Page 3 of 5 FirstFirst ... 234 ... LastLast
Results 71 to 105 of 175

Thread: Probably Not a Deben 4 Tonner ?

  1. #71
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    The end of the knee production line:

    Knees.jpg

    bevels, bevels, bevels .............
    Nick

  2. #72
    Join Date
    Mar 2015
    Location
    Perth, Western Australia, Australia
    Posts
    2,053

    Default Re: Probably Not a Deben 4 Tonner ?

    A shameless display of knees!

    Nice work, Nick, and thanks for sharing it. Yours is a neat project.

    Regards,
    John.
    http://fairmaid.blogspot.com.au/

    "It's dawning on me that I should have worked out the tumbler details more in advance, rather than rely on bluster and over confidence. But that's just silly." Jim Ledger.

  3. #73
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?



    Thanks John. It's slow work - interrupted by the need to prioritise paying jobs and maintain a smallholding !

    Two weeks working away on contract coming up, so there won't be much to report for a while.
    Nick

  4. #74
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    First pair of lodging knees installed:

    LK1_20190614_161039_resized.jpg

    LK2_20190614_161109_resized.jpg

    These replace the only lodging knees previously fitted, which were much weedier in construction and one had rotted.

    And also re-installed, the foredeck hatch coaming:

    FDH_20190616_133847.jpg

    This is a lovely piece of mahogany joinery, original to the boat. It had been attached to the beams by hope and a few dodgy screws; it now has nine M20 316 stainless bolts and three substantial screws. When removed, it had another Swiss cheese collection of holes which have all now been stopped. Mating surfaces with the beams have been primed and painted (as have the beams) and the joint, finally, sealed with CT1.
    Last edited by Whameller; 03-03-2021 at 01:03 PM.
    Nick

  5. #75
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    The knees installation continues ...

    Next up was the installation of a pair of hanging knees under the king beam; there had been none before, or under the forrard mast support beam.

    20190722_H-Knee_1.jpg

    The rather blocky appearance is because of the need to bolt through ribs which were slightly offset from the king beam.

    It was not possible to fit hanging knees to the other mast support beam, as it also supported the the half bulkheads at the forward end of the cabin:

    20190702_Bulkhead_1.jpg

    These were tongue and groove matchboarding which served no structural purpose other than to support the forward end of the berths. I replaced them with ply half bulkeads, which are tied into the beam shelf, the beam and the bilge stringer and also to vertical posts (made of Southern Yellow Pine) which are tied into the beam and a rib. The aim of this setup it to provide the support that would have been provided by a hanging knee:

    20190702_Bulkhead_2.jpg

    20190722_Bulkhead_3.jpg

    The hole in the starboard berth is where I'm going to add a foot box. The berths are only 6' long - I'm 6'4" tall ! The flat surfaces of the ply have had two coats of epoxy; the edges four coats and have been painted with underwater primer and bilge paint.
    Nick

  6. #76
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    With the bulkheads installed, I was able to fit the forward pair of lodging knees:

    20190702_L-Knee_1.jpg

    20190722_L-Knee_2.jpg

    The only element of the whole mast support structure now left to do is a new compression strut - which will require repair of one floor and designing a mast step structure from scratch (the previous strut - made from rusted out scaffolding pipe - was mounted on a loose block of oak resting on the keel):

    20190722_Mast_sp.jpg

    Where previously there had only been the afore-mentioned strut and a pair of rather weedy lodging knees aft of the king beam, there are now lodging and hanging knees (or the equivalent) on both mast support beams and tie rods to hold them together. I intend to make a rather better job of the compression strut arrangement as well !
    Last edited by Whameller; 07-26-2019 at 10:48 AM.
    Nick

  7. #77
    Join Date
    Aug 2010
    Location
    Rockland Maine USA and Woodbridge, Suffolk, England
    Posts
    530

    Default Re: Probably Not a Deben 4 Tonner ?

    Now you have all that good structure there, you could think about keel stepping the mast maybe?? Makes for a more stable gaff rig.

    Cheers – – George
    To be truly free to live, one must be free to think and speak.

    A C Grayling

  8. #78
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by debenriver View Post
    Now you have all that good structure there, you could think about keel stepping the mast maybe?? Makes for a more stable gaff rig.

