How would you do this?

[pycoed]

I can't see the problem here: nails are about the softest steel you're ever likely to find, ditto carcasing bolts. Use a decent quality HSS (high speed steel) bit & it'll fly through them. No need to go for carbide or TIN coatings etc etc , just a good quality British, American, German or Swedish made bit (e.g. Dormer, Starret) not some hardware store Cheapistan special. Try your local engineering supplier, not Walmart!
You can get long series HSS drills, don't know if the 1/2" long series will be long enough, but easy enough to weld a bit of rebar to extend the drill shank if necessary. If you have a lathe, turn down the end of the drill & drill a matching hole in the steel bar, vee out join & fill with weld. Clean up in the lathe & you'd never know it wasn't made that way.

 

[J_J]

I would weld an extension to a carbide cement drill bit and touch up the carbide point for more aggressive cutting action. I would also use a 1/2 in drill.

 

[Mace Canute]

$15ish will get you a 1/2"x12" or 18" Dewalt or Irwin twist bit on Amazon. See: DEWALT DW1614 1/2-Inch by 12-Inch Extra Long Brad Point Twist Drill Bit - Amazon.com

This will work. The bit is a metal cutting bit and will easily cut through any nail in it's path. If it dulls, sharpen it.

 

[BeezFun]

I was not only willing to rent a hammer drill and bit, but I was willing to buy one given that I've got some concrete drilling work to do in a couple months.
Rusty

I don't think anyone suggested using a hammer drill, I wouldn't do that. I think the suggestion is to put the carbide bit in a regular 1/2" drill. I think a hammer drill would loosen the fasteners on the deck and not provide any advantage given that you're trying to drill through steel.

 

[Soundguy]

yep.. carbide on a bit extender and go... carbid bits are some amazing things...

 

[not2old]

The carbide attached to the cutting edge of a concrete drill is the same material machinists use to cut metal on a lathe. I've resharpened them for metal drilling. The tip of the bit needs to be sharpened to look like a regular high speed bit. Use a slow speed if you can and use lots of pressure. The most likely problem will be breaking the carbide tip off, but considering that you're drilling wood and nails are really soft, it's not likely.
PS Don't forget to tell us how this ends.

 

[Soundguy]

yep.. nails are pretty low grade stuff..

 

[Secret Squirrel]

The carbide attached to the cutting edge of a concrete drill is the same material machinists use to cut metal on a lathe. I've resharpened them for metal drilling. The tip of the bit needs to be sharpened to look like a regular high speed bit.

Just to be clear, my original thought regarding the hammer drill and 1/2" carbide bit approach was to rent, not buy. I don't think the rental guy would have been very happy if I had turned their expensive carbide bit from a masonry bit into a metal-cutting bit. But that said, I would like to hear more about what it takes to do this conversion at home.

Also to be clear, my largest and most powerful drill here at the house still only has a 3/8" chuck. I'm sure they are available somewhere, but around here there were no 1/2" carbide-tipped masonry drill bits available with 3/8" (or less) plain shanks... hence the need to rent (or borrow or buy) an SDS hammer drill and SDS carbide bit. The rental hammer drill in question does have a non-hammer (regular) drilling setting too... which, obviously, I would have tried first. I have no desire to crack or shatter the deck's pressure treated wood (at least not any more than I already have).

Use a slow speed if you can and use lots of pressure. The most likely problem will be breaking the carbide tip off, but considering that you're drilling wood and nails are really soft, it's not likely.

Been a lot of posts about how these nails are so soft and mushy as butter, etc., and how this task should be so easy and all that. Sure wish that were the case. I should have taken some pictures of the destroyed $25 nail eater bit after going through just one of those nasty nails. Soft and mushy? I don't think so.

PS Don't forget to tell us how this ends.

I will. I had to work yesterday, so I won't be able to try the 3/4" drill bit/extension rod/hole saw approach until later today. I fully expect it to work as long as the extension rod doesn't break. After all, these are just soft and mushy old nails, right?

Rusty

 

[pycoed]

Sorry, but you are not just listening!
1. Hammer drills are useless for drilling steel or wood. Their only use is for drilling masonry, when the hammer action helps to break up the medium. Wood you need to CUT, steel ditto.
2. You DON'T need carbide to cut steel, especially the grade of steel used for nails & carcassing bolts. Carbide tools are used to cut hardened steel well & ordinary steel fast.
3. HSS will cut hardened steel adequately well & ordinary steel perfectly well. It will piss through nails & joinery grade bolts.
4. I don't think you'd find a 1/2" holesaw, & in any case it would be clog easily with the wood. It would need to be a quality brand (Starret , Sandvik)
5. "Blacksmiths drills" have reduced shanks ( you say you have only a 3/8 drill) made by a by a decent American or North European maker (Dormer, Sandvik, Guhring etc) will drill YARDS of wood with nails & bolts in without needing sharpening.
6. Do NOT use an auger bit - the cutting edges will baulk when meeting steel no matter what they are made of.
7. If you are still not listening, & insist on using a carbide drill, then you WILL need (as others have pointed out) to sharpen it appropriately to cut steel. They will do a fine job on hardened steel (let alone the crap steel in nails etc. ), but ONLY when ground with the appropriate angles, & to acceptable sharpness, for cutting steel. If you can't do this (it requires a green grit or diamond wheel & knowledge/skill of the necessary angles, which are complex), then don't bother.
8. USE A GOOD QUALITY HSS BIT.

 

[Secret Squirrel]

The End!

I will. I had to work yesterday, so I won't be able to try the 3/4" drill bit/extension rod/hole saw approach until later today. I fully expect it to work as long as the extension rod doesn't break.

I am very pleased to report that the hole saw approach, as first recommended by flyerdan and further developed by Raspy, CurlyDave and myself, has done the trick! Finally!!! Thank you very much guys! You had the right idea! :thumbsup: :thumbsup: :thumbsup:

It did take going to a 3/4" hole (vs. 1/2" desired) to allow for use of the 12" long bit extension rod with its 11/16" diameter head, but no real harm done. The 1/2" thru-bolts are all in place, tightened and everything is now sturdy as a rock! Thank God!!!

Further thanks to everyone who offered their ideas and suggestions. This is a great place. I couldn't have done it without your help.

Rusty