Bench help

[bobh]

Am in the process of making a curved bench but am a little stuck on how to fix the top onto the legs.

The bench top is 3" thick and I want to fix it onto larch legs which I will have to concrete into the ground. (Will be sited on top of a hill overlooking a loch so will have to withstand cattle, sheep and deer)

 

Bench top is similar to this

 

 

Want to fix it to legs like this (but 3 of them of course)

 

 

What's the best fixings to use? Was considering 200mm index screws or coach screws hidden under a plug.

Any thoughts welcome.

[arbmark]

mmm thats beautiful..................what was the question?!? tight fit rectangular mortice and tenons and diagonal screw thru. Made a bench once and put long oak pegs horizontally through the endgrain of the seat into the tenons to lock the seat down. U could try that.....and plenty of good grade wood glue i expect there will be better suggestions.

or angle brackets........

[agg221]

Do you mean the legs are round log sections, like in the second picture? If so, are they well seasoned? If not, the risk is that round timber tends to open up radial cracks, and it does it along the line of weakness, which is most likely to be where you've screwed through.

 

Ideally you want to fix across the grain, rather than into the end grain, particularly if it's green. I can't come up with an easy way of doing this, but I wonder if it would be possible to cut full width slots across the tops of the legs to let angle plates in to, held in place by coach screws. The heads shouldn't show too much if they're on the inner face of the leg, and could be rebated. The other half of the angle could then be screwed to the seatboard, from underneath. If 2.5" screws were used, countersunk into the angle plate, the whole thing would be virtually invisible.

 

In practice, you'd need to set up the holes in the angles and mount them temporarily in the leg tops. Then concrete the legs in, set the board on top (having greased or inked up the top faces of the angle plates to get witness marks) and then take the plates out of the legs and screw them permanently to the top. Finally, drop the angles back into the slots and screw down home.

 

Not sure if there's a better solution, can't think of one with what you're trying to do.

 

Alec

[Woodworks]

The angle bracket idea sounds neat and tidy but I don't think you would have any problem with screw and plugging with something like the Spax washer head screws as you suggest 200mm or even longer. I use these sorts of screws for heavy structural use and have never had any problems even in end grain. You would need a 25mm plug cutter for the Spax screws as the heads are quite big.

 

Hope this helps

[arbmark]

The angle bracket idea sounds neat and tidy but I don't think you would have any problem with screw and plugging with something like the Spax washer head screws as you suggest 200mm or even longer. I use these sorts of screws for heavy structural use and have never had any problems even in end grain. You would need a 25mm plug cutter for the Spax screws as the heads are quite big.

 

Hope this helps

 

Yep those big spax screws are very good, Alec's solution is very tidy. With the likelihood of animals rubbing on it big screws are needed. Even fogetting tenons and just butting the surfaces together, using angle iron pieces with plenty of screw holes along the sides of the join (you might have to square up the tops of the legs). I wouldnt use green wood for the legs for the reason Alec stated. If the seat plank has cupped at all i would use the concave surface down so that it forms a dripline to avoid water getting back around into the joints. Alternatively you could router out a channel around the lower side edge to create an upside down moat.

[welsh wood]

Tennon the legs and mortice the top then saw cut the tennons down to the depth an ins.or so from each end glue with Cascamite waterproof glue fit top and drive some narrow wedges into the saw cuts this will tighten up the joint,useing contrasting wood for the wedges IMO looks guod. Trim end of tennons and sand to finish req.

[slackbladder]

how about using a large dowel something like 2".Into the base and top

[bobh]

Thanks a lot for all the replies, plenty of options to think about.

At the moment I am still leaning towards fixing straight down into the legs. Not sure though, you guys have suggested ideas that I hadn't thought of yet so some more thinking time is needed.

Any other suggestions welcomed though.

[bobh]

OK time for an update

Finally got round to finishing this bench, in the end I got some 220mm Spax washer head screws, great things and they tightened down really well

I'll just have to keep an eye on them to make sure they don't slacken over time.

 

Fairly pleased with how this came out, but with that view I don't think many people will be looking at the bench.

 

 

 

 

Thanks again for all the advice

Much appreciated

[delabodge]

nice bench, nice view,,,,and wishing I was having a nice beer sat on it,,,fab location,,,