Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

previous by date index next by date
previous in topic topic list next in topic

Subject: Re: [Homebrew_PCBs] Re: Best method for 2oz copper on 1/16" boards?

From: Roland Harriston <rolohar@...>
Date: 2007-04-03

Actually, I believe that " J.B. Weld"
is simply a two-part epoxy system with iron
powder added.

Same basic characteristics as generic
epoxy material.

Since the iron powder does not "crosslink"
with the epoxy system, I'm not sure what
viable function it serves, save for making
the system appear to be metallic.

Once hardened, (crosslinked) it does not "soften" to any
great extent when heated, but rather, will
decompose and burn if the heat rise is
high enough.

Roland F. Harriston

∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗

warrenbrayshaw wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com
> <mailto:Homebrew_PCBs%40yahoogroups.com>, DJ Delorie <dj@...> wrote:
> >
> >
> > "d1camero" <a8723@...> writes:
> > > Phil, thanks for the info. Good idea about the sandwich - I think I
> > > will try that!
> >
> > Beware that epoxy softens when heated. If that's an issue, use
> > something like J.B.Weld, which is more heat tolerant.
> >
>
> The MSDS (Material Safety Data Sheets) for J-B WELD shows that there is
> 10-20% iron powder in the resin and hardner. Perhaps this would not be
> a good
> choice for laminating PCB material with the chance of a short via the
> adhesive layer.
>
> http://jbweld.net/techinfo/index.php
> <http://jbweld.net/techinfo/index.php>
>
>


[Non-text portions of this message have been removed]