Mortise & Tenon

[Rewound]

I have used the following before with some success but wondered if it would be frowned upon as a technique - (basically i wonder if the tenon could burst the mortise)

When both the mortise and tenon have been created and the tenon is has been made (on purpose) just a little too tight. squash the tenon slightly in a vice (lets say from 12.3mm to 11.8mm) glue it, join it and the squashed wood will regain some of its original size making the joint super tight

think of biscuits, they are squashed beech and the dampness in the pva makes them expand)

 

[dzj]

I looked it up. It's a Japanese woodworking technique called kigoroshi.
They rely on air moisture rather than glue to do the swelling.

 

[Jacob]

I have used the following before with some success but wondered if it would be frowned upon as a technique - (basically i wonder if the tenon could burst the mortise)

When both the mortise and tenon have been created and the tenon is has been made (on purpose) just a little too tight. squash the tenon slightly in a vice (lets say from 12.3mm to 11.8mm) glue it, join it and the squashed wood will regain some of its original size making the joint super tight

think of biscuits, they are squashed beech and the dampness in the pva makes them expand)

It's a bodge, not least because you often have to test with a reversible dry fit first.
In any case it'd have to be an accurate tight fit, which if you can manage at all you might as well go for an accurate push fit to start with.

 

[Orraloon]

I looked it up. It's a Japanese woodworking technique called kigoroshi.
They rely on air moisture rather than glue to do the swelling.

I had to look that up.
The Japanese Gennou & Handle Part 5 – Kigoroshi – Covington & Sons Tools
I see it gets used a fair bit where a tight fit is required like boatbuilding. Similar methods exist in western woodworking where a watertight joint is required. I recall seeing a clip of someone making an old stile wooden sink. Could not find that clip but this is the method.
making a watertight wooden box - Google Search
Like all woodworking techniques they have a place but like Jacob said hardly necessary with your standard M&T.
Regards
John

 

[Chubber]

I can't see it being very effective with, say, iroko or Rock Elm, hard and almost incompressible, but our Nipponese cousins work with a lot of softer cedarwood, don't they? Jus ' thinkin'...

 

[dzj]

I recall seeing a clip of someone making an old stile wooden sink. Could not find that clip but this is the method.

Frank Klaus made a video on YT in which he made this type of container for whetstones IIRC.

 

[duke]

An old mason friend of mine always wet his wood handled hammers and mallets when they became loose, fixed a problem nicely.

 

[Rewound]

May as well ask while I'm here. I have three of these legs to fit onto a 100mm Ø main leg.

Obviously I am going to have to get a nice fit for the rounded edge so will have to faff for ages with chisel and sandpaper - is there n easy way - any thoughts would be most appreciated, I have done them before and its a pain in the arse sort of task

 

[pgrbff]

May as well ask while I'm here. I have three of these legs to fit onto a 100mm Ø main leg.

Obviously I am going to have to get a nice fit for the rounded edge so will have to faff for ages with chisel and sandpaper - is there n easy way - any thoughts would be most appreciated, I have done them before and its a pain in the buttocks sort of task

View attachment 186984

Flatten a square onto main leg?

 

[Chubber]

Similar to above, but make opening in 'leg' to fit shoulders.

My Charles Heywood book shows a wide dovetail on the end of the legs inserted from underneath.

(Number mortises and tenons, insert in turn and using a marking knife scribe shoulder joints before setting to with an appropriate chisel.)

 

[TheUnicorn]

An old mason friend of mine always wet his wood handled hammers and mallets when they became loose, fixed a problem nicely.

until it dries again

 

[Rewound]

Flatten a square onto main leg?

Is that the standard way of doing them - certainly sounds easier.
Although in the unusual way I am making the centre leg it would mean using a chisel across the grain

 

[Just4Fun]

until it dries again

I once read that using diesel or paraffin instead of water gets round that problem because it either doesn't evaporate or evaporates very slowly. I haven't tried it myself though.

 

[duke]

until it dries again

I saw him actually pull the tools out of a bucket of water, that's what prompted my question as to why.
Older European man with a thick Slavic accent.
If it worked for him then great.

