Spilling (very long) planks

[vaddoc]

Dear all

 

As I am currently immersed in planking, I thought it might be useful to share my way of spilling planks.

In my fishing boat log I have presented in detail the way the plank run can be defined but it is a long and difficult read. Showing how to spill planks is much easier and perhaps will help some builders. 

 

So lets spill a plank in the fishing boat. T he positions of all planks have been marked on the port side and these positions will need to be transferred over to the starboard side as we go along. The planks should be twins but in reality they never are, at least in my boats so every plank needs to be individually spilled. 

 

A good compass is needed, this is the one I use

 

The plank we will be making will be a starboard plank, its sister plank on the port side is already installed. A picture is a thousand words: This is the port plank steamed in place and the markings for all the rest of the planks are visible. We need to make this plank for the other side.

Now, every new plank will have two edges. The bottom one that meets the previous plank, and this needs to be shaped so it fits well, and the upper free edge that we will define ourselves based on our markings and planning of the planks but needs to be as fair as possible.

 

I use either very stiff card or thick cardboard to make templates of the bottom edge. I cut pieces as long as possible, hold them close to the edge of the previous plank and use a compass to mark the pattern. I run the compass along the piece of cardboard with the needle on the edge of the previous plank and the pencil tip on the card. Then I cut on the line with a very sharp knife and repeat on the next segment. I glue and connect the pieces into a long continuous card pattern. This is how it should look.

This is 1:10 scale and this plank is 60 cm long. The card needs to lie comfortably without absolutely any edge bend. Even a tiny strain on the card will produce huge gaps on the other end of the plank and wood will not tolerate edge bending (It will, but only a little). This is the most crucial step, if there is any doubt the template must be readjusted. This particular template was the third one. Do not make the card pieces too wide because the angles will change and you ll be getting constantly erratic results.

 

Then, mark the positions of the frames on the card pattern.

Then, very carefully, making sure there is no edge bend at all, secure the card pattern on the wood sheet.

Run a pencil (I use 0.3 mm mechanical one) along the edge and also mark the positions of the frames. This is the result

This is the bottom edge of our plank and should fit closely to the previous plank. We need now to define the upper edge so we need the thickness of the plank at the various frames. On the port side, this thicknesses are already marked. To make sure that the two sides are as similar as possible, I ve been marking the starboard side measuring from the sheer. 

So the upper edge of our plank is marked in all frames.

Now, these widths need to be transferred to the plank, again using the compass. The width at the stem will be defined using the contralateral plank end.

All sites marked.

These points need to be connected but with a fair line. To do this we must use a baten, arranging it so that it is close to all the points.

Now this line, which is the upper edge of the plank, does not pass through all the points but it is ok. Actually, if we put the contralateral plank on the pattern, the widths are exactly the same! 

On this boat I use a very sharp knife to cut the plank with multiple passes, breaking off a segment of the blade every couple of passes. After careful cutting to the lines, the plank is produced.

Placing the plank on the boat, it does not fit well.

No need to panic, it just needs a bit of micro adjustement. We need to find the high spots and carefully sand them so the gaps will start closing. These are the high spots in this case.

After sanding and with a bit of edge bending, the plank seems to fit fine now.

These micro-adjustements and a bit of edge bevelling can continue until the fit is very close but for this boat this is enough, with some filler it will be fine. I also lightly sand the upper edge to smooth out the peaks and make fitting the next plank easier.

 

Both planks steamed in place.

And that's it! Now repeat the process 30 odd times and planking is done. 

 

Vaddoc

Edited March 14, 2021 by vaddoc

[thibaultron]

Thanks, this will be a big help!

[G.L.]

Thank you very much for this clear explanation, Vaddoc.

[Chuck]

Wonderful step by step.  And the mode is looking fantastic.

[vaddoc]

May thanks to all for your like and comments.

I have corresponded with @Jaager and I thought it would be best to continue our discussion here.

 

1-  Instead of directly using a compass or mechanical  proportional dividers directly on the mold (or for POF frame)  edge, use a tick strip so that the actual distance is part of the measurement?

Indeed, this can be done and actually I did use card strips on this boat. Anything to get the job done.

2 - One edge of the plank (the outboard edge) is always dead straight.  The spilling always done on the edge meeting the previous plank?

Not necessarily. Maybe some planks in large ships but never in boats in my experience. The upper edge of the garboard only is indeed supposed to be straight but it does not really need to. However, planning of the planking is dealt with in depth on the launch log!

3 - Divide the area to be planked into two or three zones ( more for a larger vessel).  A thin batten that defines an idea plank run at intermediate positions?

Absolutely. This boat was divided in three zones.

4 - the subdivisions would be between the battens?  

Indeed, battens were used to define the zones to ensure fairness of the curves.

5 - A planking fan could be used instead of mechanical dividers?

Ordinarily yes but this boat is actually a very difficult one to plank, the fan cannot really be used.

6 -  The garboard is the first, but instead of one, you make two identical planks - P & S at the same time?

7 -  Each  subsequent strake also be made as duplicates with the fine tuning  done on the individuals on either side? Port and starboard being planked at the same time in parallel?

8 - The battens would only be needed on one side.  I see a madness producer in trying to get symmetry. If the molds are not near identical on each side, then they need to be done over?

