Stabilization for small batch of blanks...

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Timbo

Timbo

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Joined
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Kill Devil Hills, NC USA.
I glued up some blanks made of 4 woods, one of them being Walnut which is much softer than the other woods. Turns out when you drill it, the bit go off-center toward the softer Walnut. Yes...my bits are sharp. I'm drilling on my lathe, upping the speed helps, but it does not eliminate the problem completely. I'm hoping that stabilization will get the Walnut closer in hardness to the other woods and eliminate the problem.

I'm not quite ready to buy a stabilization system, so I'm looking for someone who stabilizes with cactus juice to run 7 blanks through their system for me. Can pay with cash or blanks. Please PM me if you can help me out, and what you want in payment. Thanks.

 
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Justturnin said:
I dont think stabilizing will do any good for these. You have to bring them to +200* and I am sure that will not be good for the glue joint. Have you tried using a 60* countersink bit prior to drilling to help guide the drill bit in?

5 Piece Center Drill Countersink Set with 60° Angled Tip
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I would not be so sure about that! I have a customer who wanted to stabilize bent wood laminations after they were glued up with Titebond. I told him I did not think it would work as the glue would most likely fail. He tried it anyway and said it worked great with no issues. I have not tried it myself so am only passing on the info.
 
MesquiteMan said:
I would not be so sure about that! I have a customer who wanted to stabilize bent wood laminations after they were glued up with Titebond. I told him I did not think it would work as the glue would most likely fail. He tried it anyway and said it worked great with no issues. I have not tried it myself so am only passing on the info.
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I stand corrected. I would never have thought the glue would hold. Wow, is there anything titebond can't do?
 
Timbo said:
I glued up some blanks made of 4 woods, one of them being Walnut which is much softer than the other woods. Turns out when you drill it, the bit go off-center toward the softer Walnut. Yes...my bits are sharp. I'm drilling on my lathe, upping the speed helps, but it does not eliminate the problem completely. I'm hoping that stabilization will get the Walnut closer in hardness to the other woods and eliminate the problem.

I'm not quite ready to buy a stabilization system, so I'm looking for someone who stabilizes with cactus juice to run 7 blanks through their system for me. Can pay with cash or blanks. Please PM me if you can help me out, and what you want in payment. Thanks.

Click to expand...


I can help. I have made glue-ups using gorilla glue on Macassar Ebony and Zebrawood and it works awesome. I am not sure about helping with the centering problem, but I will give it a go if you would like.
 
Justturnin said:
I dont think stabilizing will do any good for these. You have to bring them to +200* and I am sure that will not be good for the glue joint. Have you tried using a 60* countersink bit prior to drilling to help guide the drill bit in?

5 Piece Center Drill Countersink Set with 60° Angled Tip
Click to expand...

Yes...I alway use a centering bit prior to drilling. That's not the problem. The bit starts perfectly centered, then wanders off, always in the direction of the Walnut...the path of least resistance.

You make a good point about the heat. I forgot that you can use heat to release a glue joint made with Tightbond. Curtis' comment makes me think that even though the glue bond may weaken, the resin is strong enough to hold the blank together.
 
Try step drilling it by starting with the smallest bit you have & increasing size of bit til you get to your finish hole size. You can also use a shorter bit so you have less of it sticking out of the chuck, I have actually purposely ground down bits & then put them in drill doctor just to have a stubby bit that wouldn't walk on me.

May not work for your problem but worth a try. I have also frozen pieces of soft wood & cork prior to drilling to keep them together. Works especially well on wine bottle corks.

Bill
 
Another thing you could try, if you have more wood and time for another glue-up, is to cut a small chamfer on one corner of each blank, and glue them up with the 4 chamfers towards the center. With careful gluing and clamping, you'll end up with a 'pilot hole' down the middle that will have glue squeeze out only in it. That might help with drilling issues.

