 

3. Sand from tip to tail using wet/dry silicon carbide sandpaper wrapped around a cylindrical "block" (Curv A Flex).  Progression: P80, P100, P120, P150.

 

4. Raise hairs by working synthetic steel wool from tail to tip.

 

5. Melt hairs using an inverted propane torch with a flame spreader, carefully.

 

6. Use SkiVisions Ski Base Flattener to remove melted hairs and impart final structure.

 

7. Establish 1-degree base bevel with a Sharpie and file (Vallorbe IceCut Bastard)

 

8. Establish 3-degree edge angle

 

9. Polish edges with variety of DMT diamond files

 

10. Wipe with base cleaner

 

11. Hot scrape 2x with universal hydrocarbon wax

 

12. Wax with Toko red hydrocarbon followed by light, hot scrape

 

That's where I'm at now.  I'll do final scrape/brush right before use.

 

My concerns are: (a) getting the hairs without melting pores in the ptex, and (b) will they ski fast enough.  I'm wondering if I should have added some aggressive metal roto-brushing after step 5 or 6.

 

Thanks.

post #2 of 46

Sounds ambitious and like you really care enough to make them the very best they can be.  However, wouldn't you like to assume that brand new out of the plastic the p-tex should be in ideal and optimal condition to synch up with the waxing cycles without needing to be sanded, resanded finer, etc...?  I can relate to flat filing since some skis do come concave or convex these days, re-doing the base and edge bevels after flat filing makes sense.  But, beyond that I'd think a few cycles of hot boxing would make them pretty fast without reducing the overall thickness of the p-tex and thus reducing the life expectancy of the ski.

 

Icksne' to the andingse' if I were you..

post #3 of 46

Are these the skis that were concave in one of your previous posts?

post #4 of 46
have you thought about wet sanding? it creates more gunk BUT will reduce the proliferation of hairs (have plenty of paper towels handy)

how about red, green, and white fiber pads instead of the synthetic wool?

also, perhaps a very sharp, flat steel scraper for rough hair removal followed with light pressure steel brushing may be safer than the torch...

plan on hot scraping a bunch if you wet sand...

just some thoughts smile.gif

zenny
post #5 of 46

I would not go anywhere near my skis with a propane torch for fear of permanently closing the porous base. If you must wet sand, scrape with a steel scraper and several hot scrapes afterward.

 

Karl

post #6 of 46
Quote:
Originally Posted by Xela View Post
 

Here's how I'm prepping my daughter's brand new skis (Blizzard Viva Jr.).  Clearly, this isn't the textbook approach, but I'd like to hear some constructive criticism from experienced folks.  I'm not so much interested in the what and how as I am in the why.

 

1. Wipe down with base cleaner (Tognar citric/naptha blend)

 

2. Flat file with SkiVisions File Base Flattener, tip to tail

 

3. Sand from tip to tail using wet/dry silicon carbide sandpaper wrapped around a cylindrical "block" (Curv A Flex).  Progression: P80, P100, P120, P150.

 

4. Raise hairs by working synthetic steel wool from tail to tip.    OUCH!

 

5. Melt hairs using an inverted propane torch with a flame spreader, carefully.   Major Ouch!

 

6. Use SkiVisions Ski Base Flattener to remove melted hairs and impart final structure.

 

7. Establish 1-degree base bevel with a Sharpie and file (Vallorbe IceCut Bastard)

 

8. Establish 3-degree edge angle

 

9. Polish edges with variety of DMT diamond files

 

10. Wipe with base cleaner

 

11. Hot scrape 2x with universal hydrocarbon wax

 

12. Wax with Toko red hydrocarbon followed by light, hot scrape

 

That's where I'm at now.  I'll do final scrape/brush right before use.

 

My concerns are: (a) getting the hairs without melting pores in the ptex, and (b) will they ski fast enough.  I'm wondering if I should have added some aggressive metal roto-brushing after step 5 or 6.

 

Thanks.

 don't understand.   Are these NEW, or new to her used?

 

Here is how I do old used.

