A while back I got a 25’ roll of ¼” Cu tubing “CHEAP”, later, I was checking it out and noticed that the wall thickness was 12mil - WTF?! (& country of origin was China). OK - that explained the cheap part.
On reflection, I figured that the thin wall would help on the thermal transfer. Much later (last week) I was inspired by Dixiedrifter’s post and tried to duplicate his results and had a rude surprise.
That thin walled tubing kinks and flattens at a drop of a hat. Goes through a bending die (that blue handled tool) no problem but is totally evil in a spring bender. Failed miserably 3 times to negotiate that 1st double bend that Dixie identifies as “the most difficult”. The tubing would collapse against the side walls of the spring bender and jam etc. I was winding on a ¾” mandrel (1/2” water pipe is .810” OD)
Anyway after sulking, I tried loading the tube with salt (hey guys we need somebody to do a tutorial on how to load a ¼” tube with salt – there has to be a better way that I did).
Once I got to the point I couldn’t jam anymore in there I gave it another shot.
(As my old sergeant always said “nothing is totally useless – it can always be used as a horrible example” - & he was always looking at me when he said that…)
Shit! Navigated dead man’s curve – OK (some buckling but not perfect). Quickly realized there is a definite technique you need to master (I hadn’t).
Before I started I thought that Dixiedrifter’s quote of 50$ for the job sounded high (remember the CHEAP part earlier) – but by the time I was on the second layer I was thinking "I wouldn’t do it for a nickel less".
I finished off ( with some sore fingers) and reviewing at the results – I would have graded it at 60% - (mostly for effort). I had snagged a ¾” female garden hose to 1/4:” compression fitting (that’s a rare item around here) and set about to clear the salt & see if it was worth keeping. I carefully configured this contraption in the “boss’s” laundry tubs and turned on the water – minor noises but nothing. 30 min. later the first blob of salt water (a drop a second, I’m thinking the kinks must really be restricting flow).
I get called off for dinner - 40 min. later I come back down to a minor flood, yes - most of the water is still going into the tub but the back blast is soaking: the floor, the washer & dryer, the furnace, the walls… guess the kinks weren’t that bad after all.!
Next trick was cleaning out the cardboard (I didn’t have Rid-X (50 bucks is looking like a really good deal at the point..).
Also noticed some scratches on the inside of the tubing & traced this to a burr on the end of the spring bender. I recommend that you check out yours and clean up any rough ends with a Dremel tool first.
Final results of the Mark I:
Flow rate is good, ID = 0.75” OD = 1.80”, length = 8”, tube length about 16 feet.
Wall thickness = 0.012”
Thank you HookLine& Dixiedrifter!
Time flies like an arrow
Fruit flies like a banana