Sent from my iPhone using Forum Runner
 
AeroCustoms.com said:
Try step drilling it by starting with the smallest bit you have & increasing size of bit til you get to your finish hole size. You can also use a shorter bit so you have less of it sticking out of the chuck, I have actually purposely ground down bits & then put them in drill doctor just to have a stubby bit that wouldn't walk on me.

May not work for your problem but worth a try. I have also frozen pieces of soft wood & cork prior to drilling to keep them together. Works especially well on wine bottle corks.

Bill
Click to expand...

Already tried "step drilling". Used 7mm bit in place of 10mm and the problem was worst. My guess is that the smaller diamerter bit flexed more. Stubby bit might work, but I don't have any on hand, nor the means to make one. Thanks for the suggestions.
 
juteck said:
Another thing you could try, if you have more wood and time for another glue-up, is to cut a small chamfer on one corner of each blank, and glue them up with the 4 chamfers towards the center. With careful gluing and clamping, you'll end up with a 'pilot hole' down the middle that will have glue squeeze out only in it. That might help with drilling issues.

Sent from my iPhone using Forum Runner
Click to expand...

I don't think it will work because there is still nothing to keep the bit from pushing away from the harder woods towards the Walnut. I may give it a try though. Thanks.
 
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jeweler53 said:
I hope it works for you. I did an experiment out of curiosity. I glued 3 blocks of Hard Rock Maple to a 4th block of Western Red Cedar. I was curious if I could replicate you problem.

I could not. I got a straight hole every time.:confused::confused:

Are you using wood boring bits?

Buy 6mm Metric Brad Point Bit at Woodcraft

like these?
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No...I use standard jobber bits for the most part, which have worked well for me until I ran into this situation. Were you drilling on the lathe? If not, give that a try with your wood boring bit. I'd be curious of your result if you used a jobber bit also.
 
I don't have, and am not endorsing that brand of bit. I tried it on the lathe (which I find to be more precise in general), but I do a fair amount of drilling on a drill press. My drill press is old, was cheap and is only passably OK.

In both cases it is the design of the drill that is working to your benefit. The brad point tends to stay "on center" The cutting edge is "flatter" (mine almost look like Forstner bits). The design of the bit does not place lateral pressure on the bit so it does not tend to wander.

Standard drill bits are primarily designed to drill in metal. While the work in most homogenous materials, the do not do well in material of inconsistent density.

Anyway, my thoughts. send the 2 cents if it was worth it! :cool:
 
Step 1 - Stabilization worked great...

For anyone interested, the stabilization process worked. Mannie was kind enough to stabilize the blanks for me. They survived both the Cactus Juice and the hgh temperature curing process without the glue joints failing. The blanks had been glued together with Titebond II.

They are on the way back to me now. Once I receive them I'll test the drilling process again to see if stabilizing them helps, and post the results as my final comment.

Many thanks to Mannie for helping me out.
 
Timbo said:
For anyone interested, the stabilization process worked. Mannie was kind enough to stabilize the blanks for me. They survived both the Cactus Juice and the hgh temperature curing process without the glue joints failing. The blanks had been glued together with Titebond II.
They are on the way back to me now. Once I receive them I'll test the drilling process again to see if stabilizing them helps, and post the results as my final comment.
Many thanks to Mannie for helping me out.
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Timothy I had a not too dissembler problem with a wood and metal glue up. This won't help with your current blanks but you might try it with any future ones.
In my problem the I was drilling down the center end of a 1/8" piece of aluminum sandwiched between pieces of wood. Essentially splitting the aluminum into two separate strips separated by a 7mm hole. The drill bit wanted to e "walk off" the 1/8" wide aluminum into the much softer wood. I solved the problem by "pre-splitting" the aluminum. The two pieces of aluminum are separated by a distance approximating the diameter of the bit. I just glued int a scrap piece of UHMW as a separator. It was much softer then either the wood or the aluminum. Here is the result.
IMG_3750.jpg IMG_3757.jpg

In your case you you could glue in a piece of soft pine or similar wood. Just rabbit or chamfer each piece to accept the softer wood. I would think this would work better then a chamfer alone because the variation in glue squeeze-out would be eliminated.
 
