Double Twisted Dovetail Fun

[Chris Knight]

So maybe it is indeed a male thing and you like it for all the wrong reasons?

Entirely likely!

 

[Philly]

Well-I was quite interested in the replies to this one. Surprised to hear a lot didn't like the look-maybe you need to see it in person for it to "hook" you? :wink:
I didn't post this as a "look at me and my skills" post. When I said it needed extreme accuracy it was because my first, hand cut attempt (which was to a standard suitable for fine dovetails) DIDN'T go together anything like I would of wished! When cutting dovetails you can "cheat" a little by undercutting parts of the joint and easing unseen corners to allow easier assembly. With this joint, due to its compound nature, ALL surfaces must be spot on in all axis or it won't go together. (Which is why I cheated and used the tablesaw on my second attempt! :roll: )
It is well worth having a go at interesting joints and techniques, if only to make you enjoy your regular methods more! :lol: Needless to say, I'll be back to biscuits and brads before you can say MDF!
Cheers
Philly

 

[Philly]

Oh-almost forgot. Here's a sketch of my coffee table idea. Material will be 50 mm thick, hopefully Zebrano. You can see how the double dovetail might look good on this. or not.......
Any other ideas for joining the top to the legs? Biscuited mitre, secret dovetails, dowels?

Cheers
Philly

 

[Alf]

Material will be 50 mm thick, hopefully Zebrano.

:shock: Rather you than me... :-s My gut instinct is you don't want a fancy joint in a fancy wood, but I'm probably quite, quite wrong. Be interesting to see how this one turns out, Philly.

Cheers, Alf

 

[Adam]

I have to say I liked the look of the joints.

Well done Philly!

Adam

 

[tim]

Agree with Alf on the zebrano re joints but also seems to me that its this year's 'fashion' timber and I think will date very quickly.

Re joints - how much abuse will it get? Sat on?

Cheers

T

 

[MikeW]

hopefully Zebrano. You can see how the double dovetail might look good on this. or not.......

Any other ideas for joining the top to the legs? Biscuited mitre, secret dovetails, dowels?

Hi Philly,

If I were building this table, especially out of Zebrano, I would build the sides and top using a cross-banded core out of some light but strong wood that has extremely little movement, perhaps Makore. (We usually use Makore for this. It is relatively light, high compression strength, extremely small movement in service and in our case cheap.)

I would most likely use shop-made dowels to join the top to the legs. Then again, I just might use box joints because of the thickness of the pieces as it would provide a good mechanical joint.

Then I would veneer using the Zebrano. When we do this, we cut the veneer thick so it can stand the abuse of something like a coffee table. I would shoot for a finished thickness of 3/32.

I think this design would look very nice with the crisp look veneer would provide. The distraction of joints using the Zebrano would be avoided.

 

[MikeW]

Hi again Philly,

I had another thought...which is dangerous this early for me .

In looking again at the drawing, I would also be tempted to add stringing at the points in the drawing where the drawing lines cross at each end--around the sides and across the top as well as along the top's edges.

I would use something monotoned such as Peruvian Walnut which is a close match to the darker streaks in the Zebrano after applying a finish but itself doesn't have a noticable grain to it.

Heck, with your permission I think I would like to make a version of your table as the next shop speculation piece.

 

[cambournepete]

My gut instinct is you don't want a fancy joint in a fancy wood...

I tend to agree with you Alf.

I personally prefer to see complicated joints, designs, turnings, etc in a planish wood and more figured wood used with simple joints, designs, turnings, etc so that either the design or grain stand out. Two lots of complication just serve to hide each other somewhat for me.

All IMHO of course,

Pete

 

[Philly]

Alf, Tim
We have a Zebrano fire place, so would like to encompass this timber in the coffee table somehow. Maybe I just use it for the drawer fronts?
It would look best with a mitre but on 550mm wide boards, 50mm thick I am asking for problems. And I do sit in the living room (sometimes..)-it would drive me barmy looking at opening mitre joints..... :twisted:
Know what you mean about fancy wood/fancy joint-but need the strength in this one. With the little one about, it will definitely be used as a playground!
Mike
Glad I got you excited with the design! I was thinking about veneering but have never tried it (and prefer working in solid wood!). It has to have that slab look to go with the fireplace. Any other ideas for joining it in the solid but retaining that mitred look? Loose tenons?
You go ahead and make one! I'll be starting mine in a few weeks time....
Cheers
Philly

 

[MikeW]

...I was thinking about veneering but have never tried it (and prefer working in solid wood!).

Philly, with a cross-banded (solid-wood) core and thick veneers it works pretty much like solid...just don't make mistakes in measuring and cutting <g>.

...It has to have that slab look to go with the fireplace. Any other ideas for joining it in the solid but retaining that mitred look? Loose tenons?

