Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Kolb-List:Windshield plastic crazing

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Kolb-List
View previous topic :: View next topic  
Author Message
victorbravo(at)sbcglobal.
Guest





PostPosted: Mon Mar 05, 2018 10:28 am    Post subject: Kolb-List:Windshield plastic crazing Reply with quote

John H and Kolb List,

I'm no expert on the polycarbonates or acrylics, but could this crazing be from internal stress over time? Meaning that when you take a flat sheet and bend it into a curve, then fasten it down into that curved position (the shape of the Kolb nose cone), there is a small stress put into the plastic. Over a long period of time, perhaps the stresses eventually cause the internal cracks or difference in transparency?? This is a wild-a$$ guess on my part.

Most "airplane" windshields are thermoformed, heated until the plastic is soft, so perhaps the internal stress is not as much?

If this is not a viable explanation, perhaps the previous suggestion of a bad batch of plastic is the likely answer IMHO.

Most of the manufacturers have a website or some sort of tech help phone number where you can ask a technical question. They may have seen this problem before and have a useful answer.

Bill Berle
www.ezflaphandle.com  - safety & performance upgrade for light aircraft
www.grantstar.net           - winning proposals for non-profit and for-profit entities

--------------------------------------------
On Mon, 3/5/18, John Hauck <jhauck(at)elmore.rr.com> wrote:

Subject: RE: Re: Kolb-List Digest: 6 Msgs - 03/01/18
To: kolb-list(at)matronics.com
Date: Monday, March 5, 2018, 9:11 AM

#yiv8117676239
#yiv8117676239 --

_filtered #yiv8117676239 {panose-1:2 4 5 3 5 4 6 3 2 4;}
_filtered #yiv8117676239 {font-family:Calibri;panose-1:2 15
5 2 2 2 4 3 2 4;}
_filtered #yiv8117676239 {font-family:Tahoma;panose-1:2 11
6 4 3 5 4 4 2 4;}
#yiv8117676239
#yiv8117676239 p.yiv8117676239MsoNormal, #yiv8117676239
li.yiv8117676239MsoNormal, #yiv8117676239
div.yiv8117676239MsoNormal
{margin:0in;margin-bottom:.0001pt;font-size:12.0pt;}
#yiv8117676239 a:link, #yiv8117676239
span.yiv8117676239MsoHyperlink
{color:blue;text-decoration:underline;}
#yiv8117676239 a:visited, #yiv8117676239
span.yiv8117676239MsoHyperlinkFollowed
{color:purple;text-decoration:underline;}
#yiv8117676239 p.yiv8117676239MsoAcetate, #yiv8117676239
li.yiv8117676239MsoAcetate, #yiv8117676239
div.yiv8117676239MsoAcetate
{margin:0in;margin-bottom:.0001pt;font-size:8.0pt;}
#yiv8117676239 span.yiv8117676239BalloonTextChar
{}
#yiv8117676239 span.yiv8117676239EmailStyle19
{color:#1F497D;}
#yiv8117676239 span.yiv8117676239EmailStyle20
{color:#1F497D;}
#yiv8117676239 span.yiv8117676239EmailStyle21
{color:#1F497D;}
#yiv8117676239 .yiv8117676239MsoChpDefault
{}
_filtered #yiv8117676239 {margin:1.0in 1.0in 1.0in 1.0in;}
#yiv8117676239 div.yiv8117676239WordSection1
{}
#yiv8117676239 Jack H/Kolbers:  Doubt the polishing kit would
correct my problem.  The failure is in the generic
polycarbonate I used last time I replaced windshield and
doors.  I think if I had stuck with more expensive GE
Lexan, I wouldn't be having this problem.  Right now I am scratching my head
to figure out why this polycarbonate failed.  One
possibility is a reaction to the last windshield cover I
made about 4 or 5 years ago.  I found some heavy material,
similar to Naugahyde, at a local fabric shop.  I was tired
of making new covers out of plastic table cloths every
year.  My thought is there was a chemical reaction from the
gassing of the material used to make the material.  Maybe
not.  I don't know.   Darn shame though.  The surface
of the polycarbonate is in great shape.  Thanks for the
suggestion.  john hmkIIITitus, Alabama        From:
owner-kolb-list-server(at)matronics.com
[mailto:owner-kolb-list-server(at)matronics.com] On Behalf
Of Jack Hart
Sent: Monday, March
05, 2018 10:13 AM
To:
kolb-list(at)matronics.com
Subject: RE:
Re: Kolb-List Digest: 6 Msgs -
03/01/18
  John,  I have had good luck with
using the headlight polishing kits that are sold at auto
parts stores.  The kits are not expensive compared to a new
windshield.  Try it on the windshield in a small area and
see if it helps out. Jack B. Hart
FF004 Winchester,
IN  From: "John Hauck" <jhauck(at)elmore.rr.com>
Sent: Sunday, March 4, 2018 1:02 PM
To: kolb-list(at)matronics.com
Subject: RE: Re: Kolb-List
Digest: 6 Msgs - 03/01/18  Chris D/Kolbers: -----my 1992 MKIII, is in need of
a lot of cosmetic TLC, especially the glass.  The
windshield has started crazing which gives it the diamond
glare effect when flying into the sun. 


- The Matronics Kolb-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List
Back to top
John Hauck



Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

PostPosted: Mon Mar 05, 2018 10:52 am    Post subject: Kolb-List:Windshield plastic crazing Reply with quote

Stress may very well be the culprit. Takes a lot of pressure to conform 1/8 polycarbonate to the nose pod and upper windshield frame. Doors are 1/16, but not much pressure to bend them to conform.

Thanks for the suggestion.

john h
mkIII
Titus, Alabama


--


- The Matronics Kolb-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Kolb-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group