I thought it was worth it. The need to use filler blocks depends on how few bulkheads are used on the model. Some kits have so few bulkheads that the effect on the planking leaves the hull with facets in the curves that can only be fixed by using large amounts of filler in the flat areas between the hard bends where the bulkheads are. If you kit does not have a large amount of bulkheads in order to create smooth, organic, even curves on the hull, then filler blocks are needed.
The filler blocks become the shape which the planks assume, instead of relying on the natural bend resistance of the planks to create the curves. The number of bulkheads should increase in density (smaller space between bulkheads) where the hull has sharp changes in curvature, such as near the bow and stern
Sometimes planks have weak spots where they bend at a sharper angle, and thus do not match the curvature of adjacent planks, creating offsets between the surface of that plank and the ones next to it. Those offsets are usually not extreme and are removed during the sanding process. Filler blocks remove any offsets since the first planking layer is glued right to the surface of the blocks and the edges of the bulkheads. That saves on sanding and filling. Of course, you had the extra step of sanding all those filler blocks, but the payoff is that you when shaping the blocks, you get to see the precise form of the hull curves earlier, and make smaller adjustments with filler thank you would on a lesser supported planking layer when you didn't use blocks.
Of course the overall hull is stronger with filler blocks, and far less subject to punctures from accidents, and it is noticeably much heavier.
My first kit, Corel's La Couronne, had a sufficient amount of bulkheads to ensure that the first planking layer created curves with few hard bends and flat spots, but two applications of filler and sanding were still required. The DeAgostini HMS Sovereign of the Seas had far fewer bulkheads in the stern area and midships that were required to support the planking. So, I opted for filler blocks for that model. Because massive changes to the stern were needed, the filler blocks allowed free-form carving of the stern and complete reshaping from a square tuck to a round tuck. If there were just bulkheads and planks there, such changes would have opened up huge holes in the hull and made filling those holes and reshaping of the stern far more difficult.
Personally, I don't like filling and sanding. It's VERY messy, and you have to take A LOT of time gazing at each side of your hull in sunlight to make sure you filled in all the flat spots and making sure you kept the hull symmetrical from port to starboard before moving onto the next steps in the build. Investing in filler blocks saves time later in sanding planking, and shaping those filler blocks (also messy) allows you to get the hull shape close to perfect before planking even starts. Also, any mistakes in the shape can be spotted and sanded without worrying about sanding a hole in the hull, and depressions you made by over-sanding can be filled with glued on thin layers of balsa and re-sanded quickly.
The mouse sander with 60 grit sandpaper made sanding the balsa blocks down to the level of the bulkhead edges a very fast job.
The filler blocks become the shape which the planks assume, instead of relying on the natural bend resistance of the planks to create the curves. The number of bulkheads should increase in density (smaller space between bulkheads) where the hull has sharp changes in curvature, such as near the bow and stern
Sometimes planks have weak spots where they bend at a sharper angle, and thus do not match the curvature of adjacent planks, creating offsets between the surface of that plank and the ones next to it. Those offsets are usually not extreme and are removed during the sanding process. Filler blocks remove any offsets since the first planking layer is glued right to the surface of the blocks and the edges of the bulkheads. That saves on sanding and filling. Of course, you had the extra step of sanding all those filler blocks, but the payoff is that you when shaping the blocks, you get to see the precise form of the hull curves earlier, and make smaller adjustments with filler thank you would on a lesser supported planking layer when you didn't use blocks.
Of course the overall hull is stronger with filler blocks, and far less subject to punctures from accidents, and it is noticeably much heavier.
My first kit, Corel's La Couronne, had a sufficient amount of bulkheads to ensure that the first planking layer created curves with few hard bends and flat spots, but two applications of filler and sanding were still required. The DeAgostini HMS Sovereign of the Seas had far fewer bulkheads in the stern area and midships that were required to support the planking. So, I opted for filler blocks for that model. Because massive changes to the stern were needed, the filler blocks allowed free-form carving of the stern and complete reshaping from a square tuck to a round tuck. If there were just bulkheads and planks there, such changes would have opened up huge holes in the hull and made filling those holes and reshaping of the stern far more difficult.
Personally, I don't like filling and sanding. It's VERY messy, and you have to take A LOT of time gazing at each side of your hull in sunlight to make sure you filled in all the flat spots and making sure you kept the hull symmetrical from port to starboard before moving onto the next steps in the build. Investing in filler blocks saves time later in sanding planking, and shaping those filler blocks (also messy) allows you to get the hull shape close to perfect before planking even starts. Also, any mistakes in the shape can be spotted and sanded without worrying about sanding a hole in the hull, and depressions you made by over-sanding can be filled with glued on thin layers of balsa and re-sanded quickly.
