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Base repair failing

post #1 of 20
Thread Starter 
I got a core shot a few weeks ago (around 1/9) and tried to fill it with a ptex drip candle, but that only lasted 2-3 runs.  I was not too surprised since the damage is right along the edge, directly under the front of the toe of the binding.  As such, I took it too a respectable shop in the area and had them repair it.  The work was done on 1/14, but starting on 1/30, the repair started to fall out and after today (2/2) there are now 2 places where the repair is falling out.  Is this a sign of a sloppy repair, or is it to be expected given the location of the damage?  The yellow is obviously the places where the repair has fallen out, the red is the entire repair that the shop did?

I tried filling the holes with ptex and hard wax, but neither held for more than a few runs.  This is on my SL boards and I have a race this upcoming weekend, so does anyone have any suggestions on a temporary fix to get me through the day?  Do I need to be concerned about my edge getting ripped off if I dont get it repaired by this weekend?

post #2 of 20
The thing is that P-tex sticks to itself / bases pretty well, but doesn't stick that well to metal.  You need a different material.  This is what I use:
http://www.slidewright.com/proddetail.php?prod=LK20902M
It is a little tougher to work with than regular p-tex in that you should use a base welder or base repair iron.  You also need a shaver thing and really sharp scraper to make the repair come out nice. 

A good shop has this stuff and knows when to use it.  Sometimes though, even at a good shop, you get a rookie fixing your gear.  It pays to speak to the tech and make sure.  I mean it is your gear so you should sort of interview anyone who is going to do the work if it is anything beyond a wax and sharpen (and even then in most cases). 
post #3 of 20
Ideally, the repair area needs to be clean and free of anything that will conflict with a positive bond. Ptex candles contain wax and when you make repairs the temperature of the area needs to be heated up to be close to the temperature of the repair material to avoid a cold joint. Burning candles adds carbon and is inherently a weaker bond than welding. The small size of the repair may also add to the difficulty. Some people have reported decent results soldering/welding ptex candles when pure HDPE is not in hand. You might try this if short on time and options.

The metal grip is heat actuated adhesive and bonds better to core and edge material and serves as a primer for the final repair material and seals the core better. The base repair material bonds better to metal grip than epoxy. Since it is a small area epoxy may be an option to consider. The edge is held by screws, not the base material and keeping the core sealed is most important and the size of the repair really may not affect the glide much (though less than ideal) for the short run.

Here's our weblog section on Base repair and Prep with some more background and some 'How to' examples.
post #4 of 20
Mondak - many thanks for the SlideWright link - they have some really cool stuff, and I have not heard of them before. I bookmarked them!
post #5 of 20
100% CORRECT ON THE 30 SECOND INTERVIEW MENTIONED ABOVE.

Furthermore, some times it is necessary to remove more material away from the edge of the base to do a repair like that.

Another trick or two (only to be done by some one with experience on a wood core ski, is to put 1 or 2 small staples into the wood core to give the P-Tex something to grab onto to hold it in place. Or sanding/roughing up the inside or flat anchor surfaces of the edge with sand paper to scratch it and give the repair material something to grab onto.

It is very very necessary to get any and all contaminants off the area to be repaird including wax, ski dirt, film from melted snow water, etc. This should be done with Denatured Alcohol or Acetone.

Finally, the last thing that can make this a real good repair, is after doing the large area repair, have the ski run through a base repair extruder that will heat the entire base and extrude a special P-Tex layer over any and all imprefections (this helps to seal the entire area around an edge base repair)  These machines are expensive and not very many shops have them... Usually Big Metro Shops have one.

Hope that helps...