Hmm, coffee tables need to take a lot of abuse. How about mitered dovetails? The 50mm would provide a lot of depth and hence rigidity to the dovetails and the mitered aspect would hide them and provide a clean lined look. Which in turn maintains the slab look.

The dovetails could be smaller/more of them at the outside corners and fewer/larger at the center. I think they would go fairly quickly even with the 550mm width.

...You go ahead and make one! I'll be starting mine in a few weeks time

Thank you, I will. We have five non-commission jobs started already in various stages of completion. But even so you'll get yours done before I finish off 2-3 of those.

Again, thank you.

 

[GCR]

Philly

Great drawing! I tend to think that, like others, a strongly grained timber would look fussy with the twisted dovetails. I wonder if finger joints would give you the strength required, and compliment the grain. An alternative would be to make the legs out of a plain but contrasting timber whereupon the joints would be shown to advantage.

I made a coffee table many years ago as a project in an early wood machining H & S course - it was used upside down as a toy when my boys were young! Strength can pay off!

Bob

 

[Chris Knight]

Philly,

You've asked a few questions and laid some constraints on the answers and it's getting a bit confusing!

Your joint will be strong but as others have said would probably look very fussy with Zebrano. It will also be very, very, very, very difficult to cut accurately in such thick wood!

If you want the mitred look, and strength in solid wood, then I suggest a secret mitred dovetail. If you screw up the mitre, you can always inlay a string on the corner if you leave enough meat in the mitred portion.

Personally, I would use this as an opportunity to do some veneering. It will be a lot cheaper, give you a load more options and be a new skill. Personally, I would veneer ply rather than solid wood but that is just my parsimonious nature! :lol:

Actually, ply gives you more options for joining the corners - I would suggest a kind of post and panel construction at the corners. Rebate the ply into solid wood cross members (both the uprights and the top into a common corner piece) and then you can dispense with a corner joint all together.

 

[tim]

Philly,

Whats the fireplace look like - it may make the answers/ design points easier to understand?

Can you post a pic?

Cheers

T

 

[MikeW]

... Personally, I would veneer ply rather than solid wood but that is just my parsinomious nature! :lol: ...

Hi Chris,

fwiw, crossbanding isn't solid wood in the sense of just edge-glued boards...you probably know that. For those that don't, the easiest/cheapest way to do so is:

Choose the specie for the core--pref a wood that has little seasonal movement like the mentioned Makore. Substitute as is available locally. Select flatsawn boards.
Prepare the board(s) by jointing one face and then take as little off as possible going through the thickness planer to ensure even thickness.
Cut to finished length plus a half inch or so.
Rip the boards into strips equal to or slightly less than the total thickness of the piece (core plus both veneer pieces).
Rip more enough to make the piece to be veneered. See the example for calculating number of pieces needed. Rotate each strip 90 deg and glue them. Essentially one has just created a vertical grain strips.

Example. To make a table top 20" wide by 50" long by 2" thick, take 1 inch flat-sawn boards, joint/plane to whatever thickness to ensure they are flat. Cut to length plus 1/2". Rip into 2" wide pieces. Rotate 90 deg. So if you ended up with 3/4" thick boards one would need at least 27 strips. Now glue up the pieces.
Flatten, cut to final size, etc.
The cross-banded core is now ready to veneer. Alt. you can veneer prior to cutting to final size.

So why go through all this? Trust me :twisted: it goes faster than it sounds. There are a few advantages. First is that the resultant panel is more stable than the core specie itself, including more resistent to seasonal movement. Second is that this allows the maker to work the resulting panels just as if it is solid wood with little consideration to cross-grain joining (not an issue in Philly's table). Third is that, in the case of Philly's table, the veneer can be applied *after* the joinery to completely hide the joints. This provides a clean look to the table.

 

[Philly]

Hi Guys
A picture of the fireplace, for your delectation......

Cheers
Philly

 

[Neil]

Personally, I would use this as an opportunity to do some veneering

Philly, we haven't seen any gloats from you for what feels like months (must be over a week, then :wink - isn't this a great opportunity for some gloatsome new kit like a vacuum veneering press?

Yours cheekily,
Neil

 

[Alf]

Good point, Neil. Whatever happened to a project not being worth doing unless it needs a new tool to do it? Tsk, what kind of example is this from the Gloatmeister? [-X

Cheers, Alf :wink:

 

[mudman]

Good point, Neil. Whatever happened to a project not being worth doing unless it needs a new tool to do it? Tsk, what kind of example is this from the Gloatmeister? [-X

Cheers, Alf :wink:

So what do you think the Dyson in the fireplace piccy was? :wink:

 

[Chris Knight]

So what do you think the Dyson in the fireplace piccy was? :wink:

I trust that is his little helper's toy, otherwise Mr and Mrs Philly are dwarves!