Adding Bulkheads

[acaron41120]

I have installed all the bulkheads on my keel. After a day of building I like to take a look at my work to enjoy and reflect on my progress. Today I noticed that there is about 1-1/2 inch between the bulkheads. More between some amidship. I have read about how spacing between bulkhead can affect the ship's hull and although I have never done this it did make me consider adding a bulkhead between the existing ones. Has anyone done this? If so, what are the problems I am likely to run into in doing this? Your comments will go a long way in helping me decide to do this or not. Thanks.

 

Allen

[tlevine]

Could you post a picture to better describe the problem?

[Bossman]

Acaron, I am assuming you are building a kit. People often add balsa “filler” between bulkheads. This will remedy the problem you speak. I hope this answers your question. 

[acaron41120]

I'll get a photo and post it later today or tomorrow. Have some yard repair to handle after three severe storms in 10 days.

Toni and Bosman. I have heard of adding filler between the bulkheads at the bow and stern but never between the other bulkheads. I think the filler route would be easier than guessing at the size of the added bulkhead and cutting it at the correct angle. Seems like a lot of extra work whereas adding a filler block would be easier to sand to the correct shape. What type of wood would you suggest for the filler?

[Jaager]

Allen,

What are the tools that you have access to?

Balsa seems to be the default favorite.  It is soft and readily available.  It is weak, really poor at holding planking pins, dowels, trunnels. It is no joy to work,  messy,  apparently something that your respiratory tract finds objectionable.

Basswood is available in sheets ranging from 1/32" to 1/4".  It is strong enough to hold fittings.  It carves well and is easy to hand cope.  You could also maybe add an addition to your house for what Midwest wants for enough to do the job you want it to do.

If you have access to a 10" table saw or a 14" bandsaw - to slice (resaw) pieces that will sum up to fill the gaps:

Yellow Poplar if you are determined to use a hardwood.

Pine from 2x4 or furring strip bins at your local builders supply.  Select, watch for checks, avoid species with sap runs,  Fir if you gotta, but Pine is more pleasant to work.

My choice would be Pine.  Balsa should be an eleven foot situation.

 

I looks like common way to ad the filler is to fit the pieces of filler between the moulds using a horizontal orientation.   The end grain against the moulds, cutting to fit is easier.  This also places the onus of bulk shaping the filler while it is in place on the hull.

 

Think vertical.  Think widths similar to actual frame widths,  or 1/4" each at most.

Think shaping the rough outside curve on each layer while it is 1/4".  The inside can be any shape, just make sure all of the layers between two moulds have some inside overlap.   Bamboo skewers can be used to connect the layers and make sure they line up. 

Use the mould pattern for the larger mould to get the rough outside shape for each layer.

Have the position for at least two skewer dowels on each layer.

Glue them all together.  Dry fit them between their moulds.  If there is a gap, poster board and paper can be used to make up a narrow space.

Draw the down bevel ( the bow or stern end)  and the actual up bevel (the mid ship end). The plan shape will be fat because of the bevel on the mould on the mid ship end, But it has still allowed most of the shaping to be done on thin pieces. 

Remove the filler and do the beveling on the loose section.  Now it can be glued in place between the moulds and only fine shaping is needed.

 

If you have ambition and ability to mill your own stock, now is your opportunity to be a ghoul and see if any neighbors have lost fruit trees or ornamental Pear,  Box,  Hawthorn,  Hornbeam,  Honey Locust.   Search our Wood forum for what to do with the logs.

 

Edited April 25, 2020 by Jaager

[acaron41120]

Jagger. I don't have mush for tools other than the usual swiss files, Exacto cutters, chisels, fret saw, French curve, small clamps  and sanding blocks. The only power tool I have for modeling besides a cordless drill is a Dremel tool. My other tools are for fixing aircraft and VWs. I can add the blocks if necessary and shape them by hand. It'll take some time but hey...I'm retired and I have plenty of time. Just have to wait for the local stores to reopen to get some wood stock.

 

Telvine. Below is a photo of the hull with bulkheads installed.

 

The space between the five midship bulkheads is 1-1/2 inch. The space between the front three is 1-11/16 inch and the rear three is 1-3/8 inch.

 

 

 

[Jaager]

The tops of your moulds are sort of swinging in the breeze. Filling between them is a better idea than even with those models with a central spine that gets close to the deck beam level.

See if there is a local wood workers guild.  You can probably get more help with access to serious power tools than would be imagined.

The alternative - a pack of Midwest Basswood sheets 1/4"  and  a smaller supply of 1/16" sheets.

A fret saw should work.  A good base helps.

Here is examples of what I am discussing as stock:

https://www.dickblick.com/items/33300-9412/

https://www.dickblick.com/items/33300-9602/

[Jim Rogers]

Fill in between with balsa and then fair..

[michael101]

I think you not need any bulkheads or fillers ...

if the ship its a big scale just add supports from one bulkhead to the next ,

you can see what i have done in my Hms Victory 

but when you putting the wood supports you must be sure that the keel its straight and the supports are exact without pressing the bulkheads ...

Best regards 

Michael.