The mouse sander with 60 grit sandpaper made sanding the balsa blocks down to the level of the bulkhead edges a very fast job.
It’s super worth at the front where significant curvature exists. Not so much further on along the length of the ship.
Take a look at the building log by @Thomas Marocke (this post following the link and the following)
he is not filling the space completely, but added some wider filler to have stability and also additional surface for the planking
Thank you. Something to consider
True I was thinking that myself also save on the balsa wood
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Thank you for your very informative post. You have give me a great deal to think about
Excellent idea; would consider adding the filler to the bulkhead before even installing the bulkhead
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It really depends on the distance between your bulkheads. The wider the distance the more value placing filler blocks. Kurt's photo is a great example. I believe if you are just starting out modelling, filling the space between bulkheads with balsa wood is VERY helpful as it helps the modeler "see" the profile along the length of the ship's hull. I do know some use basswood, pine and other soft woods, but I've not realized any additional benefit of using any other wood than balsa. Additionally, balsa keeps the weight down and the larger your model the weight differentiation can be significant.
One final note, now that I think of it. I've always used filler blocks.
Good luck mate! Have fun with your ship.
One final note, now that I think of it. I've always used filler blocks.
Good luck mate! Have fun with your ship.
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Certainly filling the bow and stern sections gives you additional support and gluing surface for areas where plank bends are greatest. I also added filling just below deck level so I could insert bulwark stanchions, knight heads and bollard timbers into something more solid then simply gluing them onto the deck per kit instructions (see attached phot of BOUNTY). This also meant I could properly plank bulwarks instead of using the kit supplied plywood which then had to be carefully sanded to match the 1st plank line and then veneered.
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Colonial Schooner Sultana
this will be a design and build project of the Sultana based on the Model Shipways kit, not a build log of the kit but "based on the kit"
shipsofscale.com
take a look here i filled in the bulkheads of the Sultana model.
1. Absolutely, but usually too soft!
2. Better yet, use basswood, however still a little soft.
3. Better yet, use a hardwood like Philippine mahogany (not too soft with no sap).
Too soft? Most model kit hulls typically consist of one layer of 2mm think planks covered with veneers, only supported by bulkheads and they do just fine for display models. Being soft is one of the advantages of balsa when it comes to cutting and shaping it quickly. Balsa is easily cut or dented when struck with a sharp object, but does very well at supporting planks in order to 1) control the hull curvature between bulkheads and 2) keep the edges of planks aligned to avoid offsets where the edges meet. Point 2 is the most observable benefit.
If you need an armored hull which can take BB gun hits without penetration, then balsa won't hold up, but for a display model it is sufficient. If your knightheads, fiferails, or cleats are pinned through the deck, and they need to be extra strong because of tight rigging or used for pulleys for RC control lines, balsa offers far less support than using a hardwood, but it offers some support.
If your model radio controlled, balsa reinforcement takes up valuable space for controls and servo motors, but may also offer enough buoyancy to keep your expensive model from sinking if it should leak and take on water.
Aside from the amount of work it takes to cut, glue, and shape balsa blocks between bulkheads, then shape them and clean up the messy sawdust, I can't think of any disadvantages it has. The benefits in supporting the planking are not huge, but they are noteworthy. You can surely built a hull without balsa fill, especially if your planking is thick enough to allow lots of sanding to remove offset edges, but if you are looking for increased control of the hull shape, aside from adding tween bulkheads, balsa fill offers an improvement. Is it necessary? Certainly not.
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One reminder…work carefully with balsa blocks as fillers between bulkheads. Try to shape and sand the bulkheads to finish state before adding the balsa blocks. Shape the balsa blocks to fit the space and contour between the bulkhead. The balsa is very soft and it is too easy to sand away too much in shaping the blocks. When finish sanding use a long sanding block to avoid dipping into the balsa filler block. This comes from one experience using balsa filler blocks.
Having said this I have abandoned using filler blocks. For me they do add value to the hull construction. I have had adequate support using just the bulkheads for plank support even at the bow curves.
Having said this I have abandoned using filler blocks. For me they do add value to the hull construction. I have had adequate support using just the bulkheads for plank support even at the bow curves.
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If you used 60 grit sandpaper on an oscillating mouse sander as well as sanding blocks, removing excess balsa is faster and easier. Leaving the balsa surface rough sanded allows glue to adhere a little better too.
My opinion is do not put too much of fill in wood where it is not necessary. I had seen unfortunate modelers where they had the hulls split when winter - summer humidity conditions changed in their work shops. They were in real trouble then.
I've tried using filler, but I didn't like it. The balsa wood for me was too hard to sand down. I did try a green foam once that's used to hold fake flowers in their arrangements. It was easy to cut and provided for shape for the strakes. It was also lighter than balsa.