Plastic mishap.

Signed-In Members Don't See This Ad

NLAlston

Member
Joined
Apr 29, 2017
Messages
93
Location
Amherst, NY
One day, last week, I watched a YouTube video of a guy using plastic cutoff pieces, from spent gift cards, as accents in his turned pen blanks. His outcome really grabbed my interest, and I thought that I'd give it a shot. So, two days later, I stepped to my lathe with that intent.

I don't know the reason why, but my blank came apart at the two sectioned areas, where I had glued (CA) the plastic inserts in. I did exactly as the poster had done, but MY attempt at it failed.

Last night, I decided to try, again. This time, I had a Paudauk blank, and wiped down the joining sections with acetone. I also scuffed up the plastic pieces, a bit. Unlike the other time, where CA glue ad been used, I opted for epoxy, this time.

I drill blanks on my lathe, and it was during the drilling process that one of the two glued sections broke away. The epoxy had set for about 4-5 hours, and my drilling was done in a respectable speed range. I took it slow and easy, with frequent backings for the sake of reducing heat buildup.

I would sure like to get a handle on how to successfully go about what I've aimed for, and your input would be most appreciated.
 
Signed-In Members Don't See This Ad

randyrls

Member
Joined
Feb 2, 2006
Messages
4,821
Location
Harrisburg, PA 17112
Nathan; The glue joint is definitely the weak point in an inlay blank. There is a LOT of stress on that glue joint while drilling, and think about how few square inches of glue surface are resisting that stress. Think of the cross section where the drill bit hits the card. The outside of the spinning drill bit contacts the card first and grabs it. Stress skyrockets and BANG, the glue joint fails. I have heard of (but not tried) pen makers intentionally honing a flat on the outside cutting surface to reduce the "grab" of the bit. This will increase the heat build up though.

This is the one time that a brad point bit would do well. You may also want to drill in steps. 1/8" bit, 3/16" bit, 1/4" bit, etc up to the final size.

One technique I have done is to "wrap" the blank in wood. You can cut 1/4" thick backer pieces and glue them to the outside of the blank the whole length of the blank before drilling. The backers grain should run the length of the blank.

I have seen people turn a blank round before inlaying the inserts. This allows them to clamp the blank in a collet chuck that applies even force all around the blank.
 

NLAlston

Member
Joined
Apr 29, 2017
Messages
93
Location
Amherst, NY
Nathan; The glue joint is definitely the weak point in an inlay blank. There is a LOT of stress on that glue joint while drilling, and think about how few square inches of glue surface are resisting that stress. Think of the cross section where the drill bit hits the card. The outside of the spinning drill bit contacts the card first and grabs it. Stress skyrockets and BANG, the glue joint fails. I have heard of (but not tried) pen makers intentionally honing a flat on the outside cutting surface to reduce the "grab" of the bit. This will increase the heat build up though.

This is the one time that a brad point bit would do well. You may also want to drill in steps. 1/8" bit, 3/16" bit, 1/4" bit, etc up to the final size.

One technique I have done is to "wrap" the blank in wood. You can cut 1/4" thick backer pieces and glue them to the outside of the blank the whole length of the blank before drilling. The backers grain should run the length of the blank.

I have seen people turn a blank round before inlaying the inserts. This allows them to clamp the blank in a collet chuck that applies even force all around the blank.

And, again - prime information from a member, here :).

You know, I had known (for a long time) that the glue was stronger than the wood. But, I had temporarily forgot that this fact is largely dependent upon the amount of gluable surface.

I did, indeed, use a brad point, 10mm drill bit, but had never considered stepping up, through smaller sized bits, to reduce the stress factor. From now on, methinks that I should incorporate your advice on ALL of my blank drillings. I also like your mentioning of how some turners were 'rounding' their blanks BEFORE inlaying the inserts.

I can't WAIT to get into my little shop, later today, and get busy with another blank inlay attempt. I did turn a rather nice pen, earlier last week, with an inlay from some wood veneer that I'd bought. But I'd wanted to try something a bit thicker, and it was just a short time after that when I happened across the earlier mentioned YouTube video.

I thank you so much, Randy.
 

jttheclockman

Member
Joined
Feb 22, 2005
Messages
19,082
Location
NJ, USA.
Nathan, as you progress in your pen making skills you will find there are many ways of doing things and sometimes what works for one will not work for others. I am on the other side of what was said. I stay far away from any brad point bits doing any pen turning. They are for woodworking projects in my opinion that are larger and have more surface area to support the violent twisting.

