PETG cloudy bends? - Overclock.net - An Overclocking Community
Forum Jump: 

PETG cloudy bends?

Reply
 
Thread Tools
post #1 of 15 (permalink) Old 01-20-2020, 11:12 AM - Thread Starter
New to Overclock.net
 
reaper829's Avatar
 
Join Date: Feb 2015
Posts: 46
Rep: 0
PETG cloudy bends?

I'm working with PETG for the first time, and I'm using the monsoon heat gun on low. For some reason, almost every bend comes out with cloudy smears in the bend. I've had some that have bubbles that I know are because it gets too hot, but any idea what the deal is with bends that are cloudy? Anyone else have this problem? I don't think I've been able to get one bend without any clouding. Is that just how it is with PETG? Or should the bends be crystal clear? Pictures attached.
Attached Thumbnails
Click image for larger version

Name:	20200120_133035_001.jpg
Views:	14
Size:	1.53 MB
ID:	320348  

Click image for larger version

Name:	20200120_133101.jpg
Views:	13
Size:	4.03 MB
ID:	320350  


Last edited by reaper829; 01-20-2020 at 11:34 AM.
reaper829 is offline  
Sponsored Links
Advertisement
 
post #2 of 15 (permalink) Old 01-21-2020, 04:40 PM
New to Overclock.net
 
Join Date: Dec 2019
Posts: 91
Rep: 8 (Unique: 5)
could be that you aren't heating it hot enough. Do you notice it on the inside, outside of the tube? Or is it more along the outside of the radius or the inner? If it's the outside you aren't eating it evenly enough and it's stretching the material. Another possibility is that you are cooling it too quickly by dipping it in water or something? I have my heat gun set for about 650f.

I'm guessing you are using one of the bending cores as well. Is it a solid or hollow core? It almost looks like smear marks along the inside wall of the tube. Try cleaning the core and insert using water the next time you bend a piece. Could even be debris/dust on the outside of the core that is melting into surface of the tube due to the pressure of the bend. Quite a few factors that could be influencing the haziness.
Soulpatch is offline  
post #3 of 15 (permalink) Old 01-23-2020, 05:13 AM - Thread Starter
New to Overclock.net
 
reaper829's Avatar
 
Join Date: Feb 2015
Posts: 46
Rep: 0
Thanks for the suggestions.

I notice it on the inside of the tube.

The tubes are primochill 3/8x1/2" and the tube is primochill 3/8x1/2" solid core.

I will try your suggestions and post here if anything changes. Thanks for your help!
reaper829 is offline  
Sponsored Links
Advertisement
 
post #4 of 15 (permalink) Old 01-23-2020, 08:12 AM
New to Overclock.net
 
Join Date: Dec 2019
Posts: 91
Rep: 8 (Unique: 5)
Okay, I use the primochill tubing as well. Make sure your inserted core is clean and the tubing has been rinsed out well. So there should be nothing on both mating surfaces. As it heats and you stretch around a radius the force could be pushing any dust, etc. into the softened material. Also make sure you heat evenly, but slowly. Too hot to fast and you'll melt/create bubbles in the outer skin, but the inside wall will still be too hard. Too cold and you'll be stretching the outer wall. It doesn't look like it's too cold because your radius doesn't have any ripples or thin walls from stretching. There aren't any bubbles from over-heating. So odds are good it could be whatever you are picking up from the bending insert or from the tube itself. It seems everything sticks to those core inserts and I was constantly rinsing mine off from dust, cat fur, etc lol
It could also be a lubrication issue as well. because the insert may stick to the inside of the tubing, as both the tube and the insert heat up it could be creating a contact surface that isn't sliding as you bend the radius (smearing the surface). So having a bit of water in there from washing the tube/core could help break up the surface drag cohesion.

Last edited by Soulpatch; 01-23-2020 at 09:37 AM.
Soulpatch is offline  
post #5 of 15 (permalink) Old 01-23-2020, 10:38 AM - Thread Starter
New to Overclock.net
 
reaper829's Avatar
 
Join Date: Feb 2015
Posts: 46
Rep: 0
Quote: Originally Posted by Soulpatch View Post
Okay, I use the primochill tubing as well. Make sure your inserted core is clean and the tubing has been rinsed out well. So there should be nothing on both mating surfaces. As it heats and you stretch around a radius the force could be pushing any dust, etc. into the softened material. Also make sure you heat evenly, but slowly. Too hot to fast and you'll melt/create bubbles in the outer skin, but the inside wall will still be too hard. Too cold and you'll be stretching the outer wall. It doesn't look like it's too cold because your radius doesn't have any ripples or thin walls from stretching. There aren't any bubbles from over-heating. So odds are good it could be whatever you are picking up from the bending insert or from the tube itself. It seems everything sticks to those core inserts and I was constantly rinsing mine off from dust, cat fur, etc lol
It could also be a lubrication issue as well. because the insert may stick to the inside of the tubing, as both the tube and the insert heat up it could be creating a contact surface that isn't sliding as you bend the radius (smearing the surface). So having a bit of water in there from washing the tube/core could help break up the surface drag cohesion.
I was thinking that it could be some kind of lubrication issue as well. I'll try a few things and let you know how it goes. Thanks!
reaper829 is offline  
post #6 of 15 (permalink) Old 01-24-2020, 12:20 AM
New to Overclock.net
 
Bartdude's Avatar
 
Join Date: Sep 2017
Location: UK
Posts: 130
Rep: 3 (Unique: 2)
Quote: Originally Posted by reaper829 View Post
I was thinking that it could be some kind of lubrication issue as well. I'll try a few things and let you know how it goes. Thanks!

