Drilling highly figured wood

[Sean Troy]

Hello all, I have a question (s) about drilling highly figured (quilted) Maple and avoiding blow out. The wood in question is two inches thick and I would like to drill a hole 2" dia. through the face with a forstner bit? Is that the right choice for that? Second, I would like to drill two 1/4" holes through the side (edge) of the 2" hole. The 2" hole will be about an inch from the edge of the wood. Exotic wood dowles will be inserted in the two 1/4" holes and glued in place so I don't have to go to far into the far side of the 2" hole. I would like to avoid blow out when I first come through the 2" hole with the 1/4" bit. I'll be using a drill press. Does speed of the bit make a difference? This is actually part of a woodturning art project. Thanks, Sean

[Lee Schierer]

I would drill the two small holes to depth first and then bore the larger hole. A forstner bit is a good choice, but you will want to stop short of drilling through. I generally stop when the tip of the bit just breaks the surface on the back side and then flip the piece over and complete the hole from the other side using the tip hole as the center. You could also drill a 1/16 diameter pilot hole all the way through and use that as your center and drill halfway from each side with the forstner bit.

One other way would be to tightly clamp a piece of hard wood (like hard maple) to the back side and bore all the way through. The backer piece should prevent any blow out if it is tightly clamped and both surfaces are in full contact with each other.

[glenn bradley]

I drill almost all the way through and then flip it like Lee describes. A DP fence and stops can help make sure you are aligned when you flip the piece.

[Dale Lesak]

Drill a pilot hole first. 1/6 or 1/8 hole is good. the point of the fostner bit will line up on the hole and drilling from both sides the hole will meet in the middle

[Sean Troy]

Thanks for the help. I knew I could count on SMC folks !!

[Danny Burns]

You might find these tempting.

http://www.leevalley.com/wood/page.aspx?c=2&p=62137&cat=1,180,42240

;):D:eek::D

[David Keller NC]

Sean - Lee's given you the appropriate advice. Avoiding blow-out when drilling wood is largely about strategizing ahead of time.

One thing I'll add that will help considerably is to sharpen your forstner bit, and buy a good quality German or American one, not a cheap chinese-made bit. The chinese ones are fine for drilling out waste from mortises, putting together jigs, etc..., but the ones I've owned had significant dimensional variances, roughly machined surfaces, and didn't hold an edge very well, so were not appropriate for a critical circular hole in something like rosewood or highly figured domestics where even the tiniest blow-out around the rim of the hole was not acceptable.

What I would suggest for sharpening your bit is a 1000 grit water stone slip, like the kind carvers use for sharpening their tools. Woodcraft sells them, and they're the right geometry for honing the flat on the flutes and honing the inside rim of the circular portion (btw - never sharpen the outside diameter of a forstner bit - you may change the geometry enough by doing so that the bit won't cut at all).

[Peter Quinn]

I would definitely drill the small holes first if at all possible to avoid blow out there. A brad point might make easier going of the 1/4" holes, and if possible spinning the brad point backward and advancing it into the work just a bit, maybe .015"-.025", then drilling the hole in standard rotation will help avoid any tear out at the surface. If reverse is not possible on your drill press, then securely attaching a block to the surface may help also if tear out on entry is an issue.

For a 2" through hole I generally clamp the piece securely to the drill press table with a solid backer beneath it and drill straight through with the forstner bit. Another option may be to drill a hole 1/8" undersized in you work piece, drill a full diameter hole in a piece of 1/2" MDF and use a spiral carbide flush trim bit and the MDF pattern to finish the hole in the work piece if drilling it on the drill press is not possible due to shape or size. I use this idea frequently with a whiteside 1/4" spiral flush trim bit in a trim router.

[Art Kelly]

IMO, you can't get a straight hole from a twist drill more than a few diameters of the bit, even in metal, which is sorta homogeneous.

When I want the hole to go straight, I use Forstners in the drill press. The 3/8" shaft is less likely to bend to follow the grain. When you get close to the bottom, THEN use the 1/8" twist drill to finish the penetration, flip over and finish with the Forstner.

If the work is not square (or at least with parallel sides), leave the twist drill in the drill press, flip over, and use the twist drill to align the work before clamping. Then WITHOUT MOVING ANYTHING, put the Forstner in and finish the job.

Art

[Sean Troy]

I'm always amazed at how much I learn here. thanks