You do not say what type of segmenting you are trying. Is the use of plastic cards cut on angles or straight across?? Plastic is tough to glue and hold together in segmenting. A good epoxy is needed. I prefer to use System III T88 structural epoxy. I wait 24 hours before working. Just because a glue is dry to the touch does not mean it is set up. You need to sand off all that colored marking from the card or at least get it roughed up pretty good. When gluing you need to apply just the right amount of pressure so that you do not squeeze all the glue from the joint or the joint will be starved and fail.This takes practice.

Now if you are building a segmented pen that has rings of plastic in them it is best to stack build the blank on the tube. That is drill each section ahead of time and then stack building it on the tube. You then eliminated the stress of drilling through those materials. Now you will also get stress from turning but that is another story for another day. Heat is your enemy. If you do not stack build and try drilling later then you need to keep that bit cool. If you stack build a blank you want to have the tube scuffed and want to glue both the blank materials to each other as well as to the tube. Works very well.

Good luck.
 

leehljp

Member Liaison
Joined
Feb 6, 2005
Messages
9,314
Location
Tunica, Mississippi,
I agree with both of the above fellows. There are different ways for different situations. Another method is to wrap string tightly around the segments and then either CA them or epoxy them before drilling.

Until you get experience, it is more time consuming than just "making" a pen, but the results are well worth it.

As John mentioned, I drill the segments piece by piece and stack them on the tube - that is for one type of segment; and as Randy wrote, I have added (epoxied) backer pieces over segments and also added thread/CA to others.

It depended on the type of segment I was doing.
 

SteveG

Member
Joined
Dec 21, 2009
Messages
2,985
Location
Eugene, Oregon 97404
I will add voice to another facet of your issue...one you are aware of, but may not fully be accounting for in your process. Heat build up can greatly weaken a glue joint. You addressed that by pausing and withdrawing the drill bit, but that may not have been enough. Here are some things you can do:
1. Make your drill bits sharper than they were in the prior attempts. Many pen turners rely on a Drill Dr. or some other machine/jig to enhance the sharpening process.
2. Check the heat buildup. A good guide, (but one that can yield burned fingers :eek:) is to touch the drill bit IMMEDIATELY after withdrawing it as you pause the drilling. If it is not comfortable to rest your fingertip on the bit, it may be getting too hot. No exaggeration here. A small amount of heat will vastly weaken the glue joint. (Prior suggestions serve to reinforce the heat-weakened glue joint.)
3. Use a coolant/lube. This only works for non-wood drilling. Spray Pam cooking oil on the drill bit repeatedly as you pause/ remove the drill bit.

If you use all the suggestions posted here, the "fails" will go away. :) :)
 

gtriever

Member
Joined
Apr 23, 2017
Messages
1,135
Location
Paducah, Kentucky
These are all good tips, and very informative. I'll echo John about time, time, time for the glue joints to fully cure. I've ruined too many projects by getting impatient.
 

duncsuss

Member
Joined
Jun 29, 2012
Messages
2,151
Location
Wilmington, MA
I've glued lollipop sticks to the outside of delicate blanks, and have wrapped them in cotton gauze and drizzled CA on. (Think "splints" and "plaster cast" :biggrin:)

Anything that adds structure along the length of the blank will help, I found the gauze worked really well, possibly because all the CA also seeped into cracks in the blank.
 

SteveG

Member
Joined
Dec 21, 2009
Messages
2,985
Location
Eugene, Oregon 97404
I've glued lollipop sticks to the outside of delicate blanks, and have wrapped them in cotton gauze and drizzled CA on. (Think "splints" and "plaster cast" :biggrin:)

Anything that adds structure along the length of the blank will help, I found the gauze worked really well, possibly because all the CA also seeped into cracks in the blank.

Having tried many of the options for strengthening the seg-blank, I have found the gauze/CA to be the best overall. Once you do it a few times, it is very quick to accomplish, and you can move right on to the drilling in just a few minutes. (I have stopped using the CA hardener for pen finishes, but use it effectively to move this process along.)

