Genuine Post About Real Boaty Things

You will need to steam it for a fair old time (and no, I don't know how long that is!) because Iroko is generally short grained and a real, first class, genuine, cast-iron barsteward to bend to any great extent.

I tried several times with precisely the bit you're dealing with when I built my second boat many years ago, and each time I thought 'Yep, done it!', there was a BANG and the bloddle thing snapped. In the end I gave up and used something else I had lying about. I didn't use steam, but boiling water poured onto towels wrapped round the wood. It was amazing how well the towels held the heat and how hot the timber got. Still took a fair old time though!

Agree with the poster who advised lagging the tube. Essential in my view, particularly with such a small steam source.

Anyway, the very best of luck with it and don't forget - very gently does it! It it feels it's getting too hard to get 'round the bend', back off and pop it back in the oven for a while. /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif
 
I am letting it settle down now. I did think it may snap as I was getting it across the jig for the pin, but it was OK.
You can see the second curvature in this shot as it rises toward the bow as well as bending.

finished.jpg
 
Excellent job LS, well done! Iroko's really difficult to bend and that looks a very neat job.

Don't forget the 'as fitted' piccys!! /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif
 
Thanks.
We celebrated by opening a bottle of my elderflower champange, which tasted as good as it looked!

Champagne.jpg


I just measured the wood and it was 1" square with a groove cut into it.


wood.jpg
 
Place the timber in water prior to steaming and I found that an hour per sq inch approx when using low pressure steam
 
Hi Phil; congratulations and well done. My own experience was for a toe rail for bigger boat. I steamed the wood, a bit of tropical forrest hardwood then tried to form it and it promptly snapped. Obviously a very short grain type wood.
In frustration I grabbed a bit of pine of some sort and found it would bend the required amount without steaming.

So for my opinion it all depends on the type of wood.

PS I am glad to see you have reverted to sail boats again. olewill
 
Nice! My only (small)niggle is that is hardly a scarf joint- needs to be around 4:1 or better to qualify.
This type of post is in the best PBO tradition, unlike most of the current mag.
Andrew
 
I'd agree with that, although in this instance the purpose of the joint is to help locate and prevent the new piece of capping coming off the gunwhale as the old capping is very firmly bonded.

I did in fact get some useful suggestions for the job (which was going ahead anyway). The lagging and the inclination of the steamer being the most useful, and also mention of pins in the jig rather than the brackets I'd put on. Without a removable pin I wouldn't have got the piece across the blocks on the jig as I was bending in two planes.

Various estimates of the time needed were useful indication. I spent more than an hour steaming and used 3 kettles of water (I filled up the Aga kettle with boiling water from an electric kettle without a pause in the steaming.
One useful point I found was that if I filled the Aga kettle above the spout outlet it (naturally) shut off the steam to the steamer.
I suppose the time needed would depend on various things such as steam production capacity, size of steamer pipe and ambient temperature, as well as the type of wood.

I don't think I'd attempt it with Iroko again /forums/images/graemlins/grin.gif

It now remains to be seen if it stays bent when I take it off the jig. I did over-bend it a bit so I may come out just about right.
 
The wood supplier suggested using the old lake tradition of leaving the wood in the lake for a week and just forming it wet.
As I'll be bonding it to the GRP hull I don't think wet wood would be a very good idea, so passed on that one.
Also, I bet he was talking about the larch planks which most of the char boats are built with.
 
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