Replies to This Discussion

Permalink Reply by Loren Warner on January 8, 2018 at 4:08pm

Use #40 (A4) as pilot hole, then open to #30 (A5).  After which, debur, etch, and prime accordingly.  

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Permalink Reply by John Austin on January 8, 2018 at 9:48pm

Use #40 (A4) as pilot hole, then open to #30 (A5)

I agree to pilot with #40 and then expand to #30, but a #40 is for A3 (3/32") rivets and silver clecos and

a #30 is for A4 (1/8") rivets and copper clecos. (A5's are 5/32"-black clecos)

John

N750A

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Permalink Reply by Loren Warner on January 9, 2018 at 10:03am

Thanks for the correction John

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Permalink Reply by Joe Hopwood on January 8, 2018 at 4:14pm

When I first began there was a document that gave general instructions.  Also there were numerous references to other documents that contained accepted procedures.  I would recommend a review of these.  It could prevent much rework.

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Permalink Reply by Damon Brantley on January 8, 2018 at 10:00pm

Drill out first to #40, then cleco. Then delay enlarging to #30 for as along as is practical. My personal experience is that you want to delay doing anything that can not be undone for as long as possible. At the very least you save your self the time of drilling #30 holes if you discover that the #40's are not in the correct location.

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Permalink Reply by dewayne clardy on November 18, 2020 at 3:26pm

always pilot holes first then step up to final size it makes a cleaner , and lessen the chances of drill bit walking on you. if you wanted to be real anal/ professional you can buy bits with pilots on them, ie double margin or core drills. that way the pilot on the bit will follow the pilot in the skin. lessens chances of holes moving on you.

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