Thread: Celtic knot

Hi Fumbler, can't really answer your question as I haven't played around all that much with glues other than to glue and clamp now and come back tomorrow when it's had good time to set (though I see your dilemma).

However, your project sound intriguing, any chance of popping in a few pictures to show what you are doing?

definitely. stay tuned. I will post progressive shots (if I can remember to take whilst on the sled)

I had a go at a Celtic knot in a rolling pin. I allowed an hour between cuts, using titebond II (mainly a decorative piece). It worked perfectly well. I had a few issues with re-aligning the knot bands and I decided it was a good idea to match the width of the band to the kerf of the saw and to work to pre-marked centreline.


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Fumbler,

As I know nothing about Celtic Knots, I did a search and found this: https://www.youtube.com/watch?v=BHagbZN4XRw

You could put a couple of tight wraps of tape around the glued area, turn round close to the tape, retape on the round areas and finish turning.

It would not be good to get a face full of turning parts if it came unglued. You might also do some research about making the glue dry faster, warm timber, microwave, etc.

Just on a safety point I would be waiting 24 hours before spinning that up on the lathe. As the work is sliced through on the diagonal at many points so is not really long grain joints. You may get away with it but you have no excuse if you don't. As to making good use of shed time then turn something else while waiting on glueups.
Regards
John.

45min glue time between cuts, but I think 1 lifted when clamped, I clamped sideways and endways and forgot about top ways. Anyhoo, I want be turning this for at least a month so glue will have well and truly cured. Here's the pics.
1. Timbers to be used
IMG_4492.jpg
2. On the sled
IMG_4493.jpg
3. Cut 1
IMG_4494.jpg
4. Cut 2
IMG_4495.jpg
5. Cut 3
IMG_4496.jpg
6. Cut 4
IMG_4497.jpg
I will post last pic shortly. As I said I may be out fractionally.

'Tis a bit late now, you seem to have found a happy balance where it works for you, but I found that the best way is to not quite cut all the way through. This does mean a little more waste, but the benefits make up for this!

For a celtic knot to look 'right' every insert has to be exactly the thickness of your saw kerf - even the first cut - and leaving a mm or two connecting the two ends allows for an easy check of thickness while maintaining the alignment.

As a bonus, it gives added strength during gluing so you can shave a few minutes off the waiting time when in a hurry to get the blank finished.

It's always advisable to let the completed glue-up cure for a few days before turning, of course...

Yep, I won't be turning this for a while and although I may be slightly out, I made the slips to the exact size of the kerf. I cut a slot in a scrap price then sanded down via the drum sander to the exact size. But not bad for a first effort.

here 'tis finished before turning.

IMG_4498.jpg

Looking good!

I also suggest you be very, very careful when marking the centres and mounting on the lathe. I don't know how many 'wonky' celtic knots I made before I came up with my current me-proof method for ensuring correct registration.

All the best with this. I was going to say you can use thick CA on one face and accelerator on the other.

Also, for pens where the ultimate dia is pretty small, try getting the angles a lot steeper, around 20 degrees or less works better than 45.

Originally Posted by dai sensei

try getting the angles a lot steeper, around 20 degrees or less works better than 45.

Cheers Neil, I will try that next time luckily this is for a candle stick. I was sitting in the garage pondering life, whilst watching glue dry and found some small offcuts and thought what can I do with these, so here it is. I have a few other bits to add yet so hopefully I can still keep them centred. but definitely will try a flatter knot next time.

Originally Posted by Skew ChiDAMN!!

Looking good!

I also suggest you be very, very careful when marking the centres and mounting on the lathe. I don't know how many 'wonky' celtic knots I made before I came up with my current me-proof method for ensuring correct registration.

Im sure I'll get there, but I was rushing and forgot one of the clamps so I expect it to be off a bit. Please let me know your 'me-proof' way and I'll see if I can follow. I may end up making a permenant sled for cutting.

Originally Posted by Fumbler

Please let me know your 'me-proof' way and I'll see if I can follow. I may end up making a permenant sled for cutting.

Many people square the blank, do the cuts and glue-up, re-square and then mark the centres. I found that errors crept in and even the most perfect looking blank would often end up with one long loop and one short in the final result; it took me a while to realise it was my remounting at fault.

So... now I square the blank, mark centres as accurately as I can then mount and turn only the central section round where I'm doing the cuts, leaving the ends squared for registration against a table/fence.

The cuts are done on the table saw, setting the depth of cut to a mm or two less than the total blank thickness so it stays together as one piece. (As I alluded to earlier.)

I find this has three benefits:

1. If the "lip" between the rounded section and the squared ends isn't the same all around, I hadn't centered it for turning properly and I can either abort now or make the effort to tweak it so that things are brought back into balance. Which way I go depends on the timbers used (how costly? Do I have more?), how confident I am in my success, whether I have the time or, sometimes, from just not knowing when to give up.

2. The ends are already correctly marked/centred/punched for remounting. <- This has saved me many wasted blanks.

3. If I glue in a strip that's just a skew-whiff oversize it can bow the blank w/out me noticing. With the two ends still being squared I can place the blank against a flat surface or straight edge and double-check that it's still true before committing to the next stage.

I didn't mention it before because many folk seem to find your way perfectly OK. But if there's any possibility of doing something wrong, I'm the sort that seems to unerringly find it.

Originally Posted by Skew ChiDAMN!!

I didn't mention it before because many folk seem to find your way perfectly OK. But if there's any possibility of doing something wrong, I'm the sort that seems to unerringly find it.

I think your not alone on this one, i always feel that nothing ever goes to plan or I forget 1 viral step in my haste. But that's what makes things challenging, interesting and frustrating all at the same time. Enjoyable stress I call it. And thanks for your tips, I'll keep that in mind next time.

i am very short on space and the correct/decent tools so it takes me a month of Sundays to get things finished as limited access to a well appointed workshop.