> On Monday, May 8, 2006 4:10 am, Stefan Trethan said
>
> Yes, the longer curing epoxy is much better. You only need to look
> at the
> mixing proportions, the 5 minute stuff uses 1:1 while the better
> stuff
> uses much less hardener. That additional hardener is material that
> doesn't
> do any favours to strength and chemical properties i guess.
>
> It turned yellow first as well. Then brown, and then soft.
>
> 24h curing is a lot of time though (with my patience ;-) ), so i'll
> stick
> to 5-minute epoxy for most stuff. I like the long shelf life of
> epoxy
> compared to other glues.
> For example that neutral curing silicone i bought not that long ago
> for
> the silicone paper tests - it's dead already. Doesn't cure any more.
> The
> acidic silicone just hardens up and you immediately see it is no
> good any
> more. But the neutral curing one will not harden, it stays a paste
> (though
> thicker and less shiny), but will not harden any more at all. So
> that's no
> fun at all, noticing a day after that the work was for nothing and
> you
> have to remove the gunk again. Learned my lesson - if it appears not
> as
> sticky as it used to try if it will still cure before using it!
>
> ST
I used Goop glue to build an etching tray for my FeCl3 tank, and have
also used it to glue handles to holding trays in both FeCl3 and HCl +
H202 tanks. Never had any failure or leakage. Stuff will glue pretty
much anything permanently.