# Watertight Mortise&Tenon + Peg; What type of joint is this called?



## Edward King Solomon (Apr 11, 2014)

This is an ancient shipbuidling method used by the Greeks, what type of joint is this hybrid M&T + Dowel/Peg system? Small gaps become water tight when the wood expands, but what kind of joint is this?


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## tc65 (Jan 9, 2012)

Those are floating tenons with pegs so, pegged floating tenon? 

I don't know if they would have been drawbored, if so, probably the bottom of each tenon was pegged and the top holes on the tenon would have been offset slightly so when the peg is driven it pulls the boards tighter together. - Drawbore floating tenon?

Since it was on a boat/ship, there was probably a name for that type construction, but I don't know what it was.


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## Manuka Jock (Jun 27, 2011)

Edward King Solomon said:


> This is an ancient shipbuidling method used by the Greeks, what type of joint is this hybrid M&T + Dowel/Peg system? Small gaps become water tight when the wood expands, but what kind of joint is this?


Some say that the method is Egyptian .
Not that that means anything 

http://www.jimsboats.com/webarchives/2001/15jun01.htm#WOODEN%20BOAT%20CONSTRUCTION%201


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## Manuka Jock (Jun 27, 2011)

This page here may have better technical info than those above .

*MONOCOQUE PLANKING* 
MORTISE AND TENON PLANKING (Mediterranean) 



















http://worldwideflood.org/ark/basic_hull_design2/monocoque_planking.htm


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## Edward King Solomon (Apr 11, 2014)

I was investigating this design for an outdoor hot-tub that has the following appearance, should I pursue this project (tub rests on a concrete slab, none of my concrete patio has ever been used for anything).

Other than filling the tub with the hose, the system is entirely self contained and separate from the house. It would be used for large gatherings, such as Fourth of July or Memorial Day


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## Manuka Jock (Jun 27, 2011)

Three of the graphics failed .

What timber do you have in mind ?
How are you going to build the difficult bits , the corners , 
all eight of them ?


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## Brian T. (Dec 19, 2012)

That's fairly silly = you make a kerf bent box.
We all know that there's only one corner to seal.

In a 5/4 WRC plank, 6" wide, I can cut the roll-over corners in about 20 minutes each.
I will try, this summer, to develop the patience for the bending.


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## Edward King Solomon (Apr 11, 2014)

Manuka Jock said:


> Three of the graphics failed .
> 
> What timber do you have in mind ?
> How are you going to build the difficult bits , the corners ,
> all eight of them ?


4x8 Cedar.

The corners would simply be mortised and tenoned horizontally instead of vertically, using the same draw bored peg system.


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## Manuka Jock (Jun 27, 2011)

Good idea , that'll do it .

Looking at the photo in the link that I posted ,
this one , and after reading this in the Hull Data box ...


> *Strakes (planking) *
> Thickness 35 to 100mm (1.4" to 4"). Usually pine. Sometimes as thin as 20mm.
> Widths variable but at lest twice the depth of the tenons.
> Evidence of double planking and use of waterproof membrane, lead sheathing etc between layers.












... I wonder if the photo shows the inner face of a ship's lapped plank , 
and I also wonder if the planks lapped half and half with their fellows . The tennons being let into the side of the timber , rather than down into the edge .


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