Glad to hear that the stabilization was successful and I hope the drilling will also be a success. Can't wait to hear how you make out.

For what it's worth, I'll describe my technique for handling a similar problem.

On a lathe, I have successfully drilled into the endgrain of soft woods with variable consistency by using an endmill mounted in the tailstock of the lathe. An endmill is shorter than a drill bit and much stiffer. I drill carefully, in small steps, and thereby make a 1.5" deep pilot hole of the correct diameter in each end of the blank. This leaves the center portion undrilled so far. I then use a parabolic drill bit of the correct size mounted in the tailstock to drill out the center portion, going in small steps and clearing the debris frequently.
 
magpens said:
Glad to hear that the stabilization was successful and I hope the drilling will also be a success. Can't wait to hear how you make out.

For what it's worth, I'll describe my technique for handling a similar problem.

On a lathe, I have successfully drilled into the endgrain of soft woods with variable consistency by using an endmill mounted in the tailstock of the lathe. An endmill is shorter than a drill bit and much stiffer. I drill carefully, in small steps, and thereby make a 1.5" deep pilot hole of the correct diameter in each end of the blank. This leaves the center portion undrilled so far. I then use a parabolic drill bit of the correct size mounted in the tailstock to drill out the center portion, going in small steps and clearing the debris frequently.
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I'm sure it'll work, but I don't do metalworking so it wont make sense for me to invest in an assortment of endmills. Thanks for the tip.
 
I would be interested in knowing if you find a difference in standard HSS drill bits and brad point bits (parabolic or not). I still believe that the standard HSS bid will do a much poorer job in wood than almost any brad point bit. I have been turning pens only for the last year, but I have been drilling holed in expensive (and sometime exotic) woods for decades. I would never use a standard "jobber" bit to do the job. I am only asking because I am curious if you find a similar result.
 
jeweler53 said:
I would be interested in knowing if you find a difference in standard HSS drill bits and brad point bits (parabolic or not). I still believe that the standard HSS bid will do a much poorer job in wood than almost any brad point bit. I have been turning pens only for the last year, but I have been drilling holed in expensive (and sometime exotic) woods for decades. I would never use a standard "jobber" bit to do the job. I am only asking because I am curious if you find a similar result.
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Hey Dick...I think you're overstating the significance of using bradpoint vs. jobber bits for 95% of the holes one might drill in wood. I think you might be right when it comes to this special case where woods of different hardness are laminated together. You would be right also if you need a really clean entry and exit hole. Between pens, keyrings, stylus, razor handles, etc., I've probably drilled a thousand holes in wood with jobber bits without a problem. Yes...bradpoint bits may work better, but you don't need them most of the time.
 
Final word on this problem...

Stabilizing the blanks made a difference, but it still wasn't perfect. The photo on the right is the stabilized blank drilled using the exact setup as the unstabilized blank on the left. As you can see, the exit hole is still off center, but not as much as before. I need to catch up on some flat work projects for now, but at some point in the near future I'll try drilling one of these blanks with a bradpoint as Dick suggested to see if it will do a better job.
 
GaryMGg said:
Tim,

What about drilling from both ends and trying to meet in the middle?
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The holes would be in the center at both ends of the blank, buy they would meet in the middle off-center...although it would be off-center by half as much. I can use the stabilized blanks with the hole a little off center, and make some nice pens I know would sell. However, I need the hole to be perfect to make the pens I originally envisioned, at the higher price point I had in mind.
 
I would suggest maybe a single flute gun drill type of drill, but they don't come cheap. If you have access to metal working machines (mill, lathe) you could make your own.

They don't flex and are designed to drill straight deep holes, but can work for shorter depths. we use them from time to time to drill water jackets in molds. You wouldn't need the coolent hole in it bascally you would cut the flute, rough shape the point, then heat treat, and sharpen the end.
 

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