drilling with a spade blade

[space-time]

i have a project where I need to drill about 40 holes, 5/8" diameter, 20 will be 1" deep and 20 will be 2" deep, all at an angle of 45 degree in respect to surface. All these in wood, I am not sure what type but the wood used in construction. It doesn't appear to be a hard wood, my guess it is some cheap wood used by the builders.

I have used drill bits before, but never a spade blade. I have some basic question, such as do I need lubrication? I have 2 drills, one Hitachi corded and a Bosch 12V lithium. I guess both are able to do the job, will see which one feels better in my hand. I have 2 sets of spade blades. The Craftsman has a sharp tip, but no thread, so I need to push it. The Bosch blade has a conical tip with thread, so I guess it will self advance somewhat, but I still have to push I guess.

My questions really are if I should use some lubricant to keep the blades cool and finish the 40 holes without destroying the blade. also, it would be nice to get smooth edges with minimum chipouts.

I guess it would be best if I get a piece of wood to practice first before I start the real work. I can take my time, I don't have to finish this quickly, so I can take a break in between if the blades get hot of if I need to recharge in case I decide to use the Bosch drill.

Any other advice or tips is appreciated. Thanks

[Carm]

Spade bit is a bad decision. It will more than likely break one of the wings because they are not made to drill at 45 degrees.

Pre-drill the holes with a smaller bit. Step up drill bit sizes.

[OWC Jamie]

Exactly what Carm said. You want to use a Forstner bit. They are not expensive and are used to drill a flat bottom hole - for cabinet work. And no lubrication required, just take your time and do a few holes at a time. Should not overheat doing them slowly and not into really hard hardwood.

[space-time]

Great! I will pick up one of those at Home Depot later today.

Thanks for the info.

[cbelt3]

Another vote for a Forstner bit here. I assume you are sinking holes for pegs or equivalent. Also think about making a jig to hold the angle if you are using a handheld drill. Nothing more than a hardwood block that has a bore of the right size. You can set it all up so the drill bottoms out on the jig at just the right depth of the hole.

Do note that a Forstner bit will NOT clear the chips all the way out of the hole the way a twist drill will. You will need to vacuum chips out, possibly as you drill. You can add a vacuum port to your jig if you want to get fancy. They also produce larger chips than a twist drill, so be prepared for that.

Oh, and the cheap Harbor Freight bits will work, but get dull pretty fast.

[OWC Jamie]

One other suggestion since you need to drill at angles - drill in a little bit straight / flat, THEN change to your 45º angle. Starting any bit not flat will cause it to jump a bit because you will only be drilling with one extreme edge of the bit. This way you'll keep the wood from chipping out as much - a Forstner bit will shave the surface and cut a nice clean round hole immediately. Only saying go in 1/8" or so flat and then change to the 45º. Trust me it'll work better.

[Ken Sp.]

If the 45° angle is critical, you may want to set up some sort of jig so that it will be accurate every time.

Edit. Oops didn't see CBelts post.

[davester]

More important than the bit type is that you use a drill guide like this one for drilling at 45 degrees:


They're about $50 at Home Depot, $20 at Harbor Freight.

A Forstner bit will give you a slightly cleaner hole but doesn't center as well as a spade bit. I'd probably just use the spade bits, which will work fine as long as you drill slowly and use the drill guide. You probably do not want to use the one with the screw on the front because you'll have to reverse every time you want to pull out.

[artie67]

Space-time, thanks for keeping me from my work. Solving your type of problem takes up a part of my normal day.
Spade bits. No, as the point to cutting wing seems to be about 45° and getting it started is a problem.
Forstner bits are worse. Tiny nib to start and turn? No, thanks.
Normal drill or Bradpoint wood drill would work best.
You will need a jig to get the proper angle. davester's suggestion would work well, but you would need a better quality tool like one shown. The HB one is plastic.
I think I have an extra 5/8" bradpoint with 3/8" shaft in the drill bucket. PM me if interested in the drill(free) or making the jig.
Also, for the forum, you need to add more info on the the project. We are guessing that maybe pegs for supporting things, I don't know. It would help.

[space-time]

artie67 wrote:
Space-time, thanks for keeping me from my work. Solving your type of problem takes up a part of my normal day.

You're welcome. My pleasure

artie67 wrote:
Also, for the forum, you need to add more info on the the project. We are guessing that maybe pegs for supporting things, I don't know. It would help.

here you go. previous owner installed these 45 degree 1/2 sticks in this 4x4 piece of wood (which is really 3.5 x 3.5"). Seems soft, I don't think it is a hard wood. The sticks came loose. They are many years old.

I found 48" long 5/8 diameter dowels at Home Depot. They seem stronger and should last longer than these 1/2. the problem is that if I install at 45 degree, I would need slightly longer sticks/dowels which are not available locally. So I plan to change the angle just a bit, maybe 40 degree or so. I want to have 1" into the lower/left post (not shown in this picture) and 1" into the upper/right post (the one shown here). I plan to drill a 2-3" hole in here, stick the upper end into this, then place the lower end into the 1" hole and slide it in. Gravity should keep the sticks down, and they can be easily taken out if necessary to repaint or replace. To fix the visible damage I plan to use some wood filler and repaint the whole thing.