Heated rear screen - baffled

PostPost by: NYK » Wed Feb 20, 2019 1:40 pm

I needed a heated rear screen for my Plus 2 restoration. I could only find an early (vertical element) screen in need of some work. The elements and the top and bottom horizontal connecting bars appear unbroken, they are bronze in colour and appear to be just under the surface of the glass not surface printed. Above the horizontal connecting bars is a surface printed silvery electrode. The silvery surface layer is in poor condition and needs to be replaced. I can show electrical conductivity along unbroken parts of the silver electrode but cannot demonstrate any conductivity along the bronze heating elements.
I?m sure the bronze elements are not surface printed because in places I can see scratches in the glass across the heating elements but using a high powered lens can see that whilst the glass is scored the element is clearly intact and uncut, also if you run your finger nail over these heating elements you can?t really feel any edges as you might expect if it was surface printed.
So here is where I get confused! If I am correct in saying that the bronze elements are under the surface of the glass, how can this make electrical contact with the surface printed silver electrode and if I?m wrong and the heating elements are surface printed why can?t i measure any resistance along their lengths?
NYK
Third Gear
Third Gear
 
Posts: 417
Joined: 27 Jul 2017

PostPost by: Craven » Wed Feb 20, 2019 2:41 pm

If it?s a laminated screen the element can be between the two layers, look for a connection along the edge near the silver patch.
Craven
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1624
Joined: 14 Sep 2013

PostPost by: NYK » Wed Feb 20, 2019 3:04 pm

Craven wrote:If it?s a laminated screen the element can be between the two layers, look for a connection along the edge near the silver patch.


I?ve try to photo the screen so you can see what I mean. The contacts for the supply voltage are at each end of the screen, current flows into the top horizontal bar and flows through 12 screen elements to the bottom horizontal bar (not in shot) and then flows back up the other 12 elements to the top horizontal bar, which of course has a break in the middle as seen in the photo. There are no obvious edge connectors.

d6015fab-85e7-47bc-a6fd-9ef008f61529.jpeg and


You can see how the silver layer overlays the bronze, for it to work current has to flow from silver to bronze, If anyone has one of the screens and a multimeter I would be interested to know where you can measure conductivity.
NYK
Third Gear
Third Gear
 
Posts: 417
Joined: 27 Jul 2017

PostPost by: Craven » Wed Feb 20, 2019 3:47 pm

If it?s a single sheet of toughened glass, may be you are just seeing a ghost of a long gone element, the ones I?ve seen have been detectable with a finger nail, surface printed.
Craven
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1624
Joined: 14 Sep 2013

PostPost by: NYK » Wed Feb 20, 2019 5:00 pm

Yes, perhaps you are right, I had sort of assumed the silvery colour had just been on the top and bottom bars, but I guess there is no reason to suppose it did not also cover the bronze colour and in fact thinking about it, there is every reason to suppose it did! Bugger looks like I?m in the hunt for another heated screen which seem to be as rare as rocking horse whatnot.
NYK
Third Gear
Third Gear
 
Posts: 417
Joined: 27 Jul 2017

PostPost by: Craven » Wed Feb 20, 2019 6:03 pm

Craven
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1624
Joined: 14 Sep 2013

PostPost by: NYK » Wed Feb 20, 2019 6:58 pm

I guess if all else fails that?s a possibility. Not directly available is the U.K. of course
NYK
Third Gear
Third Gear
 
Posts: 417
Joined: 27 Jul 2017

PostPost by: Bud English » Wed Feb 20, 2019 7:54 pm

Craven wrote:https://www.frostfighter.com/clear-view-defrosters-about.htm


I'm sitting here with two rear windows, one with and one without the defroster, and hadn't made my decision on which to install when the time comes. I broke a connection tab off removing the working, original, heated screen. Knowing that these repair component pieces and supplies are available (see their catalog pages) gives me options. Thanks for that posting.
Bud
1970 +2S Fed 0053N
"Winnemucca - says it all really!!"
Bud English
Fourth Gear
Fourth Gear
 
Posts: 942
Joined: 05 Nov 2011

PostPost by: 69S4 » Thu Feb 21, 2019 7:21 am

Craven wrote:https://www.frostfighter.com/clear-view-defrosters-about.htm


Just need to come up with a hacked version of their products to deal with Stromberg carb icing :lol:
Stuart Holding
Thame UK / Alpe D'Huez France
69 S4 FHC
Honda GoldWing 1800
Honda CBX1000
Kawasaki H1 500
Yamaha XS2
69S4
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1124
Joined: 23 Sep 2004

PostPost by: Chrispy » Sat Feb 23, 2019 12:53 am

On my early plus 2 it had horizontal heating elements, however they were in very poor condition. They were surface mounted and most were broken. I scrapped them all off and it looks MUCH better. Not much use if its cold and damp, but that's not common where I am :lol:
Chris
Elan +2 #0245
Exige S2 Supercharged
Chrispy
Third Gear
Third Gear
 
Posts: 309
Joined: 29 Oct 2017

Total Online:

Users browsing this forum: No registered users and 23 guests