True stone Blanks.

[wimkluck]

I have several true stone blanks. Years ago I made 7mm slimlines out of these blanks. I know that it is britle when you do a pressfit.
What is as save wall thickness. I will fit a brass tube inside and no pressfit.

 

[jttheclockman]

Not sure what you are asking but my thoughts and opinion is that it is a huge waste to put trustone on a slimline. They are an expensive blank and if you have the 7/8" ones that is a lot of wasted material. There are many different acrylics that can mimic the look if you are after that. If you just want to use up, why not put them up for sale? All trustone blanks are not the same. Some have actual stone particles in them and those are more brittle and tougher to turn. But many are just acrylic so same rules apply. As far as what is a pressfit. never heard the term used.

 

[BULLWINKLE]

Not to mention that the trustone dulls your chisels to a butter knife edge in no time including carbide chisels.

 

[gbpens]

If you insist on using Trustone at least cut the pieces on the diagonal so that you get 2 slimline pens out of the blanks. To avoid cracking when assembling gently file the items to be pressed in and then glue them. Be very careful on the twist mechanism.

 

[Darios]

The handful of tru-stones I've used I've not had a problem with any cracking during assembly. That could just be luck but I also make certain that the blanks are squared up and run a deburrer around the inside of the tube right before assembly.

 

[wimkluck]

Not sure what you are asking but my thoughts and opinion is that it is a huge waste to put trustone on a slimline. They are an expensive blank and if you have the 7/8" ones that is a lot of wasted material. There are many different acrylics that can mimic the look if you are after that. If you just want to use up, why not put them up for sale? All trustone blanks are not the same. Some have actual stone particles in them and those are more brittle and tougher to turn. But many are just acrylic so same rules apply. As far as what is a pressfit. never heard the term used.

The Question is the waste and I want to use it on a bigger fountainpen. I have a few sets but the cap has no tube inside and this set required a thin wall thickness. So how thin is save?

 

[randyrls]

Wim; You can do this but these things are necessary (as others have said). You want to minimize the stress you put on the blank.

1. Drill the blank but don't allow the bit to break through the end of the blank. Cut each blank about 1/4" (5-7mm) longer than the finished size. Mark tube length on the size of the drill bit. Drill only until the mark disappears into the blank. Stop there and cut the un-drilled end to finished length.
2. Expand the brass tubes slightly until the fittings are a slip fit into the brass tube.
3. Solid and complete glue coverage. Scuff the tubes. Polyurethane Gorilla glue is a good choice but you must check the blank after about 20 minutes as the glue will sometimes cause the tube to slide out of position.
4. Use a sanding jig to square the blank to the tube. Don't use a pen mill.
5. Lack of stress on the blank. Use a disk sander to round the corners of the blank. Use care when turning.
6. Glue the fittings into the finished blank with Loctite. Put the Loctite on the inside of the tube and twist the fitting into place.

You can do this safely.

 

[Darios]

In addition to what Randy said (though there seems to be mixed opinions about Gorilla glue itself) one things you might be able to do is
a) trim a thin wedge off of two sides of the full blank, essentially making it a smaller square. I do that in order to build a stock of segmenting material down the road.
b) go for a wider 'curve' to the pen itself. That will give you a thicker spot of material for the mass of the pen. See this post just today for an example. https://www.penturners.org/threads/saturn.177196/

 

[jttheclockman]

The Question is the waste and I want to use it on a bigger fountainpen. I have a few sets but the cap has no tube inside and this set required a thin wall thickness. So how thin is save?

I assume you are talking about making a kitless pen. If that is the case you will be threading the blank and such. So this all is out of my knowledge base. I am sure others can help. I think there is mixed messages here. Some are telling you how to avoid cracking blanks when using tubes and so I suggest you go into more detail with what it is you are asking. Sorry I can not help