Segmenting is whoopin my tail

[snyiper]

From the first celtic knot I saw here I was hooked!! Couldn't cut straight to save my soul, tried table saw, no zero clearance or sled. Tried band saw, nope small table top saws are hard to keep the blade from turning. Old mitre saw up in the joist, nope wore out and saw missing!! Ok I buy a sweet stanley clamping miter box and saw sweeet!!! I can now cut nice straight angles by hand....next issue the Knot did you know 45 deg cut make a awfully tight knot? I do now! I have tried copper credit cards and aluminum flashing all blew apart close to the end. I have used Gorilla glue, thick,thin and med CA tried 5 min epoxy all exploded. The only thing I can figure is that a noobie learning to turn should not try celtic knots on slimline pen blanks!!! So with this new found knowledge (the hard way) I am backing up a tad and going to do some simple stuff separating different material with slims anyway. Those of you that can do a slim have my utmost respect That is something I will one day conquer! Thanks for letting me rant, yea I just blew apart another one....LOL

 

[mredburn]

A slim line has to be tough there isnt much material there to work with to start with.

 

[CSue]

Hang in there Glenn. One pen at a time.

 

[gvanweerd]

I have a bowl full of exploded acrylic from my learning how to segment. keep it up. and try try again. you will get it. Keep it tight.

 

[fernhills]

Buy a lot of extra slimline tubes, then all you lose is time. Takes time, hang in there. Carl

 

[hewunch]

When are you blowing up? When you are turning or drilling the blank? If when you are drilling are you using a twist bit or a brad point? I have found that brad points are terrible about blowing things up and I only drill with twist bits. Hope that helps

 

[akbar24601]

Hi Glenn,

For what it is worth, here is my two cents. Especially if you are trying to use metal inserts, keep your tools ultra sharp and your cuts ultra light. Typically you will blow up if your tool catches the metal and tears everything to pieces. Brass being the worst, Copper second, Aluminum being the easiest. I have used CA with all of my segmenting and it does work. Believe me, I have had my fair share of failures and have spent much time on hand and knee retrieving pieces to try and re-glue and try again.

If your problem occurs during drilling, again especially with the metal inserts, you need extra precautions. If you are using metal inserts, then a brad point bit is not a good choice period. Depending on the size of the kit, I will pre-drill 7mm and then go to the appropriate size. You are doing a slim so that doesn't help much. Nice sharp bits and slow drilling. Take your time. Drill some, stop, how hot is your bit getting. If you over heat the bit/blank you will get separation. Take your time. I will typically but my blank between centers and turn round before drilling. An extra step that you can take is that while mounted between centers, wrap the blank in paper towel and saturate with thin CA. Once hardened, turn round. Now drill the blank and it won't blow up on you. At least not during drilling.

Remember, CA is your friend. Do not be afraid to add more to the blank as you turn it down. It may not prevent a blow up, but it certainly can't hurt.

 

[snyiper]

Thanks for all the kind words as well as tips and encouragements. No worries about giving up Ill step back and reflect but let it whoop me...not a chance....LOL
My explosions happen when turning when I am almost to slimline size...It appears my tool will catch and poof then you know you start inventing words...LOL Im still drilling on my press and did find the hard way no brad points on seg's so I use twist drills. I have blown all up using a skew as well as my poor mans woodchuck. Ill stick with straight segments first then progress to the angle cuts...

 

[akbar24601]

Another thought Glenn,

for starts with your segmenting, use pieces of veneer, thin slices of wood or even construction paper for your inserts. These will all absorb much more glue and provide you with less chance of blow up. Giving you more time to concentrate on your cuts and obtaining a finished product. Then you at least have something very tangible to look at and tweak and continue onward.

How thick are the metal inserts that you are using?

 

[parnelli_97]

I had that problem a lot with slimlines, after looking over several of my blanks I found small air gaps between the blank and the tube. I had to make sure to coat the tube and inside of the blank then put them together and wiped off the excess. Since then no more explosions. So make sure there is good adhesion between the blank and tube.

 

[Nate Davey]

I am in the same boat as you are with Slimlines, although not having them explode on me. I drill my blanks with a 1/4" bit which seems to be about the same size as the ID brass tube. That way I can slide them on my mandril and not waste tubes. I made a simple little 45 degree sled for my band saw to get the angles repeatable as well.

 

[snyiper]

Well I will take all of this and head back into the shop... I hand cut all cuts with stanley clamping mitre saw.....not sure of thickness but credit card is snug as is a cd. Ill try drilling the blank first undersize then cut in some simple segs before I attempt the all elusive knot!!!! Just got a bunch of thin from Mannie so I should have plenty to do something even if its wrong!!! Hmm perhaps Ill try segmenting with clay!!!!

 

[jleiwig]

Are you clamping your segments too tight and forcing out all the glue? That's one of the problems I had on a segmented pendant I made. I thought the tighter the better, but I squeezed out all of the glue.

 

[PenMan1]

Free Information --- For what it is worth.

When working with segments, casein, ebonite, gemstone, and true stone, I keep a brand new carbide tipped skew chisel just for those things. They are $22 and when it gets dull, I buy another and keep it seperated just for the materials listed above.

Once my carbide tipped skew gets sharpened it goes into the rack of chisels for "regular" pens. I like a brand new factory edge for the items that I have spent days or weeks preparing.

If I normally turn at +/- 1,800 rpms, I slow the lathe down to about 900 to 1,000 rpms and take very light cuts. Additionally I NEVER use any type of gouge on my segmenets. I take any corners off by either a belt sander or hand sanding.

Also, once my segments have been glued and set (at least over night) once I have rounded the blank with the sander, I put another coat of thick, gap filling CA all over the blank and let it set for another 2 hours before putting it on the lathe.