Fillers between bulkheads: pros & cons please?

[bruce d]

I am doing my first ever fairing of a POB model (scratch built Mediator from Jeff Straub plans). My gut feeling is that I should have fillers between some of the bulkheads where the gap is greatest and/or the lines change. The bow fillers are necessary but my lack of experience leaves me seeking advice about the rest of the hull and stern.

As the shape emerges from my sanding efforts it seems now is the time if it is going to happen. Common sense says to use wood softer than the bulkheads.

Are there any negatives or cautionary tales about bulkhead-fillers?

 

Thanks in advance,

Bruce

[JohnLea]

Give some thought to future clamping space and/or angles.  I didn't and had to redo some.

[wefalck]

In principle, fillers are a good idea, particularly, when bulkheads are thin and spaced wide apart. The need for them also depends on how thick the planking will be - thin planks tend to kink much more than thicker ones, of course. In your particular case, however, I have the feeling that fillers might not really be needed, as your bulkheads are quite thick and closely spaced.

 

The wood used for the fillers should be about the same hardness as the bulkheads, if it is too soft, you might sand hollows into them between the bulkheads, if it is too hard, it is a lot of work to shape them.

 

Looking at your model, I have the feeling that you might want to define the rabbet line better. It looks, as if you won't have much space for the planking above the bulkheads in the midship section. But then I don't know, how you will construct the keel.

[allanyed]

I took a look at the plans as I have an interest in this vessel as well.  I realize the lines drawings by Jeff Staudt are copied directly from ZAZ6368 from RMG and very accurate. I did notice that there is no windlass or other device forward as found on every other vessel of her type and size (or even smaller than Mediator) that I could find on the RMG Collections site.   Does anyone know if this vessel had no windlass or is this an omission on the drawings for some reason?   Would the crew actually have to manhandle the anchors via the cathead without mechanical help?   I find it hard to believe there was no windlass or  a small capstan, but surprises are not new in this hobby of ours.  TIA

Allan

[bruce d]

6 minutes ago, wefalck said:

you might want to define the rabbet line better. It looks, as if you won't have much space for the planking above the bulkheads in the midship section. But then I don't know, how you will construct the keel.

Eberhard,

The keel is a little wider than the plywood former so will become a useful part of the puzzle. I am planning on tacking a dummy in place for the planking to be replaced later. Also, I am counting on being able to finish the rabbet with the dummy in place.

Very sensible comments on the hardness of the fillers, thanks.

[bruce d]

11 minutes ago, allanyed said:

I took a look at the plans as I have an interest in this vessel as well.  I realize the lines drawings by Jeff Staudt are copied directly from ZAZ6368 from RMG and very accurate. I did notice that there is no windlass or other device forward as found on every other vessel of her type and size (or even smaller than Mediator) that I could find on the RMG Collections site.   Does anyone know if this vessel had no windlass or is this an omission on the drawings for some reason?   Would the crew actually have to manhandle the anchors via the cathead without mechanical help?   I find it hard to believe there was no windlass or  a small capstan, but surprises are not new in this hobby of ours.  TIA

Allan

Well spotted Allan. Digging in records shows that she was fitted with a capstan while in Portsmouth dockyard between May and June 1745. It was at this time the lines were taken off and despite seeing pumps and stoves we do not see a windlass. 

Mediator had been roughed up when captured by a French privateer off the Needles and then suffered further bruises when re-taken by the RN the following day. She was needed back in convoy service urgently and repairs were quickly authorized plus instructions given to record her lines. 

Despite the artist meticulously recording other details (such as the miss-matched stern windows which reconcile with hasty repairs) I saw no hint of a previous windlass in the correspondence or the plans. If it hadn't been for the capture by the privateer and re-capture the following day there would be no drawings.

NMM describes her as 'purchased' but this is not entirely accurate. She was owned by a RN officer who bought her in the West Indies and contracted her to the RN for the supply crisis. She foundered and was lost at Ostend in a storm just a few weeks after release to duty from Portsmouth dockyard. 

I will eventually write the tale and post it.

[Jaager]

55 minutes ago, allanyed said:

Does anyone know if this vessel had no windlass or is this an omission on the drawings for some reason?

Allan.

I place a windlass in a disposable category.  Being on the deck, it would not be all that difficult to add, remove, or replace.  Is it possible that its presence on construction plans would mean that the yard was expected to provide it?   For as built,  if the captain had to pay for it,  when missing,  it may suggest that the current captain cared more for his purse than his crew.  

If a windlass is missing on the contemporary data and it was not a subject of comment,  I would think that for a modeler to add one of leave it off either choice would be correct provided that the style was correct for the era.

 

 

5 hours ago, bruce d said:

Are there any negatives or cautionary tales about bulkhead-fillers?

Most POB fillers that I have seen use horizontal pieces of wood.  Doing it that way allows for an easy fitting of the pieces between the molds.  It is easy to do with a Byrens saw or a disk sander.  I see that as false economy.  Getting the contour when fixed between the molds is a lot of work - especially from a balk state.

 

Think vertical layers between the molds-  a loaf of sliced bread,   You already have the shape.  It is the stations.  Two consecutive stations on the same pattern.  Because the station interval also includes a mold thickness,  a temporary sacrificial layer that is the thickness of a mold is needed for off the hull shaping.  I would use a white Pine construction timber as the filler.  I would make the thickest Pine stock be ~1/4".  Use however many slices are needed to fill the interval.   The yellow Pine that you use as topside fillers would work if it is not sappy.  The white Pine family is just sweet to work.   The moulded dimension of the filler just needs to be wide enough that bamboo skewers (two or three)  can keep the filler layers aligned - so a hollow can be as much as you wish.  If your stock layers come up a bit short  on the sum needed to fill the gap, a piece of poster board would work, if you are not up for a lot of custom thickness sander work.   Most all of the contour shaping can be done off the hull using a sanding drum.  Leave just enough for final fairing using the molds in place. 

If you had planed for vertical fillers before the first mold was placed,  the alignment holes could be a part of and drilled into the molds so that the fitting would be idiot-proof. 

 

It looks like your central spine and the molds define the top of the rabbet.  I think that I would find it a nightmare to place the garboard and plank ends on the hull and the try to slip a keel with a rabbet into the gap.  I would want the keel and stem and sternpost in place before I started planking.   

As for planking, wale first.   then garboard.  Probably two gores  outer strakes working in.  use the planking fan for each strake.   If a gore is 6 strakes, pre planing for all 6 strakes at the beginning - at all goes out the window after the first strake. 

 

 

[Pete Jaquith]

Hi Bruce,

 

I used fillers on my 14 Gun Brig Fair American build.  The fillers were bass wood, and they were a great help in fairing the hull.  The model was single planked with 1/16" bass wood planking.

 

Regards, Pete

[allanyed]

3 hours ago, bruce d said:

such as the miss-matched stern windows which reconcile with hasty repairs)

This is an interesting point as well as the missing windlass.   I thought it might be a matter of one pair being stern lights and the other pair gun ports similar to those I have spotted on other similar size sloops.

 

Just as an FYI I found a drawing of a small single masted sloop, albeit early 19th century (1808), showing both a windlass and a capstan.   Go figure.....     https://www.rmg.co.uk/collections/objects/rmgc-object-85782

[bruce d]

Not noticed a pump actually under a capstan before. I suppose it's an anchor boat, anything that works is OK.