Wrong way to do a celtic knot

Curt Fuller

Member
Messages
348
Location
North Ogden, Utah
I said I'd show how to do a celtic knot but when I did this one I learned what doesn't work. The pictures still give an idea how it all works but this one didn't work very well.
The first picture shows how to cut the wood. The angle can be anything from 20 to 30 degrees, I like a 25 degree angle best. It also shows how the insert piece fits in the cut.
Then the second pic shows how to clamp it for glueing. The third is a picture of the V blocks for clamping it. Let each glue joint dry for an hour or so before making the next cut.

You make the same cut four times turning the wood 90 degrees each time (onto each side). You're cutting through the other glue joints on the 2nd, 3rd, and last cuts. The fourth picture shows what it looks like after all 4 cuts have been made and all the glueing is done.

But what I realized on this piece is this. The piece that you glue in should be the same thickness as the saw kerf from the cut. My saw takes about a 1/8" kerf and I was glueing in pieces of 1/4" baltic birch plywood. This makes the piece grow each time you glue in another piece and the result is that the rings don't line up. It still gives an interesting design, but not the celtic knot I was trying to do. So I guess I was just lucky on the first one I did by using inserts that were pretty close to 1/8" thick.
 

Attachments

  • first cut.JPG
    first cut.JPG
    27.6 KB · Views: 62
  • clamping setup.JPG
    clamping setup.JPG
    33.8 KB · Views: 65
  • v blocks.JPG
    v blocks.JPG
    27.2 KB · Views: 52
  • after all four cuts.JPG
    after all four cuts.JPG
    30.8 KB · Views: 99
Last edited:
This is the goblet that came from that glue up. It's Purpleheart with 1/4" baltic birch plywood for the rings. 7" tall x 1.75" diameter with a 3/16" stem and a couple interlocked captive rings on the stem.

For turning a goblet I think this is as good of a tutorial as I've seen and is how I do it..

http://www.turnedtreasures.com/project.html/goblet.html
 

Attachments

  • purpleheart plywood goblet.JPG
    purpleheart plywood goblet.JPG
    66.9 KB · Views: 83
Last edited:
Thanks for the explanation Curt. I will keep a note of it to try in the future. If you didn't say anything I would not have noticed. :thumb: Very nice goblet. It always seems segmented turnings are a complete mystery until the creator fesses up and then it is always, oh ya.
 
Very nice and very neat!

I'll have to give that a go, for sure.

I'll have to make my own plywood, as finding void free plywood here is not easy.

Same as the saw kerf eh?

Do you cut these on the SCMS, or the table saw?

You must clean up the sides of glue etc before you cut, right?

Cheers!
 
Stuart, I cut these on my el cheapo table saw but it seems like a nice miter saw would work better if I had one. As for cleaning up the glue, I just knock off the dried glue on a belt sander.
 
Curt thanks for the tutorial. I got to thinking about doing this with a lidded box. I think that may turn out kinda cool. I'll post a picture when done. Thanks again for the idea.
 
Yea. Great tut.

Going to put that on my roundtoit list.

I'm thinking custom chiesl handle.
 
Top