joining oak board to make a swing seat

[TominDales]

I'm planning to make a new swing seat (upgrade the look of the garden) out of oak.
The design calls for a board 60cm by 20cm by 3.5cm thick, it then has 4 hole drilled in the corners to hold the rope.
I have several old planks that are too small in one dimension, ie 3.5cm thick but only 14cm wide or wide boards that are too thin ie 2cm thick.

Should I a) join the 3.5cm thick boards14cm wide along the length to make it 20cm wide (cut off the 8cm) or b) join two thin boards to make upto 3.5cm thick? ie one on top of the other or c) buy a new piece - looks very pricy.

Needs to withstand the weather for 6 months of the year.
Want to look a bit like this.

 

[recipio]

It's going to be easier to edge join the thick boards assuming you have a set of sash clamps to glue them up. Don't forget to use a waterproof glue.

 

[TominDales]

It's going to be easier to edge join the thick boards assuming you have a set of sash clamps to glue them up. Don't forget to use a waterproof glue.

Thanks I've got the blue waterproof evostick exterior, I thought I'd use Dowel and edge but joint. Otherwise I was going to glue two boards flat down one on top of the other and maybe a few holding screws from underneath. The dowel method is virtually invisible, as long as the joint doesn't start to open over time.
Thanks Tom

 

[recipio]

If you have a perfect edge joint the board will expand and contract in unison . The dowels will not stop that but they help with alignment. The wood should be reasonably dry of course.

 

[okeydokey]

Have you considered a length of (new) scaffold board - quite often made of Spruce - well the ones in Wickes are and might already be the size you need would take a stain/etc if you wished.
It may split a little (like most wood) left out in the weather. A board would give sufficient for you be able to replace every year or so with little effort, you can sometimes get short new boards from scaffolding suppliers.
Maybe better is to see if there is a sawmill near you they can easily provide the size out of a a oak offcut or short board.

 

[Jacob]

Maybe have the boards with a gap between them and a cross batten at each end?

 

[RobinBHM]

I'm planning to make a new swing seat (upgrade the look of the garden) out of oak.
The design calls for a board 60cm by 20cm by 3.5cm thick, it then has 4 hole drilled in the corners to hold the rope.
I have several old planks that are too small in one dimension, ie 3.5cm thick but only 14cm wide or wide boards that are too thin ie 2cm thick.

Should I a) join the 3.5cm thick boards14cm wide along the length to make it 20cm wide (cut off the 8cm) or b) join two thin boards to make upto 3.5cm thick? ie one on top of the other or c) buy a new piece - looks very pricy.

Needs to withstand the weather for 6 months of the year.
Want to look a bit like this.

View attachment 136625

I wouldn’t risk an exposed glue joint externally, especially one that sits horizontal.

It will delaminate from the ends, not so much failure of the glue but the differential expansion and contraction of the the individual pieces will create large enough forces at the joint to make it fail.

Jacobs idea is best

 

[TheTiddles]

Run a full length loose tongue down the edge of each piece, outdoor glue, you’ll be fine.

 

[TominDales]

Thanks all for your advice. I've decided to go with slats as Jacob recommended, it also allows for better economy with the wood, solves the glue fail issue, and the Mrs is ok with that justifiying it using Jacobs argument about wet and rot, was well received. I'll will allow for expansion in the joint. so thanks everyone.
I feel I'm now a true member of the forum. I initially just read posts, then started to reply to posts, but would forget to ask questions before starting jobs. I'm now in the habit and its saves a huge amount of time and mistakes getting the collective brain power of this forum.

 

[Pritchardsinteriors]

Hi..I'm new to the forum so hello all!
You can pick up 9 x 2 sawn planks really cheaply and no messing about gluing up?
Just an idea.