 

Here is how I do NEW.  8 part video.

post #7 of 46

Why not a heat gun instead of a torch?  Really though, having your iron too hot when waxing ruins the bases.  I'd leave the p-tex alone and just hot box them if they are new.

post #8 of 46

Seriously? Propane torch to melt hairs??? Why bothering with all these unless you are doing some Youtube video of most ridiculous way to destroy skis. It would be easier if you would just take chainsaw and cut skis and throw them away.

Sandpapers are great to do kick wax zone on xc skis, so kick wax holds better, but they shouldn't really touch glide zones of skis (in alpine skis that's really whole ski ;) ). Stone grinding nowadays costs few euros/usd, and it makes things A LOT better then sandpapers. So try to find place, where they do stone grinding, put ski through this, and then continue with steps 7-12 skipping step #10.

post #9 of 46
Quote:
Originally Posted by primoz View Post
 

Seriously? Propane torch to melt hairs??? Why bothering with all these unless you are doing some Youtube video of most ridiculous way to destroy skis. It would be easier if you would just take chainsaw and cut skis and throw them away.

Sandpapers are great to do kick wax zone on xc skis, so kick wax holds better, but they shouldn't really touch glide zones of skis (in alpine skis that's really whole ski ;) ). Stone grinding nowadays costs few euros/usd, and it makes things A LOT better then sandpapers. So try to find place, where they do stone grinding, put ski through this, and then continue with steps 7-12 skipping step #10.

 

+1

 
Ya torching your skis is prolly one of the worst things one could do.  Second worst is sanding them.  A stone grind is the best treatment for your base, period.
post #10 of 46

    I've never tried it myself, but I have seen friends wet sand with automotive paper--they said the results were decent. I'm sort of going under the assumption that a quality grind is either unavailable close by or cost prohibitive?? for Xela, but who knows :dunno  The thought of a torch makes my skin crawl :eek.

 

    zenny

post #11 of 46

Let me approach this from an entirely different perspective!

 

Why the hell would you go through all of this on a brand new pair of Junior all mountain non-race skis.:confused:confused

 

Folks do some very weird sh_t when it comes to tuning. :eek

post #12 of 46
true dat!!! biggrin.gif

zenny
post #13 of 46
Quote:
Originally Posted by zentune View Post

true dat!!! biggrin.gif

zenny

 

I couldn't help myself! :o

post #14 of 46

This is a good example of why you should not drink anything stronger than beer when in the tuning shop!!!   :D 

 

Have you thought about skiing them over rocks to stone grind them????

post #15 of 46

What's funny is that I cruised right past the parts about using a blow torch on the bases and didn't even register them.  Then I saw people going :eek, re-read the OP and also went :eek

 

I suppose you could use a torch very carefully, and from a safe distance to do something, but that's kinda like using an atom bomb to blow sawdust off your bench hahaha..

post #16 of 46

Back when I was ski teaching I used to wrap sandpaper around a flat file and sand them, use a BBQ grill brush to give them a pattern and so on. It seemed to work well enough at the time but I wouldn't do that now what with the stone grinding equipment available. I can't imagine using a torch on them though!

post #17 of 46
Thread Starter 

Well, I'm getting approximately the ridicule I expected.

 

My experience with brand new junior skis isn't great.  They all seem to be out of flat in some way.  It may not matter too much, but it's also good tuning practice.

 

By the way, the torch thing comes from here, about 2/3 of the way down.

 

I guess I'm just a DIY guy.  I'm not really inclined to schlep my skis someplace where I'll pay enough for a decent dinner to have some teenager run them through a machine.  And, I like to keep as much base material as possible.  The filing and sanding seem to remove the minimum required.

 

The mess of wet sanding sounds like reason enough for me to avoid it.  We're not talking racing here.

 

Is there much difference between fiber pads and 3M #0000 white pads?

 

I'm not sure a heat gun would be hot enough to work well.  The point is to make a fast pass that will melt only thin pieces of ptex.  Ironically, the cooler heat gun would have to be moved more slowly and would heat up the whole base more.  I don't even know if these bases are sintered or not.

 

Yes, they are (were) brand new from the plastic.  But that doesn't mean they were in perfect shape.  The closer I get them to perfect now, the easier tuning will be during the season.

