Makeing dining chairs

[ozwinner]

Hi, me again.
I sound like that add for Yellow pages...........:D

I want to make some dining chairs.
Can I biscuit joint them, rather that using dowels?
Would it be as strong using biscuits? ( and a nice cup of tea, please )....Mmmmm

Cheers, Allan

[Shane Watson]

One word.... NO....

[ozwinner]

Hi
So I take it, it's NO.
What about mortice and tenon.
How would Huon go as a chair, not too weak is it?
Cheers, Al:)

[Shane Watson]

Now your starting to speak english! ;) hahah..

Nothing wrong with huon either a good 30% of the chairs I have worked on in my life have been pine.

[journeyman Mick]

Doorstop, I've never even seen the stuff in rteal life, but isn't it called "Huon Pine"? Is that just another misnomer like Milky Pine? (not a pine at all, but a fast growing rainforest species AKA Cheesewood)

Mick

[Suresh]

There is a very good furniture maker in Maryborough, Charlie Borvalino who makes a lot of Ironbark furniture.
He needs to make his legs with a very thin profile, where a mortise and tenon would leave very little timber remaining. He uses biscuits but also very strong adhesives and other design features to make sure that the joint survives.
I have been experimenting with biscuits and find them strong enough BUT you must use the appropriate adhesive and corner blocks etc.
Suresh

[q9]

I have been informed by a jointer friend that adhesives used for chair legs are "secret" - once someone finds something that works, they don't like telling anyone.

I will make an assumption that you could consider any of the high strength industrial epoxies or two-part wood glues. However, be prepared to pay. Aviation grade epoxies will be around $400+ per kg (unless you know a polymer-chemist ;) ) but are fiercly strong. For wood glues, I have been told that the AV 501 (? dodgy memory) is a good-un.

Another piece of advice I will offer is this: consider carefully the direction of forces acting on the joint and the effects of leverage, and plan your jointing strategy to suit. A single dowel/biscuit in the middle of a joint for a chair leg wont last long.

[ndru]

A single dowel/biscuit in the middle of a joint for a chair leg wont last long.

Make sure your insurance covers you when you have your boss and his wife around for dinner and the chair you made falls apart under his wife's weight... http://www.my-smileys.de/CyberMChair.gif http://www.my-smileys.de/angryfire.gif http://www.my-smileys.de/Bolt.gif

[BrianT]

Ozwinner, 'scuse me for a moment please'

but hey, NDRU, please tell me you AREN"T using a tax-payer funded computer to download the 'funny faces' etc.

We're 'sposed to be strugglin' for a $ in SA

:D ;)

BUt if you are, what is it. :rolleyes:

Brian @ Burra

[BrianT]

It's OK for you mob down in the swamps Doorstop, even the rocks a still looking for a drink up this way :p but the vines at Clare are doing OK so the world is at peace.

An' I reckon that govvy car was probably a mate of mine - he's always complaining he can't get enough wood for the home fires :rolleyes:

Brian @ Burra

[ndru]

We're 'sposed to be strugglin' for a $ in SA

I don't have a window in my office, crosswords make my head hurt and hiding out in the toilet gets pretty boring - I need something to see me through 'til 4pm! Besides, my computer only costs the equivalent of two heart bypasses in a public hospital a year ... :D

On a more serious topic, here's the smilies web site (http://www.my-smileys.de/). I hope your German is OK...

[Shane Watson]

If you use an expoxy or any adhesive without some give in it on a chair (specially one of poor design/constrcution) your asking for trouble... Got to www.avsyntec.com.au for actually test reports on such joints where they sugest using a two-part acid cure PVA. And I can back that up from gluing together thousands of the buggers with this stuff and only had about 2 from memory come back to me with failed joints - yeah the owners weren't small.....

[Suresh]

AV 515 is their new polyurethane adhesive, they rate it very well. I have been using quite a bit of it and am very impressed. Easy to use, strong as anything. It has give, that is, it is not a brittle hard join like epoxy. Waterproof.
The only complaint, a small one, is that it is a bugger to get rid of the excess. Does not sand off like epoxy or pva.
Suresh

[q9]

It is wrong to think that epoxies have no "give". Some epoxies are made specifically to have good flexure properties and some are very stretchy indeed. Some epoxies are rubber toughend and I can guarantee that you can belt them with a hammer and they will not shatter or break.

[echnidna]

Dowels and mortice and tenon joints have a very high mechanical strength even without any glue. Biscuits just dont have the same mechanical properties.

In olden times hide glue was preferred for chairs and is still a very good glue for the job. (Food grade Gelatine can be used as hide glue - its the same thing just more hygenically refined).

PVA is ok as it has the slight flexibility needed in chair joinery. Both of these can be dismantled for repairs. Expoxies are rigid and may crack with the flexing of the chair parts.

I have seen commercially manufactured chairs (beech) with motice and tenons glued with (generic brand) liquid nails.

Ironbark is a very heavy timber so its necessary to use thin sections or the chair would end up being so heavy clients couldn't rearrange furniture readily. It also doesnt glue well with normal wood glues so expoxies etc are needed.

You will never find an antique chair made of softwood. There are technical reasons relating to the cellular makeup of timber
but I have forgotten the indepth details

I seem to recall huon pine is a type of ancient beech. So it should be ok