Segmenting

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KenB259

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I have a question regarding segmenting. On occasion, as I'm turning rather delicate blanks, I flood the blank with thin CA. My question is, If I have glued the blank up with epoxy, does flooding the blank with thin CA do anything at all? I am thinking I'm probably wasting my time and CA, unless I have done the initial glue up with CA. What do you all think?
 
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elyk864

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When you do the epoxy is it in a vacuum chamber? If not I'd say some of the epoxy is not going to get in all the spaces like thin CA does.
 

KenB259

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No, I don't use a vacuum chamber for glue ups. That brings up another question though. Does anyone use a vacuum chamber when gluing segments?
 

John Eldeen

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I would believe stabilizing the outside with thin CA will help reduce the stress on the inside giving you a better chance of making it to the end. Thin CA is cheap insurance as far as I am concerned.
 

KenB259

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Thinking outloud here, but I believe a vacuum chamber would pull the glues from the blank. The glue would be dry when you rerelease the vacuum and actually do more harm than anything else.
 

magpens

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@KenB259

I assume that your intention in flooding with CA is to add strength to your segmented blanks

I am not sure what your concern is ... are you worried that the CA won't stick to the epoxy used for your glue-up? . Or are you worried there will be an adverse interaction between the CA and the epoxy ?

I honestly believe that you have nothing to worry about. . I have done what you describe many, many times and in my experience there has never been any adverse effect.

What's more, I have reason to believe that flooding with CA in fact DOES strengthen the segmented blank. . As stated about, thin CA is very effective in filling voids (which epoxy sometimes does not do), and the CA treatment is a good insurance that your turning will be successful. . You would be well advised to repeat the CA flooding several times as you approach the final diameter. . I do the repeat application after removing each 20 thou thickness of the blank material. . Perhaps I am overdoing it, but I would rather not ruin a segmented blank that I have spent hours constructing.

The idea of "soaking" the drilled blank with thin CA before gluing in the brass tube is also a good one. . However, you will probably have to redrill the blank after the CA "soak". . My use of the term "soak" in this context does not literally mean the immersion of the blank in a container holding the CA. . It simply means a liberal application of CA to the internal diameter of the hole using a looped wire to transfer the CA into the hole.

Hope this helps.
 

jttheclockman

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Well here are my thoughts. If you are using epoxy to glue the segments then the CA will do nothing to the glue joints. If you soak the blank with CA before you glue in tube then all you are doing is making a slick coated surface and yes epoxy will stick to just about anything so no harm there but over kill in my opinion. If applying CA to the outside as you turn you are strengthening the fibers around the joints. If using acrylic blank you are wasting your time . Just my opinion.
 

Humongous

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The CA should help as it will soak into the porous material deeper than an epoxy, assuming that you are using wood or similar material. This will be helpful to prevent chipping especially with smaller segments and segments near the ends.
 

KenB259

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Thanks to all who responded, I'll just keep on as I have been doing. I recently switched to system 3 epoxy and it appears to be a lot better than the BSI I have always used.
 

mark james

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My question is, If I have glued the blank up with epoxy, does flooding the blank with thin CA do anything at all?
Sure, as you turn the blank down, "un-epoxied" sections will be repeatedly exposed, so a CA flood will assist. I do this frequently (Epoxy the segments, epoxy the tube, CA as I turn).

When you do the epoxy is it in a vacuum chamber? If not I'd say some of the epoxy is not going to get in all the spaces like thin CA does.
Yup, the CA flood will assist to keep the segments solid.

I assume flooding the blank fills any gaps in the segments and reduces the possibility of tear out.
Yup, again.
Try soaking the inside of the blank with thin CA before gluing in the tube. Let the ca completely setup before gluing in the tube.
This is also good practice. Eventually, the very inner layer of wood is left, the least stabilized unless you did this to work from the inside-out.

@KenB259

I assume that your intention in flooding with CA is to add strength to your segmented blanks

I am not sure what your concern is ... are you worried that the CA won't stick to the epoxy used for your glue-up? . Or are you worried there will be an adverse interaction between the CA and the epoxy ?

I honestly believe that you have nothing to worry about. . I have done what you describe many, many times and in my experience there has never been any adverse effect.

