Working in green oak

[CWatters]

Got an 18 foot long oak beam arriving next week so I guess I'd better figure out how to work it!

How do experts cut your 2" wide mortices? Google suggests the obvious method of drilling holes and squaring up with a chisel but what sizes holes do you go for? One site recommends using a 2" ships auger but that sounds like a heck of a big drill? Am I going to have to take out a Gym membership or buy shares in a power drill manufacturer?

 

[paulm]

Hi Colin,

Never done anything like this in green oak, but guess it depends on the equipment you already have to hand to some extent.

If you only have a weedy cordless drill then that will mean you're stuck with smaller bits, but if you have a larger more industrial type corded drill you could use larger drills, or perhaps even go with a good old fashioned brace and bit if you have one and want the exercise !

Not much help I know, but a bit more info' would probably help, and is it just one mortice or loads of them for example ?

Cheers, Paul

 

[jasonB]

I use a 20mm auger in a SDS+ drill, this is a good size for pegs as well, I do tend to use a 40mm chisel so the two times 20mm works out well, you may want to go upto 25mm drill for 50mm mortices.

Jason

 

[CWatters]

Thanks for the replies. I'll have about 6 or 8 to do so perhaps not worth investing in expensive tools. Will see what my drill will turn and perhaps hire a bigger one for a day if necessary.

 

[MikeG.]

Colin,

Green oak is easy! I don't think there is anything nicer to work. A 25 or 30mm spade bit in a normal 240V electric drill will fly through it, and the chiselling is simple too. I would suggest you get hold of a 1-1/2" chisel, or even a 2", though. You'll soon think of the stuff as hard cheese rather than timber. Properly green wood will actually spray water off the drill as you withdraw it from the wood.

Don't forget to allow for vast amounts of shrinkage across the grain, and do your draw-bore pegging straight away.....pegs of seasoned oak. I always make sure that there are shoulders all around tenons, because shrinkage can reveal the mortices otherwise.

Anyway, have fun!! What are you making?

Mike

 

[plug]

I use green oak at work all the time, I have always drilled out the mortices first with a 20-25mm drill bit (flat or auger), them chop out the rest with a 40mm all steel chisel (from Axminster) and a 4 pound club hammer.

 

[big soft moose]

we do a fair bit in green and part seasoned at work - we use a multico morticer with a half inch chisel and do multiple passes if we need wider widths (though admittedly the weight of an 18 foot beam might make this impractical - the most we work in is 6"x6" x 8' )

 

[RogerS]

Colin...you don't mention the other dimensions. If your cross-sectional area is large have you thought about (a) how you are going to get it in to work on and (b) how you are going to get it into position?

You also didn't say how deep the mortices were. If they aren't that deep then why not rout out using a 1/2" kitchen worktop cutter?

 

[CWatters]

This is what I'll be building..

The oak is for the front posts and front eaves beam. Cladding will either be waney edge oak or larch. Not sure yet if I will add diagonal wind braces as well but I should have enough oak coming. There are brick pillars at the base of the posts not shown in the drawing. Roof will be clay tiled.

The beam under the eaves is 8" x 6" x 18 foot so plenty heavy. The verticals are 6" x 6" posts so bit more manageable. I plan to assemble the beam and posts flat on the ground as close as possible and then raise it up. Previous experience is limited to hanging a 12 foot gate on an oak post. That post was 8 inches square and 8 foot long and quite a struggle to get in the ground - so I have some idea of the problem ahead.

 

[MikeG.]

I hope you have lots of people available to give you a hand!!!

Mike

 

[RogerS]

Colin

I really really recommend you hiring a Genie Lift. It makes light work of lifting and manouevring beams like yours. What price a hernia/slipped disc?

I hired mine from Travis Perkins. One of the best hires I've ever done. Magic bit of kit.

Roger

 

[CWatters]

Thanks for that suggestion. I was thinking winches or a fork lift truck, I didn't know this sort of man powered lift existed..

http://www.travisperkins.co.uk/hire/pro ... 1&img=4297

Edit: Just calculated the weight of the big beam at between 220lbs(100Kg) and 350lbs (160Kg). Volume is about 6 cubic foot. That appears within the limits of the 2.5meter Genie. HSS has it on hire at £64 for the day or £75 for a weekend.

 

[MikeG.]

Deleted!

 

[dickm]

Think I'd be worried trying to use that lift anywhere other than a nice flat factory floor. Problems of stability on the slightest slope, and wheels that size would disappear into the soil unless you are really lucky.
Got any friendly local farmers with a rough terrain materials handler?

 

[RogerS]

Think I'd be worried trying to use that lift anywhere other than a nice flat factory floor. Problems of stability on the slightest slope, and wheels that size would disappear into the soil unless you are really lucky.
Got any friendly local farmers with a rough terrain materials handler?

True but hopefully Colin will have a nice concrete slab.

Colin..the other thing to worry about is how are you going to get it from where they literally drop it off the lorry and where you need it. Lengths of soil pipe works well or just get some slings from machine mart and drag behind your 4x4.

Below are a few pictures that I took of my mini-project

 

[milkman]

ou may find you have to hire a more powerful drill to handle a 2" bit.

Genie lifts or roustabouts excellent things Also 3 -4 handy people to lift it to the site!

Timber framers often use heavy tired trolleys a bit like this:

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[chris_d]

CWatters,

Apologies for this distraction but I noticed that you installed a sprung latch on the gate that you hung. Would you mind sending me a close-up photo of the latch-to-post assembly since I also need to install one and it has defeated me thus far in terms of getting a reliable geometry?

Cheers,
Chris

 

[CWatters]

My digital camera has packed up so I'm restricted to photos I took when it was done. This is the best one I have...

The correct proceedure is to hang the gate on one post then dig the hole for the other post. If the latch post is only a 6" post it's position is quite critical. Normally the gate should overlap the post 1" but if you do that the space for the latch is only 5" wide which can be very tight. The hole for the catch is too near the left hand edge of the post. I found this out the hard way. It would be easier if a 7" or 8" post was used both sides. The post in the photo is 6" and the overlap with the gate about 0.5".

It might be easier to use this type of latch in some cases...

 

[CWatters]

PS. The catch is about 2" lower than the strap on the gate to allow for the gate to drop a bit.

The spring force with this type is allways moderately strong and you have to manually close the gate - you can't really slam it as it would be a bit violent. I'm not too sure how to reduce the spring tension. One possibility might be to drill a line of holes down the length of the spring and enlarge until it's right - but I've never tried this and the edges of the holes would probably rust.

 

[CWatters]

Regarding moving my oak beam around... I used a sack trolley on the 8" sq 12 ft gate post. Only moved one end of it at a time! Wasn't too bad. This time I will have to move the beam about 50 yards up a gentle slope as not possible to get the lorry any closer.

I think I'll arrange things so that I only use a Genie to do a straight lift. That should be possible. Unfortunately it at the moment where it will need to stand to lift the beam is grassed. I will eventually need to put hardcore down there so I can bring that bit of work forward and ensure it's got a steady base.

There is a man in the USA who moves stone blocks around that weigh over a tone on his own...

http://www.youtube.com/watch?v=lRRDzFROMx0