Any suggestions for some decent spade bit extensions? I'm tired of the Irwin junk falling apart and breaking, I lost three of them inside a wall today. the set screw ones (Irwin) are tedious to assemble when you're crammed into a tiny dark attic, plus they won't accept the hex shanks. The sleeve lock type (Irwin) accept hex shanks, but they twist in half or come unhitched a lot. Just looking for some good quality if anyone has used some they would recommend.
I try to avoid spade bits- as abusive to the drill as they are to the operator. Ever considered a small auger bit? They are long enough you won't need an extension and since they are 1 piece.. nothing to loosen or fall off inside a wall. Just make sure your batteries are well charged. I love my 1/4 auger for doing little stuff- that and a cordless drill is like a mini-holehawg.
I'm with Ryan (Trollog) on this one, I tried the old spade bit when I started my apprenticeship, they last a few days, at the best. Get yourself a good auger bit, they are available in diameters from 5/8" up to 2". One other thing, the easiest way to break your wrist is to use a spade bit in hard Red Pine, when the drill jams.
I have a lot of auger bits. I am considering using them for this purpose, but I will still need extensions. I am drilling 4 and 1/2 feet down from the top plate in this particular rewire, sometimes the blocking is up to six feet down. I drill two 1" holes in the top plate, one for the drill and one to look thru. Then I drill the wall blocking with extensions. I have used the flex bits but they are not so great, hard to control and they don't stay sharp for very long. Sometimes they blow out the side of the plaster wall.
I do a lot of historic homes, where the plaster is best left undisturbed.
It's a tough situation because of limited height in the attic, the distance to the lumber, and the age of the lumber. Maybe you could try an auger bit which will cut better...with the set-screw type heavy-shank extensions which won't break. You could pre-assemble extensions if there is enough height in the attic. This way there is more time in setup, but once you get there the hole drilling will be easy...with a right-angle drill.
Although I've never done it, you're job might be a little easier if you gave yourself a generous slot in the upper plate. You could take out quite a bit of the plate (1" X 12") which would allow more angle in feeding the extensions, as well as a better view.
Those Forstner-style bits with a worm screw in the center that all the plumbers use for their holes are also nice for larger holes in wood, and they will fit on those hole hawg extensions. They are way more stable and easier to conrol than paddle bits and cut pretty good when they are dull, GREAT when they are sharp, and are substantial enough to snap a few nails if need be. They're easy to resharpen with a few passes from a file. They don't go as small as paddles, but the sizes on the small end will probably do the trick in most cases. The one problem with all of it is getting these things extended 6 feet.. 6 feet of holehawg extensions would get expensive quick if cost is even an issue, but on the other hand, you would have a variable extension you could lengthen or shorten in 18" segments as needed- nice when you are in a 2' crawl space and need to get a 6' extension down a hole. You might need to tap extra set screws into the standard extension to help control the wobble inherent in a shaft with so many junctions in it. On the "pro" side, however, forstner bits operate great at lower speeds than paddles which seem to like to spin as fast as possible. I agree with you totally on the flex bits.. junk. Never found a place to use them where something else wouldn't work better and with less trouble.
It always amazes me, just how many different ways we use to make a hole! No matter how many methods you have, there's always another that you need....
I've got away from the spade bits, in part because they are useless after you bump into a nail. In general, I find ship augers to be a better choice.
That is changing, though. I have become a real fan of the forstner-type bits.
As for the long 'flex' bits, I have had decent results with them. When making a long reach ... and I have the space ... I have run multiple extensions inside a length of pipe as an assist to keeping things in line and on track.
Big, I use several diamitors of the the flex bits for just what u are talking about. I drill 2 haole on topplate 1 for bit 1 to look down. The 5/8" flex bit is 6' long and has a larger shank, then I make sure to get it in the middle of the cross cat. It does get tough on the old plaster walls the plaster laying on the cats destroys the bits. I try not to use the flex bit that are like the ship aguer cause you cant sharpen them they need to have the bit tapered back. http://www.milwaukeeconnect.com/webapp/wcs/stores/servlet/product_27_40028_-1_681903_192645_192327#