PETG wrinkles + balooning + bubbles

[krojew]

Hi,

I have a large problem trying to bend some PETG tubes. I can't seem to get the temperature right (or rather anything right). Most of my bends got wrinkles on the inside. I've read that this is an issue with too little heat, so I got the tube closer to the heat gun. The result was heavy balooning and bubbles so, I got my tubes a little further away. Then I got both wrinkles (which suggest too low temp) and bubbles (which suggests too high temp). I've wasted a lot of tubes and got nowhere near a perfect bend. I'm using Primochill rigid bender for assist, but I don't know if it's an issue here. Does anybody know what might be going on here? I'm going through tubes like crazy and loosing my mind.

[tiberiusmoon5]

Your going too fast,

put the tube under heat and wait,

as your rushing you will get wrinkles and as your rushing with higher heat your burning it.

[THFourteen]

What tubes and silicon insert are you using exactly?

 

i had a few issues myself last week. 

 

Keep the tube reasonably far away from the heat gun and set the gun on low. 

 

Keep rotating and moving the tube so the heat doesn't concentrate on one area 

 

bend the tube slowly not quickly

[krojew]

12 minutes ago, THFourteen said:

What tubes and silicon insert are you using exactly?

 

i had a few issues myself last week. 

 

Keep the tube reasonably far away from the heat gun and set the gun on low. 

 

Keep rotating and moving the tube so the heat doesn't concentrate on one area 

 

bend the tube slowly not quickly

I'm using Alphacool 16/12mm PETG with their insert. I keep my gun at medium, which is 350C. Lower temp is only 100C and I don't know if it's enough.

[Shadowman]

1 hour ago, THFourteen said:

 

Keep rotating and moving the tube so the heat doesn't concentrate on one area 

 

 Totally agree make sure your doing the above as this is what i was not doing.

[Dea Stenger]

3 hours ago, THFourteen said:

bend the tube slowly not quickly

As OPs partner in crime I gotta ask - do you mean slowly in one movement or can I reheat the tube and continue the bend?

[THFourteen]

2 hours ago, Dea Stenger said:

As OPs partner in crime I gotta ask - do you mean slowly in one movement or can I reheat the tube and continue the bend?

I had some bad results reheating the tube to continue the bend. Other people might have had different results as I'm not experienced but basically if I didn't get the bend right first time and tried to reheat it, it usually ended up deformed. 

 

I meant more when bending the tube, don't force it too fast, bend it gradually around whatever you are using for bending. Also once you've bent it, hold it in place for a minute or so whilst it cools. 

 

My my best ended up being the last one where I discovered my sons bubble bath bottle had the perfect radius for bending the tube round exactly. 

[GhostHitWall]

You want all the radius of bending area is heated up evenly and slowly to the same temp inside out.

 

You can rebend it if the bend isn't large.

For a 90 degree, it's very visible to see the mark when you rebend things.