And even after all that it still can break out on you.
post #6 of 20
Quote:
Originally Posted by bosrocker51 View Post

Mondak - many thanks for the SlideWright link - they have some really cool stuff, and I have not heard of them before. I bookmarked them!
No problem!  They are a great resource for sure.  His blog shows how to weld with a base repair iron in a video somewhere and it is really good.  I buy all my stuff from there for my ski tuning "hobby"
post #7 of 20
Yep, SlideWrite or Tognar can get you the stuff you need, copolymer, etc. I've repaired a couple of core shots recently and have had good luck with the hard base repair ribbon. You need a base reapir iron to apply it but it works nice.
post #8 of 20
Thread Starter 
I have been looking at various base repair irons and I have been leaning towards the soldering iron type for the broadest application options (ribbon, wire) and lower cost; however, I still feel that there must be a way around the $40 low temp soldering iron which would go for $20 at home depot.  Has anyone used one of the multitemp soldering irons such as www.electronix.com/catalog/product_info.php/cPath/331_333/products_id/15011?  (dont know if that one is any good, just a concept)  How much will the tip size effect my ability to perform successful repairs?
post #9 of 20
My experience is that PTex will fall out of holes this size more rapidly than when not along edge.  Your choices are to continually fill the gouge or have a base patch repair performed.  A base patch is essentially a new patch of base material epoxied in place followed by base grind and tune.  It should be a permanent repair.

Below are pictures of a base patch.  The first shows the affected area with the old base material cut out and ready for a new patch.  The new patch material is sitting on the ski beside this area

Section cut away and new patch material

The next picture shows the ski after the completed repairCompleted repair

Mike
post #10 of 20
Thread Starter 
Mike,

Do you have to bond the edges of the repair to the surrounding material?
post #11 of 20
Smoth

In this repair after removing the old base material and cutting the patch to fit you lightly sand the core (metal in this case) for adhesion and then I wiped with acetone - probably something better but is what I had.  the wipe down removes oils, etc... but I worry about its affect on the remaining base material so is very light.  Then I use a two part epoxy - in this case West System with the fast hardener.  I use this because it is good stuff and because I have it on hand for my boat...

Once the epoxy is mixed I put it on the base in the affected area.  Then I put the patch in place.  Note that when pushing the patch into position the excess epoxy oozes out around the patch filling any voids (this answers your question I hope).  As celophane wrap does not adhere to epoxy I wrap that around the ski in the affected area (after first taping sides of ski) and then place a metal scraper over the base over the celophane and clamp.





The above pictures show the area wrapped in celophane and the taped sidewall.  The clamps have been removed in the second picture after 24 hours and then the ski sits an additional 24 hours.  The West epoxy I use has a cure time of 24 hours and full cure of 7 days.

Once it has cured for 48 hours I use body file to remove any excess epoxy and then I take to a local shop I trust for a base grind.  This last step is not completely necessary but improves the look and structures the base.  I am thinking the Ski Visions base flattening tool would also work for this.

The excess epoxy bonds to all areas beneath and surrounding the patch.  It is a much more permanent repair than filling with PTex.  This is the process that shops follow for these repairs when they require it as well....

It can be done at home but if you screw up that could be bad ...

Mike
post #12 of 20
Thread Starter 
Is there a minimum size for the repair?  I see that your piece looks to be several inches long (maybe 5).  Is that necessary, or would it be alright just to cut out an area maybe 1/2" more than the damage?
post #13 of 20
My repair shown in the picture was large.  probably larger than it should have been.  I sispect a minimum size is required for proper adhesion.  The patches are usually cut in half moon shape as well - usually with a cutter made for that purpose. 

There are probably some shop techs here who can provide more information.

In my case I just asked at a local shop who I worked with and the head tech described the process and gave me the base patch material.  Since I work with epoxies all the time it was pretty straight forward.  Note that I have only done this twice but would not hesitate to do it again for repairs along an edge.

Mike
post #14 of 20
Note - for now I would just keep filling that hole to see if it will take.  Use taht as the outside edge to put the edge at less risk

Mike
post #15 of 20
Quote:
Originally Posted by mikehoyt View Post

My repair shown in the picture was large.  probably larger than it should have been.  I suspect a minimum size is required for proper adhesion.  The patches are usually cut in half moon shape as well - usually with a cutter made for that purpose. 