Dip your insert into some soapy water, that will help on removal too. I used some standard washing up liquid when I did my PETG bends

"No s*** lady, does it sound like I'm ordering pizza!"
Corsair 900D
(29 items)
CPU
Intel E4790k Haswell
Motherboard
Asus ROG Maximus VII Watchdogs
GPU
EVGA 1080 SC Gaming
RAM
Corsair Dominator Platinum
Hard Drive
Samsung SSD
Hard Drive
Samsung SSD
Hard Drive
Samsung SSD
Optical Drive
LG Blu Ray Rewriter
Power Supply
Corsiar AX1200i
Cooling
EK XTOP Revo Duel D5
Cooling
2X EK Radiator 360 PE
Cooling
EK Supremacy EVO
Cooling
EK 1080 Full Cover Waterblock
Cooling
Aquero 6 XT
Cooling
Aquero MPS 400 Flow Sensor
Cooling
9X Gentle Typhoon Fans
Cooling
Aquacomputer Hubby7
Cooling
4x Aquacomputer Splitty9
Cooling
Aquacomputer Poweradjust USB 3 Ultra Version
Case
Corsiar 900D
Operating System
Win 10 Pro 64
Monitor
Asus ROG Swift PG279Q 27" 2K WQHD 165Hz IPS G-Sync 2K Gaming Monitor
Keyboard
Razer Blackwidow Soft Touch
Keyboard
Razor Orbweaver
Mouse
Razer Deathadder 3500DPI
Mouse
Razer Mouse Mat
Audio
Sound Blaster X-Fi Titanium Fatal1ty Champion Series
Audio
Yamaha RX-V381 5.1 Channel Receiver Amplifier
Audio
Tannoy 5.1 Speakers
▲ hide details ▲
Bartdude is offline  
post #7 of 15 (permalink) Old 01-24-2020, 03:16 PM
New to Overclock.net
 
Join Date: Dec 2019
Posts: 91
Rep: 8 (Unique: 5)
Quote: Originally Posted by Bartdude View Post
Dip your insert into some soapy water, that will help on removal too. I used some standard washing up liquid when I did my PETG bends

That's usually what works for me. A couple drops of soap will lower the drag coefficient to zero and depending on how tricky you want to get it makes core removal (or re-insertion for a tweak) that much easier. PETG tubing is new to me, so I've been experimenting with bends/limits that the tubing can take. Here's a piece I've been monkeying around with. It's been wrapped around a 1/4" SS rod and the tubing is premochill 1/2x3/8" with a solid core insert. They are pretty tight and the deformation on the outside is pretty minimal. Inside is still wide open with plenty of clean run and no fluid choke points. Was thinking of it as an option for more fluid volume instead of adding a small reservoir. But mostly just to test and see how far it would push the limits.
Attached Thumbnails
Click image for larger version

Name:	Coil.jpg
Views:	15
Size:	1.48 MB
ID:	321318  

Soulpatch is offline  
post #8 of 15 (permalink) Old 01-24-2020, 04:47 PM
New to Overclock.net
 
Join Date: Aug 2019
Location: Kentucky
Posts: 301
Rep: 13 (Unique: 12)
@reaper829 Chances are you won't notice once you have fluid in the loop, I can barely see it in the pic.

Open Air Build
(13 items)
CPU
i9
Motherboard
ASUS ROG Strix Z390-H Gaming
GPU
MSI GEFORCE GTX1080 TI GAMING X 11G
RAM
Corsair Vengeance LPX DDR4 DRAM 3000MHz
Hard Drive
Samsung 970 EVO
Hard Drive
WD Blue
Power Supply
EVGA SuperNOVA
Cooling
All PrimoChill parts (Rad 360, Pumps D5, Fittings, and Acrylic Tubing), Byskey CPU&GPU Blocks
Case
Praxis Wet Bench
Operating System
Windows 10 Pro
Monitor
Asus Predrator
Other
Thermaltake Commander F6 Fan Controller
Other
DIY Sleeved Cables
▲ hide details ▲
smilinjohn is offline  
post #9 of 15 (permalink) Old 01-24-2020, 06:26 PM
New to Overclock.net
 
Join Date: Dec 2019
Posts: 91
Rep: 8 (Unique: 5)
Quote: Originally Posted by smilinjohn View Post
@reaper829 Chances are you won't notice once you have fluid in the loop, I can barely see it in the pic.

Good call smilinjohn, hadn't thought about that myself. Unless he's running a colored fluid that is solid colored then it likely wouldn't show anyway.
Soulpatch is offline  
post #10 of 15 (permalink) Old 01-29-2020, 01:20 PM - Thread Starter
New to Overclock.net
 
reaper829's Avatar
 
Join Date: Feb 2015
Posts: 46
Rep: 0
Success!

[Posting for anyone else in the future who has this same issue.]

The problem seemed to be a lubrication/silicon cord removal issue. If the water wasn't soapy enough, it was leaving interior streaks on the inside when I pulled the silicon cord back out. Adding more soap and making sure the silicon cord was soaked fixed it. I also twisted as I pulled the silicon cord back out of the tube, instead of just pulling on it. A combination of these things resolved the issue.

I also noticed that if there was a streak right after I pulled the tube out, I could actually re-lubricate the silicon cord and twist it back in gently and it removed the smear. I couldn't do this with older tubes that had streaks, only recent ones. There must be a short time-frame where the streaks can be removed before it is permanent.

You're probably right that I wouldn't even notice it, but I may be doing clear liquid, so didn't want to have to drain the loop after the fact if I could see the streaks.


Thanks for the help everyone!
Attached Thumbnails
Click image for larger version

Name:	20200129_150733.jpg
Views:	9
Size:	3.11 MB
ID:	322656  

reaper829 is offline  
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Overclock.net - An Overclocking Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off