Jump to content

21 ft Yawl Longboat for a Sixth Rate by vaddoc - Scale 1:10 - Plans from the National Maritime Museum


Recommended Posts

Gary and Brian, many thanks!

I am not sure if I ve mentioned it but I am actually thinking for this boat not to use tree nails to hold things together, like I did with the Deben. I d like to try brass wire 0,7 or 0.8 mm, threaded. There will be no glue holding the planks, just the threads. The planks will be initially fastened to the temporary frames with 0.6 or 0.65 mm brass pins, then removed. The biggest problem will be lining up the plank overlap (2.5 mm) and the frame inside (4 mm sided) - for all 2000 or so rivets. I ll do a bit of testing when time permits and will post the results.

Link to post
Share on other sites

Life went a bit into overdrive but still I managed to do a bit of work.

First, I glued the cant half frames with thickened epoxy using the jig to hold them in place. They came out fine but I forgot to take pictures.

 

Then I made the decision to use the solid wood keel and trimmed it to shape-I think it will be fine.

I then made the sternpost and the knee and I fiddled a bit with it, to make sure it sits flush with both the keel and sternpost.

 

Then I made the stem. Initially I wanted to laminate it but I decided to make it from overlapping 4 mm thick pieces. Not historically accurate but certainly faster and simpler.

20200823_164748.thumb.jpg.ddbd50968f80ccd57c94968deccb44a6.jpg

20200823_180407.thumb.jpg.ee35b57f539159b6a2ccda11e10ab182.jpg

20200824_194409.thumb.jpg.98c5dcd3afad3f31de15d39c588950b5.jpg

Then I worked on the jig. It needs to be completely flat and it seems that the boat will need to be built upside down. We ll see

20200830_172843.thumb.jpg.b6f99381febc59a3dad9c2087f311dd2.jpg

20200830_172850.thumb.jpg.31f0c61d33eb21456a113f65b64b6c9f.jpg

I also made a brilliant purchase, a 1 m steel ruler. I really don't know how I managed so far without it! Lovely thing

20200830_172920.thumb.jpg.67376b3ddbdd661133d4862b8c6b68ac.jpg

20200830_172955.thumb.jpg.f88832480e39278aaed964f37e8a448d.jpg

Then I assembled everything together and of course they don't fit. The frames seem ok but the sternpost and stem don't have any reference points so they are not in the right place and need to be further trimmed.

20200830_180017.thumb.jpg.d40e35dd29405675581e43a2069054a0.jpg

20200830_180037.thumb.jpg.1852833ec5700c89e44b511792cb1cfa.jpg

I checked the bevels once more now that most pieces are in place and it really looks ok

20200830_180259.thumb.jpg.75d89c1b704f9917a333ee07c59c9d21.jpg

Then I hit a snug. In the plans the Transon needs to be 5 mm thick but I do not have 5 mm think pear sheets but I do have 4. Only solution to shim the sternpost-I think it will be fine.

 

There are still many other tasks to be completed. Somehow I need to trim and align everything, secure the frames to a near vertical position and cut the rabet on the sternpost and keel-this last job will be difficult.

Then the sternpost and knee will need to be securely attached to the keel and the whole thing somehow to the frames. I need to make the transom and fit it to the sternpost squarely.

Baby steps...

Link to post
Share on other sites

In my "Miss Caroline" model build I used small brass nails to secure the keelson to the moulds. I also used them to secure the strakes as I went, the resultant holes are tiny and easily filled with a little wood filler. In my case the floor boards cover most of the holes in the lower hull anyway and I would assume the same would apply in your case but they are so small you have to look for them to see even the ones in plain view up the sides of the hull. My hull is more spartan than yours will be too so they'll disappear easily.

 

Link to post
Share on other sites

Thanks Bedford, indeed this is an option. I have several sizes brass or steel pins from 0.5 mm to 1 mm or I could use micro screws. The planks could be glued or tree nailed to the ribs. I just would like to investigate whether threaded brass wire alone (I think 0.8 mm) could be used. There would be 10 threads in each 2 mm plank and frame/rib which should be plenty strong. No holes to fill, just the wire to cut flush. The challenge would be to re use all the holes, this means not a single rogue one. Statistically this is impossible as there would be 2000 holes or so but I ll give it a go.

I am thinking of using initially 0.5 mm pilot holes with 0.5 mm steel pins to go through the lapstrake overlap and into the temporary frame. The pins would later be removed, the hole opened up to 0.6 or 0.7 mm going through the permanent rib at the same time and all secured with the threaded wire. Plenty to go wrong!

 

1mm wire behaves fine but 0.7 mm tends to twist along its axis almost to braking point. I hope 0.8 mm will be safer while still acceptable in scale.

 

Regards

Vaddoc

Link to post
Share on other sites

A bit more work done and time for another update.

The boat is progressing very slowly. I cannot work as often as I would like and It takes me a while to remember where I left things, it is a pretty complex boat. Also building (kind of) the Chapelle's boat at the same time is not helping much...Still, some real progress made today.