    Cheers – – George
    It's something that I have been thinking about, George. As you'll recall, I'm planning to use the Deben 4T sail plan (as modified by your father) as the basis for her rig. The mast which I've acquired is exactly the right length for this - assuming that it's deck stepped (which its butt is currently designed for). To keel step, I would have to scarph about four feet onto the butt. That, in itself, is not a problem to do - but it would put the joint in the way of the putative mast partners. Even with a good scarph ratio and a joint well glued (i'm inclined towards resorcinol for this, rather than epoxy), I'm hesitant to have the joint at such a major stress point. I'd welcome your thoughts.
    Nick

  9. #79
    Join Date
    Aug 2010
    Location
    Rockland Maine USA and Woodbridge, Suffolk, England
    Posts
    530

    Default Re: Probably Not a Deben 4 Tonner ?

    Hmm... a well done scarph is as strong as the wood being scarphed – but somehow I agree that I might also be uneasy about having a scarph right at the partners – though I guess that's a gut reaction rather than a scientific one!

    You can't scarph the extra length on the top?

    Cheers -- George
    To be truly free to live, one must be free to think and speak.

    A C Grayling

  10. #80
    Join Date
    Sep 2007
    Location
    Benfleet Essex UK
    Posts
    472

    Default Re: Probably Not a Deben 4 Tonner ?

    If you have a mast the right length use it as is. A tabernacle makes it easy to raise & lower the mast & on a boat this size it can be done easily on your own in a short time. Far outweighs any advantages a keel stepped mast may have on a boat of this type. Other wise you will always be looking for a crane or derrick to drop the mast.

  11. #81
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by debenriver View Post
    Hmm... a well done scarph is as strong as the wood being scarphed – but somehow I agree that I might also be uneasy about having a scarph right at the partners – though I guess that's a gut reaction rather than a scientific one!

    You can't scarph the extra length on the top?

    Cheers -- George
    I don't think so, George. If you look at the top:

    20190724_204715_resized.jpg

    the mast tapers to 2.5" diameter and is then stepped down to 2" for the last 6". The butt is more promising:

    20190724_204737_resized.jpg

    5" diameter and parallel sided for 4' or so. But, acknowledging what you say about the strength of well made scarphs, I intuitively don't really want to put one in way of the partners.

    I'll probably stay with deck stepping.
    Nick

  12. #82
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by keith66 View Post
    If you have a mast the right length use it as is. A tabernacle makes it easy to raise & lower the mast & on a boat this size it can be done easily on your own in a short time. Far outweighs any advantages a keel stepped mast may have on a boat of this type. Other wise you will always be looking for a crane or derrick to drop the mast.
    I tend to agree with you. George has extensive knowledge of the Deben 4T (my boat isn't one, but very similar), as his father built them and with his naval architect background I value his input as I plod on with this rebuild.
    Nick

  13. #83
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    A minor marine miracle ...

    I have known since I surveyed the 4 Tonner that the cast iron keel had - contrary to all conventional wisdom on galvanic corrosion - been fastened with bronze keel bolts. This was done in 2005, the earliest piece of history that I have for the boat. I've been guiltily conscious that I needed to pull at least a couple to check their condition; all the heads and nuts, meanwhile appear in good condition, so I continued to put it off.

    I needed to remove the foremost floor for repair (of which more later), so that keel bolt became the first to be inspected:

    20190803-Keel_bolt1.jpg

    20190803-Keel_bolt2.jpg

    Other than a small amount of corrosion where it had been exposed to seawater at the bottom of the bolt, it is in remarkable condition after 14 years !

    Which one to pick next for inspection ?
    Nick

  14. #84
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    52,603

    Default Re: Probably Not a Deben 4 Tonner ?

