Sorry if this seems like a basic question, but I just want to make sure that I'm not being misled by the guy at Home Depot. I don't have a lot of experience with compression fittings and this is my first time using copper coil tubing (I'm moving a furnace humidifier).
I bought the tubing from Home Depot as I'm moving a humidifier and connecting it to the hot water line so I was told that I should use copper tubing for hot water. I told him that I'm connecting it to an existing valve (even showed him the picture below) with a compression fitting. He then tosses me the pictured sleeve and insert.
When I was attempting to connect the tubing, I wasn't sure which direction the sleeve was supposed to go (sharp or gradual angle toward valve), so I did some searching online and found people using metal sleeves and some people using no sleeves at all.
Now I'm not sure if this guy gave me bad advice (I know, shocking) and I tired to find the right way to do it online, but I couldn't find anything but conflicting information. What is the correct way to connect this tubing so I don't end up with a leak?
Photos: https://imgur.com/a/nS1f3UD
Videos
I'd use a small tubing cutter to cut tidy/clean ends on both ends of the 1/4" copper pipe ...
... cutting off whatever portions of the 1/4" copper pipe are kinked or deformed. I'd then slip on a compression fitting called a 'union' ...
... which requires tightening with a pair of wrenches. Wikipedia has a general article on compression fittings here. You-tube hosts a concise 3 minute how-to video regarding installing compression fittings on plastic or copper pipe. The copper tubing portion of the demo starts at 1:45 ...
http://www.youtube.com/watch?v=eQGL8MBLlaE
Small tubing cutters such as the one pictured above will cut diameters 1/4", 1/2" and 3/4" and anything in between. The small size of that cutter design makes it excellent for tight confines. It would be the first one I'd buy for my tool box. You could also use a medium size cutter, such as the one used in this 90 second tutorial ...
http://www.youtube.com/watch?v=nLB3MomrXd0
The small cutter works in the same way. There are two main points to keep in mind when using either of these tubing cutters ...
1) Tighten the cutter only a little bit each time, making a number of light scores around the pipe instead of several deep ones.
2) The cutter wheel needs to continually track in the previous score, so keep a close eye on the score and make sure the score is not spiraling along the length of the 1/4" copper pipe, which can happen if the pipe is bent or deformed in the area where the cutter is being used.
After the cuts are completed, the cut ends of the 1/4" pipe need to be very close to circular (for example, not deformed into an oval). If they are not circular, then even if the ferrules can be forced onto the 1/4" copper pipe, the fitting will leak. If the ferrules do not slip on easily, it might be due to the ends of the 1/4" pipe being out-of-round, or (unlikely) due to defective ferrules. Using a tubing cutter will help ensure the cut ends of the 1/4" copper pipe are circular.
Alternatively, a hacksaw (or similar) can be used to cut clean ends on the 1/4" pipe. This will likely result in ends with sharp edges and a burr. Remove these with sandpaper. Clean ends will allow the ferrules slip on without gauging, which would lead to a leak. A fine-toothed file can be used instead of sandpaper, but the copper dust/shavings will most likely clog the teeth of the file.
Here is a 7 minute how-to video from England regarding leaks at compression fittings:
http://www.youtube.com/watch?v=aez4ctMtbuI
I would start by doing what the previous poster suggested by using a tubing cutter to remove any deformed tubing. I would then use "Shark Bite" fittings to join the two ends. Shark Bites are universal fittings that just push on. With them, you can join copper to copper, copper to PVC, Copper to pex, PVC to pex, etc. They are a bit expensive, but are quick, easy, and most importantly, they work. If you pipe ends up too short after trimming, you can just use an extra Shark Bite and an extra length of pipe.
http://www.sharkbite.com/
There ya go.