 

As for why?  Well, they needed some work and it's a hobby.  They're kids' non-race skis; so, not too critical.  If it goes well, though I may do this with adult skis.  I'm not the type to be superstitious about materials.  I prefer to understand their properties.  In this case, we're talking about plastic and metal.  I'm treating them with cutting tools, abraisives, solvents, heat and wax.  The goals are flatness, texture and sharpness.  The pitfalls should be predictable.  It seems that ptex hairs are the major boogey man and the torch is an attempt to address that.

 

I do most of my drinking when I'm not tuning.  I don't like to mix alcohol with sharp objects, power tools, solvents and (now) fire.

 

I guess we'll see how crazy I am when the snow comes.

 

Thanks for the feedback.

post #18 of 46
Quote:
Originally Posted by Xela View Post
 

I'm not sure a heat gun would be hot enough to work well.  The point is to make a fast pass that will melt only thin pieces of ptex.  Ironically, the cooler heat gun would have to be moved more slowly and would heat up the whole base more.  I don't even know if these bases are sintered or not.

 

If they're not sintered, /definitely/ do not use a torch near them.    It is way, way too easy to bubble up a part of the base and partly-burn it.   It winds up looking like the worst ptex candle job ever, with that sort of brown orangepeel texture, only stickier and permanently part of the base.

 

(OK, I'll confess I did this with my pine tar torch.   Once.    I tried to clean up the burnt bits with a base planer then razor blades then with a pansar file and gave up- too gummy and sticky).

 

post #19 of 46

As I wrote before... torch??? You are inclined to have some teenager run them through a machine, but you are perfectly fine using propane torch on them? I'm sorry but I really don't get it.

As for "keeping as much base material as possible" goes, sure stone grinding shaves off quite a bit of material, even more if skis are not flat, but you don't do this 5 times a year. Skis are fine for 5 stone grinds for sure, which means for normal people 5-10 years. Are you planning your daughter will use these skis for next 10 years?

post #20 of 46
Thread Starter 

I get the sense from many of the responses that people are thinking "flamethrower" when I say "torch".  It's one of these.  The entire process takes around five seconds and the bases are barely warm afterward.

 

Primoz, this probably isn't surprising, but I trust myself with a torch more than a teenager with a machine.  If you can't trust yourself, who can you trust?

 

Maybe my daughter won't need all that base material, but I have another daughter, and friends with kids.  The skis should have a long, useful life before they end up in the landfill.

post #21 of 46

I know how these torches are (I have been using them years ago to "soften" xc ski waxes, klisters in particular) so no I don't think about them as flamethrower, even though it would be cool view to see you do this with flamethrower :D
But thing is, there's no point in doing this at all, except damaging ptex... even if it's not flamethrower. I have no idea if I will manage to explain this, since it's most likely too much for my English but let's still give a try. Let's forget all about damaging base etc., and concentrate just on end effect. When you burn/melt those hairs, material doesn't evaporate, but it stays there. So those soft hairs are gone, but you have 100.000s of small and hard spikes now. You melt that hair, which sort of collapse and form little spike, which you most likely won't see and you won't even feel with your hand, but they are there, and they don't help when skiing ;)

But if you really think doing skis with sandpaper and then "melting" hairs with torch is better then some "kid stone grinding" them, it's fine with me ;)

post #22 of 46

I wonder if heating the bases in this way opens the pores to accept more base wax? You could be on to something.

post #23 of 46

One of the most entertaining posts I have read in quite a while. I love this place!

post #24 of 46
Quote:
Originally Posted by Xela View Post
 

I get the sense from many of the responses that people are thinking "flamethrower" when I say "torch".  It's one of these.  The entire process takes around five seconds and the bases are barely warm afterward.

 

Primoz, this probably isn't surprising, but I trust myself with a torch more than a teenager with a machine.  If you can't trust yourself, who can you trust?

 

Maybe my daughter won't need all that base material, but I have another daughter, and friends with kids.  The skis should have a long, useful life before they end up in the landfill.

