[Land-speed] Dzus Fastener Question

[23weldon]

Most of my collection of ordinary size 5 Dzus Buttons have a taper of 120 
degrees included angle.  McMaster-Carr sells 120 degree countersinks on 
catalog page 2466:
http://www.mcmaster.com/#catalog/118/2466/=hvzzal
But I'm not sure that 120 degrees is right for the self ejecting buttons 
Mayf wants to use.
The above page shows single, 3 and 6 flute countersinks in two different 
steels.  There's also the question in my mind what is the best way to drill 
and pilot (if needed) the hole to keep from making a mess of the fiberglass. 
Hand drilling a nice finished fiberglass panel would scare me if I didn't 
know the right way to do it.
I don't think Mayf has much in the way of lathe capabilities out there in 
Pahrump to make a piloting setup; so he's probably going to have to buy what 
he needs.    He may be able to cobble up an aluminum or steel plate to go 
under the panel and put a conical depression in it with the countersink to 
guide the end of the countersink to the right depth.
Ed Weldon

----- Original Message ----- 
From: "Larry Mayfield" <drmayf at mayfco.com>
To: <land-speed at autox.team.net>
Sent: Friday, June 08, 2012 6:43 AM
Subject: [Land-speed] Dzus Fastener Question
>I have all the tools for installing all manners of Dzus fasteners.
> Except one, lol. I am going to use self ejecting buttons on fiberglass
> and that will require that I "dimple" the fiberglass in order to install
> the button and spring assy.  Large drill bits seem to have the wrong
> angle and shape: so what works? .......... mayf
drmayf at mayfco.com