Need a good Epoxy

[hockeyman]

I have a Minivan as a second car, and the passenger side window keeps coming loose from it's window mounts. There are two mounts at the bottom of the window that hold it, and they are shaped in a "U". The window sits inside of them with some sort of glue that holds them in place, but the original epoxy came loose once when the windows were frozen one winter and every epoxy I've used so far only holds up for about 3-5 months, then breaks loose.
So far I've used the quick-set 4 minute epoxy and then the standard 1 hour clear epoxy. It's the stuff that comes in the plastic tubes and squeezes out to be mixed.

I need something better...ALOT better. Basically, something that won't crack over time.

Any suggestions??

[hockeyman]

Oh, and I also need it asap. I really cannot wait for a mail order.

[rhodeymark]

Find a Marine Supply store - they have waterproof epoxys that hold boat seams together. Strongest stuff I have ever used and you don't want to get any on your fingers. Only drawback is you can't use the window for 48 hrs with this stuff.

[Pewter2K1]

the longer it takes to cure, the stronger it is... and yes, i second marine epoxy... West systems makes some good stuff.... not sure what the smallest size you can get it in, because its expensive.... and it takes at least 24 hours to set and 48 to cure completely

[hockeyman]

Cool, marine epoxy it is then...thanks!

[rhodeymark]

West - I believe that's the one I have. It was like $20 for a medium tube, and it is the most versatile glue I have ever used. One drop of their black epoxy even stopped a pinhole in my canvas top from further fraying - permanently. If I ever rip a seam that is what I will use to delay the inevitable.

[zlexiss]

What are you doing for surface prep? That's going to be your #1 factor, as good bond prep will make a difference of an order of magnitude, versus epoxy formulation which is only about a factor of 2.

1. Get everything off the window and channel. Bare metal and glass. The metal should be a fresh, non-oxidized surface (i.e. if it's aluminum, bond within a couple hours, or re-scuff with scotchbrite)

2. Clean well with solvent to remove all dirt and oil. 90% isopropyl from a drugstore should do fine. Give it 15-30 minutes to flash off completely.

3. Be very anal on the mix ratios. If you're more than 5% weight or volume off, strength will suffer.

4. Do not disturb the bond until it's past handling cure. Any shift or movement before than will weaken the bond a whole lot.

You might want to look at an alternative to epoxy with better properties for this application. Not sure on sources (I work in aerospace), but a 2-part urethane adhesive will keep a very tough bond, won't get brittle like epoxy at lower temperatures, and has some elasticity to withstand shock.

-Jeff

[hockeyman]

I've prepped the glass before with alcohol, but I haven't tried the scotchbrite pad. Also, I let everything cure for at least 24 hours before I attempt to try it.

I'm about to go out and tear it down again since the sun finally came out!

Thanks again!

[Skinny]

If the marine epoxy doesn't work, go to a GM dealership and ask for some window sash epoxy. Thats the stuff that was originally there (assuming this is a GM van, otherwise it's likely to be a very similar epoxy). It's kind of expensive (about $24) but it doesn't come apart.

[Razzer]

Go to gm parts store and get some gm body adhesive (epoxy) great stuff and extremely strong. May be a little exspensive, but they use it to hold body panels in place.