Steaming oak ribs

[Richard Darley]

I need to replace some oak ribs on my 1964 traditional Norwegian keelboat. Have seen a site which recommends using a wallpaper steamer as a source of steam, and judicious use of plastic drainpipe etc. Sounds logical, and becuase I only have a four to replace...looks a good option as an equipment hire solution....anyone tried this? Any tips? Richard

 

[stuhaynes]

Steaming ribs

I need to replace some oak ribs on my 1964 traditional Norwegian keelboat. Have seen a site which recommends using a wallpaper steamer as a source of steam, and judicious use of plastic drainpipe etc. Sounds logical, and becuase I only have a four to replace...looks a good option as an equipment hire solution....anyone tried this? Any tips? Richard

Hi Richard, Absolutely nothing wrong in using a wallpaper steamer, we've done it this year. I made up a box from 3/4 ply because it retains the heat better. It will work. I guess the proviso is the extent of the curve you want on the ribs. I found that rather than steam the wood and then try to bend it in situ it's better to make a former because you have all round access and can clamp much more quickly. You may have to slightly overbend to allow a bit of spring back.
As I understand it ( I ain't no expert) if you want a tight curve you may have to use 'green' oak. The kiln dried stuff tends not to bend as much or as easily. I'd check a bit more on this forum if you do need tight bends.
Hope this helps, Stu

 

[Redwing228]

As I understand it ( I ain't no expert) if you want a tight curve you may have to use 'green' oak. The kiln dried stuff tends not to bend as much or as easily. I'd check a bit more on this forum if you do need tight bends.
Hope this helps, Stu

Richard,

I second what Stu has said. 'Green', i.e. freshly sawn oak works best. If I have had to steam timber that is a bit on the dry side, then a week or so of soaking (by immersion) after cutting helps the process. Try experimenting but make sure you have plenty of timber available to allow for breakages
Bill

 

[old_salt]

Yes 'green' oak is what you want, and don't worry if you find it not going in to shape you can put it back in the steamer for a second go.
We only broke one rib in 60+ and eventually used that in a short rib.
I made my steamer from an old fire extinguisher with an immersion heater element stuffed up it, a water level can at the side to top it up and a 10ft length of 8" and 10" alloy pipe lagging with the polystyrene between them 3" hole up into it in the middle plywood ends and away we went.

 

[cliffordpope]

Put the wood in a polythene tube. You can bend it in situ, judging how flexible it is becoming, and leave the bag on until fully bent into position. Then rip the bag off.
I use a wallpaper steamer and plastic cut from old fertiliser sacks, wrapped round and stapled together. Stuff rags in the end to contain the steam.

For a long length of wood, eg a plank, fix it at one end and slide the bag along, fastening as you go.

 

[Richard Darley]

Oak ribs

Well thanks for all your encouragement. Today I popped into the boatyard and ordered some green oak for collection Saturday...and will go with wallpaper steamer now you give me confidence. Many thanks! Happy boat repairs!

 

[MRF]

Richard, my wife and I restored an old wooden narrow boat and although our planks were huge, 2"x10"x34'-6" we used a steamchest from a friend and tried our first one using the timings an "expert" gave us. That plank ended up as roof beams because it was nowhere near enough. We were told an hour per inch. Forget that! We ended up around four hours per plank and it went in like soft cheese, but you have seven minutes, no more. And wear the heaviest leather gloves and more that you can find. It's unbelievably hot!
We fired it with an old oil drum 2/3rds full of water on a quickly welded up 1" tube cradle, then lit a big bonfire under it with all the rotten timber we took off the boat. Every old rag and jumper stuffed in the open end of the chest. If you don't get it right, you can't put a curved plank/rib back in a straight chest!

Get everything ready and to hand first, including beer for the helpers and prepare for expletives. By the third plank, we were all sweetness itself. Almost blase!

Good luck,
MRF

 

[monkey_trousers]

my quick and easy steam box was 4 second hand scaffolding planks - think they were a quid each!

