Converting Plank on Bulkhead Model to Waterline Model

[CarolusMagnus]

Hello dear shipmodelers and thank you for letting me join you on this forum!

I'm building a tartane for the tabletop game Blood and Plunder.
For that I ordered the Billing Boats kit "Le Martegaou" which is a 19th century french river boat.
It's shape is very similar to 17th century single mast tartanes. So thats why I chose it.

The only problem is that for it to work as a playpiece it needs to be cut at the waterline.
When I ordered it I didn't know what the keel and bulkheads would look like and assumed I would be able to just cut them short.

However looking a the model it seems this will result in the keel and half the bulkheads falling into pieces.
See here the dry fit of the model with the waterline marked with a pencil (the waterline was taken from the plan, I might lower it a little):


I was thinking about this quite a bit.
Should I just build the model as is and cut later? I'm really scared of this for multiple reasons:
For one I don't own a bandsaw. I would have to do it with a fretsaw likely resulting in an uneven cut.
Secondly I don't think the boat would have enough support by the planking and the deck alone. It might become unstable.

The other option would be to use the existing bulkheads as templates to cut new ones.
I could join the front and rear of the keel with some additional plywood. The only new parts I would have to cut are the three bulkheads in the center.
This would be a bit of work cutting with a fretsaw, but it would have the added benefit that I could raise the boats side to closer resemble my inspiration.

This is roughly what it ideally should resemble when finished:


What do you think? Any suggestions?
Whilst I'm not new to modelling and scratch-building this is only my second wood model ship so any help is apreciated.

 

[Davidp]

how much of the bottom of the hull do you have to cut off? what material is the model made from? do you have a compass with a pencil on it?

 

[Jerome]

I would cut the waterline on all the pieces first.
Then mount the cut frames and such to a custom cut base board to give you a flat bottom.
Then plank the hull as you would a full hull build.
A Dremel type tool would be handy when it comes to cutting the base board to size.
A drum sander attachment would be a good tool to shape the base board.

 

[CarolusMagnus]

I would cut the waterline on all the pieces first.
Then mount the cut frames and such to a custom cut base board to give you a flat bottom.
Then plank the hull as you would a full hull build.
A Dremel type tool would be handy when it comes to cutting the base board to size.
A drum sander attachment would be a good tool to shape the base board.

The dremel tool was a good idea. I went to the hardware store and bought one yesterday. I considered using a base board as you say but the dremel gives me confidence that I can do without redesigning some of the lower parts. I think with the sawblade attachment I should be able to cut deep and careful enough to cut the lower hull without damaging the model. I started building yesterday. The basic frame and the planking of the deck is finished. Now comes the planking of the sides. This is how far I have come:

So far I'm not too impressed with the kit. I bought two kits simultaneously: this, the Matregaou by Billing Boats and the Ketch Scotland by Corel.
Whilst the Billing Boats kit set me back only 80€ and the Corel kit 110€, I think the Corel set is much better value for money. It is overall a much more comlex kit with a lot more detail and better instructions.

The Billing Boats kit lacks nails to fix the planking to the sides which leads to some creative solutions on my side.
(Maybe I should just "lend" the nails of the Corel kit?)
Also the side planks are of low quality. They are fragile, even using warm Water to bend them. One of the planks so far even had a branch hole.
The side board on top has to do quite a violent compound curve before the stern of the boat. There is basically no support you are able to use to fix it that way and I'm unsure wether the harsh corner that is produced is correct. (No amount of sanding would have fixed that since it would have resulted in alteration of the bulkhead entirely.) I will see later how this turns out.

I will update you once I come to cutting the lower hull.

 

[AndyA]

The basic frame and the planking of the deck is finished. Now comes the planking of the sides.

While you still can, glue in some pieces to attach the upper parts (above the waterline) of the port sides and starboard sides of the three middle bulkheads. These need not be too neat, they just have to keep the two sides in position. Next time you build a waterline model, consider using the "bread-and-butter" technique (see pic below). Fair winds!

 

[Jerome]

Beware of the saw blade you bought for your dremel tool.
Those have a tendency to “catch” on the wood and rapidly advance towards the operator.
I cut myself quite badly a few years ago with one of these saw blades so be very aware.