    Is the floor out? Any sign of delignification?
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  15. #85
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    This is the foremost floor as removed:

    20190803-Floor1.jpg

    It was only fastened to the boat by the keel bolt; all the copper nails to the planking had been cut through. I suspect that it had been removed at some time and, when replaced, refastening to the planks was overlooked. There is evidence of compression damage in way of the keel bolt:

    20190803-Floor2.jpg

    20190803-Floor3.jpg

    20190803-Floor4.jpg

    but otherwise a very sound piece of oak. Using my guiding principle of keeping as much original material in the boat as possible, I cut out the damaged wood and scarphed in a new piece of laminated oak:

    20190805-Floor5.jpg
    Last edited by Whameller; 08-05-2019 at 05:46 AM.
    Nick

  16. #86
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Tool of choice for boring the keel bolt hole through the new oak:

    20190805-Tool_of_Choice.jpg

    Much more controllable than a power drill for this job and possibly more torque as well - that's a 16mm auger bit.
    Last edited by Whameller; 08-05-2019 at 05:41 AM.
    Nick

  17. #87
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Peerie Maa View Post
    Is the floor out? Any sign of delignification?
    See #85. No sign of delignification - just compression damage. No sign of any damage to the keel timber either.
    Last edited by Whameller; 08-05-2019 at 05:49 AM.
    Nick

  18. #88
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    52,603

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Whameller View Post
    This is the foremost floor as removed:

    Attachment 42622

    It was only fastened to the boat by the keel bolt; all the copper nails to the planking had been cut through. I suspect that it had been removed at some time and, when replaced, refastening to the planks was overlooked. There is evidence of compression damage in way of the keel bolt:

    Attachment 42623

    Attachment 42624

    Attachment 42625

    but otherwise a very sound piece of oak. Using my guiding principle of keeping as much original material in the boat as possible, I cut out the damaged wood and scarphed in a new piece of laminated oak:

    Attachment 42626
    Cant see the pikkies.
    Invalid Attachment specified. If you followed a valid link, please notify the administrator
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  19. #89
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Peerie Maa View Post
    Cant see the pikkies.
    Have just edited by deleting and re-uploading pics. Hopefully OK now ?
    Nick

  20. #90
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    52,603

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Whameller View Post
    Have just edited by deleting and re-uploading pics. Hopefully OK now ?
    Yes, that worked.
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  21. #91
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    I've just pulled the No 6 keel bolt (2nd from aft). It's in exactly the same state, if not slightly better, as No 1. Phew ! This one will be under the engine, once installed, so was a good one to check before that happens.

    On the principle of 'if it ain't broke ....', I'll leave the rest be for the moment and inspect them on a rolling basis over the coming years.

    Meanwhile, I b****red the thread on the No 1 bolt while driving it out - so I'll have to have a new one made up. This time in galvanised steel, I think.
    Last edited by Whameller; 08-05-2019 at 03:33 PM.
    Nick

  22. #92
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    52,603

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Whameller View Post
    I've just pulled the No 6 keel bolt (2nd from aft). It's in exactly the same state, if not slightly better, as No 1. Phew ! This one will be under the engine, once installed, so was a good one to check before that happens.

    On the principle of 'if it ain't broke ....', I'll leave the rest be for the moment and inspect them on a rolling basis over the coming years.

    Meanwhile, I b****red the thread on the No 1 bolt while driving it out - so I'll have to have a new one made up. This time in galvanised steel, I think.
    Try cleaning it up with a triangular needle file before junking it. You have probably only swelled one or two turns.
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  23. #93
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Peerie Maa View Post
    Try cleaning it up with a triangular needle file before junking it. You have probably only swelled one or two turns.
    Good idea - many thanks. I'll try that.
    Nick

  24. #94
    Join Date
    Nov 2010
    Location
    Wellington, NZ
    Posts
    850

    Default Re: Probably Not a Deben 4 Tonner ?

    The best for cleaning up the thread would be a thread file.
    I got one 30 years ago, and have found it great for bringing threads back to the correct profile.
    I did a quick search and they are available, not cheap but will sort out your keel bolt.

  25. #95
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Slacko View Post
    The best for cleaning up the thread would be a thread file.
    I got one 30 years ago, and have found it great for bringing threads back to the correct profile.
    I did a quick search and they are available, not cheap but will sort out your keel bolt.
    Great suggestion. Many thanks.
    Nick

  26. #96
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Sister Act

    I'm now working towards getting the aft part of the hull prepared for installing the new Beta 14 engine. The first step is sistering or replacing some cracked ribs (a total of 15 to do in the full length of the boat. The originals are steamed oak and many have already been sistered - some, I suspect at the time of construction.