 

[prv]

I have nothing to add to CliffordPope's post, but I wanted to emphasise it in case you miss it among all the other answers. Wood is traditionally steamed in a rigid box and then quickly transferred to be bent before it stiffens, but that's only because in the past a rigid box was the only option. His method allows you to keep applying the steam even as you bend the wood into position. I'll admit to not having used it, but it looks very handy and is what I'll be trying next time I need to bend anything.

Pete

 

[Seanick]

Make sure you machine the new timbers (Steamed timbers, sawn frames, ribs are a body part..) with the grain correct, ie, going across the width if the timber.

Wallpaper stripper? Fine bit of kit. Just promptly dispose of the wallpaper fitting to avoid any distraction from working on your boat...

Rule of thumb, steam for one hr per inch, or divisions of that. If you over steam the timber may become brittle.

 

[cliffordpope]

but it looks very handy and is what I'll be trying next time I need to bend anything.

Pete

It works. I invented it myself, but later discovered that it had already been used by someone.

I replaced about 30% of the ribs in my 21 foot cutter, with nothing more than old plastic sacks, a kettle, a tube and a bung, and an old primus stove. Model B, using a wallpaper stripper, came to me just after I had finished.

It works really easily. You don't need to bother about estimating the steaming time, you test it as you go. If there is a tighter turn, you gently ease the wood as far as it wants to go, then steam for a bit longer.

I steamed a 20 foot plank in situ. I fastened it to the stem, and then slid a 3 foot length of plastic back towards the stern, bending and clamping as I went. While waiting for later sections to steam I got on with fastening the forward portion.

You don't have to slide the polythene off straight away. Sometimes it is better to get the wood wedged and clamped into position first, then rip the polythene off when all is secured.

 

[Latestarter1]

I need to replace some oak ribs on my 1964 traditional Norwegian keelboat. Have seen a site which recommends using a wallpaper steamer as a source of steam, and judicious use of plastic drainpipe etc. Sounds logical, and becuase I only have a four to replace...looks a good option as an equipment hire solution....anyone tried this? Any tips? Richard

My favorite journeyman claims that plastic pipes for steam boxes are free!

He turns up on a job with local free papers, scans adverts for second hand wallpaper steamers, pays between five and ten pounds each, he usually uses three.

The steamer box pipe is the thick walled yellow variety which works a treat. When I asked about the source of the free steam box tubing he expained that nice people leave it by the side of road for him, sometimes for months at a time. He picks up a length uses it, and than returns it to the stack from where he got it. This man is very keen to re-cycle, wallpaper strippers go back in the free ads at the end of the job.

What else can you expect from people who stand on a plank they are working using an adze beteen his feet wearing leather open sandals!!

 

[121]

Not sure I would ever have a 2nd attempt and brew up an already steamed timber - the wood will already be dried out after the 1st attempt and the extra cooking will make it brittle & I would think would do little for the longevity of the finished piece (assuming it didn't give way on the 2nd fit).

The only other thing to add, I would chambfer the top edges to reduce any tendancy for grain checks to run into a crack under stresss.

 

[cliffordpope]

Not sure I would ever have a 2nd attempt and brew up an already steamed timber -.

That's another advantage of steam-in-a-bag, you only use one attempt, and that's of precisely the right duration for the section of wood you happen to be bending.

 

[old_salt]

Not sure I would ever have a 2nd attempt and brew up an already steamed timber
I think you may be referring to my post.
The point I was making was if you have taken too long to set the rib and are having difficulty to get it to bend put it back in and give it some more steaming and usually it will bend like a piece of spaghetti.
We had only one rib split on us and that I would put down to bad selection and grain.
Well thats what I found, but then our Oak was green it was bought as a tree cut down and quarter swan and we kept the ribs immersed in a brine bath as well the last ribs to go in where well over 12 months old,

[/IMG]

[/IMG]

[/IMG]