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Base Repair

post #1 of 25
Thread Starter 
Since I am a tuning freek I figured I would start another thread.

I was just repairing my wife's ski bases after she hit a whole patch of rocks sideways last weekend on skis that were just stone ground. Yeah it was early season but skis are meant to be skied. Plus what would I do with all my tuning gear.

I used to use drip candles and a mini torch when I first started doing base repairs. I used to repair every scratch just for fun.

Now I use a p-tex iron (looks like a soldering iron) with different tips and repair/metalgrip string or ribbon for major damage. I only repair deep gouges and sideways slices if they will affect the skis in a way that I would notice.

Here are my normal steps. I feel the base with my hands to see how bad the hits are. If they are deep enough or on the edges I clean the damaged area and scrape it with a metal scraper to flatten any pushed up p-tex from the rock damage. I heat the repair string with my ski specific p-tex iron into a thin layer (too much tends to pull the whole repair out when scraping) and press it in while heating the original base material. If the p-tex is missing from the edges then I use metalgrip repair string. I use a steel scraper to press in the molten material and then use the scraper or a surform to flatten the repair after it cools for awile. I also take off any minor hairs that may have formed from light base scratches that wasn't repaired.

I was just wondering what you guys use, the steps, and how often you do base repair work?
post #2 of 25
Scalce, I have been relying on ski shops to do my grinding and tuning. Used to do it myself, but got out of the habit. The results just are NOT there for me. Could you put together a list of recommended supplies for premium ski tuning. Objective, is to get up to speed and get this done right.

As to your original thread my techniques were so primitive when I did it my self, I cannot answer as it would tend to incriminate me. Not only that, but in most matters I am a very accomplished DIYer. I am even a moderator on Bob Vila's board (see tomh). How about a shopping list!
post #3 of 25
I used to use a lot of candles, now I only use them for detailing when the snow is soft. They just wear out in a day.

I love the metal grip and use it with the iron on most big gouges. I f they aren't deep enough for the metal grip they can be 70% removed with the scraper and file.

I have had great luck glueing in a strip of ptex. Whenever I break a cross country ski (often)I strip the base off and get a nice piece of ptex with some glass backing whick glues in well.

You are right, skis are meant to be used. I have a couple I keep perfect and some I will saw in half to fit in the trash next time the saws-all is out. Had some great runs on the sawsall specials.
post #4 of 25
Thread Starter 
Originally Posted by Cirquerider
How about a shopping list!

I have everything on the site with a red * plus the steel scraper, repair ribbon, and drip candles.

Also if you don't already have a plexi sharpener then I would get one as it can sharpen the steel scraper as well. Just using a file works but it works better when there is a 90 degree lip on the sharpener to give a nice sharp, even edge on the scrapers.
post #5 of 25
Thanks, This time of year I'm often asked if there is anything I'd like that is "reasonable" in price. Looks like some good candidates on this list. What file guide do you suggest?
post #6 of 25
P-Tex candles for me. Haven't had any real problems with my repairs, and 75% of them have held.
post #7 of 25
I prefer the P-Tex ribbon and iron. Candles are a good temporary fix, but if I'm going to do it at all I prefer to do it once.

And, if you want a sharp metal scraper you should look into how to sharpen a scraper for woodworking.
post #8 of 25
Thread Starter 
Originally Posted by Cirquerider
What file guide do you suggest?

I have this from a while ago but I know some people who just use a file screwed to a bench.

I prefer something that is specialized for sharpening even though this is only plastic with a small panzar file.

I'm pretty sure there are cheaper ones.
post #9 of 25
I've always wondered: Why bother with p-tex candles? The repairs look terrible (mine were always full of carbon), and the material doesn't stay put.

The other option, buying special guns or irons and mail-ordering huge reels of plastic, never appealed to the MacGuyver in me.

Instead, I've had success for years with 2-part 30 min. epoxy, clear or black. You can fill giant gaping voids--which I generate with alarming frequency in my quivering bases--at about $0.50/shot, and without any specialized tools or hard-to-obtain materials.

