High speed steel will dull very quickly in FR4. Carbide drills are the only way to go. As soon as the drill dulls (within seconds) it starts to grab the material, rather than cut. The first hole with a new HSS bit probably will be OK - after that, you'll get smearing and tearing.
Donald.
----- Original Message -----
> From: "kbyrne10@... [Homebrew_PCBs]" <Homebrew_PCBs@yahoogroups.com>
> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> Sent: Tuesday, November 22, 2016 1:56:41 PM
> Subject: [Homebrew_PCBs] Copper Clad Board
>
> I recently etched some thin brds .032 size with muratic acid and hydrogen
> peroxide per 3/4 cup muratic acid & 1 & 1/2 cup hydrogen peroxide mixture. I
> coated the traces with liquid tin then center punched the pads. I started
> drilling the pads with a dremel like variable speed moto tool and brand new
> high speed drill bits only to have pads pull away from copper clad brd.
> Why did this happen? Does anyone know as all I can tell is these are cheep
> orient type board stock bought in large pieces from a E-Bay buyer. It also
> took 15 to 20 min to etch boards at 120 degree temps. Professional positive
> brds in 1/16 thickness etched quite fast plus the pads did not pull away
> from fiberglass
> at all. Am I right to assume that I got a bad batch of boards from E-Bay.
> Any input would help me figure this one out as other board stock did not
> behave like tis over the past 4 years also.
>