None of the lines in the grid are still functional. I don't expect to need the defogger function, and I'm considering scraping the whole grid off. Has anyone done this - is there any downside?  Is the grid somehow partly etched in the glass, and will leave a mark anyhow?  If so, I'll just leave it alone.

I'm guessing most of us have defroster grids that haven't worked for 30 or 40 years.  There's been lots of discussion on repairing, replacing and removing the grid over the years.  Here's a link you may find helpful.

 

Yeah, I did indeed read through dozens of posts on numerous threads, but I couldn't find one where someone just ended up stripping the grid off totally.  Or perhaps the ppl who put in the defroster blowers did exactly that.

As I understand it they are baked on during window manufacture.  I don't think that they can be scraped off.

I remember somebody posting a better web page about it, maybe even a video, but here's good old Wikipedia.

https://en.wikipedia.org/wiki/Defogger

"These conductors may be composed of a silver-ceramic material printed and baked onto the interior surface of the glass, "

This looks new.  Don't remember seeing it before.

https://www.amazon.com/Permatex-09117-Complete-Window-Defogger/dp/B000ALBZJY

I tried using the existing grid lines as a guide for a thin pinstripe mask, it was prob 2x wider than the existing line. The problem was I was never able to get a consistent line drawn for an even thickness application of the conductive paint. Maybe some kind of foam applicator would work but I doubt it. the problem is getting the paint on thick enough to carry current. No matter what I tried it went south quickly. Patching one small section is one thing, but for me replacing the entire grid with conductive paint just did not work out.

The Permatex product uses a stencil.  But I think most of our old windows have just degraded over the whole surface.  It would be a lot of painting.

https://www.permatex.com/products/specialized-maintenance-repair/defogger-repair/permatex-complete-rear-windowdefogger-repair-kit/?locale=en_us

1. Using the small brush provided, apply the repair compound over the top of the stencil. (E) Make sure that the repair compound overlaps with both ends of the broken line.
2. Wait for the surface to become tack free. Repeat the application procedure three (3) times. Look through the window from the inside; there should be no light showing through the repaired area. If light shows through, apply another coat of repair compound.

Edited May 26, 20213 yr by Zed Head

I once nearly bought a screen where it had been all but wiped off while in storage. It must be possible to get them off with some care, but the question you gotta ask is, will it leave behind ghost lines? If not, then this may be a good way to go ....

https://frostfighter.com/clear-view-defrosters-16.htm

The spacing are ever so slightly different and will result in phantom lines if removing the old lines leaves a mark.

I suppose I'll do the obvious, and see if I can scrape it cleanly in the most inconspicuous place possible.

If I were gonna try this, I would scrape a small area with a razor blade and then polish the glass with something like meguiars mirror glaze on an electric buffer

Edited May 27, 20213 yr by Patcon

Before you scrape it, I would try some solvents. Acetone, Methanol. Maybe some paint remover?

Might get lucky and find something that will just wipe it off?

7 minutes ago, Patcon said:

polish the glass with something like meguiars mirror glaze

They make specific "glass buffing" stuff... Cerium oxide.

I've not looked into the specifics, but I assume it's harder than what they use in paint compounds.