polecat702

Is there a way to get the glass lenses out of the plastic housings with out breaking the lenses, or the housings? I have a spare fog light assembly with a good lens, and one with a cracked lens. The plastic frames need to be swapped.

Any ideas, are the lenses glued in?

dr bob

"Other Cars" use an adhesive that softens at around 300F. If you don't get a good answer you might try heating the assembly in the oven and see what comes loose. Take all the little plastic arms and other sensitive pieces out, maybe the reflectors too.

worf928

I have a set out on a bench. I'll take a look and report back.

jetson8859

Roger sells just replacement lenses so they are definitely removable. IIRC you heat them to around 215 or 220 and can then remove the lenses.

You might give Roger a call as I'm sure he has the instructions for his replacement lenses.

worf928

Yup. They're glued on.

Rob Edwards

Did a quick experiment with a foglight that had taken a rock hit:



Started with 15 minutes at 225oF, then took a big flatblade screwdriver and started prying. The adhesive was a bit more gooey but I was cracking off bits of glass without any give.

Back into the oven at 250 for 15 minutes. The adhesive could be scraped but it was still holding.

Back into the oven, 10 minutes at 300. Softened enough to separate.

I suspect that 325 would be ok, the plastic housing was still fine at 300.

polecat702

Thanks Rob, you're the master!

I'll do it tomorrow!

Mark R.

That's a great experiment Rob. You should be a science teacher..!

Speedtoys

How much glue stayed in the housing..is there enough there to put in new glass/plastic and seal up well?

Rob Edwards

The adhesive is kind of all-or nothing, some stayed with the housing but some went completely with the lens.

Begs the question of what the adhesive _is_....

ROG100

Clear RTV works fine for the install of the new lens.

Rob Edwards

The channel in the foglight housing for the adhesive is 6 mm- I think that this 7.5 mm Morimoto butyl glue looks interesting, and is available in gray. Roll out to desired thickness, install in the channel, heat at 265 for 7 minutes, press together.

https://www.theretrofitsource.com/mo...lue-51567.html

traxtar928

Be absolutely sure you've heated the glass and housing entirely, and DON'T PRY on it... I've chipped the glass lens on previous vehicle's fog lights because I was impatient and thought I could get it loose enough to overcome the adhesive using a pry tool and sharp blade.

The nice thing about the 928 fog lights is that the reflectors and other sensitive bits can be removed from the back so you're really only baking the glass and housing. I've tried using mineral spirits on the adhesive and it's really slow going and doesn't work well. I think that using an aggressive adhesive remover would make a reseal with RTV not work as well as it could if the remover was left behind in any way (like being saturated into the original adhesive and not completely wiped away).

hacker-pschorr

How you know Rob's wife is out of town

Rob Edwards

Meh, I spent the whole freaking weekend R&R'ing the convertible top canvas on her CLK, I earned some buytl-rubber-adhesive-smell-on-her-cutting-board points.

You think 928s are Germanically maniacally complicated? Pfft.