Homebrew PCBs

On Tue, 03 Apr 2007 22:34:26 +0200, DJ Delorie <dj@...> wrote:

>> The MSDS (Material Safety Data Sheets) for J-B WELD shows that there
>> is 10-20% iron powder in the resin and hardner.
> Doh!  Nevermind.  Still, epoxy and heat don't get along, something to
> keep in mind.
> (jbweld is known to me because it's used to hold model rocket engine
> mounts in place, instead of epoxy)


Why do you get that impression?

FR4 _IS_ glass in an epoxy matrix.

In fact, JB weld itself is an epoxy if i'm not mistaken, only they take  
more $ for the brand and packaging.

There are different kinds of epoxy, for example the cheap 5 minute stuff  
is far less strong and resistant to chemicals than the longer curing  
versions. I expect it is also not very good with heat but i never used it  
in such an application. Shouldn't be too tricky to get hold of a high  
quality epoxy that is comparable to the PCB itself.
If stuff gets that hot in electronics there's a problem somewhere anyway.

ST