What am i doing wrong?

itsjeff · May 16, 2020

Okay so its my first loop and need some help, so i set my heat gun im using acrylic btw, so i heat up my heat gun at low temperature which is 750F the lowest, ofc i have my tube at a distance and not close, i take my time roating slowly. When the tube gets hot i make the 90• angle https://imgur.com/gallery/7uPRF7J and thats how my tube looking after i finish? Wobbly at the side. The 90• is perfect, but the sides are a bit fat and wobbly. I found the only way to get rid of those fat sides is when the tubes are hot, i psh the tube beside a table at both sides. I watched a couple of youtube videos and they all bend by hand no pushing and nothing crazy? What am i doing wrong? Because i literally checked every guide out there, im not overheating and spreading the heat perfectly across the tube and taking my time.could this be a silicon cord issue not snug enough? Because my silicon cord is off by 1mm and not snug fit

Bombastinator · May 16, 2020

29 minutes ago, itsjeff said:

Okay so its my first loop and need some help, so i set my heat gun im using acrylic btw, so i heat up my heat gun at low temperature which is 750F the lowest, ofc i have my tube at a distance and not close, i take my time roating slowly. When the tube gets hot i make the 90• angle https://imgur.com/gallery/7uPRF7J and thats how my tube looking after i finish? Wobbly at the side. The 90• is perfect, but the sides are a bit fat and wobbly. I found the only way to get rid of those fat sides is when the tubes are hot, i psh the tube beside a table at both sides. I watched a couple of youtube videos and they all bend by hand no pushing and nothing crazy? What am i doing wrong? Because i literally checked every guide out there, im not overheating and spreading the heat perfectly across the tube and taking my time.could this be a silicon cord issue not snug enough? Because my silicon cord is off by 1mm and not snug fit

Partially. Could also be just Shakey hands. You might also be picking it up before it firms up again. When I’ve seen a silicon plug used it was always really snug. Without a snug fit you’re going to ge small kinks and flat spots. It looks serviceable though.

For Science! · May 16, 2020

1 hour ago, itsjeff said:

could be a couple of things, so here are a two things that came to mind based on your description:

1 - Silicon insert may not be snug

Yes, if it isn't snug you are making your life more difficult than needs be. I always buy the silicon insert from the same company that sells the tubing. For my EK tubing, it's snug enough that I use water+dishsoap to get it to go in and out smoothly.

2 - Force applied in strange directions

If you are heating a large section of the tube while spinning it like a rotisserie there is a chance that you will be introducing minor wobbles here or there as you apply small bending forces across the tube. When I bend tubes, I always have a method where I heat up the center point of the bend on one side fairly intensely, then the other side (i.e. rotate 180 degrees, once) and then gently heat up either side of the centre point before conducting the bend in one clean sweep. If you do weird things like push the tube together, it can cause ripples and buckles. So I personally don't recommend the rotisserie method and would recommend you to define your heating method.