 

[duke]

I once read that using diesel or paraffin instead of water gets round that problem because it either doesn't evaporate or evaporates very slowly. I haven't tried it myself though.

I will check this out, thanks.

 

[throbscottle]

Is that the standard way of doing them - certainly sounds easier.
Although in the unusual way I am making the centre leg it would mean using a chisel across the grain
View attachment 186986

Making flats was my first thought too. Personally I don't have a decent chisel so I'd use abrasive as much as possible - starting with a rasp. Or make a jig so you can do it with a router. Or make judicious and careful cuts on a well set-up sliding mitre saw (flippin' miracle machine). Or even abuse a hole saw (my hole saws are very abused...). Ok maybe not that! Whatever, it minimises the amount left for chiselling. Looks quite a challenge. I know I'd struggle with the fit even on a normal centre piece.

My other thought, and this is something I'm sure I've seen on old furniture, is to change your design so the bulk of the shoulders of the tenon are cut away at an angle, or curve, leaving just a few mm of actual shoulder that you don't really see when it's fitted

Either way I'd do some tests first.

Nice looking piece, looks kind of snappable too! - Does it have rod down the centre or something?

 

[Chubber]

If you don't have a decent chisel, you need at least one for what is a fairly complex job! It seems therefore unlikely that you have 3/4" in-canel gouge and a slip stone.

You have already invested a good deal of time and labour in the job so far, don't risk wasting it.

Have you cut the mortices yet?

Get a 1/2" and 3/4" bevel edge chisel with full length blades and practice sharpening them before you go any further. (I'll not start a sharpening war here!)

Cutting straight lines is easier than fettling curves (IMHO) so I would go for cutting out a rectangular opening, it looks as though 3/16 - 1/4" deep should do it.

Feel free to disagree or go elsewhere for solace, I won't be offended!

 

[--Tom--]

If you know the diameter of the column a drill bit of the same size can be use to cut the corresponding cove - best done before the rest of the tenon shaping though.
Hot gluing a scrap on could give a centre to use for drilling. Otherwise as said scribe it in with a gouge

 

[TRITON]

I like to wet my dovetails after fitting and prior to sanding.

I'd watched a vid on Kigoroshi years back. it was a simple 1/2 lap to create a cross. Joint cut, it didnt go or fit together. A few taps here, a few taps there and the two components slid together perfectly.
I was very much in awe.

 

[Rewound]

Making flats was my first thought too. Personally I don't have a decent chisel so I'd use abrasive as much as possible - starting with a rasp. Or make a jig so you can do it with a router. Or make judicious and careful cuts on a well set-up sliding mitre saw (flippin' miracle machine). Or even abuse a hole saw (my hole saws are very abused...). Ok maybe not that! Whatever, it minimises the amount left for chiselling. Looks quite a challenge. I know I'd struggle with the fit even on a normal centre piece.

My other thought, and this is something I'm sure I've seen on old furniture, is to change your design so the bulk of the shoulders of the tenon are cut away at an angle, or curve, leaving just a few mm of actual shoulder that you don't really see when it's fitted

Either way I'd do some tests first.

Nice looking piece, looks kind of snappable too! - Does it have rod down the centre or something?

It has a M12 through the centre - helped clamp it together then come in handy for the lathe, and will eventually give it great strength. Although saying that, its Pitch Pine and it doesn't split that easily along the grain

If you don't have a decent chisel, you need at least one for what is a fairly complex job! It seems therefore unlikely that you have 3/4" in-canel gouge and a slip stone.

You have already invested a good deal of time and labour in the job so far, don't risk wasting it.

Have you cut the mortices yet?

Get a 1/2" and 3/4" bevel edge chisel with full length blades and practice sharpening them before you go any further. (I'll not start a sharpening war here!)

Cutting straight lines is easier than fettling curves (IMHO) so I would go for cutting out a rectangular opening, it looks as though 3/16 - 1/4" deep should do it.

Feel free to disagree or go elsewhere for solace, I won't be offended!

luckily I have access to a proper morticer (probably from the 50s) but it makes a nice job, and I have my own chisels for it so can get a nice finish. Anyways thats bits done. Going to start working on fitting it together the morrow - its a time consuming jo that I don't care for - hence asking for an easier alternative