Failed blanks: causes and uses?

[AZturner]

Hello,

I'm new to turning and already have a few failed blanks laying around. What might have caused the issues on these two, and is there a creative way to utilize them now or are they just trash?

(Blank on left is cocobolo with epoxied tube, blank on right is ironwood that split during drilling.)

Thanks!

 

[Dragonlord85]

We need a little more information to know why these blanks cracked. When did the cracks occur, during drilling or glueing in the tubes or as you started to turn them.

 

[ed4copies]

Blank on the right is an easy repair: CA in the crack, then clamp it closed tightly for a day.

 

[Haynie]

There are two reasons I get cracks in my blanks

If the tube is in and I tighten it on the mandrel and it was not squared right or there was junk in the tube.

Cracks during drilling have been cause by dull bits. Keep them both and segment maybe.

 

[Dan Masshardt]

If the one one the left is a 7mm tube, you could prob get one of the little stylus things our of it.

 

[AZturner]

We need a little more information to know why these blanks cracked. When did the cracks occur, during drilling or glueing in the tubes or as you started to turn them.

I was in the process of milling the cocobolo blank in my drill press vise; when I pulled it out, it looked like that. I do not think it was all that tight in the vise...is cocobolo a fragile wood?

The ironwood cracked during drilling. The bit was loading up badly with rock hard chips, which I stopped to frequently pry out.

Blank on the right is an easy repair: CA in the crack, then clamp it closed tightly for a day.

Thanks, I'll give that a try, but I think it might be too wide of a crack.

There are two reasons I get cracks in my blanks

If the tube is in and I tighten it on the mandrel and it was not squared right or there was junk in the tube.

Cracks during drilling have been cause by dull bits. Keep them both and segment maybe.

Bit is almost brand new, but kept filling fast with rock hard chips as mentioned above. What does 'segment' mean?

If the one one the left is a 7mm tube, you could prob get one of the little stylus things our of it.

Perfect, thanks!

 

[ed4copies]

Thanks, I'll give that a try, but I think it might be too wide of a crack.

It was one piece of wood, before it cracked. Unless you are missing part that "flew out", it will be one piece of wood again. You will have to redrill and I would sharpen the bit before doing that---but the blank WILL "heal" if done properly. You will do it often, if you make thousands of pens.

Stuff happens!!:biggrin::biggrin:

 

[Dale Allen]

I'll throw in a word on the left one. You have to go easy with the pen mills.
In this case the blank is still square and it looks like the blank is just a bit wider then the mill is in diameter. When the blade of the pen mill is going from the narrow side and heading toward the corner, there is suddenly a lot more wood there to cut. The blade is acting somewhat like a chisel. The wood grain direction is also aiding the situation.

 

[mrcook4570]

Cut your blanks longer than the depth to which you will drill. After drilling to your desired depth, then expose the 'exit' hole by cutting the blank to the desired length (still leaving just a little for squaring after the tube is glued in place). This will prevent a lot of blanks from splitting when the drill exits the blank.

 

[Haynie]

Segment means cut it into pieces, glue it to other pieces in a pleasing pattern and make a pen out of it.

 

[AZturner]

OK, thanks for all of the tips. I will look up segmenting.

 

[AZturner]

Well, I was able to salvage the crushed cocobolo blank from my first post. I cut it to length of the PSI Patrizio tube (shorter than the pen stylus kit tubes I started with) and it just barely cleared the bushing at the torn out section. You can see the little section that was cut off in the photo.

 

[Dan Hintz]

AZ,

Next time, turn off the ripped portion and replace it with part of a different blank (this is the beginning of segmenting). I do this on the (rare ;-) ) occasion that I blow out the end of a blank.

 

[mikespenturningz]

I have also done exactly what Dan is talking about but you did a good job salvaging into the Patrizio too. That pen came out very nice.

 

[mikespenturningz]

There is an entire forum for segmenting. It is in the blank making forum. It is a very active group too.

OK, thanks for all of the tips. I will look up segmenting.

 

[beck3906]

The left blank could be salvaged by using crushed turquoise piled on the area and then dribbling on CA to hold it in place.

 

[BSea]

I think most of us have done what Dan has done. They even have an official name. they are called OOPS RINGS. I've even done them on purpose.

I always save my cutoffs, and cracked blanks. I use some for veneers, and some for fake centerbands on slimlines.

There is an entire forum for segmenting. It is in the blank making forum. It is a very active group too.

Spoken by one of the current segmenting super stars.

 

[bradh]

Another repair option: used, then dried, coffee grounds. Pack them into the crack with CA and the repair will look like a bark inclusion.

 

[OOPS]

Hello AZ: A pen I have made frequently by using my OOPS blanks is the Retro sold at Woodcraft. (Others sell a Retro, but they are not the same as the Woodcraft Retro.) It uses two small blanks, so generally there is plenty of material left after a crack or blowout to still make one of these. I have used different kinds of wood for each section, (mix and match, in other words,) with good results. It is a solution worth considering.

 

[AZturner]

Thanks again everyone. OOPS, that sounds like a good option. I will pick one up next time I'm at woodcraft.

 

[CrimsonKeel]

The left blank could be salvaged by using crushed turquoise piled on the area and then dribbling on CA to hold it in place.

this is what i was going to suggest. I blew out a blank exactly like that one and its what i did to salvage it