First of all, I printed out the patterns for the bow and stern to check how close to the CAD designs the wood pieces actually are. Happily, they are very close.

 

20200906_112459.thumb.jpg.aa8c74b895c865dd1c59469d49194276.jpg

20200906_112522.thumb.jpg.242b66e1bc93f34ff8335c6c6ce495ce.jpg

20200906_112531.thumb.jpg.21235c79fa23261746d6ad5b7eaddc62.jpg

20200906_113228.thumb.jpg.ecf41def779c021aa4a4f9d2f32bfee0.jpg

20200906_113338.thumb.jpg.4f7dc63109a5a72bbce9183c7d8e065e.jpg

20200906_113332.thumb.jpg.7a052e8412b57cf7e9cbaaf91a377bf8.jpg

I then finished the transom. I thought of leaving wood on for a safety margin, as I think is standard practice in actual boat building, however it is much easier to sand the transom now.

20200906_125143.thumb.jpg.4493e1878faaac65a71d7f29370e68ff.jpg

20200906_125158.thumb.jpg.ba4e73ade5b998bec5516da1c1c77901.jpg

I then glued and screwed the sternpost to the keel. I first drilled 0.7 mm holes to the keel, then taped the sternpost to the keel and hand drilled the rest of the way in the sternpost. Then I counterdrilled the holes in the keel to accept the head of the screw and screwed the 2 pieces together, with PVA in between. The joint is rock solid, the holes will be filled later on.

20200906_132228.thumb.jpg.a164ef30997ff3dfe9151cedf990db2f.jpg

20200906_133639.thumb.jpg.af8c010c0df0fd8f3c64c3b89e60c415.jpg

20200906_140838.thumb.jpg.3a3730a3de62b344f3a71b175f2f2797.jpg

20200906_140846.thumb.jpg.58b5b9482320576fe292dfe6b10c9409.jpg

20200906_140902.thumb.jpg.2e78b7bb39fbbaa04f0c3596d62bb294.jpg

The procedure was repeated for the stem but here I hit a snug: The keel will need to be notched for the rabet and might hit the screws if placed laterally. So I drilled new holes, this time at the midline. The stem looks like Swiss cheese but I ll fill the holes later on.

20200906_193836.thumb.jpg.9f7c56b45ba70e369829d1ead1392682.jpg

Then, I made again the hog or apron as the previous piece had some dents. Now, I had to figure out a way to make sure the frames are correctly placed/spaced but also that the keel is secured to the frames but in a non-permanent way, so that the frames can be removed later and replaced with ribs. The way to do this will be to screw wood pieces to the apron and glue the frames to these pieces. Then unscrew these when it is time to remove the frames. So here it goes:

 

The previous apron was cut up and wood inserts were made to go in between the rib spaces. The sides that will be epoxied to the frames were marked. Then these were lightly glued to the paper template of the apron

20200906_123223.thumb.jpg.a18bae7c512010af887d388756f832ad.jpg

20200906_123857.thumb.jpg.8ad7cded0265c74f30e92caf2609cbaf.jpg

Now, the keel has a slight bend laterally so i used some clamps to bring it in line with the apron..It straightened a lot

20200906_130043.thumb.jpg.f833dd69faff55bbb17462091bb0404d.jpg

20200906_130048.thumb.jpg.1b677f45195af7bc1bb56509ae2845c2.jpg

Next the filler pieces were removed, the paper template removed from the apron which was then sanded clean. Then the pieces were screwed on again and the assemble glued and screwed on the keel

20200906_153955.thumb.jpg.e0946dc5efec5a9703b6812b2cb4d2d2.jpg

20200906_155904.thumb.jpg.e2b24ede30c367abe80500655d980fbc.jpg

20200906_193808.thumb.jpg.9b4808c1e329a4230c46010465e2b050.jpg

 

20200906_193827.thumb.jpg.210d94b70e2583fb8a4cac6b40433306.jpg

This did not go as well as I would like because the apron, being very wide and only 2 mm thick, cupped from the liberal use of PVA. I do not think this will be a problem as it could uncup when dry but either way, a lot of it will be chiselled away and it will be invisible under the floors.

 

Regards

Vaddoc

Link to post
Share on other sites

Some more progress, time for another update. Things are getting now a bit complex, I ll try to explain as best I can

I have been able to work on and off on the boat so far but this is now becoming increasingly difficult, for the next few months, I ll be working 6 (and a bit) days a week so I expect things to slow down to snail pace.

 

First of all, I decided to lighten the frames significantly. After the planking is completed, I will need to install steam bend ribs in between the frames and simply there will not be enough space for my hand to fit in. So, I cut large pieces off but left two cross beams, one at the base and one mid-frame that will be easy to cut off later on with the dremel wheel. The frames are still very solid.

20200910_122231.jpg.9631706390d0f0f7427dbcb39e5a3fb8.jpg

20200910_122239.jpg.786fae5a1c00e32bbbd6b7254b68b476.jpg

Next was the big job of cutting the rabet and shaping the hog. Now, this was properly difficult.

