# How do I prevent Corian from cracking?



## Shemmy2 (Apr 15, 2010)

When I've finished lathing and polishing the Corian blanks and proceed to press-fit the slimline pen tip, the Corian will crack 50% of the time.  I've dipped the Corian in water, oil, spit ... and I've pressed the tip (or clip) quickly, slowly, even really really slowly.  But, too often the blank will still crack.  Help!


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## Mack C. (Apr 15, 2010)

Shemmy2 said:


> When I've finished lathing and polishing the Corian blanks and proceed to press-fit the slimline pen tip, the Corian will crack 50% of the time. I've dipped the Corian in water, oil, spit ... and I've pressed the tip (or clip) quickly, slowly, even really really slowly. But, too often the blank will still crack. Help!


Hi Shemmy; Yup, its a stress fracture that happens with Corian. With the slimline there isn't much meat there to stop it. I lost half a Cigar pen the other day due to it. 

Make certain your tube is very very clean inside, i.e. no epoxy or wax etc. stuck in there. May help, may not. Grin and bear it. Turn another and get on with life!! I don't think it's within your control.


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## JBCustomPens (Apr 15, 2010)

You could also file down the parts that go in the tubes and CA or epoxy them in.


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## KenV (Apr 15, 2010)

I use a craft knife (Exacto or similar) to get a long taper debur on the end of the tubes, and work for a finger press fit.   Locktite is your friend as it will hold tightly but you can still take things appart if needed.   You will also not have degassing problems that are possible with CA glue.

Snakewood, ebony, corian, and similar have little tolerance to stress so cut the problem with light fits and locktite.


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## hewunch (Apr 15, 2010)

You could also not glue the tube at the end you have cracking. I did this and it really helped.


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## Robert Taylor (Apr 15, 2010)

i have had success with pre-stretching the tubes by assembling the the parts in the tube, then removing them. then i glue the pre-streched tubes in the corian and proceed as normal.


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## Shemmy2 (Apr 15, 2010)

I like the pre-stretch idea! I'll give it try. Thanks.


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## snyiper (Apr 16, 2010)

I use a chainsaw file inside the tubes before assembly. This helps remove any burs near the edge as wll as any trash in the tube I may have missed.


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## Craftdiggity (Apr 17, 2010)

I just made a bunch of stone pens and my best advice is to file down the hardware until it slips in with little resistance and then use CA or epoxy to hold it.  Corian is a bit more flexible than stone, but the principle is the same.  If you are still getting cracks after stretching the tubes out, then try filing down the parts.  I think that this is the safest way in any case because I seem to have more bad luck disassembling parts than anything else.  YMMV.

Chris


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## Timbo (Apr 17, 2010)

Wow...some good ideas here.  I had the same problem and began filing down the parts for a light press fit.  I'd also use CA if I filed too much and the fit was only finger tight.  None of the pens with filed parts cracked, but the process is time consuming.  Pre-pressing seems like it might be a quicker process, I think I'll give it a try too.


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## DurocShark (Apr 17, 2010)

I use a tapered punch and wrap some 400 paper around it to file the inside lip of the tube down.


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## Wild Turkey (Apr 18, 2010)

I have made 100's of Corian pens and I use a deburr tool on the ends of the tubes to put a bevel on the tube and a chain saw file ran up and down the tube several times to ensure no residue or glue in tube.  Then use a pen press and gently install hardware and I lose very few pens to cracking, but it does happen sometimes.


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## barkisini (Apr 18, 2010)

If you decide to use glue, try the blue Locktite...at least then you'll be able to get it apart if you need to.


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## knifecut (Apr 18, 2010)

The one I did came pre bored, so the hole seemed too large for the tube, but the CA glue kept it in place.

I also beveled the inside edge of the tubes with a sharp knife, making sure no glue residue was remaining. The kit needed very little pressure to press the parts in.

Couldn't say which feature it was, but the slimline didn't crack.


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## randyrls (Apr 18, 2010)

Shemmy2 said:


> I like the pre-stretch idea! I'll give it try. Thanks.



Gary;  Yep, that is how I do it too!  On 7mm tubes I use a close fitting transfer in a twisting motion to expand the last 1/4" or so until the fitting is a close slip fit.  It only takes a gently twist.  You may have to use a slightly larger drill bit on some tubes.

Glue, trim, and turn the blank as normal, then put a drop of glue on the inside of the tube.  Don't put the glue on the fitting, the glue will  squeeze out onto the surface of the fitting.  Insert the fitting with a twisting motion to spread the glue over the inside of the tube.  Use Loctite, CA, or Epoxy.


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## elody21 (Apr 20, 2010)

The simplest thing to do is after gluing the brass tube in and before turning, champher the brass tube slightly with any counter sink bit. Alice


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## jtdesigns (Apr 20, 2010)

I use the small round drum sanding bit on a Foredom or Dremel to ensure I have no adhesive inside the tube.  Works great and fast too.


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## CSue (Apr 20, 2010)

Sounds like you've got plenty of suggestions here.  What I've found works for me is simply to make sure the ends of the blanks are perfectly squared - and I sand the ends  by hand after I turn and before I press fit them to make sure there isn't any corian overhanging the ends of the tubes.  Even the smallest bit can lead to stress fractures.


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## jaeger (Apr 22, 2010)

CSue said:


> Sounds like you've got plenty of suggestions here.  What I've found works for me is simply to make sure the ends of the blanks are perfectly squared - and I sand the ends  by hand after I turn and before I press fit them to make sure there isn't any corian overhanging the ends of the tubes.  Even the smallest bit can lead to stress fractures.



In hindsight, I'm am suspecting this to have been cause in a couple of my failures, including cracks in wood. It kind of gives me the jitters whenever I am pressing certain type of components. 

Great topic!!! Great response!!!


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## Rfturner (Apr 22, 2010)

The first 50-75 pens+ were made from corian, I found that I just had to take a little more time. I often used a round file on the inside of the tube. I did this until the fit would not stress the blank. I almost always glue components in on most pens. When pressing together I would go very slow and make sure that the blank and the component were perfectly aligned. If a blank did crack I would disasseble, reglue, turned slightly more and refinished.


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## Jgrden (Apr 23, 2010)

Rfturner said:


> The first 50-75 pens+ were made from corian, I found that I just had to take a little more time. I often used a round file on the inside of the tube. I did this until the fit would not stress the blank. I almost always glue components in on most pens. When pressing together I would go very slow and make sure that the blank and the component were perfectly aligned. If a blank did crack I would disasseble, reglue, turned slightly more and refinished.


You've actually found a market for those pens?  I can't Pay people to take them.


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## Rfturner (May 15, 2010)

In my area there are alot of contruction companies. I think that the main reason is that it is a material that they would not expect on a pen. I have about 100 colors of it and most look like stone. it did help to that when I started making pens I did not have a large budget so I looked at the materials that gave the best amount of product that looked good. I bought 400 pieces 1/2 x 1/2 x 5 inches for $40 counting shipping it allowed me to make more mistakes cheaper than other materials with a nice high quality pen

The picture is one of my early pens made from Corian, it is one of the uglier colors I have most look better


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