Here is another tip: once you wrap and CA the blank using the guaze method, you can mount it between centers, and lightly turn away the irregular shape of the blank that you have just created, leaving as much if the 'wrap' on there as possible. By turning it on centers that ARE THE ACTUAL CENTERLINE OF THE SEGMENT PATTERN, you can then mount the blank to the headstock using a collet chuck, KNOWING that the lathe drilling step will be right on center also. This is absolutely critical to accomplish accurate drilling for some types of segmenting work where you are segmenting a symmetrical pattern.
 

jttheclockman

Member
Joined
Feb 22, 2005
Messages
19,082
Location
NJ, USA.
The Op has not given any indication of how elaborate this segmenting is. If it is simple ring segments there is no need for all the extra support. The glue and the heat are the key factors. I have glued and drill very complicated segments without any extra support such as scallops and never had a problem. There is a learning curve to doing segmented work. Maybe he can show us a photo of what he is attempting and we can offer more info from the photos.
 

Woodchipper

Member
Joined
Mar 15, 2017
Messages
5,138
Location
Cleveland, TN
When I built custom fishing rods, I let the epoxy (Two Ton Epoxy) for reel seats and grips set at least 12 hours. Got me curious to try your idea.
 

NLAlston

Member
Joined
Apr 29, 2017
Messages
93
Location
Amherst, NY
The Op has not given any indication of how elaborate this segmenting is. If it is simple ring segments there is no need for all the extra support. The glue and the heat are the key factors. I have glued and drill very complicated segments without any extra support such as scallops and never had a problem. There is a learning curve to doing segmented work. Maybe he can show us a photo of what he is attempting and we can offer more info from the photos.

Sorry that it took longer than expected, to get back here, but I've been crazy busy.

My segmenting was far from any sense of being elaborate. In fact, it was quite simplistic. What I'd done was to cut two 45 degree slices, in the pen blank, about 3/4" apart. It was, of course, at those two sliced locations that I glued those plastic pieces in, and then married that 3/4" section back into the blank.

I am remembering, now, how I had really torqued the clamp down, and THAT might have been the biggest culprit. I'd hoped to have gotten into my shop, sometime this past evening but - as already stated - there was just so many other things that I had to attend to.

But I (due to YOU folks) have been armed with some good knowledge - which will greatly aid me in my next venture into this area.

Many, many thanks to ALL of you.
 

jttheclockman

Member
Joined
Feb 22, 2005
Messages
19,082
Location
NJ, USA.
Well drilling angled plastic makes it that much more challenging. That is a good reason to stay away from brad point bits. Many people have done many examples of angled segmenting so it is doable. Good luck.
 

NLAlston

Member
Joined
Apr 29, 2017
Messages
93
Location
Amherst, NY
Well drilling angled plastic makes it that much more challenging. That is a good reason to stay away from brad point bits. Many people have done many examples of angled segmenting so it is doable. Good luck.

Well, I just (very recently) visited Harbor Freight to pick up a 29pc Titanium plated drill bit set. I don't know if these will provide any advantages over the brad point bits, but it's certainly worth a shot :).

One drill bit that needed, for a Manhatten pen kit, was a 27/64 bit. I was just turning a straight (Bocote) pen blank, this time, so couldn't evaluate how it may have fared on a segmented blank. It did seem to cut a bit slower than the brad point bits I'd been using. But, then, it could also have just been my imagination.

I REALLY like the looks that can be obtained by segmenting, but think I will wait, a little, on attempting more, until such time as I can implement some of the preparation methods which have been offered, here.

Actually, it won't be just SOME. I intend to develop some degree ofa relationship with ALL of what has been offered - to see works best for me.

Many thanks to EVERYONE.
 
Joined
Apr 10, 2013
Messages
554
Location
Arkansas
Not all...

Also, I have found that not all "plastics" are glue-able! Before using any plastic components, i hav started gluing strips of the plastic together to see if it will hold together.....I have discovered that some of my choices have not stuck together with CA or Epoxy...so, find that card or plastic sign that you intend to use and make sure that it will stick to itself! Also, I have started using an acrylic "bullet" point bit that I found from PSI to drill my segmented sections.
(They are on page 139 of the last 2 catalogs)
 

NLAlston

Member
Joined
Apr 29, 2017
Messages
93
Location
Amherst, NY
Also, I have found that not all "plastics" are glue-able! Before using any plastic components, i hav started gluing strips of the plastic together to see if it will hold together.....I have discovered that some of my choices have not stuck together with CA or Epoxy...so, find that card or plastic sign that you intend to use and make sure that it will stick to itself! Also, I have started using an acrylic "bullet" point bit that I found from PSI to drill my segmented sections.
(They are on page 139 of the last 2 catalogs)

Thanks, Phillip.

