Forstner vs Spade for veneer?

[Floyd Cox]

Will Forstner bits work to drill through veneer glued to plywood or do I need to use a spade bit to help prevent tear out?
Holes are 1/4“& 1/2“
This is for the face for the clock in May 2019 wood magazine

Thank you

veneer.jpg

[Ted Calver]

I would sandwich/clamp the piece tightly between two sacrificial boards and use a forstner bit to drill the holes through the sacrificial pieces.

[Jim Becker]

What Ted said. You could use a spade with the "sandwich" but you'll want the type that has the scoring cutters at the edge to get a cleaner cut from that particular type of bit. But I typically use Forstner.

[Floyd Cox]

Thank you guys for the help

[andy bessette]

A Forstner or Fuller bit should do a clean job without the need to first go through a sacrificial piece. A backer is necessary though to avoid breakout on the backside. I would never consider a spade bit for 1/4" holes in veneer.

[Floyd Cox]

Thank you.

[Richard Coers]

Unless the spade bit has spurs, it will blow up the veneer.

[Chris Fournier]

A spade bit is for construction not woodworking. I've done both and even then a spade bit is the last choice.

[Zachary Hoyt]

It may depend on the quality of the bit in question. For holes that small I would prefer a brad point drill, but for bigger ones I prefer Forstner bits because they seem to have less runout. Maybe there are quality spade bits in existence, but I have not encountered them myself.
Zach

[Lee Schierer]

For zero tear out use the method Ted suggested with the finish piece sandwiched between sacrificial pieces either Brad point or Forstner bit will work best.

[Randy Benway]

Hi Floyd,
I must disagree with just about everything you've been told. I'm a retired wood patternmaker. Drilling a hole on size, on location, with decent finish is critical. When fabricating wood patterns and core boxes, everything was drilled then pinned with precision ground steel pins. It was MANDATORY that you had tooling that bored accurate holes. We all had Forster bits as well.... they were INVENTED 100 years ago for pattern work.

I suspect the drill bit that others are advising you to use is actually a multi-spur bit. The name Forster bit and Multi-spur bit have somehow become interchangeable now-a-days. THEY'RE NOT! They are two different animals and they behave totally different. It seems every type of drill for wood is being marketed as a Forster bit. This is a true Forster bit:

Attachment 407225

Note the sharpened but smooth rim and small center spur. The Forster doesn't require the center spur to be engaged in the wood to remain on-axis. Forster bits do ONE thing well: they HOG STOCK like nobody's business! Patternmakers would use a Forster bit to hog stock away before going to a wood mill or over-arm router to profile a shape. The old guys had 2 or 3 of them in their Gerstner... sets are worthless. They are the WORST at boring holes. The small center spur makes drilling on center very difficult. They require high tool pressure so can only be used in a drill press. That high tool pressure also means MASSIVE BLOWOUT when exiting a hole. That's not what they are designed for.
This is a multi-spur bit:

Snap13.jpg

Multi-spur bits typically have a larger center spur that make drilling to a center line reasonable. They require less tool pressure so can be used in a hand drill. They definitely require the center spur to remain engaged or they'll 'spit out' the work piece fairly quickly. They leave a reasonably good finish but will also cause blow-out... you need to drill from both sides and meet in the middle to avoid blowout.

You mentioned your application is boring 1/4" and 1/2" holes. In that size, you can't beat a standard 118 deg drill bit. I own many brad-point drills (even a full set of Cleveland brand from 1/8"-1"...frightenly expensive 35 years ago) they all bore slightly oversize, are difficult to sharpen, and leave an average finish. Brad points also REQUIRE that you bore from both sides to avoid blowout. Brad points don't like end grain either. Patternmakers all used standard 118 deg drill bits when it counted. They are easy to sharpen, require low tool pressure, loves end grain, and leaves a good finish. As stated before, just use a piece of scrap as a backup and you'll get good results. Hope this helps! Randy

[Floyd Cox]

Randy, thank you for this information. Just for my curiosity, I'll do some test drilling with all three that were suggested. In the machinist bits for this size hole I'm assuming they need to run at a high speed?

[andy bessette]

...
I suspect the drill bit that others are advising you to use is actually a multi-spur bit... This is a true Forster bit:...sets are worthless. They are the WORST at boring holes. The small center spur makes drilling on center very difficult. They require high tool pressure so can only be used in a drill press. That high tool pressure also means MASSIVE BLOWOUT when exiting a hole...you can't beat a standard 118 deg drill bit... Brad points also REQUIRE that you bore from both sides to avoid blowout...

Randy--most of your post is simply wrong, despite your claimed vast experience. It's Forstner bits we referred to, not Forster. Sets are imperative, just like other types of bits (I have 2 sets). The center spur is absolutely necessary. They can in fact easily be used in a drill motor. 118-degree twist drills will badly chip out the surface of the wooden workpiece unless a sacrificial top piece is used. Brad point drills don't blow out the far side if you use a backer block, which you always should on work whose underside will show.

[Randy Benway]

Hi Andy,

I don't claim to be a good speller, that's for sure... but I'll compare woodworking resume's with you anytime.

My point was that Forstner bits and Multi-spur bits are used inter-changeably when they shouldn't be. You didn't say what actual type(s) of bit you're raving about. I'm glad they work for you.

My friend invented a new type of drill jig years ago. I would go to the woodworking shows/stores and help him demo. It was AMAZING to us how so many woodworkers struggle to bore good, on-size holes. Almost every time they were using their 1400 rpm cordless drill and a brad-point.... made us smile. He used a commercial sharpener on his twist drills and ran them with a 2500 rpm corded pistol drill. Slicker than corn-through-a-goose... especially the end grain. All this tooling existed in the 80's when I served my apprenticeship in the pattern shop... I'm just passing on a little of what I learned.

Floyd,

Don't take my word for it. Grab one of your nice 1/4" or 1/2" twist drills and put it in your drill press. Spin it at 2500 rpm or more, back up the bottom, and try it on any veneered stock you want.

Regards,
Randy

[Pete Staehling]

FWIW, I never use anything on top and always have gotten nice clean holes on the top with forstner bits. I do find that a backer piece and/or care is require to avoid blowout in the back on exit. It helps to have nice sharp bits.

Brad point bits are okay, but IME forstner bits work better.

Avoid spade bits for any woodworking. They are for rough work like drilling holes for romex in wall studs.