The dreaded gap between tube and blank

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Sly Dog

Sly Dog

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Hey all,
After squaring a hybrid blank recently I noticed a drilling issue on one end, a sliver of a crescent moon that looked like this:
BA398439-D4BA-486C-BBB0-3FE364477982.jpg

The gap looks hollow but is actually filled with epoxy; nevertheless it meets the outer diameter of the bushing I intend to use. I did paint both tube and hole. I don't know how far along the tube the gap is, but it just looks like a blow up waiting to happen. It's a nice blank and I'd like to salvage it if possible.

The only remedy I can think of is to use a parting tool to turn down the affected region to the tube and glue on a segmented end cap (maybe on both sides), though that will be hard to make look good.

As the Dude said, maybe my thinking has become too uptight, man. :laugh: Anyway, I appreciate any thoughts, suggestions you might have.

Russ
 
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Yep no way out. Use a oops band and will hide it or use a larger kit if possible. Could also do a bulbous looking turned blank. Good luck.
 
If it is filled with epoxy all the way through you shouldn't worry about a blow out if you take light cuts with a sharp tool. Once I turned it to size I'd see how it looks and if I wasn't happy turn it down to below size. Then take shavings and backfill it with them and ca glue. Let it dry and then turn it back down to the appropriate size. Its risky but it might work?
 
Sly Dog said:
Hey all,
After squaring a hybrid blank recently I noticed a drilling issue on one end, a sliver of a crescent moon that looked like this:
View attachment 184142

The gap looks hollow but is actually filled with epoxy; nevertheless it meets the outer diameter of the bushing I intend to use. I did paint both tube and hole. I don't know how far along the tube the gap is, but it just looks like a blow up waiting to happen. It's a nice blank and I'd like to salvage it if possible.

The only remedy I can think of is to use a parting tool to turn down the affected region to the tube and glue on a segmented end cap (maybe on both sides), though that will be hard to make look good.

As the Dude said, maybe my thinking has become too uptight, man. :laugh: Anyway, I appreciate any thoughts, suggestions you might have.

Russ
Click to expand...

Check with calipers the OD of the components, there may be enough timber to be OK to turn.

And, using end caps is not too tough, and can look quite nice with some attention to contrasting materials. I simply us any available stick/scrap wood of the approximate dimension wanted (eg, 1/8", 1/4", etc) to get the two ends equal, part it down to the tube on both ends, drill the tube holes in the end cap material and you are good to go.
 

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I'm afraid I have to disagree with my fellow penturners. To me it looks like the hole is simply too big for the tube...ie; wrong drill size used.
I honestly don't think an oops band will help.
I'd see if the tube matches another fatter kit or take a chance and just go for it, you may be lucky....if it blows, it blows. :wink:
 
I've had that happen when the drill is started off center ; the starter hole end becomes elongated. I've compensated on occasion by leaving the blank long and gluing the tube in past the elongated part, or if the gap isn't extreme by filling it with CA. But looking at the photo, in this case I see no options other than making a new blank or using oops bands.
 
I'm not optimistic, but I would turn it. At worst, you can just turn off the timber and re-use the tube (assuming you've not overly shortened it while squaring). I've gotten away with a sloppy drill job a few times, a couple times, not so much. How does the other end look? I'm not sure it's the wrong sized hole--I've had bits follow the grain in wooden blanks and produce an exit hole that's too big, even having center-drilled first and I drill on my machinist's lathe so it's pretty rigid.
 
Is this an ongoing issue you have or just a one-off thing? It does look like a nice hybrid blank. I'd take the same size tube and while holding it butted up against the end of the blank backfill it with dust and CA. Would avoid the barrel trimmer especially since it looks like a hybrid blank and a barrel trimmer just loves to eat hybrids for dinner. Opt for the disc sander, then just turn it. As someone said, if it blows, it blows but you should be fine if the rest of the tube is firmly secured in the blank.
 
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I had that happen a couple of times. Can't really say what caused it. Here's what I did- I got a thin needle and put the point in the space between the tube and blank. I ran a couple of drops of thin CA down the needle and into the space. Tap the blank lightly to get the CA down even more. Once, I had to do this twice to fill the gap.
 
1 or 2 out 20 barrels, I will get that whether I drill on a press or lathe, whether I use a new/sharpened bit, drill and 1/4" at a time or 3/4 at a time. I might just stink at drilling.

My only "somewhat successful" work-around is to try to keep it centered when gluing...and that doesn't work all of the time.

I also think the hole is too big versus OOO.

What is a oops ring?
 
Thank you for those suggestions - you folks are awesome. Though I share some of your pessimism, of course I will take it slowly and carefully with my toes crossed and hope.

