If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #2628
Joined: Fri Jan 15 2010, 12:23AM
Location:
Posts: 627
I need some help here,
Is there a difference between flame polishing lexan and acrylic?
when I try to flame polish lexan, it goes clear, but sometimes I get bubbles forming on some places, so I wonder how to prevent bubble build up?
I was polishing it with a butane torch, with about a 1 inch flame, letting the tip of the flame barely touch the plastic.. is this too close? or should I just move faster?
Registered Member #2390
Joined: Sat Sept 26 2009, 02:04PM
Location: Milwaukee Wisconsin
Posts: 381
I remember i used to work at a place that did that some years back. I never did it,but I am pretty sure the torch they used was nitrogen and oxygen. There was no color to the flame and it polished the material beautifully. Their products were made of numerous plastics including lexan and acrylic. Hope that helps!
i have experience with acrylic only and here is what I've learned:
there are acrylics that tolerate the flame for longer (the surfave melts, but takes longer for bubbles to form). It is much easier to polish those because they need much less preparation (sanding). I also have some big sheats of plexy that will form bubbles almost imediatelly after melting. The cure for this is to use first rough sanfpaper (I use 160) and after that - finner sadpaper - (I use 400) - make the surface as smoot as possible. After that you have to be pretty quick with the flame. Look it under such an angle that when the surface melts you be able to clearly see it and move on. If bubbles form - you can sand the spot and re-flame it again.
Bubbles ususally form when you try to polish some big scratches, without sanding them before that.
Registered Member #2261
Joined: Mon Aug 03 2009, 01:19AM
Location: London, UK
Posts: 581
This mentions additives for PMMA that is to be heat worked:
A small amount of acrylate comonomers are routinely used in PMMA grades destined for heat processing, since this stabilizes the polymer to depolymerization ("unzipping") during processing.
Perhaps that explains different samples reacting differently to flame polishing.
Registered Member #2390
Joined: Sat Sept 26 2009, 02:04PM
Location: Milwaukee Wisconsin
Posts: 381
Heres something cool! If you brush the edges of youre material with something like "polycrylic" it will dry crystal clear and will get rid of those nasty tool marks! May take a few coats but it will look great!!
Registered Member #2628
Joined: Fri Jan 15 2010, 12:23AM
Location:
Posts: 627
Thank you for your help everyone,
Ive got it fairly clear using the above methods, and I still get a few bubbles here and there, but it is not the flaw of the method, but the flaw of me. (held flame too long, time to do more sanding)
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
Flame polishing lexan