 

Actually skis do not need to be totally flat. As long as they are flat about 10mm in from each edge they will ski absolutely perfectly. Grinding, sanding or otherwise trying to remove additional concavity (I assume they are concave not convex) will do nothing for the ski's performance except shorten the life of the bases by removing too much material.

 

Fibertex on a roto-brush is a much safer and more effective way to remove any hairs from grinding or sanding. By the way both my boys raced at Junior Olympic Levels up to and including FIS J1 in all four events and I never did anything even close to this folly you have described. Or more recently as a master's racer, my older boy ran the fastest run of the day on skis I prepped. No torching or sanding on his Atomic GS ski!

 

Many machines today, ie, Montana, Wintersteiger, have no human interaction when actually grinding the skis,  the skis are placed in a cradle and the machine does it all; a push of a couple of pre-programmed buttons and the machine does the rest.

 

all this goofy sanding and torching, to make a junior all mountain skis "faster"? Faster than what?

 

How about this, You having a conversation your daughter,before torturing her new skis and let her ski on them first.  "Honey, how do  your skis feel"?   "Gee, great dad!  Thanks for doing a minimal wax  job on 'em and checking with me before you torched them! They feel great and they have just the right amount of glide, I don't like them too slippery they kinda run away with me!


Edited by Atomicman - 9/26/13 at 9:14am
post #25 of 46

^^  So true that a base does not need to be perfectly flat.  Many skis have taper in the tips and tails.  That's the way they are made.  True a deep pocket will cause suction, but a bit of concavity that smoothly transitions without a pocket will be fine too.   Okay, I gottta' go to w**k!

post #26 of 46
Quote:
Originally Posted by Jacques View Post
 

^^  So true that a base does not need to be perfectly flat.  Many skis have taper in the tips and tails.  That's the way they are made.  True a deep pocket will cause suction, but a bit of concavity that smoothly transitions without a pocket will be fine too.   Okay, I gottta' go to w**k!

 

Thumbs Up   :D

post #27 of 46

 
A blender could also take care of those little hairs/fibers in the p-tex

 

post #28 of 46
Thread Starter 

You guys are great for keeping with this.

 

Primoz, I think the point of turning the little hairs into little blobs is that they're more likely to come off when scraped.  I have no desire to leave them there.

 

While I realize that bases don't need to be 100% flat, I do like to get them reasonably close.  This helps because my sharpening guides index off the base.  Fewer surprises.

 

I really appreciate the guidance toward the metal scraper.  I'm going to spend some quality time getting acquainted with my Sandvik.  I think a metal roto brush may be in my future, too.

 

A lot of people are recommending pads.  Should I be looking at Omni-Prep or Fibertex or some 3M product.  Or are they the same?

 

Finally, I'm not trying to make the skis faster.  I'm just aiming for a known initial state to start the season.

 

Thanks again.

post #29 of 46

You should be aiming to make the skis go faster, I think. They will ski so much easier.

post #30 of 46

   Xela, Atomicman is correct in that as long as the concavity is confined to the center of the bases near the tip and tail and the outer 10 mm's near the edges are flat you are good to go. Have you scoped these skis with a true bar yet? If they fall within these parameters I'd leave them alone...

 

  Metal brushes are great but as with any brush light to medium pressure is all you need--it's the tips of the brushes that we want on the ski and in the structure. Excessive pressure will bend the bristles rendering the brush less effective. Generally, your metal scraper will work the top of the structure, metal and other brushes the bottom, and fiber pads a bit of both. 

 

  3m or fibertex both work well. Speaking of fiber pads, I use these in a roto set-up:

 

http://www.svst.com/ItemForm.aspx?item=ROTO8&Category=219d76d6-ed93-4284-9fa6-8fa5cb5253fc

 

ROTO8LRG.jpg

 

    They work great and are easy to use. The purpose of all of this as I'm sure you know is to smooth and refine the structure of the ski, removing hairs in the process. This will make them "faster" which as oison points out makes them easier to ski.

 

   So again, I would really recommend re-evaluating the flatness of these skis and weighing the pros and cons of major base work. I am curious--where did you hear of this idea to "melt" the hairs with a torch?

 

   zenny

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