6, 7, 8 Indeed, the two sides should theoretically be identical. In my experience they never are. They can be quite close but in this boat I cut a few corners and each plank is individual. But if someone has such a steady hand to make each frame and each pair of planks completely symmetrical, the work would be cut in half.

9 - A jig could be used to locate the mold positions on the plank stock?

Sure but it is easy to mark the positions on the card template

10 -  Once a plank has been fixed, the open are is measured with a new tick stick and a new (one less) interval be measured?  If there is one place where error creep is a certainty, it is with planking.  If a gap needs 12 planks to close it, dividing the whole space into 12 segments at the beginning and trying to use them for every plank will not turn out like you expect, hope  usually?   A new subdivision measurement after each strake will mitigate error creep?

Yes, up to a point. Some builders do not like to mark the plank positions, they just do as you suggest and plank away without fully marking each plank beforehand. I think this needs huge experience and an ability to imagine the planks just looking at the frames. I like to mark the run of each plank, as I would like it to go, but I am not fixated on my planning. Some time a plank wants to lie a bit higher or lower than my marking, or to be a bit wider or more narrow-that's fine by me! I also trim or shim the frames if the plank suggests it is needed.

 

This is how the boat looks now-it's mothballed until I finish planking the yawl

[Jaager]

Thank you Vaddoc,

My questions were accepted and answered in exactly the light that was my intent.

 

One step that was not addressed is that

11 - With 3 zones, the planking sequence should be garboard zone up #1 , then Rail down #2,  then turn of the bilge zone last?

[Jaager]

Oh and, now that I think on it,  question #2  - one side always dead straight - may be  from clinker and not necessarily carvel planking.

[vaddoc]

1 hour ago, Jaager said:

11 - With 3 zones, the planking sequence should be garboard zone up #1 , then Rail down #2,  then turn of the bilge zone last?

Well Jaager, to my opinion, clinker or carvel does not really make a difference planning the planking.

 

The deciding factor to divide the hull into zones is basically to minimise the curvature of the planks and the aggressiveness of spilling. A batten that runs through the most curved and hollow parts of the hull will be pretty much straight so the planks above and bellow this will be of reasonable curvature. Also, the point where the sternpost meets the transom must be a zone. This combined with eyeballing to make sure it looks good!

 

Maybe also have a look at the Launch log, I ve posted the whole process there but it indeed makes a long and difficult read.

 

[Dziadeczek]

Some degree of edge (lateral) bending is possible, if you pre-wet your plank in luke warm water and carefully heat bend it.

Long time ago I posted an entry on this topic, including a link to a short video by a German modeler Gebhard Kammerlander who demonstrates this technique. 

He speaks German, but the video is "in English" for everyone to understand  😁 .

Go about 3/4 down this page to find the video.

 

 

I learnt how to spill planks from an excellent brochure by the late Jim Roberts "Planking the built up Ship Models", (which, I understand, is still available from Model Expo). Jim describes there authentic practices of ancient shipwrights (a bit simplified for ship modelers). This technique never failed me.

I use a set of proportional dividers (a paper strip alternatively), and I fashion two planks at the same time - one for each bulwark (since they should be identical, if your hull is perfectly symmetrical). I sand one edge of a plank a bit angled so that it abuts tightly the next plank on a curved hull.

 

Regards,

 

Thomas

Edited November 1, 2021 by Dziadeczek

[vaddoc]

4 hours ago, Dziadeczek said:

Some degree of edge (lateral) bending is possible, if you pre-wet your plank in luke warm water and carefully heat bend it.

 

Absolutely Thomas, however in 1:10 scale, most woods in 2 x 10 mm will resist edge bending except to push a bit fully into contact, spilling must be very close. Edge bending followed by twist along the axis of the strip are much more difficult to convince wood to accept than simple bending into a curve.

This spilling method is nice but I d think mostly for planking larger ships.

I ve never seen seen this type of dividers before, seems like a useful tool to have and not only for planking. How are they called?

[Jaager]

23 minutes ago, vaddoc said:

I ve never seen seen this type of dividers before,

Those are, I believe, proportional dividers.   The thumb screw adjustment is probably an old style and an inexpensive model.  I wonder of one arm could move up and down independent of the other?   It would make precision a bit of a problem.  I have a set of K&E 6"  dividers and the pivot is rack and pinion.  My only complaint is that it does not rack down to 1:1.  But there is no reason for it to do so, except that it is not useful for correcting an aberration in  the <10% range.

[allanyed]

Does the shape of each plank as shown on a planking expansion drawing show the actual shape of each plank?   If it does, there are no planks with a straight edge on either side for their entire length except that the garboard appears to be close. The upper edge rises slightly aft and the lower edge is reduced forward to follow the rabbet. 

 

One example can be seen at   https://commons.wikimedia.org/w/index.php?title=Category:Ship_plans_of_the_Royal_Museums_Greenwich&filefrom=Saint+Albans+RMG+J4033.jpg#/media/File:Squirrel_(1785)_RMG_J6457.jpg

 

Allan

[DelF]

Hi Vaddoc

 

I started using proportional dividers this year and would highly recommend them. Here's a link to my description of using them in my build log. I wouldn't go for the cheap modern ones you might find on Amazon. Fortunately good second hand ones are usually available on ebay.

 

Thanks for the tutorial on spiling by the way - very informative.

 

Derek