The kits come with die cut patches and a stainless steel template. You clamp and cut the damaged area with a utility or other sharp knife.

dcpb_th.jpg bt2-no-bars.gif
post #16 of 20
Thread Starter 
I have already filled it 4 or 5 times since the shop repair just to make through practices/races.  my last race is tomorrow, so next week I will have more than 2 consecutive days when I do not need the skis, so I will try a more permanent repair and still have a few weeks of skiing to test the repair. 

The price on that steel stencil is ridiculous.  $30 for what amounts to a piece of steel with some generic cutouts.  Needless to say, I will be making my own.

Any suggestions on a good epoxy that can be bought in reasonable quantities (5oz for under $15 shipped would be nice)?  I looked at the West System stuff, but it looks like you need to buy in bulk
post #17 of 20
And I ask myself why I keep spending my time trying help out ungrateful skiers....knock yourself out on round 5. I'm going skiing with the repaired core shot that took 15 minutes to fix long term with the right tools the first time.

Quote:
Originally Posted by smoth View Post

I have already filled it 4 or 5 times since the shop repair just to make through practices/races.  my last race is tomorrow, so next week I will have more than 2 consecutive days when I do not need the skis, so I will try a more permanent repair and still have a few weeks of skiing to test the repair. 

The price on that steel stencil is ridiculous.  $30 for what amounts to a piece of steel with some generic cutouts.  Needless to say, I will be making my own.

Any suggestions on a good epoxy that can be bought in reasonable quantities (5oz for under $15 shipped would be nice)?  I looked at the West System stuff, but it looks like you need to buy in bulk
post #18 of 20
Thread Starter 
Given that I currently do not own the tools needed for the job and have no way of obtaining them in the next 3 days, I have time to consider my options.  As a college student, money is already very tight, so if there is a way that I can save $20 for an extra hour or two of work, I will be all over it.  Just because you have the money to purchase the specialty tools and/or have them on hand before you encounter a problem, does not mean everyone on this board does.  This is the first time out of the past 5 years of skiing that I have had a base problem that is larger than a minor scratch.  Please do not take it as though i am ungrateful for your help.  Just because I do not want to spend the money on the product you suggest does not mean that I will disregard your suggestion, I will just look for a less expensive alternative.  As I said, the stencil is just a piece of steel with some arbitrary cutouts.  I can probably get a piece of metal scrap from someone who works in the prototyping lab at school and go cout out some curves with the school's dremel. 
post #19 of 20
Smoth

You can cut the patch material using any curved item as a guide. Is just trickier.  The $30 for teh package described is a great price because it also includes the base material and all you need is epoxy.  Given that the epoxy costs more than that you are better off having a patch done at a shop since you will not be doing this more than once.

In my case I maintain a fleet of demo skis and skis for 5 people in my family as well as those of friends.  It would be worth my while to have this kit.  Also I have a lot of tools accumulated over 25 years and a shop bench set up in my house.  I also have a boat where I am constantly using epoxy.

For now just keep filling the gouge and keep that edge on outside.  Once you scounge up some moeny get a base patch done at a shop.  Cheaper in the long run.  Also a lot cheaper than a new pair of skis which is what you may need if you catch that edge on something and damage the ski.  P-Tex always erodes out of any fill and sometimes this is faster than others.  Think of this as part of your ski tuning ritual and you will be fine.

Mike
post #20 of 20
Just because you are a 'poor college student' (who still has the time and can afford to ski) does not mean you shouldn't consider a better choice of words.

FTR, I was simply providing the image and a brief explanation of a template option of a previous post, which is one of many approaches you can take. The soldering iron core shot repair seems very appropriate for the repair image you initially posted and a repair patch seems like overkill. YMMV.

Some other descriptions (plus try searching for others):
-Base Repair Options Wiki
-Base Repair Welding versus Dripping Napalm (see different irons)
-Base Repair Technique page

It won't be the last ding you will receive and depending on coverage and frequency, you will need to get repairs done eventually. I've had two this season, along with some deep gouges. Depends on where you ski and the conditions. Off Piste and steeps equals more repairs.
Edited by Alpinord - 2/13/10 at 8:14am
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