I drilled on the lathe and am sure I used the correct sized bit. I drilled three blanks in a row and all were fine except this blank, which only had one end with a gap; the other end was tight. I'll give it turn tomorrow or Monday and post a pic - if it survives.

Again - thanks for your time and have a great weekend!

Russ
 
TonyL said:
1 or 2 out 20 barrels, I will get that whether I drill on a press or lathe, whether I use a new/sharpened bit, drill and 1/4" at a time or 3/4 at a time. I might just stink at drilling.

My only "somewhat successful" work-around is to try to keep it centered when gluing...and that doesn't work all of the time.

I also think the hole is too big versus OOO.

What is a oops ring?
Click to expand...

Tony - I think an oops ring is the end cap idea - that's my interpretation anyway.
 
Woodchipper said:
I had that happen a couple of times. Can't really say what caused it. Here's what I did- I got a thin needle and put the point in the space between the tube and blank. I ran a couple of drops of thin CA down the needle and into the space. Tap the blank lightly to get the CA down even more. Once, I had to do this twice to fill the gap.
Click to expand...

That's a clever idea - thanks.
 
TonyL said:
1 or 2 out 20 barrels, I will get that whether I drill on a press or lathe, whether I use a new/sharpened bit, drill and 1/4" at a time or 3/4 at a time. I might just stink at drilling.

My only "somewhat successful" work-around is to try to keep it centered when gluing...and that doesn't work all of the time.

I also think the hole is too big versus OOO.

What is a oops ring?
Click to expand...

Tony, an oops ring shown here. One of mine.
 

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skiprat said:
I'm afraid I have to disagree with my fellow penturners. To me it looks like the hole is simply too big for the tube...ie; wrong drill size used.
I honestly don't think an oops band will help.
I'd see if the tube matches another fatter kit or take a chance and just go for it, you may be lucky....if it blows, it blows. :wink:
Click to expand...

Hey I said that too:rolleyes::rolleyes::rolleyes:
 
Sly Dog said:
I drilled on the lathe and am sure I used the correct sized bit. I drilled three blanks in a row and all were fine except this blank, which only had one end with a gap; the other end was tight. I'll give it turn tomorrow or Monday and post a pic - if it survives.
Click to expand...


Russ; Did you make any other blanks of this kit? When I am making the first of a kit, I print a copy of the instructions for my binder. The instructions have the nearest COMMONLY available size drill bit, NOT necessarily the best fit. I often find the correct drill bit is NOT the one on the instructions.

I have a 115 drill bit set (Fractional, Number, and Letter set) and a metric set too!

I start a size or two smaller than the stated drill bit size. Try the brass tube and then step up to the next larger drill bit. There are several good drill bit size charts in the library.
 
randyrls said:
Sly Dog said:
I drilled on the lathe and am sure I used the correct sized bit. I drilled three blanks in a row and all were fine except this blank, which only had one end with a gap; the other end was tight. I'll give it turn tomorrow or Monday and post a pic - if it survives.
Click to expand...


Russ; Did you make any other blanks of this kit? When I am making the first of a kit, I print a copy of the instructions for my binder. The instructions have the nearest COMMONLY available size drill bit, NOT necessarily the best fit. I often find the correct drill bit is NOT the one on the instructions.

I have a 115 drill bit set (Fractional, Number, and Letter set) and a metric set too!

I start a size or two smaller than the stated drill bit size. Try the brass tube and then step up to the next larger drill bit. There are several good drill bit size charts in the library.
Click to expand...

That's a good point, Randy. I used the 27/64 bit recommended for the Sierra kit. I haven't had this problem in the past, but I have heard that other sized bits may achieve a better fit. I don't have that comprehensive bit set...yet. :smile:
Thank you!
 
Epilogue:

The blank did not blow up! I did drip some thin CA in the gap which was mostly epoxy, and I think that helped.

The bad news is that the thinnest part of the blank sanded through to the epoxy. So, I got some practice at trying to save the blank with oops rings. Here's how it turned out:
066992D2-628A-4982-A701-3246F9DF35D6.jpg

Not great but not a total loss either.

Appreciated your time and suggestions!

Russ
 
Sly Dog said:
Epilogue:

The blank did not blow up! I did drip some thin CA in the gap which was mostly epoxy, and I think that helped.

The bad news is that the thinnest part of the blank sanded through to the epoxy. So, I got some practice at trying to save the blank with oops rings. Here's how it turned out:
View attachment 184213

Not great but not a total loss either.
Appreciated your time and suggestions!

Russ
Click to expand...

Occasionally one kind of wood butted up against a different kind or color looks good, but usually a silver, brass, copper, or white or black ring as a separator - as you did - make it look great and intentional. Yours does!
 
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