Flexiteek Flexibility

[Tranona]

Guwales usually go because water gets down between them and the GRP so capping them in the way I suggested would stop that.

You should enjoy steaming. Lots of jumping around with hot floppy bits of wood and trying to get them on before they cool down. Consider getting them to shape by clamping then leaving them to dry in situ. You can then glue them on rather than bolting. Don't forget to brace across the beam to give yourself something firm to bend against and keep the shape before you fix them permanently.

 

[JumbleDuck]

Guwales usually go because water gets down between them and the GRP so capping them in the way I suggested would stop that.

Yes, something is needed there all right.

You should enjoy steaming. Lots of jumping around with hot floppy bits of wood and trying to get them on before they cool down. Consider getting them to shape by clamping then leaving them to dry in situ. You can then glue them on rather than bolting. Don't forget to brace across the beam to give yourself something firm to bend against and keep the shape before you fix them permanently.

I'll make a jig, I think, and leave them on that to cool. The front and back thirds aren't nearly as curved as the middle bit, so if I can get the middle reasonably bent the whole thing should be springable-into-place.

 

[Quandary]

Adam Way (Ole Boots' boatbuilder) replanked a round sterned fishing boat based holiday cruiser outdoors in the basin here last winter, the planks were larch about 150x 50 so needed a bit of bending.
He had clear polythene tubes (like the stuff carpet comes wrapped in) which enclosed the parts of the planks that needed bending and a steam generator. I thought it had the following advantages, low thermal mass so quick to heat up, translucent so you could see what was going on, and flexible so you could check how it was bending and not over steam. It was also easy to localise the bending by moving the ends in or out.
Cheap to do if you could source the plastic tube, we used to buy rolls of paper in the drawing office wrapped in a smaller version, about 4' long by 4" dia.

 

[JumbleDuck]

Adam Way (Ole Boots' boatbuilder) replanked a round sterned fishing boat based holiday cruiser outdoors in the basin here last winter, the planks were larch about 150x 50 so needed a bit of bending.
He had clear polythene tubes (like the stuff carpet comes wrapped in) which enclosed the parts of the planks that needed bending and a steam generator. I thought it had the following advantages, low thermal mass so quick to heat up, translucent so you could see what was going on, and flexible so you could check how it was bending and not over steam. It was also easy to localise the bending by moving the ends in or out.
Cheap to do if you could source the plastic tube, we used to buy rolls of paper in the drawing office wrapped in a smaller version, about 4' long by 4" dia.

Thanks. I like the idea of flexible containment.

 

[Quandary]

Thinking about it, I can not see how it would not be easy to get some clear polythene sheet, roll a strip of it round a piece of something, overlap and fold to make a joint and staple to form the tube. It is only going to be used a couple of times so elegance and durability are not going to be big issues? Seal the ends with clothes pegs?

 

[JumbleDuck]

Thinking about it, I can not see how it would not be easy to get some clear polythene sheet, roll a strip of it round a piece of something, overlap and fold to make a joint and staple to form the tube. It is only going to be used a couple of times so elegance and durability are not going to be big issues? Seal the ends with clothes pegs?

I dream of a steaming machine, with the wood wound slowly through a sealed steam area by rollers whose spacing is varied continuously to impart a desired profile to the bent wood. That's possibly a bit over-elaborate for the task in hand, though.

 

[Quandary]

I dream of a steaming machine, with the wood wound slowly through a sealed steam area by rollers whose spacing is varied continuously to impart a desired profile to the bent wood. That's possibly a bit over-elaborate for the task in hand, though.

We all have our fantasies, mine would be a bit different from yours.

 

[Tranona]

Been on a tour today of the Boat Building Academy in lyme regis. watched the instructor bend a piece of 25*12mm green oak to a tighter radius than you require without steaming - although that will be required when it becomes the ribs of a new build clinker dinghy!

 

[JumbleDuck]

Been on a tour today of the Boat Building Academy in lyme regis. watched the instructor bend a piece of 25*12mm green oak to a tighter radius than you require without steaming - although that will be required when it becomes the ribs of a new build clinker dinghy!

It's not so much a matter of how much it bends before breaking, as what forces would be locked in if I did so. We shall see.

Meanwhile my wallpaper steamer arrived from Amazon today, Aitken & Howard have offered me green oak or opepe in suitable sizes and Flexiteek have sent me a sample of their stuff ... even if it is too floppy for the gunwale I may use it as a rubbing strip.

Tomorrow, all being well, we do some experiments with steam.

 

[PuffTheMagicDragon]

Don't forget to take and post photos as you proceed!
We will then regale you with an expert chorus of "Nah! That's not the way to do it! You should have.....etc."

p.s. Do make sure that you have strong gloves handy. Wet steam is nasty stuff!

 

[JumbleDuck]

Don't forget to take and post photos as you proceed!
We will then regale you with an expert chorus of "Nah! That's not the way to do it! You should have.....etc."

I would expect nothing else. You can get started now: I have today acquired a 3m length of 68mm PVC downpipe and a 45^o junction. I'm going to cut the pipe in two and fit it to the junction, where I'll inject the steam. That way the hottest bit should be the middle, where I need to bend it the most. I'll do some experiments on scrap wood this weekend.

p.s. Do make sure that you have strong gloves handy. Wet steam is nasty stuff!

Welding gloves all ready.

Update: My Flexiteek nosing section sample has arrived as I was typing this. It's flexible, but less flexible than I thought. I think a layer of that inside and out might well do the job. Must ponder ...

 

[PuffTheMagicDragon]

Update: My Flexiteek nosing section sample has arrived as I was typing this. It's flexible, but less flexible than I thought. I think a layer of that inside and out might well do the job. Must ponder ...

I obviously don't know how long is the sample but, while pondering, bear in mind that a short length of anything usually appears to be much stiffer than a longer piece. Walking briskly with a one-metre length of 2 x 1 gives the impression of a stiff piece of wood while doing the same with a four-metre length of the same material will soon have the ends waving up and down.
Just a thought
:encouragement:

 

[JumbleDuck]

I obviously don't know how long is the sample but, while pondering, bear in mind that a short length of anything usually appears to be much stiffer than a longer piece. Walking briskly with a one-metre length of 2 x 1 gives the impression of a stiff piece of wood while doing the same with a four-metre length of the same material will soon have the ends waving up and down.
Just a thought

Yes indeed. I'll have to confirm with some tests, but I think it's about twice as flexible as a bit of 6mm teak strip I was playing about with. Laminating the (thin) fibreglass with two identical strips will give a bending stiffness eight times as high as a single strip, which I think would be OK with some reinforcement at the rowlocks.

Pros: it would be dead easy to do, and I'd never need to worry about varnishing. Cons: the flexiteek would cost £200 whereas wood looks like being £100 including either delivery or diesel to collect.

Hmm. Has anyone used flexiteek for this?