Moisture content for outdoor furniture - should i be worried

[Sawdust=manglitter]

Am planning to make some outdoor furniture with some 2" and 3" thk oak, but was wondering whether i should worry about drying it to a certain moisture content before working with it and particularly applying protective finish?

 

[ED65]

Is the wood currently not dried fully or something?

 

[Orraloon]

You should start with seasoned wood not green. I wont go into percent readings to keep things simple. The attachment below can be used as a guide but dry as in from a wood merchant calling it seasoned is fine. Any coating to be applied while wood is dry. I would go for one of the outdoor oil finishes as they are easy to redo later with just a wipe over. Dont know what is available in the UK but here in Oz there are oils for outdoor furniture and wood decks. The deck stuff is ok to use too and is cheaper. When it goes outside coated or otherwise it will take up moisture so construction has to allow for a lot of movement. A solid glued up top would soon warp left outside. Slatted tops are the usual for outside tables. Stainless, brass or galvanised fasteners too. (perhaps skip the gal as steel stains oak black).
If it lives outside year round be prepared to refinish it every year.
Regards
John

http://www.mibnet.se/home-improvement/h ... tures.html

 

[YorkshireMartin]

I'd think it depends on a whole range of factors. Intended usage, design, and joinery method the most pertinent. For some things you could use green timber, for others you'd need to have well seasoned.

Can you provide more details?

 

[Sawdust=manglitter]

Apologies for the late response!

Well I've got a nice 3" thick slab of oak that I'd like to use to make a simple chunky bench for the garden. It's around 25% moisture content at the moment, hence this post. I'm expecting to need to leave it dry for a while before working on it, but by how much if it's going to live outside?

Sent from my iPad using Tapatalk

 

[Orraloon]

I guess if it is to be just the full width slab set up on legs of some kind for the rustic look then just go for it. There will be wood movement in a slab like that whatever you do. Those cracks will need something doing or they will spread. Butterfly ties/buttons should hold them. The link gives the idea.
Regards
John
https://www.youtube.com/watch?v=U3qXaz3B0jU
Regards
John

 

[Jacob]

Counter-intuitive but in fact thick wood is less durable than thin wood in the outdoors. This is because thin stuff has a greater chance to dry out thoroughly in summer - halting the progress of insect and fungal attacks.
Also depends on detail design - slats rather than solid, open joints to avoid water retention, brass fittings etc.

 

[Sawdust=manglitter]

Thanks for the replies. I was already planning on making some butterfly keys for the cracks. I know thicker chunkier wood isn't exactly the most stable, but my very particular client (the OH) knows what she wants!! So I obviously don't want to mess it up, hence wanting to dry it sufficiently before working on it

 

[RobinBHM]

Thanks for the replies. I was already planning on making some butterfly keys for the cracks. I know thicker chunkier wood isn't exactly the most stable, but my very particular client (the OH) knows what she wants!! So I obviously don't want to mess it up, hence wanting to dry it sufficiently before working on it

Given your location, I wonder if instead of leaving it to dry out more, maybe you should get the hosepipe on it

 

[YorkshireMartin]

Whatever you do it's going to need regular treatment and maintenance. Keep the joinery chunky and very simple.

PS. Non-woodworking "other halves" only *think* they know what they want.... A few minutes sitting on a fungus infested wet log would soon change their perspective.

 

[Sheffield Tony]

Watch out for sapwood on your oak, that will rot much faster than the heartwood, and be more prone to insect attack.

 

[Sawdust=manglitter]

If I tried even hinting that she only 'thinks' she knows what she wants I'd be sleeping in the workshop (which probably wouldn't be too bad if it was heated!)

I was tempted to try out a UV resistant epoxy coating like that used on boats, like...
http://www.fyneboatkits.co.uk/supplies/ ... poxy-slow/
In my mind that would also help dimensionally stabilize the wood and also harden the sapwood. It would also prevent moisture penetration, but still not sure what kind of moisture content i should be aiming for prior to working etc.