All the prep, post-patch planing/scraping, and the rest is the same, but you can do it anywhere, anytime (at the condo or cabin, for example, or on the road). And the epoxy seems to accept wax just fine.

The only downsides that I've come up with so far are:
1) You have to let the patch sit overnight to set up thoroughly, and;
2) any spot you patch is destined to be softer than the surrounding factory p-tex by a slight margin.

Anybody else tried this and found an achilles heel that I'm unaware of?

post #10 of 25
post #11 of 25
One cool thing I read about and made for myself is a roller to press the ptex in. They sell them for a lot of money. I took a metal scraper and bent it around a jar to make it about a 1/2 of a circle. Then taped the ends so I can hold it. I use that to press the p-tex in. This year I just bought an extruder gun, we'll see how well that works. in initial testing it's good, but puts an awful lot of ptex down compared to candles. It doesn't smoke and create carbon, or poison me either.

Anyone else use an extruder gun have any comments on it?
post #12 of 25
Thread Starter 
Originally Posted by ShawnB
Anybody else tried this and found an achilles heel that I'm unaware of?
Epoxy doesn't absorb wax like p-tex.
post #13 of 25
Thread Starter 
Originally Posted by SkiMangoJazz
Anyone else use an extruder gun have any comments on it?
Damn man

You're more of a gear whore then me.

Keep me posted on how the gun works.

The drawback of candles and irons is that you inhale the fumes which I assume can't be great for you.
post #14 of 25
Originally Posted by Scalce
Damn man

You're more of a gear whore then me.

Keep me posted on how the gun works.

The drawback of candles and irons is that you inhale the fumes which I assume can't be great for you.
I guess so, but I haven't bought any moonstones yet so you got me there

I installed an exhaust fan in my garage/tuning area so as not to inhale those fumes. That's some bad stuff to breathe.

As to the gun it was $130. My candle repairs just keep falling out. I still think I'll use the candles for small gouges and the gun for bigger ones.

An old time tuner I know always said to do p-tex with candles iin multiple passes rather than trying to fill the hole all at once. He also doesn't let the stuff dry very much before scraping it off the surface. He taught me a very good body position where your elbow is to the inside of the table side of the ski and your hand is basically like writing with a pen moving down the ski. Gives a lot more control that way.
post #15 of 25
That p-tex gun is a GREAT idea! I think I'm gonna pick me up a hot glue gun to mod for that!

Further on with base repairs..

At work, we use a p-tex welding iron, burning candles, and something that hasn't been touched on yet...the hot air method.

The thing's about 6 inches around, heavy, and a foot long, with a metal and green plastic body. It actually heats air to 650*F, and blows it out a thin nozzle in the end, so you can melt the p-tex, heat the area around where you're adding, and control the works a whole lot easier, without creating carbon.

The flame method works great, it's just a matter of learning to control the flame so carbon doesn't form.

Scraping the excess from any of these methods is often done wrong...

I always let it harden as much as possible, then using a VERY sharp stainless scraper (sharpen it up before and during every job!!) take long, light passes over the ptex. The idea here is to shave the excess off in thin amounts, so you are left with a final product that is smooth, level, and solid.

Then, depending on the extent of the repair, I'll either take the ski to the belt, or touch it up by hand with some sandpaper, and then finally, wax it really good.

A proper repair should be smooth, nearly invisible, and last a long time, with no chance of falling out.
post #16 of 25
Has anyone else tried "cleaning up the edge" of the gouge with a razor blade. I have found that the P-Tex candles (yeah I'm too cheap to buy a gun) hold much better if I "clean up" the edge of the gouge, providing a better surface for the candle P-tex to fuse with the base.

Also, another thing I have done when dealing with larger scale base repairs is the take the razor blade and undercut the base, cleaning the edge of the damage and providing a locking point for the repair, the only thing I have had to do with this method is make many passes with the candle, and drip in many small layers.
post #17 of 25
That's exactly what I do also, Manus.

I cut around the gouge, making the torn edges as regular as possible--this makes the filling much more predictable and practically rules out air bubbles gripping onto rough spots in the base mat'l, as is their wont.