20200910_122256.jpg.4858dbdff7d9cf04c64c21e078ea6dd4.jpg

It is impossible to follow the lines in the printed templates due to the large tolerances of my work but I am not too far off either. One interesting thing though is that the boat seems to have corrected my draft error. In my plans I had made the rabet a curved line but now it seems to have flattened.

 

I started cutting the rabet mid ships where the planks meet the keel almost vertically, still however it made a difference in the fit.

20200911_181333.thumb.jpg.31bc0047a6f6dabca9830407c9156d0c.jpg

First photo is fit without rabet, second with. Difficult to capture but it is better.

20200911_181348.thumb.jpg.46c6cafbc97e463dc8c60991bc492eec.jpg

20200911_181402.thumb.jpg.bf28069201c9b7bfb8955ddc526fee83.jpg

I then took a break to clean and sand the transom as it will soon need to be fitted. Lovely solid piece of pear wood.

20200911_201115.thumb.jpg.eae1dd44613d9624a59127ffd8e88f2f.jpg

Then I thought I wood install the sternpost knee. This is screwed and glued.

20200911_201124.thumb.jpg.b82a6093ffeae5a59287df0f04b2e0b2.jpg

20200912_170742.thumb.jpg.b367bc10d0a586fd2346b7d064a2dc1a.jpg

In the photo above I have also added some wood next to the knee, cutting notches for the two aft frames. Let me explain why:

 

It is very important for the garboard plank to be fully supported along its bottom edge. The rabet is not enough, this is why the hog is needed to add more supporting timber. However, I made two mistakes.

One is that I did not make it long enough. It should extend from the sternpost to the stem so that after bevelling, it will support the plank for all its length. So, I am adding wood to the stern and will do the same for a short distance at the bow.

Second mistake is that I did not make it thick enough. Putting the bevels, it gets very thin. So the pieces that I had screwed on top of the keel, thinking they will be just temporary and used to hold the frames in position will need to be permanent. These will also help with the ribs later on as their position on the keel will be already defined.

20200912_170752.thumb.jpg.b5b514ff8a4656483d2165e38f818e59.jpg

I have replaced the pieces that will not be used for gluing the frames, the ones that will be sacrificed are marked with an X, these will be removed with the frames after planking and replaced with nice wood without screw holes.

20200912_170733.thumb.jpg.e9a84bff71526b0fc7116cb5b8f36e21.jpg

Then I cut the rabet. Forget about plans! It was done with just eyeballing the angles and using small pieces of wood. 

20200912_194954.thumb.jpg.988fdc354d7e03a8a392700eebdbdc42.jpg

20200912_195027.thumb.jpg.c6336b75ae9296c6f4582e5d4781c750.jpg

20200912_195035.thumb.jpg.193668a56e905eadf3ffe21cb4d85c80.jpg

This is where more wood needs to be added to support the gardboard up to the stem edge.

20200912_195058.thumb.jpg.500cb6b74dbb19c6643d09dd9186106c.jpg

I tried a piece of 2 mm cardboard to see how the planking would go. It looks ok!

20200913_115749.thumb.jpg.29faf44fd5c83874ebe3b9f9112dae09.jpg

Then with a big push I finished the rabet. A bit more material needs to be removed from the sternpost

20200913_115811.thumb.jpg.af6cdd67b3612390acebb7c5a39bd00e.jpg

20200913_115816.thumb.jpg.1558c9ceb45d6269b47f0779b8f1862a.jpg

20200913_183416.thumb.jpg.8957368b8902d846d0a29f924e7cf01e.jpg

Now, another task was actually to reshape and sharpen my 4 mm chisel. So far I have been sharpening it free hand but now the bevel is so curved that it affects its function. Now, a few years ago I had made a simple honing guide with scrap wood, metal and bearings. I dug it out and used it. Perfect results! The next photos show the jig and how curved the chisel was. Since I ve honed it to a mirror finish

20200913_183504.thumb.jpg.00e41ee41348258c988e1d701dc567e2.jpg

20200913_183510.thumb.jpg.531aa36a9cd33529628b137ca26eaad6.jpg

20200913_183541.thumb.jpg.64da56a0487276c7f3990e77ab0747f7.jpg

20200913_183554.thumb.jpg.70f85c8160e1d6b5a483a424d4de72df.jpg

20200913_183633.thumb.jpg.417114660ca7f2113c0139dfa7351b05.jpg

There is also another thing that is troubling me, the wood I chose for the planking. I chose 2 mm beech. For the Deben I had used 2 mm maple which was perfect and very pleasant to work with, easy to cut, easy to shape and bend. However, the beech I received is much harder and resists bending plus it is 2,2 mm instead of 2. The planks will be cut with a knife so I expect a big struggle. I hope at least that the wood will respond well to steam bending (it should really being beech).

 

As Brexit is getting much closer I put in another big timber order from Germany. I will have enough lovely wood to last me for years, pear, beech and cherry. I hope it will not rot or cup with the huge variations in temperature and humidity we have hear in Britain.

 

Regards

Vaddoc

 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...