Type of wood for filler blocks?

[Matt H]

I am a high school CAD drafting and wood shop teacher so I have access to various types of lumber. I have alder, red oak, wormy maple, cedar, spruce, African mahogany, and walnut. I was planning on using some scrap I have lying around the shop for filler blocks. What species listed would be best? Does it really matter? I was thinking of going with alder because it is the cheapest and I have it in abundance. 

 

Second question is that I have read it can be good to have the filler blocks level with the deck level of the bulkheads to give a nice solid base for the deck. Similarly, having the filler blocks go out to the outboard edges of the bulkheads makes for a good surface for the planking. So essentially creating a solid hull with filler blocks between all the bulkheads from deck to keel to outboard. Is there any downside to doing this?

 

I posed this question in my build log but I didn't get an answer there before it got buried in other build log posts, so I'm posting here.

[Pete Jaquith]

Matt,

 

I have had good experience with filler blocks, both to assist in hull fairing and to support planking.  I recommend something firmer than balsa such as bass, pine, or popular.  I have attached pictures of my Fair American  build for reference.

 

Regards,

Pete

[Matt H]

1 hour ago, Pete Jaquith said:

Matt,

 

I have had good experience with filler blocks, both to assist in hull fairing and to support planking.  I recommend something firmer than balsa such as bass, pine, or popular.  I have attached pictures of my Fair American  build for reference.

 

Regards,

Pete

Thanks Pete, I like how you did it. It makes sense to put them in the bow and stern where the hull curves to allow a better base for the planks to adhere to, but not in the center where it isn't necessary for planking. As far as the deck goes I may add a smaller filler block on the upper and inner part of the bulkheads between every other set of bulkheads that will create a good base for the deck planks. Thanks for the pictures.

[Pete Jaquith]

Matt,

 

For decks I added liners at the deck edge (to support plank ends) and around the masts to reinforce rigging points.

 

Regards,

Pete

[ASAT]

Matt, I’ve always used balsa for filler blocks as it sands easy and there is less chance of altering the bulkhead shape  if you use a harder wood - it lets you use the bulkheads as a guide and shapes so readily. As far as the deck I usually make a false deck from some 1/64 or 1/32 ply if the kit didn’t come with one - that way you can lay out all the grates and deck furnishings on it and configure your planking plan on it.....

[ETNZ]

I used balsa on my build of HMS Agamemnon, it was as good as useless in my mind. In future I would use a soft wood but much firmer than balsa which would accept a pin and hold it without straining to push it in. 

 

[Jaager]

Alder should work.  A species near the plywood hardness  makes shaping it more work to no real advantage.

Going all the way inside the hull gives a base that is firm enough for one layer of planking - if two layers is the design.

If the below the waterline hull is to be coppered, adding the plank thickness to the filler dimension and scabing that layer

to the face of the molds (bulkheads) = no planking needed in the way of the copper.

No - to using it as a deck underlayment.  Trim the inside of the filler to be  a bit thicker than the frames would be.  They do not

need faring - rough and staggered at that face is sufficient. 

[Matt H]

Thank you all for the info I appreciate it, it is all very helpful. Pete thank you for the pictures and explanations, I also did bump into your build log and looked through the first page in detail earlier today for a bit.

[Matt H]

I think I will use filler blocks in the stern and bow sections for the bends of the planks. As far as the decks go I will add small filler sections along the outboard edges and around the mast positions.

Essentially following a similar design to what Pete showed in his photos and build of the Fair American.

 

I have decided to go with Alder, that is what I have in abundance, but it is also the lightest of the woods I have and the least dense. So it shouldn't take too much to shape. I'll update my build log when I am done, I may come back and post a picture or two here.

[BANYAN]

Just to add to the conversation; whatever you use you have to consider that wood WILL move (swell/reduce) with humidity etc.  If using grained woods try to match the grain direction on both sides using the same wood type.  If no room is allowed between some sections it may distort the hull but probably minimal?  May not be as great an issue once all the planks are on as this will provide additional rigidity.  The more experienced will know.  The bulkheads are usually ply so they are not prone to this wood movement.

 

I have used balasa successfully BUT I always coat the outer (gluing) surface with a diluted PVA glue solution to fill the 'pores' and give a better sticking surface to the filler.

 

cheers

 

Pat

[Matt H]

Thanks for the input Banyan, I do plan to have the grain run the same in each section. The thickness, width, and length directions of each filler will run the same as each other filler.

[BETAQDAVE]

Here is an article that I posted back on April 13 in the Filler Block topic under the heading Building, Framing, Planking and plating a ships hull and deck.

 

   When I first saw this posting of this topic, I was reminded of seeing that in the March/April issue of Ships in Scale there was a short article on converting POB construction to solid hull construction by Robert Brandt.  In his article, he described his method of using foam blocks to fill in between frames allowing him to use a single layer of planking that would have continuous solid support and eliminate the problem of hollow spots in between frames.  (Something quite important if you intend to use a natural finish rather than painting the model.)

    He thought that by using extruded polystyrene foam for his blocking, the ease of cutting and shaping the blocks was easier than using wood.  As an added bonus this would add very little in terms of weight.  The excellent compressive strength of this type of foam doesn’t hurt either.

    Shown below are the illustrations of his method that were shown in his article.  (Currently being reviewed by my assistant.)

     A version of this type of foam that is readily available throughout North America is Dow Blue Styrofoam.  STYROFOAM™ Brand Insulation is the original extruded polystyrene foam insulation, invented by Dow and first manufactured by them in 1941.  Dow's blue colored extruded polystyrene Blue Board's closed cell structure and lack of voids resists water and water vapor penetration thus protecting underlying materials from water damage. 

    This product is also available in several sheet sizes and thicknesses and is relatively inexpensive.  It does however, require the use of a particular type of adhesive, as some types of adhesive will dissolve the board. 

 

   There is also very little in the way of shrinking or expanding due to temperature, so once it's in place it would be very stable.

[Matt H]

Thanks Dave, very useful information I'll consider that option as well. I am building the Syren and it is only a single planking, however it will be copper plated. Your assistant looks like he/she is very deep in thought!