All cuts are back beveled into the base, mechanically "keying in" the patch. This way, the summbicch t'ain't never comin' out, see.

And I agree with Scalce; he's right that epoxy does not have the exact properties of p-tex, and in the long term undoubtedly won't hold wax as well. But it does hold it. To wit: I just examined my oldest boards, each with about 5-8 epoxy patches <:> , both BIG and small. The skis had been hot waxed, scraped down, and skied for one day. Wax is generally missing about 0.5 - 1.5 cm in from the edges, on both p-tex and epoxy surfaces; wax is generally present throughout the center, on both p-tex and epoxy surfaces--to the same degree. The wax retention rate may differ, but not by too terribly much...

So don't worry, wax doesn't just fall off epoxy. And epoxy fills all in one go, scrapes down super flat, and is easy and cheeeeeap.

Probably not for your race skis! But for any other use, I personally don't bother with any other method. Most days I ski, I whack a rock or three, but I've kept my various skis flat, true and slippery for about four years now, spending a total of about $11 in doing so. I just wish I had as good a method for rehabilitating my poor edges.

In the end, it's just one more way to skin that particular cat. No offense to anyone else's methods taken, I hope...

post #18 of 25
Rookie tuner here. I put two pencil eraser head sized holes all the way through my base material. Some base material is sticking up and needs to be planed down.

It sounds like for holes all the way through the base material that some people have had some success with just ptex, especially if you use a razor blade to help the ptex find purchase. Any other suggestions/thoughts on this?

What do people advise for planing down the base material that is sticking up out of the holes?

post #19 of 25
For planning down the base material that was smashed up...just use your razor blade. But be carful not to press to hard and make a huge side cut by mistake. To help the p-tex hold try ruffing up the insides of the hole with the exacto for me .

I actualy do the opisite of cleaning up the gouges to make the p-tex hold. I do clean out any crud or rock fragments (so there is just base material in there) and then hit the section with some dewaxer to get out any oils/wax or what not out. But i actualy try to ruff up the insides of the gouge with my razor blade...i make little "hooks" and "ridges" to give the p-tex a less smooth surface to adhere to (if its a really sketchy section i'll heat it up a bit with the torch before dripping in the p-tex). But if your way works assume don't change it... just my 2 cents.
post #20 of 25
Nice thread resurrection...

Best for re-flattening the base:
1. Stone grind, but the whole ski may not need it
2. Base flattener - like the SkiVisions tool - does a nice job on this stuff
3. Surform blade - be careful not to introduce new gouges or make the current one bigger
4. Metal scraper - could take a lot of work, but does the job (make sure you put a cutting burr on the edge of the scraper first)

For the base fill I recommend:
1. Copoly first - this is P-tex with some epoxy. Use this as the first layer after "roughing" up the inside of the hole (x-acto knife works best)
2. P-tex ribbon melted in with an iron - do this with multiple thin layers on top of the copoly. Don't try to do it all at once (kind of like painting in multiple coats).
3. Patch press - this is the large metal "block" that can be "rocked" over the patch to provide pressure while the P-tex patch cools. It ensures a strong bond without bubbles.

Deep gouges (or core shots) really aren't well served by P-tex drip candles. The patch will not be as strong and will either fall out or shrink up so that it requires multiple re-repairs.
post #21 of 25
Noodler, you bring up some good points, especially about pressing the P-Tex, however, you mentioned Copoly (I've never heard that term), but what you are describing is basically what is used to perform a Base Weld (When there is contact between base repair and edge material, the heat conductivity can create issues with proper hold, but the welding material has epoxy to grab the metal as well as the P-Tex base material).

Noodler, as for your recomemdation about the metal scraper with a cutting burr, use caution here, same as trying to flat-file with a ski file, general pressure created by the hands will actually create a bending in the material (file or scraper) causing the ski to not be flat (with a file, the natural bend is typically just shy of 1 degree - in terms of creating a base bevel). I would be VERY careful when using a metal scraper to flatten the ski as it can be VERY tricky.

