rear window demister: broken

Hello,

I noticed this morning that of the 13 elements (?) on my rear windscreen, only seven are working! That's pretty much half. The strange thing is that the failed ones are all over the place, i.e. it's not just the bottom ones. I could understand the bottom couple getting scratched by squashing things in the boot but I can't imagine how the others have failed. Do they just burn out with age or has something scratched them?

Can they be repaired successfully? I've seen these kits that you are supposed to paint on. Do they work? Is it just silver (the metal, rather than the colour!) paint?

Thanks, Stephen.

Reply to
Stephen
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The paint stuff does work but the template they normally provide is far to thick to be a neat repair so make your own.

The tricky part can often be finding the break.

MattF

Reply to
MattF

finding the break can be done by misting the window, either naturally or with some hot water, put the heated screen on and watch, the condensation allows a tiny amount of current to flow and shows as a litle demisted spot on the non working track. ring it with a sharpie and repair as needed, the kits work fine, good masking tape is neater than the cardboard cutout.

Reply to
Mrcheerful

The window was iced over and I switched it on and sure enough I got a tiny circles on the broken elements, which I assume is where the break is. I still don't quite see how it works: if a current passes surely the whole thing would heat up and clear, but it does work.

Now another silly question: what's a sharpie?

With the kit do you just paint over the element or do you have to do anything else first? I wasn't sure whether the element was covered in some sort of lacquer that need to be lightly sanded off to make a good contact with the paint from the kit?

Any recommendations for a good kit? I've used google and found the one made by Granville but I also found a forum in which a poster said it had received bad reviews. I wasn't able to find those bad reviews myself, so I am not sure how true they are.

Another suggestion I found via google was to use a pen of conductive paint. They sound easier to use than a paint brush; are they?

Thanks, Stephen.

Reply to
Stephen

Stephen gurgled happily, sounding much like they were saying:

Marker pen

Reply to
Adrian

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felt tip pen in other words

Reply to
Redstar

Like all heating elements they can just fail with age.

My SD1 Rover has a wire bridging two parts of the element which is hidden by the surround rubber. That's a common failure point on that screen resulting in more than one 'strip' failing. And very difficult to fix.

By the cost, they do use real silver. They certainly work - but not in my experience for long. Most likely to be successful repairing a break in just one strip.

Reply to
Dave Plowman (News)

Thanks. That's what I thought from the context but wanted to make sure. I'd never heard of that brand before!

Reply to
Stephen

AFAIK a repair I did on the rear screen on my Vitesse in 1988 is still OK. Was just a break in one horizontal strip, bridged it with what appeared to be a thick metallic paint using the provided brush. Very simple to apply, and in my case very effective. Mike.

Reply to
Mike G

I've had about a 50% success rate with them.

BTW, it's best to apply the paint on a warm, dry day!

Chris

Reply to
Chris Whelan

the condensation carries enough current to warm that bit, but not everywhere (I guess) but as you see the idea works. I am surprised that anyone does not know that a sharpie is a felt pen that writes on nearly everything, I guess you don't see TV adverts! well done! Granville kits work fine, I can't remember about lacquer n the elements, but it sounds likely, the kit will say. I think that Maplins sell a suitable conductive paint for circuit board repair.

Reply to
Mrcheerful

Can't see the point in that. If you have damage to a PCB, you simply bridge the break or replace the track with single core copper wire, soldered in place.

Reply to
Dave Plowman (News)

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