Planking a hulll - help! (1st timer, all thumbs!)

Hi All,

I just stumbled on the IOM site, and downloaded the building tips & tricks document (like, 65 pages!!)

I’m a little confused… They seem to start, but don’t really finish…

The keel stringer & gunwales / deck rail are doubled up, yet the 1st stringer is glued to the formers / shadows. I assume they are ‘tack glued’ to be removed later…

When are the formers / shadows removed?
When is the hull removed from the building board? I assume after glassing (adding the glass cloth & resin).

I’m assuming the hull is planked, sanded, and then glassed. It is then removed, and the internal / deck work starts…

And I’m assuming deck stringers are copies of the top portions of the formers / shadows. And are fitted as such, in place of the formers / shadows. Deck longerons are then added to these stringers…

Any help / pointing towards pictures is greatly appreciated!!



After 65 downloaded pages, you may want to finish the job and download the USOM construction guide :

It’s geared towards the US one meter, but the basic construction technique is the same, plus you have a step by step explanation and most important figures.

Couple of suggestions: IOM have a minimum hull weight, so balsa is OK but not mandatory, you may use other woods (if you decide to go the wood way). Remember IOM and USOM have different displacements, and as a rule of thumb no CF on IOM (it can be used for some fittings, but it’s easier to avoid it altogether and save your self a headache). You can build the keel following the USOM plan (wood/CF laminate - actually the keel is the only place in a IOM where CF is almost mandatory for stiffness - the exception to my previous rule), but again the IOM has t have a minimum weight, so other woods beside balsa are an option.

Hope this helps.
EDIT: You may also find this building “blogs” helpfull.

Michael Sharmer (slow to load!):

Anders Wallin: (more high tech … )

Gio, is that you?? :slight_smile:

Yep, that’s me … I’m glad to se tha you are back into sailing - are you giving up car racing? Unfortunatelly not much of that (sailing) going on arround here…

I was actually going to post a picture of your Triple Crown as an example of a pine build hull…

Hi gio,

yeah,that’s the doument I downloaded. it seem to teh be the same regarldess if you have teh hi speed, or download teh 4 parts…

I’ll follow teh other links as time permits!


Lots of photos of my first IOM build on another forum.

You have answered most of your questions! I plank the shadows without getting any glue (CA) on the shadows if possible. Pins to hold in place till there are enough planks to hold the shape. Once planked, sand smooth and glass outside. When cured, you can remove from shadows, sand and glass inside.

Or leave on shadows, polish up and use as a plug to make a mold of. It is lots more work, but if you have several guys wanting hulls, it saves time in the long run.

If you use balsa , use heavier balsa than you would for a us1m ,like 10-12 pound/cu ft.

You dont need the weight savings like you do for a us1m and the lighter wood 5-7 pound/cuft is way to prone to damage.

If you use balsa ,dont get CA glue on the outside of the hull , it makes it hard to get a smooth finish because the glue is so much harder than the balsa .

Thanks robert,

yeah, from my ‘plane days’ skins were always butted with aliphatic (carpenter’s glue) cuze it sanded nice. I woud expect to use the same here… No ‘ridge lines’.

Aliphatic glue works great, so does sig sig-ment glue although its alot stinkier. You can also carefully glue it from the back( where you can reach ) with medium CA.

We have different experiences! I will never use “yellow” glue again because it does not sand! I had no problems sanding the CA glue lines on my planked hulls. I used 80-100-150 grit and held the ends of the sandpaper and let it conform to the curve of the hull. I used it on a semi flexible block to help find the high spots. And using CA, I can plank a hull in a couple of nights. Aliphatic glue takes way longer! And I run out of pins too :slight_smile:

The one hull a friend planked with aliphatic carpenters glue was a disaster trying to get sanded smooth. The glue is too rubbery to sand and would roll up under the paper. We ended up scraping the whole thing.

CA is still the best solution.
Couple of things can be done to avoid the “ridges”, you can use the gel CA and glue only the "inside part of the plank - easy to to if you scarf the palnk, or glue the planks to the frames (covered with tape) and not to each other. The hull will be kept together by the FG/epoxy, and the inside can be easily sanded smooth without worrying about low/high spots.

There are alot of variables. I used thinned titebond( I have not tried other brands) , have no gaps so I get thin glue lines.

It sands easier for me than ca, but it is very slow planking by comparison.

Sig sig-ment is like the old balsa model cement , it dries a little faster than titebond, but it is alot softer than both ca and titebond( also slow, but sands nice).

I have built three us1m’s (6lb wood) and used thin ca for the first one and was not carefull about getting it on the ouside of the hull.It was really hard to sand it fair, because the ca was so much harder than the wood( 6lb wood is like foam).

The last one I used medium ca and was very carfull to only get glue on the inside edge of the planks. That was the best combo of fast planking and easy sanding.

I dont like to use any filler, because of weight and I dont paint my hulls.
I start with 150 or finer if I can, and dont usually have to do much sanding to get the hull fair.

There are alot of ways to do it, whatever works best for you, is best.

polo shirtschi flat irons