D-Rock, for what you were saying about base planing with a razor blade, with a light touch, a razor scraper (like a paint scraper with a razor edge) works well, or if that freaks you out, a planing blade (like from a wood plane, a lot of little razor sharp cutting blades) again with a light touch works well to "plane" the base back to normal works well.

Now in terms of scuffing up the edge before P-Texing, basically its doing the same thing as undercutting. You are creating a greater surface area for the P-Tex to grab a hold of. The only difference, basically, is that undercutting locks the repair in, scuffing will typically only create a greater amount of surface area for the P-Tex to grab a hold of. The one thing I would say though, is again, both of these methods truely do require quite a light touch.

For deep repairs, the best advice in general, as mentioned a few times is to add MANY thin layers or repair material. This is by far the most important. If there problems with this, a method that heklped me in the past was to create a "dam" outside of the repair area. This allows for more thin layers of repairs to ensure the entire repaired area is able to be filled.
post #22 of 25
I should clarify - My first 4 points weren't directed at re-flattening the base (I titled them wrong). They were really about how to knock down base material that has been raised above the normal base level of the ski due to damage. Sorry if I caused any confusion.

Copoly is Tognar's term for their P-tex/Epoxy combo "string" used to provide greater adherence to non-P-tex parts of the ski base like the metal edges and the core.

BTW - These days I would NEVER attempt to flatten an entire ski with a metal scraper, although in the "old days" that was the prescription.
post #23 of 25
I've been repairing my ski bases for over 40 years.

In the late '80s, I bought a BOSTIK model 260 glue gun.

This manufacturer also had gun accessories for skis in the form of 1) white colored plastic sticks for ski repairs, and 2) a small metal blade which can be attached to the gun's nozzle so that when also heated by the gun, the hot blade can smooth out the repair area before light sanding or final scraping.

At the time, white colored repair sticks were very practical because many skis had white colored ski bases. These ski repair sticks had a slightly different composition to them compared to regular glue sticks.

Ordinary glue sticks tend to change in softness as the temperature varies and can have a tacky feeling to them even at room temperature.

In the '90s, ski bases started being black colored and I switched to using black P-TEX wire which I bought at ski repair shops, 10 feet at a time.

I could burn this plastic wire (designed specifically for a different type of heat gun) into the ski bottom like an ordinary P-TEX candle, only this 1/8" thick plastic wire was much easier to work with because only a small amount of material melted and dropped on the ski at any moment.

The only problem with burning any type of plastic, is that as it burns, it tends to throw some carbon into the melt as well as creating tiny air bubbles.

But if you keep the burning wire fairly close to the ski surface so that the small blue flame that surrounds the burning end of the wire barely touches the ski base, then I find less carbon and less bubbles are created and the flame has the additional benefit of pre-heating the ski base surface slightly before the melt drops into place.

This extra heat vaporizes any minute residual ski wax in the repair area which increases the chances of the hot plastic bonding to the original ski base.

If you move your hand right, you can deposit a continuous flow of plastic into the gouge, as opposed to a series of drops. Maintaining the correct angle of the end of the wire is critical, else you get either too much melt or too little for the particular speed that you want to sweep the wire end along the gouge.

Once cold, I scrape off the excess plastic with an acrylic ski scraper blade as opposed to a metal one, lightly moving in both directions. This brings out the excess plastic in flakes similar to how ski wax comes off with the same scraper.

I find the plastic blade edge which is duller than a metal blade, seems to be re-heating the surface of the repair due to the greater abrasion and this seems to reseal the surface better than a metal blade which slices and perhaps tears a bit as well. However, if I had a professional gun capable of melting real polyethelene, then this harder plastic would require a metal scraper blade. But for my much softer plastic wire, an acrylic scraper blade works well for me.

While this plastic wire is not as hard compared to the real P-TEX in the ski base, it is harder than ski wax, and it tends to stay put inspite of sking over abrasive snow. When I wax over the repair, the ski wax seems to hold, although it has been mentioned in this forum that all repair plastic is far less porous (especially after having been burned) than the original ski base material with its different molecular structure.

