Show me your holes.... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

tonypaul · 11-27-2010, 02:42 PM

I need to start drilling new holes for all my trim. I have diagrams for the upper and lower trim but not the tailgate and eyelid trim. My hood still has the holes but everything else has been replaced or filled in by the PO. Does anyone have pics of their front fenders or tailgates without the trim on- with the holes showing??
Thanks!

LONGHAIR · 11-27-2010, 05:30 PM

First and foremost, do NOT use a regular "twist drill" type bit. You will be very up-set by the bending/tearing that they can do in unsupported sheetmetal. They turn into a "cork-screw" as they break through. This gets you a big nasty burr, a dent, or a "volcano". Bits that are designed for sheetmetal don't have spiral flutes, so they don't do that. "Step drills" are great for this kind of thing.

tonypaul · 11-27-2010, 05:51 PM

Quote:

Originally Posted by LONGHAIR

First and foremost, do NOT use a regular "twist drill" type bit. You will be very up-set by the bending/tearing that they can do in unsupported sheetmetal. They turn into a "cork-screw" as they break through. This gets you a big nasty burr, a dent, or a "volcano". Bits that are designed for sheetmetal don't have spiral flutes, so they don't do that. "Step drills" are great for this kind of thing.

Thanks for that info! I did drill some already and a couple holes came out a little corkscrew. I bought some brand new drill bits and drilled some more and the rest came out fine. My drill bits where really old... I need to research into "Step drills"...... Where can I get some of these?

Thanks again!

LONGHAIR · 11-27-2010, 06:24 PM

Lots of places sell them. Major retailers like the "big home centers", Sears, maybe you have a local "tool store" ...then there is always the internet.

The size of the hole matters to some degree. In really small holes, you can get by with twist drills, especially in thicker sheetmetal of these older trucks, but the bigger the hole, or the thinner the metal is where this gets more important.

Check this link

tonypaul · 11-27-2010, 06:41 PM

I got some of those step drill bits, but my concearn is that the holes I need are 17/64ths and 11/32nds for most of the trim. The step bits I have dont have these sizes. I did just go and drill a couple new holes and I found that if I use a real small drill bit and then a little bigger and so on untill I reach the desired size it comes out fine..... I will look around to see if I can find the step bits with the right sizes....

Thanks for all your help!

11-27-2010, 02:42 PM	#1
tonypaul Registered User Join Date: Nov 2009 Location: Austin Tx Posts: 639	Show me your holes.... I need to start drilling new holes for all my trim. I have diagrams for the upper and lower trim but not the tailgate and eyelid trim. My hood still has the holes but everything else has been replaced or filled in by the PO. Does anyone have pics of their front fenders or tailgates without the trim on- with the holes showing?? Thanks!

11-27-2010, 06:41 PM	#5
tonypaul Registered User Join Date: Nov 2009 Location: Austin Tx Posts: 639	Re: Show me your holes.... I got some of those step drill bits, but my concearn is that the holes I need are 17/64ths and 11/32nds for most of the trim. The step bits I have dont have these sizes. I did just go and drill a couple new holes and I found that if I use a real small drill bit and then a little bigger and so on untill I reach the desired size it comes out fine..... I will look around to see if I can find the step bits with the right sizes.... Thanks for all your help!



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