Ok thought I would do a quick tutorial on how to wind coils. First you need a jig. Mine is pretty simple, a 1/2" black iron pipe run thru a couple 7/8th bearings bolted down to a table with a pillow block. There are three eye bolts installed near the end to ensure that the coil gets plenty of grip when turning.
Step one. Using a small tubing bender from harbor freight, put a slightly less than 90 degree bend in the tubing and run it thru the eye bolts.
Step two: After running the tubing thru the bols, turn the eye bolts at an angle to better grip the tubing and screw them into place.
Step three: This is the second most difficult part after the final bend after coiling. Slowly start the tubing around the mandrel while holding it down to keep it from kinking. Once you get this one down it gets a lot easier.
Step four keep turning:
Step five: Keep on turning while allowing about an 1/8" on an inch of space between the tubing... keep holding down so the tubing doesn't kink.
Step six: Once you get the inner coil as long as you want it, it is time to start the outer coil. However again you need space between the tubing for maximum effect. To accomplish this I used a notebook cover would around the inner coil and secured with some sacrificial zip ties. To start the coil around the tube simply pull it over and turn while holding down.
Step 7: More winding.
Step 8: At this point I decided to add on some cardboard tubing to increase the final diameter of the coil to better match the exterior of 2" copper tubing using exactly one round of cardboard. I recommend a 50-50 mix of notebook/cardboard to create a dual size coil.
Step 9: When you get to the end, be sure to leave about an inch unwrapped. This will allow your uptubes to fit better. This is the really tricky part... if you can get this done your home free. I bent the tubing carefullly with the benders and then finished up with some channel locks and the spring bender.
Step 10: Cleanup of copper. Soak in warm Rid-X or weak lye solution for about one hour then take it down to the local car wash and blow out the cardboad with the pressure wand.
Final fit pics:
Well thats how it is done. No salt or other BS just a nice clean coil. Attention: I will soon be offering these coils for sale for $50 each plus shipping anywhere in the USA. While very easy to wind as shown above, keep in mind that there is a bit of a learning curve. It can take hours to build a jig, if you screw up winding one at any point and you have to start all over again from scratch, and its a one shot affair... you only need one coil that should last a lifetime. Time and materials can easily add up to more than the price I am asking. If your interested in purchasing one already completed, drop me PM for details... I take Paypal and will be happy to list it on Ebay.