    I decided to go down the laminated route. Here are the first three being laminated in place - wrapped in clingfilm (Saran wrap in North America ?) and secured through the holes (previously drilled and counterbored) in the planking by 3mm chipboard screws into blocks of wood with penny washers under the heads:

    20190812-Sistering1.jpg

    20190812-Sistering2.jpg

    20190812-Sistering3.jpg

    Once the glue (I used epoxy thicked - slightly - with silica) had set, they were removed and tidied up with block plane and sand paper:

    20190813-Sistering5.jpg

    And then copper nail riveted into place:

    20190823_Sistering8.jpg
    Nick

  27. #97
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    And a final gratuitous riveting shot:

    20190823-Sistering9.jpg

    These three were probably the most accessible ones to do, in the lazarette. My assistant drill and dolly-weilder was my younger son, who has no boat building experience - so this was a trial run to get the teamwork right.
    Nick

  28. #98
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    I tried cleaning up the bronze keel bolt with a thread file but, sadly, I had indeed b*****ed it and distorted it beyond redemption.

    So I had a local engineering shop run this up for me in steel - which I'm happier putting into a cast iron keel:

    20190830-Steel_keel_bolt.jpg
    Nick

  29. #99
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    52,603

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Whameller View Post
    I tried cleaning up the bronze keel bolt with a thread file but, sadly, I had indeed b*****ed it and distorted it beyond redemption.

    So I had a local engineering shop run this up for me in steel - which I'm happier putting into a cast iron keel:

    20190830-Steel_keel_bolt.jpg
    Bright Shiny mild steel? Welcome to the world of rust.
    We replaced bolts through cast iron with the original wrought iron, a much better prospect.
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  30. #100
    Join Date
    Aug 2019
    Location
    Twin Falls, Idaho USA
    Posts
    47

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Peerie Maa View Post
    Bright Shiny mild steel? Welcome to the world of rust.
    We replaced bolts through cast iron with the original wrought iron, a much better prospect.
    The vast majority of “wrought iron” these days is, in fact, mild steel. Not much difference, metallurgically speaking...

  31. #101
    Join Date
    Jul 2000
    Location
    N.E. Connecticut.
    Posts
    6,968

    Default Re: Probably Not a Deben 4 Tonner ?

    There is a huge difference in longevity between true wrought iron and mild steel. Unfortunately true wrought iron is really no longer produced in the world, To find it you have to find it ‘salvaged’.

  32. #102
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    52,603

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Recon1342 View Post
    The vast majority of “wrought iron” these days is, in fact, mild steel. Not much difference, metallurgically speaking...
    That I doubt. Wrought iron has very little extraneous elements alloyed with the iron. There is much less carbon and manganese in the mix. It is extremely difficult to remove alloying impurities when scrap steel is added to the furnace. That is why cars made from recycled mild steel rusted out so quickly.
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  33. #103
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    52,603

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Whameller View Post
    I tried cleaning up the bronze keel bolt with a thread file but, sadly, I had indeed b*****ed it and distorted it beyond redemption.

    So I had a local engineering shop run this up for me in steel - which I'm happier putting into a cast iron keel:

    20190830-Steel_keel_bolt.jpg
    Now that you have got it, what were you planning to coat it with when installing it?
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  34. #104
    Join Date
    Aug 2019
    Location
    Twin Falls, Idaho USA
    Posts
    47

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by nedL View Post
    There is a huge difference in longevity between true wrought iron and mild steel. Unfortunately true wrought iron is really no longer produced in the world, To find it you have to find it ‘salvaged’.
    Absolutely correct. It has to do with the impurities in the wrought iron. They flash rust, and that oxide in turn helps prevent further degradation of the metal. The same can be accomplished with mild steel by allowing it to surface rust and then spraying it with a rust converter, generally consisting of tannic acid and a polymer base. The conversion process turns the rust from an oxide into a phosphate, which will be highly resistant to further rust...

  35. #105
    Join Date
    Mar 2008
    Location
    West Wales, UK
    Posts
    669

    Default Re: Probably Not a Deben 4 Tonner ?

    Quote Originally Posted by Peerie Maa View Post
    Bright Shiny mild steel? Welcome to the world of rust.
    We replaced bolts through cast iron with the original wrought iron, a much better prospect.
    Acknowledged. However, wrought iron is hard to source in West Wales and the price quoted for one bolt was scarily high. I intend to be very careful coating and caulking it when installing and will pull after the first season in the water to check condition.
    Nick

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •