Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: ferretjuggler on May 03, 2014, 06:52:41 PM

Title: Bonded Windscreens
Post by: ferretjuggler on May 03, 2014, 06:52:41 PM
Is it possible to remove one from a scrap vehicle and recycle it?

Just shows how behind the times I am.
Everything I own uses rubber gaskets or dum-dum compound.

I was told that careful use of a butane torch will soften the glue and allow removal without breakage.
Fumes given off are Cyanide based so caution advised.

Can it be done or mission impossible?
Title: Re: Bonded Windscreens
Post by: georgen on May 03, 2014, 06:58:36 PM
I would not remove one like that, its a pain in the arse but you can use those snap blade push out knifes, but dont snap it off just extend it right out and cut away from inside, dont try to rush it and push on glass before totally free or it will break, is it toughened or laminate, toughened can take a bit shit Laminate can be done but its a slow Job. 
Title: Re: Bonded Windscreens
Post by: ferretjuggler on May 03, 2014, 07:18:27 PM
Cheers
The guy who fitted a new screen to my Citroën AX hacked off the old screen with a knife thingy.
But that screen was smashed.
I didn't know if it worked for a good one too.
Just an example of being told something years ago and it stuck in my head until now.  :017:
Title: Re: Bonded Windscreens
Post by: georgen on May 03, 2014, 07:20:58 PM
as said its a ball ache but can be done, there are proper tools to take them out but they for taken broken ones out so do more damage 99% of the time, but ive seen quite a few took out the way I said.
Title: Re: Bonded Windscreens
Post by: Brynjaminjones on May 03, 2014, 11:11:57 PM
I think it's possible but difficult. I had the windscreen on my XJ pulled by a windscreen company to find the source of a leak, and even they smashed it in the process.
Title: Re: Bonded Windscreens
Post by: ferretjuggler on May 03, 2014, 11:40:00 PM
I think it's possible but difficult. I had the windscreen on my XJ pulled by a windscreen company to find the source of a leak, and even they smashed it in the process.
FFS
I could have smashed it for you for the price of a pint.  :017:

No seriously
I bet they charged you the full price of a new screen even though they had fucked up.  :wsmile:
I bet you wished you'd had a crack at it yourself instead

I pulled the screen out of a J series Cherokee by cutting away the rotten rubber gasket.
Made a perfect job of it.
Laid the screen down carefully on a wooden trailer bed and walked away.
Then there was a sharp "ping" , and when I went back to it the inner layer of glass had split straight down the centre line.
Weird!
Gotta expect that sorta thing with 40 year old stuff. :011:
Title: Re: Bonded Windscreens
Post by: The Smiths on May 04, 2014, 07:56:38 AM
I've cut out XJ screens before - using a long sharp knife, and going steady
Title: Re: Bonded Windscreens
Post by: Dave69 on May 04, 2014, 10:35:53 AM
most of the time you WILL crack the screen,

if you want it intact then be prepared to spend some hours slowly paring away the bonding goo, as this take literally hours. don't use heat, break a hacksaw blade and grind a sharp edge. this will keep a strong but thin blade and will allow for it to bend slightly for access between the frame and glass. keep resharpening it periodically.

a coil branch saw can work but it ends up catching the glass and increasing the chances of a crack starting.

i have done five windows for work and 4 cracked, time was one window a day for removal. sounds excessive but the bonding agent is tough
Title: Re: Bonded Windscreens
Post by: ferretjuggler on May 04, 2014, 10:55:01 AM
Cheers Dave.

Starting to sound like a real PITA TBH

Pity there's no chemical agent that will dissolve the adhesive.

Title: Re: Bonded Windscreens
Post by: eastryjeep on May 06, 2014, 12:39:20 PM
Never tried it, but what about an old guitar string or similar with a bit of current across it to heat it. Sort of like a hot wire cutter.

I have seen it attempted with cheese wire but again that screen got broken and it was being done by some independent fella with only his own money to lose.
Title: Re: Bonded Windscreens
Post by: ferretjuggler on May 06, 2014, 01:55:22 PM
Good thinking Batman :098:

No doubt just a case of trial and error and dogged persistence.

I wonder what temperature the adhesive melts at ?

Nichrome wire is the stuff to use I think.

Aircraft modellers have been using it for decades to cut foam wings with.
Title: Re: Bonded Windscreens
Post by: bigjeepzj on May 06, 2014, 03:50:46 PM
nichrome wire is the stuff.
It's what heating elements are made of
Title: Re: Bonded Windscreens
Post by: georgen on May 06, 2014, 04:42:28 PM
the problem with wire is it takes the straight line path from inside to outside, and as glass is normally recessed slightly and take your interior trim parts like dash, headlining etc into account, the chances are heightened that you damage trim inside and/or damage glass as wire will work its way to glass edge, the material used to bond screens in is very dense and strong, after all vehicles with bonded screen get a lot of strength from the design of having bonded glass and not old school rubbers.
Title: Re: Bonded Windscreens
Post by: Dave69 on May 06, 2014, 06:03:04 PM
hot wire is painful to use as the chances of getting burnt is high. great if you line cauterized knife cuts in your fingers, fire risk is also an issue with the interior trim. the hassle involved doesn't really make it easier.

if you want it done quickly call the experts but expect even them to crack the screen
Title: Re: Bonded Windscreens
Post by: bgbazz on May 06, 2014, 06:59:45 PM
Seems like a shit load of trouble/risk/chance just to get a worn out, fragile screen for little cost...and then you still have to fit it to something else!!  :017:

Just wondering.
Title: Re: Bonded Windscreens
Post by: eastryjeep on May 07, 2014, 06:56:56 PM
New idea!

Select likley looking stone from flowerbed, tape on screen in zone 'A', hit stone with mallet, remove stone and tape but do NOT claim on insurance as that is illegal.

Damn, did I really type that?
Title: Re: Bonded Windscreens
Post by: bgbazz on May 07, 2014, 07:06:28 PM
New idea!

Select likley looking stone from flowerbed, tape on screen in zone 'A', hit stone with mallet, remove stone and tape but do NOT claim on insurance as that is illegal.

Damn, did I really type that?

I can pretend I didn't read it....but I agree anyway.