Soldering a wire on a glass window

[HarryD]

I know this is not the Z4 forum but I am asking anyway.

The power wire to the defroster lines in my Z4 soft top has separated from the metal tab that is glued to the glass. The soft top has a glass window incorporated into the top that cannot be replaced separately.

It looks like I can whip out my trusty Weller soldering gun and reattach the wire. I am concerned that the heat from the soldering gun will stress the rear glass and crack it which will then require I replace the ENTIRE soft top. Does anyone here have any experience to doing this repair without first detaching the tab from the window (it is a pain in the *** to reattach the tab, I have done it 3 times already).

Thanks for your thoughts and support.

[rsscotty]

I don't know if this will give you an option, but Loctite makes a electrical conductive glue that is made for rear defogger repair.

[HarryD]

Originally Posted by rsscotty

I don't know if this will give you an option, but Loctite makes a electrical conductive glue that is made for rear defogger repair.

You mean something like this? It is what I used to attached the tab to the window.

[Superman]

I would do everything to avoid using a soldering iron on glass. The glass is laminated, which I assume you know.

[HarryD]

After much research, I finally tackled this little project.

I decided against soldering because it was unclear if it would damage the glass window.

When I examined the wire closely, I fond it was NOT soldered but glued onto the tab.

A bit of research revealed two options.

Atom Adhesives makes an Epoxy for this purpose: https://atomadhesives.com/window-defroster-repair-kit/.

On my workbench stash, I have the Permatex product pictures above: https://www.permatex.com/products/specialized-maintenance-repair/defogger-repair/permatex-rear-window-defoggerelectrically-conductive-tab-adhesive/

Comparing the products, it seems that the Atom product takes some time to initially cure and needs to be held in place for 24 hours.

The Permatex product initially sets in 1 minute and then you wait 24 hours to complete the cure. This plus the fact I had some on hand led me to use this.

After examining the wire, I found it was an insulated braided wire. I cleaned the wire with acetone (to remove any adhesive), rubbed with emery cloth and used a hammer to flatten the end. I cleaned the window tab with acetone and emery cloth. Followed the instructions for the glue and after 24 hours tested.

Success!

[2.7RS]

Great tip!!

I was wondering how to resolder my windshield antenna.

This should do. Thanks

[Dpmulvan]

Should be no problem soldering you can use some thermal paste around the area as an extra precaution.