I'd use a Forstner .....
Posted by: pilotwingz on Oct-14-13 11:12 PM (EST)
-- Last Updated: Oct-14-13 11:15 PM EST --
..... because it makes a much ceaner and precision bore , has far less blow out on the other side as well .
In any case you need to go through slowly . Not meaning rpm slow (cause upper range rpm helps make a cleaner cut) , but slowly as meaning "light" pressure on the drill's forward motion . Although not necessary , it's an advantage if you can get a backer block tight up to the inside to punch into a slight amount (someone may have to hold this for you while you drill the bore .
A Forstner "shaves" away material (between it's cutting ears) more like a plane does .
Anyway , it's plastic and the more pressure and slower rpm create more heat , and the larger the dianeter of the hole the more magnified that becomes ... higher speed and less pressure makes less heat . Heat softens and melts plastics , so the less the better when boring , cutting .
FE used a Forstner ...
The Kayak Wing
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