How many thousandths stretch??

[ed4copies]

Here's the scenario: Christmas is coming, so I decided to make a few Jr. Gent ballpoints in BOW. I have quite a few blanks, so I'm off and running.

Well, short version of the story: First one--BEAUTIFUL!! CA finish is impeccable, mount the hardware and CRACK, the clip makes a severe crack in the upper barrel---throw that one out, learn something--recover the parts from the "already assembled" bottom.

Now, the second and third (I learned not to do ONE at a time), again all goes pretty well with the CA over BOW (I always hold my breath) and I get to assembly. File out the inside of the bottom barrel, install the components three-quarters of the way with my hands, then take everything out and apply epoxy and put it back together (successfully!!). Get to the top and find the clip holder "mic's" at .004 larger than the hole. Again, do some filing and finally, I have .002 difference between the hole and the fitting, on both the centerband and the clip.

It is at this point I realize I don't KNOW what I WANT!!! What is the OPTIMUM??? As Russ has said, CA won't forgive or stretch. So, MUST we epoxy the parts together???

Has anyone actually figured out what we NEED to hold the parts in place, but NOT crack wood or it's finish???

I did insert them (with epoxy) at the .002 difference, and it worked. Should I now accept this as the way to avoid cracks? Or have some of you "wood guys" got a better suggestion???

Thanks for you input!! My wood supply can't afford many errors!!

 

[mrcook4570]

All parts will eventually work loose if they are not glued in place, so I epoxy all parts in place. Clips and trim rings on threaded couplers work loose faster than other parts.

 

[Russianwolf]

Another place that you can get some clearance is the drilling/gluing of the tubes.

If you drill the hole tight, doesn't leave much room for the brass to stretch. If you use a hard glue, again, not much room to stretch. I've not had any problems as long as the tube slides easily through the hole, and using GG since it give a little.

drill too tight or use a hard glue and .......Crack.

 

[ed4copies]

Another place that you can get some clearance is the drilling/gluing of the tubes.

If you drill the hole tight, doesn't leave much room for the brass to stretch. If you use a hard glue, again, not much room to stretch. I've not had any problems as long as the tube slides easily through the hole, and using GG since it give a little.

drill too tight or use a hard glue and .......Crack.

Yes, I DID BOTH of these. But the cap half was actually a pretty large hole, the bottom was tight. And I always use CA---but then, I usually do resins!!

Thanks, not too old to learn, yet!!

 

[Russianwolf]

Yes, I DID BOTH of these. But the cap half was actually a pretty large hole, the bottom was tight. And I always use CA---but then, I usually do resins!!

Thanks, not too old to learn, yet!!

I switched to GG for everything now. Even the resins. They have a GG that dries white, so I paint the tubes white and dip the blank in water right before inserting the tube. I get a great white bloom on the ends and know they are good to go.

since GG expands, it fills any gaps better than CA, and like I said it stays a little flexible so allows movement in the material without doing damage.

 

[snowman56]

I have the same problem this morning with some Honduran rosewood.How long dose the GG take to set up? Never used it .

 

[randyrls]

Ed; I had problems with cracking corian slimlines. To avoid this, I would "expand" the last quarter inch of the brass tube with a transfer punch twisted sideways until the fittings were a slip fit on the tube. This may affect the bushings. I would then glue the tube into the blank. The blank, may need a slightly larger drill bit than normal. I used PU glue to make a somewhat flexible glue joint. Put a dab of glue inside the tube and insert fittings with a twisting motion. This keeps the glue on the inside and off the fittings.

Hope this helps.

 

[Russianwolf]

full cure in 1-2 hours (30m-1h for the fast cure formula). I've gone to the lathe in 30 minutes on the regular, but may have just been lucky.

Normally I do pens in batches or about ten or more so by the time I drill all the holes and glue all the tubes I'm ready for a break. Then the time isn't much of an issue.

