Mid 80's Honda: gauge cluster glass is glued in: separate how?

My 85 Nighthawk 650 was recently forced off the road by an asshat truck driver and I went down. (Guy stopped, looked, then took off...)
Among the damage is a cracked glass lens in the gauge cluster. I've taken the cluster apart down to the bezel which holds the glass. The glass is glued in.
Two auto glass shops have said "Can't help you."
Honda, of course, has none to sell me.
I've put a WTB over at the nighthawk forum. Might hear from someone.
Here's the question: two, actually--
Why did Honda glue the lens into the bezel???:eek1
Do any of you have the hot tip on getting the lens out? (I've tried heat from a hair dryer. Softened things, no movement)

TIA

Oven?
Heat gun?
dynamite?

they might have glued it to keep moisture out maybe? i would try to soak it in something like paint thinner or something.

Check out headlight posts on car forums about HID retrofits and/or angel eyes retrofit.
They bake the plastic lenses at some temp and time and they come right apart.

If you have a replacement lens you could try to carefully break the glass and pick the pieces out, then when it is out you could figure out the best way to fit a new lens in place.

Thanks, guys. I'm sniffing around HID kit sites.
I don't have replacement glass. Hope to get the existing piece(s) out fairly intact to make/size another.

I know the fix for my early 80's Suzuki's with similar issues was to dremel or saw the whole speedo in half right below the glass bezel (chrome of some sort) and then glue the assembly back together. If your cut is in the right spot you won't have an obvious repair line.

Soak it in ACETONE.

If you used a hair dryer and it softened up some, more heat should take care of it. Beg/borrow/steal a heat gun with adjustable thermostat and slowly turn it up until the glue softens to the point of being able to remove the lens. If you have a hi/low heat gun, just sweep the air stream back and forth slowly to regulate the heat.
FWIW, a quick search suggests that appropriate oven temp to melt the glue is between 200 and 250 degrees, for anywhere from 5-10 minutes. I'd start at 200 for 5 minutes, pull the housing and test. If it's getting soft, put it back in, check every couple of minutes. After 10 minutes, I'd remove, let it cool and jack the oven temp up to 215-220. You want a slow temp increase, as you have no idea at what point the plastic will start to melt/deform. I'd think you'd be safe up to about 275 or so, but no point taking chances.
G

Acetone?
I'm a tich worried about trying that: the whole assembly is plastic. The lens is glass. I touched a bit of acetone to the back side and it began eating away at the plastic. What I'm calling silicon/glue is in a channel, thus contained, sort of. But while the acetone is sitting on the glue, it's also sitting on the plastic.
Can't think of a way to get the acetone on the glue without it landing on the plastic too.

what diameter replacement lens do you need?

I was thinking the gauge case would be steel. Yeah, acetone and plastic does not go well together.

You might want to google making a hotwire cutter. 9V battery and some Nichrome wire, as long as you can get the wire through in one spot, could free that lens.

You are right keep the chemicals away from the plastic.:eek1

This is mid80's styling, so the gauge cluster is sort of rectangular. Circles would be easy!
"Sort of" means there are angled corners and a center notch.
It's all plastic. From the inside or looking down at the lens, there's an outer shell upon which the glass rests. Then an inner piece, pressed and glued down onto the glass and to edges of the bottom piece. No place to pry without breaking glass. The glue isn't readily accessible, it's a good .5 inch below the edge of the plastic insert that's the keeper for the glass.
Obviously, Honda didn't plan on anyone having to repair this thing!
I'm waiting to hear from a guy who has a complete cluster he's parting out. Might have a bezel+lens for me.
I think I'll try the oven idea in the meantime...

http://www.bikebandit.com/houseofmotorcycles/1985-honda-night-hawk-650-cb650sc/o/m151694#sch407708

#11

Tried this:
oven, 200 degrees F, turn oven off, insert bezel.
wait 5 minutes. Adhesive rock solid.
Repeat, wait 10 minutes. Adhesive rock solid.
I'm nervous about going longer, although the hard parts remained hard and unwarped.
Higher temps?
Still waiting to hear from a guy who says he MIGHT have a spare to sell me. Until then, I'm proceeding cautiously.
Meanwhile a new round headlight assembly has arrived, to replace the trashed rectangular headlight on the bike. Going to replace all the turn signals with LED versions. New foot peg is on its way from fleabay. Putting reflective tape on the scraped parts of the top box.
Bought a voodoo doll and a box of pins for the guy who forced me to go down...

Keep that thing out of the oven. By the time you get it hot enough at the very minimum the lubricant is at risk of running out of the speedo head bearings.

Again, the original is broken so might as well break the rest of it out and proceed from there. It would be a great waste of your time and money to put all this effort into heating stuff up only to find afterwards that your speedo needle bounces and won't read over 35.

He said it was emptied out. It's just the shell now, so it's safe in the oven

Oh yes. Sorry if it isn't clear.
I'm dealing with plastic bezel only, not the case holding the speedo and tach and lights.
The plastic bezel, off the guage cluster, with its broken glass lens.
I appreciate the ideas/suggestions.

Oh wow, reading comprehension hasn't been my strong point this week!

One approach would be to try and shave a sliver off with an exato knife and play with it to see what softens it up.

One approach that might work is to use a small flame and concentrate on heating up the glass, possibly just enough to soften the glue so you can scrape it off.