You know? I hadn't even come close to considering that some plastics might have characteristic properties which might pose issues with being glued. However, I don't think that this is the problem, here. Rather, it has to be something that I - myself - am doing wrong. I say that because of watching a YouTube video, some time back, where the poster showed a segmenting sequence, and where he'd used plastic gift cards. He bonded the plastic parts to the wood pieces with CA. He journeyed through the drilling process with no splinting, gauzing, or anything like that. the effect was beautiful, and his method seemed so simple - leaving me to think that even I (a novice pen turner) could do that.

I KNOW that it WILL happen, for me - sooner, or later :).
 

NLAlston

Member
Joined
Apr 29, 2017
Messages
93
Location
Amherst, NY
I found the gauze worked really well, possibly because all the CA also seeped into cracks in the blank.

So, Duncan (just so I fully understand), are you saying to wrap my segmented blank with gauze and, then, wet that entire gauze blanket with CA? If saturation is what would be needed, I have no problem with that. I just want what (how much) would actually be required, so as not to, unnecessarily, waste glue.
 

NLAlston

Member
Joined
Apr 29, 2017
Messages
93
Location
Amherst, NY
Also, I just ran into another post (at another forum, and dating back to 2008), where someone was faced with a very similar dilemma. The responder, to the OP, mentioned about using epoxy to bond plastic to wood. He said to sty away from the 'quick set' epoxy (whichiswhat I have, in the little twin tube plunger, from Harbor Freight), and to opt for the 60-minute set epoxy. Leave it to cure for at least twenty four hours, and the bodied pieces would NEVER fail.
 

OklaTurner

Member
Joined
Dec 12, 2016
Messages
44
Location
Edmond, Okla
Now if you are building a segmented pen that has rings of plastic in them it is best to stack build the blank on the tube. That is drill each section ahead of time and then stack building it on the tube. You then eliminated the stress of drilling through those materials. Now you will also get stress from turning but that is another story for another day. Heat is your enemy. If you do not stack build and try drilling later then you need to keep that bit cool. If you stack build a blank you want to have the tube scuffed and want to glue both the blank materials to each other as well as to the tube. Works very well.

Good luck.

This is what I do.
 

magpens

Member
Joined
Feb 2, 2011
Messages
15,913
Location
Canada
Stacked Building of Segmented Blanks

As I understand it, the OP relates to segmenting at a 45* angle.

The latest posts just above suggest stack-building over the brass tube using pre-drilled sementing pieces. That's a good idea for 90* segmenting with plastic sheets or credit cards.

But ... How do you pre-drill the thin plastic at 45* ?
 

NLAlston

Member
Joined
Apr 29, 2017
Messages
93
Location
Amherst, NY
As I understand it, the OP relates to segmenting at a 45* angle.

The latest posts just above suggest stack-building over the brass tube using pre-drilled sementing pieces. That's a good idea for 90* segmenting with plastic sheets or credit cards.

But ... How do you pre-drill the thin plastic at 45* ?

That's EXACTLY what I'd been pondering.
 
Last edited:

JP1337

Member
Joined
Aug 24, 2016
Messages
34
Location
VIC
As I understand it, the OP relates to segmenting at a 45* angle.

The latest posts just above suggest stack-building over the brass tube using pre-drilled sementing pieces. That's a good idea for 90* segmenting with plastic sheets or credit cards.

But ... How do you pre-drill the thin plastic at 45* ?

That's EXACTLY what I'd been pondering.

Just thinking off the top of my head...

Maybe you could drill a spare bit of wood straight down the center, then cut a slot at a 45 degree angle to hold the card.

You could then slide a card into the slot, it being held at a 45 degree angle would ensure it is drilled correctly on the angle, and becomes a simple jig for quick drilling of multiple cards at consistent angle. slide card in, drill, slide card out and slide next one in.....
 

jttheclockman

Member
Joined
Feb 22, 2005
Messages
19,082
Location
NJ, USA.
Stop and think it through. The simplest way is to elongate the hole. The hole is not crucial on a thin piece. It will not be seen. The other thing that can be done is cut a block of wood such as a piece of 2X4 at a 45 degree. Double stick tape a piece of thin plastic or metal to it and drill a hole straight through using a drill press. The rest of the blank can be drilled as normal and then just cut pieces on a 45 degree.
 
Top Bottom