 

[ed4copies]

Ed; I had problems with cracking corian slimlines. To avoid this, I would "expand" the last quarter inch of the brass tube with a transfer punch twisted sideways until the fittings were a slip fit on the tube. This may affect the bushings. I would then glue the tube into the blank. The blank, may need a slightly larger drill bit than normal. I used PU glue to make a somewhat flexible glue joint. Put a dab of glue inside the tube and insert fittings with a twisting motion. This keeps the glue on the inside and off the fittings.

Hope this helps.

Very interesting, Randy. Thanks for the idea!

 

[BRobbins629]

I think its time you stopped using tubes.

 

[ed4copies]

I think its time you stopped using tubes.

My immediate reaction was, "Where were you LAST week!!" Then, I realized these are ballpoints. Don't think I can get around the tubes on a ballpoint, can I??

 

[wolftat]

Ed, are you using a board stretcher first?

 

[ed4copies]

Ed, are you using a board stretcher first?

Only when I cut the blanks short. Didn't need it on this one:biggrin::biggrin::biggrin:

 

[keandkafu]

I have not tried the GG because of the expansion it gives. But it appears that my fears are unfounded. I thought with the expansion, it would crack the wood before I even started. Plus it would keep me from CA'ing my fingers together every time I make a batch of pens!

I'll try GG and see if it works for me. Do you recomment dipping the blank in water or just run a wet swab through the hole? Do you need to plug the ends or is it easy to remove from the ends?

Kevin

 

[KenV]

Ed -- Loctite is easier to use than epoxy and works well -- and you can decide how firmly you want to attach things.

the tolerance question is always a good one to ask. Do you releive the edge of the tube to start the fittings. That is worth about 0.002 all by itself.

 

[Russianwolf]

I have not tried the GG because of the expansion it gives. But it appears that my fears are unfounded. I thought with the expansion, it would crack the wood before I even started. Plus it would keep me from CA'ing my fingers together every time I make a batch of pens!

I'll try GG and see if it works for me. Do you recomment dipping the blank in water or just run a wet swab through the hole? Do you need to plug the ends or is it easy to remove from the ends?

Kevin

yeah, it foams and comes out the ends, doesn't blow them up.

I dip cause it's quick and easy. if I'm doing it in the kitchen I'll just run water from the tap through the hole. Swabbing would work fine, just need a little water for the curing to start. No need to plug. I use a razor to trim the bloom off the end and if some gets in the tube it comes out easily with my round file (usually just pops right out like a plug).

 

[randyrls]

yeah, it foams and comes out the ends, doesn't blow them up.

Use caution with polyurethane, it can push the brass tube sideways out of the blankduring curing. Nothing is worse than come back after gluing in the tubes and finding one sticking about a half an inch out of the blank :frown::frown::frown:

 

[BigguyZ]

Use caution with polyurethane, it can push the brass tube sideways out of the blankduring curing. Nothing is worse than come back after gluing in the tubes and finding one sticking about a half an inch out of the blank :frown::frown::frown:

I had that happen on several blanks! Well at least it's an opportunity to put a decorative "oops ring" on them....

 

[RussFairfield]

Ed, you have proven one more time that the less time we have to do something, the more likely everything will go wrong.

 

[jleiwig]

I had that happen on several blanks! Well at least it's an opportunity to put a decorative "oops ring" on them....

The easiest way to fix that is to use some of the small 6" quick grip style clamps that HF sells. I just picked up four more for .99 each. Works great and the glue doesn't stick too well to the pads on the ends of the clamps. Here's a picture of what I'm talking about. This is from VisExp's blog which is where I believe I first learned of this idea. Simple, but genius in my mind!

 

[BigguyZ]

The easiest way to fix that is to use some of the small 6" quick grip style clamps that HF sells. I just picked up four more for .99 each. Works great and the glue doesn't stick too well to the pads on the ends of the clamps. Here's a picture of what I'm talking about. This is from VisExp's blog which is where I believe I first learned of this idea. Simple, but genius in my mind!

Yeah, I saw that and thought it was a good idea. I haven't been over to HF recently, however. I need an excuse to go. :wink: