90 Degree Parting... Whats the trick?

[Sawzall]

New guy here trying to learn the tricks of the trade. I have made a few Classic "Parker" style fountain pens and overall they turned out pretty nice. I used Cocoboa as I really like the look of the grain. I have 2 different parting tools, both are Benjimans Best from Penn State. One is 1/8" and the other is 5/32". I like the 5/32 the best but I am not getting a perfect 90 on the part. There is still a slight angle which prevents the center band from resting perfectly against the wood. I am looking for some guidance on the best way to achieve a nice straight part.

Thanks

Tim

 

[jttheclockman]

Practice, practice, practice. I don't know the kit you are talking about but I am guessing you are looking to make a tenon so the centerband slides over it. ????? If this is the case are you having trouble getting the size of the tenon right?? Or is the shoulder of the tenon standing proud?? If the shoulder is proud then you need to adjust your angle of the tool and point more toward the body of the blank. If you can't get the size right use a caliper.and slow bites. Other than that you need to give us more info as to what you are trying to do. Any parting tool can do the tenon and in fact I like a skew better but no big deal.

Again after rereading your post I am lost as to what you are doing. When you say parting, are you cutting a blank in 2. Why not cut on a saw of choice and use a mill to square the ends?? Need more info. Sorry.

 

[ldb2000]

Tim , it sounds like you are not cutting straight into the blank but are either letting the parting tool slide or you are cutting at an angle . Either way you can lay the parting tool on its side and angle the point to clean up the tenon . Take very small cuts until you have a 90 degree tenon .

 

[Sylvanite]

Instead of aiming for a perfect 90 degree end on the tenon, I undercut it slightly. That way, any error is on the inside where it isn't visible.

Regards,
Eric

 

[wdcav1952]

As said, practice and practice. I took a small cheap flat head screw driver and sharpened it. That works best for me to refine the tenon.

 

[ed4copies]

Instead of aiming for a perfect 90 degree end on the tenon, I undercut it slightly. That way, any error is on the inside where it isn't visible.

Regards,
Eric

AND it encourages the glue to go to the INSIDE instead of resting on the pen surface where you will have to clean it off.

 

[OKLAHOMAN]

As said by others practice, practice and I also undercut slightly when I make the tenon on the Little Sicily fountain.

 

[BigguyZ]

Undercut, and make sure your parting tool is ground such that the cutting edge is perfectly perpendicular with the flat of the chisel side. That can affect how easily you can create a clean shoulder with your parting tool.

 

[JerrySambrook]

If the tool is not sharp, especially at the corners, meaning there is a small radius there, and it is dull, then the tool will walk away from that corner, and will not allow a crisp straight cut to be made. This is caused by the tool following the material left behind, and actually forces the tool away from the tenon shoulder
Make sure the tool is sharp, crisp, and square

Jerry

 

[jason_r]

Undercut, and make sure your parting tool is ground such that the cutting edge is perfectly perpendicular with the flat of the chisel side. That can affect how easily you can create a clean shoulder with your parting tool.

A note about undercutting.

At a woodworking show a few years ago I expected the demonstrator
to undercut the edge when taking off a bit to replace part of the original
blank with imitation ivory- replacing the center band.

He pointed out that if you undercut it then turn the pen to final size,
you will end up revealing the gap. Thus for this situation you want
a perfectly square cut.

I haven't done this yet on any of my pens, but have kept this point in mind.

 

[Sawzall]

Great info All. Thank you for the responses. The pen kit I am working with in this instance is the Classic Fountain Pen by PSI. The directions tell you to measure 1 7/8 and remove the material from there to the end for the center band. I have made 4 of these to order out of Cocoboa and overall they turned out nice. The customer was very happy. However they would be even nicer if the centerband was perfectly fit to the wood instead of just a hair off. My parting tools are brand new so they are sharp.
I think in this case undercutting would work well. I am going to try that on my next fountain pen. I like the sharpened screwdriver idea also. I may give that a try on some practice pieces. Thanks again for all of the comments.

 

[Allenk]

Just as a side note, Sawzall, just because your tools are new, doesn't necessarily mean they are sharp... unless, of course, they are Thompson's. So far, every tool I've ever bought needed to be sharpened, except his.

 

[BigguyZ]

A note about undercutting.

At a woodworking show a few years ago I expected the demonstrator
to undercut the edge when taking off a bit to replace part of the original
blank with imitation ivory- replacing the center band.

He pointed out that if you undercut it then turn the pen to final size,
you will end up revealing the gap. Thus for this situation you want
a perfectly square cut.

I haven't done this yet on any of my pens, but have kept this point in mind.

I absolutely agree there. That's why I cut my shoulder for Euro's AFTER I finish the barrel, but before final sanding/ polishing (so there's not a sharp edge that leads to the CB).