What's more, I have reason to believe that flooding with CA in fact DOES strengthen the segmented blank. . As stated about, thin CA is very effective in filling voids (which epoxy sometimes does not do), and the CA treatment is a good insurance that your turning will be successful. . You would be well advised to repeat the CA flooding several times as you approach the final diameter. . I do the repeat application after removing each 20 thou thickness of the blank material. . Perhaps I am overdoing it, but I would rather not ruin a segmented blank that I have spent hours constructing.

The idea of "soaking" the drilled blank with thin CA before gluing in the brass tube is also a good one. . However, you will probably have to redrill the blank after the CA "soak". . My use of the term "soak" in this context does not literally mean the immersion of the blank in a container holding the CA. . It simply means a liberal application of CA to the internal diameter of the hole using a looped wire to transfer the CA into the hole.

Hope this helps.
Mal's entire post is an excellent summary!

The CA should help as it will soak into the porous material deeper than an epoxy, assuming that you are using wood or similar material. This will be helpful to prevent chipping especially with smaller segments and segments near the ends.
Yup!
 

KenB259

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Thanks again. The only thing I haven’t done is apply thin ca to the inside after drilling. I will start going that. Hopefully those pesky celtic knots will no longer be pesky.


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leehljp

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I have a question regarding segmenting. On occasion, as I'm turning rather delicate blanks, I flood the blank with thin CA. My question is, If I have glued the blank up with epoxy, does flooding the blank with thin CA do anything at all? I am thinking I'm probably wasting my time and CA, unless I have done the initial glue up with CA. What do you all think?
In some situations it will help, but there are other methods that will accomplish that "strengthening" the delicate blank. I have used a method that long gone member "Eagle" (and sometimes some of us still refer to him) brought up: On delicate blanks, he would wind string around a blank (already glued up) and then CA the string. This would give extra strength to the blank as he / we turn it. I would turn half of the blank, then wind more string around freshly turned part and CA it, then turn the other half down.

A year or two later, someone here suggested wrapping gauze around a blank and CAing that. That is what I do now on occasion.


On that pen above, you can see the black and the holly, each are segments. The dangers of just one not sticking totally to the other, the danger of just a tad too high of RPM would send it flying into pieces, destroying the blank. I used epoxy on the tube and segments. I was afraid that it was going to explode, and I didn't have enough experience to know what it would do, so, yes I added string around it and CA'ed the string to hold it together and turned parts at a time. When I build things, I tend to over build, over strength and be overly cautious in unknown situations - particularly with delicate blanks. It might be overkill for some, but I hate seeing beautiful blanks exploding! It is worth the extra time being cautious like that on delicate blanks.

Yes, use CA on it but put a layer or two of gauze on it before adding the CA.
 

jttheclockman

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Again there is alot of opinions. I will say this any 5 min epoxy is not as strong as full cure 24 hour epoxy. I use System3 T88 and swear by it. Strongest epoxy I ever used. I use JB weld clear 5 min. for those quick jobs and it holds well.
https://www.systemthree.com/products/t-88-structural-epoxy-adhesive

This was the last knot I made. Used that epoxy and it is black acrylic and aluminum the epoxy was tinted with black epoxy additive. Had no problems turning.
 

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ramaroodle

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No, I don't use a vacuum chamber for glue ups. That brings up another question though. Does anyone use a vacuum chamber when gluing segments?
Never heard of that. Is that a thing? I'll try anything to reduce the odds of a blank flying apart.
 

ramaroodle

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Again there is alot of opinions. I will say this any 5 min epoxy is not as strong as full cure 24 hour epoxy. I use System3 T88 and swear by it. Strongest epoxy I ever used. I use JB weld clear 5 min. for those quick jobs and it holds well.
https://www.systemthree.com/products/t-88-structural-epoxy-adhesive

This was the last knot I made. Used that epoxy and it is black acrylic and aluminum the epoxy was tinted with black epoxy additive. Had no problems turning.
Very nice symmetrical and clean knot. What kind (thickness / source ) of aluminum did you use? I've had the best luck so far with flashing.
 

KenB259

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Again there is alot of opinions. I will say this any 5 min epoxy is not as strong as full cure 24 hour epoxy. I use System3 T88 and swear by it. Strongest epoxy I ever used. I use JB weld clear 5 min. for those quick jobs and it holds well.
https://www.systemthree.com/products/t-88-structural-epoxy-adhesive

This was the last knot I made. Used that epoxy and it is black acrylic and aluminum the epoxy was tinted with black epoxy additive. Had no problems turning.
I just ordered some of the system 3 T88 from Amazon. If it gets JT’s stamp of approval , it must be good stuff.


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