Sometimes after applying the plastic wire and scraping, there are some tiny air bubbles mixed in with the melt and I have to add a second or third layer to minimize this effect.

I also conclude that the plastic in the P-TEX candles (3/8" diameter) is very much like the plastic wire I use, meaning that both seem to burn at the same temperature and deposit with the same relative hardness, or lack of it.

On the other hand, the ordinary plastic glue sticks and the ski base repair sticks which came with my Bostik glue gun seem to melt at a much lower temperature than the P-TEX repair plastic (wire or candles).

I found this out the hard way when this morning, I tried inserting the 3/8" diameter P-TEX candle stick in the 1/2" diameter barrel of the glue gun with the hope that pure melted P-TEX would come out of the gun without any carbon or bubbles.

The P-TEX candle needed much more heat than the BOSTIK gun could provide and I had to create extra pressure by ramming the P-TEX stick through using an ordinary glue stick pressing in from behind. I eventually damaged the soft rubber barrel of my glue gun and the glue started leaking out through new cracks in the barrel. Whatever partially melted P-TEX candle that was coming out of the gun, it was not hot enough to work with.

So this was an experiment with bad results and I don't recommend anyone try this at home and damage their glue gun.

I went back to burning the plastic wire and I am now convinced that this will remain the best option for me to keep using in the future.

I pay about a dollar a foot for the plastic wire and when I go away on a two week ski trip where I am skiing nearly every day over rocks hidden by off-trail snow, I can go through 5 to 10 feet of repair wire during the vacation.
post #24 of 25
Originally Posted by montreal View Post
I've been repairing my ski bases for over 40 years.

In the '90s, ski bases started being black colored and I switched to using black P-TEX wire which I bought at ski repair shops, 10 feet at a time.

I could burn this plastic wire (designed specifically for a different type of heat gun) into the ski bottom like an ordinary P-TEX candle, only this 1/8" thick plastic wire was much easier to work with because only a small amount of material melted and dropped on the ski at any moment.
Interesting, I bought some P-tex wire from the local shop and melted it in with a soldering iron. It came out like crap, with voids and such. Playing around with the wire, I found I could light it with a match, even though I have been told pure P-tex will not burn. Apparently, P-tex candles have wax added, which burns, and inturn heats up the P-tex.

Playing around with the wire, it seemed like what was actually dripping was wax. It was silky smooth, soft, and scraped just like wax would. I'm not sure what they sold me, but it got thrown out fairly quick.

In the end, I dug out the repair and used a base repair stick from SlideWright. Melted in really smooth with a soldering iron, and I cut it down with a sharp chisel. A quick pass with a brass brush added some structure.
post #25 of 25
Originally Posted by krp8128 View Post
Playing around with the wire, it seemed like what was actually dripping was wax. It was silky smooth, soft, and scraped just like wax would. I'm not sure what they sold me, but it got thrown out fairly quick.
I have no idea what has been added to P-TEX candles or P-TEX wire that makes them burn.

With P-TEX candles, they were intended to be burnt, so they may need an additive. But the plastic wire I use was intended to be fed into a repair machine, so I can't imagine that the manufacturer would add anything to encourage this product to burn. They must both burn naturally.

I don't believe this plastic wire or candles are made of the same plastic as real P-TEX base material which melts at a much higher temperature.

I agree that as the plastic wire burns, it drops more like a liquid wax than a melted plastic. And once cooled, this burnt plastic is more brittle than the original unburnt plastic wire.

In spite of this fragility, I am astonished at the quality of the repair that this wire can deliver, and how long it lasts.

The best repair system I have ever seen was at Mattis Sport in Val d'Isere where the ski and a ribbon of plastic is fed into a machine and the ski exits the other side with the ribbon totally fused into the ski bottom.

Prior to the entering the machine, the ski mechanic will scrape down by hand part of the original ski base so that the ribbon fuses to a clean surface of ski base. I have seen narrow ribbons used for limited damage, or 4" wide ribbons used to completely replace the ski bottom.

After the ribbon has fused, the new irregular surface is leveled by passing the ski across the grinding drum.
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