Stefan Trethan wrote:
> Hi,
>
> just want to let you know 5 minute epoxy glue is not really suitable for
> long term use in CuCl, even out of the wet above the etchant it's no good
> idea. Came apart after maybe a year, maybe even longer. Turns brown and
> soft.
>
> Replaced with some plastic rivets "welded" in.
>
> OTOH rubber seems to hold up well, although i was worried because some
> compatibility page said it might not.
> Wide rubber bands that provide the PCB clamping force, cut from a bicycle
> tire, look like new, if possible even better.
>
> silicone is also just fine.
>
> ST
>
Interesting. I've had the "24hr" epoxy continuously immersed in CuCl for
8+ months and I can't detect any physical change except that it has gone
more yellow. But it went yellow in the first month, and hadn't changed
further since. I think not all epoxy is the same. I've always avoided
the 5 minute stuff, as it never set as hard or durable as the others.
I'm using low viscosity epoxy (http://www.westsystem.com) sold for fiber
glass work to glue/seal various items permanently immersed in 20%
sulfuric acid copper plating solutions, and my CuCl etching tanks. No
problems after 1 year. In other parts I've used a structural type
adhesive non flowing gel epoxy and find it stands up equally well
permanently immersed. The color changes to yellow over time.
Adam