Base Repair 101
Fortunately, however, it’s usually not that big of a deal. The majority of damaged bases can be repaired with some inexpensive equipment and a bit of know how. After reading this article, you should know how to handle simple, small base repairs. And since we have officially entered the spring skiing and riding season, chances are good that you’re going to have a few close encounters with a rock or two.
Look familiar?
Note that by small repair, we mean smaller than a quarter. If the base gouge or core shot is any larger, you might want to go to your local shop and request a base weld, which should cost approximately $20–30. Shops have specialized equipment that makes the job easier and decreases the likelihood that the repair will later fail.
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Comments:
Questions? Comments? Tell us what you think.
March 27, 2012 at 10:12 am
Couple things:
1) You make no mention of wearing a mask or having proper airflow while doing p-tex repair. Although it probably won’t kill you, breathing p-tex fumes is very bad for your health.
2) Most P-Tex candles, although better than doing nothing, are not designed for “core shot” type repairs. For this, there are a bunch of other products and techniques to increase the chances of it holding. Your standard P-Tex candle is NOT the BEST tool for the job.
March 27, 2012 at 11:28 am
Jeff: Good point about ventilation. I always wondered why one of your eyes twitched whenever you hear George Michael songs. P-tex fumes are something to be avoided in large quantities and I know just speaking for myself, I’d never want to ruin the pleasure of my Wham vinyl collection. It’s just too risky and I feel bad you’ll never be able to enjoy “Careless Whisper” like you once did. But I think most people will realize some breathing room is a good thing as soon as that candle fires up.
As far as size of repairs being dealt with via candles…it just depends on the repair. I’ve filled plenty of core shots with candles and have never had one rip out. (So have lots of other people…for years). Sure extruders/base patches/repair guns might be needed if it’s a bad one but candles are cheap and it’s worth trying before dropping more money in a shop. There’s no ‘given’ that a candle repair won’t work.
Nice write up Sam!
March 27, 2012 at 12:07 pm
Thanks for the comments, Jeff, and you’re right—we’ve added a word about ventilation. As for wearing a mask, certainly if you are using high-fluoro waxes and either waxing or dropping hot p-tex on there. But if you don’t use high-flouro waxes (like 99% of the population who aren’t racing), then working in a well ventilated area or opening a window—especially for the “smaller than a quarter” sized repairs this article addresses—is a good practice.
March 27, 2012 at 10:30 am
From my personal experience – TOKO Base Repair Powder
( http://www.toko.ch/en/products/tools/base-tuning/repair-powder-40g-transparent )
is much-much better than burning candles (requires hot Iron, so for indoor use only)
March 27, 2012 at 12:32 pm
Great article and this brings me back to my days of doing all my own base repairs. Good tips and this will get the job done for sure. This will also help people realize just how easy it can be with a little instruction. Thanks Blister
April 1, 2012 at 7:17 am
You state that a red or orange flame is getting too much oxygen and burning too hot and that ideally the flame should be blue. A blue flame would actually be hotter and using more oxygen than a red/orange flame and presumably is better because it is burning cleaner. A flame giving a red/orange colour suggests that there is unburnt or partially burnt material in the flame and these could be responsible for the black flecks you then find in the repair.
April 1, 2012 at 9:05 am
Neil, you are definitely correct. The blue flame will be the hottest part of the flame while a red/orange flame will not be as hot. The red / orange color is typically a sign of partial / incomplete combustion. The wording in the article is perhaps a bit misleading so let me try to clear it up here.
The idea with holding the tip of the candle as close to the base as possible (and slowly spinning the candle as well) is to control the rate of oxygen transfer to the flame more than to control the temperature. By controlling the rate of oxygen transfer to the reaction, we can also control the rate at which the hydrocarbons (and additives) are combusted. When the flame gets more oxygen, (ie, you move the candle from the base or stop spinning the tip) oxygen is no longer the limiting reactant in the combustion. What limits the combustion then begins to be the availability of hydrocarbon. When oxygen is no longer the limiting reactant the flame has a tendency to spread out in a sense. It is looking more material to burn because now it has enough oxygen. It begins to burn in a less controlled manner, though not technically hotter than the blue flame, but the candle is exposed to more heat overall. You only want to be liberating the polymer at the tip of the candle. When the flame tries to consume more hydrocarbon than it has oxygen for, you get partial combustion and small black flecks in the repair that are by products of combustion. By keeping the combustion localized to the tip, you get more complete combustion and a cleaner repair.
I know that isn’t the most complete explanation, the process is actually fairly complex and involves a decent amount of chemistry. Let me know if you still have questions though, and I apologize for the vague wording in the article!
-Sam
April 1, 2012 at 9:26 am
Sorry Sam the chemist in me couldn’t help commenting. Thanks for clarifying.
May 30, 2012 at 10:11 am
Thanks for the info. I’ve never concentrated on spinning the candle before. Repairs will be better in the future.
October 26, 2012 at 11:06 pm
A drip p-tex candle is the wrong way to repair an edge core shot. Those candles don’t stick to fiberglass or the metal edge, It will probably rip out the next day You need something to bond the ptex to the base fiberglass and metal edge, epoxy or metal grip is the only way to make it a permanent bond between the surfaces.
Keeping the burning candle as close to the repair as possible is to minimize carbon buildup, a blue flame is hotter because it’s a controlled amount of oxygen. When fire gets more oxygen than it needs it wants to spread out to grow and consume more combustible material. That why it’s large and orange/red. You don’t want to minimize the temperature of the candle but get it as hot as possible to burn clean and efficiently (reduce carbon) and to keep the ptex drip molten while it somewhat bonds to the ptex base.
A ptex drip candle is only effective on a non core shot where the original base is still in tact, and even then it’s unlikely that it will become a permanent bond, most likely have to fix it on a yearly bases if it’s a decent size chunk. Get a core shot at the hill, fix it to prevent water damage with a drip candle then get it fixed properly when you have the opportunity.
October 27, 2012 at 7:54 pm
Hey Ryan, thanks for your comment.
You’re correct that large base repair is better done with other techniques. The idea with this article is to get the reader familiar with the ptex candle because it is a cheap and easy fix that can solve some (not all) issues. It’s easily accessible to the average skier.
For the note on flame temperatures, you can read my response to Neil above. The concept is just a bit above a 101 article, hence the simplified explanation in the article. Thanks for your feedback!