Jump to content

Tom Lathrop

  • Posts

  • Joined

  • Last visited

  • Days Won


Everything posted by Tom Lathrop

  1. I have finally had time to run quickly through your pages of construction. You are making my little boat into a much bigger project that looks very impressive. It is far too much to adequately discuss after a cursory look here but many thing you have done are quite extensive and beyond the simpler concept of the original. Robust is one term that I would use for much of the construction and I can see the boat cruising comfortably and easily on any coastal waters that LIZ and her mates have encountered. I hope to follow the progress as you develop a new Bluejacket.........Tom
  2. Oyster is right about a fuel tank. In addition to being a very good choice, a fuel tank made to fit the chosen space will allow for far more fuel to be carried which can be significant on long cruises when fuel supply spaces may be distant from each other. The volumetric difference can be significant if that is a problem for you. I would be very interested in seeing your initial design requirements as well as the changes you made. It is sometimes quit a surprise to see that a Bluejacket has been built or is being built that I was not previously aware of. Your build is one of those that was not known to me and that is very interesting as well as it should make a great cruising vessel. The largest Bluejacket that I know of up to now has been a 29 footer in South Carolina. That particular BJ is also of wider beam than the original design and runs well. I do not consider twin outboards to be a great factor in safety as modern outboards are very reliable. I also think that a smaller kicker is the better choice as long as it uses the same fuel as the main engine. The greatest issue with most any motor reliability is the fuel or battery and most that choose multi outboards use a common source for one or both of these. If reliability is thought to be an issue, multiple motors make multiple sources for whatever mechanical problems that might occur. Experience of Bluejacket builders for 20 years show the above to be true. On the issue of transom width. The outboard powered Bluejacket has proven resistant to the danger that some low power or shaft driven boats can have when running down wind in waves where they often have a tendency to broach. The outboard thrust is easily steered to counter any tendency for the boat to broach so I have widened the stern of later Bluejackets. The stern was originally narrowed to avoid broaching running down large waves as a safety factor that has proven to be not needed. Can you take any advantage of that at this stage of construction?
  3. Hi Alan, experience is usually the best teacher. Actually I've had no problem with well sheathed plywood rudders on small boats although Joe shows what can happen when an adequate sheath might have prevented it. We did have a glass reinforced foam rudder shear off approaching Ocracoke is a strong wind in a Grand Slam 26 footer though. It was the same mode of failure as well. The glass sheath was inadequately strong and was rebuilt much stronger than the original one by S2.
  4. Plywood is a wonderful material that is better than lumber in many applications. A cantilever that is loaded across the thickness like a foil is not one of them. I started sailing life wit both a plywood daggerboard and a plywood rudder. The DB failed while righting a capsized boat and the rudder was replaces by a more stable solid wood one. Many plywood foils do not fail but none are as stable as a laminated solid one would be. I suggest you make a new one in teh manner that C&B recommends.
  5. Dave has the most useful location for a wind indicator. I now use the mast main head which is the most accurate and best. I needed racing help on lakes when first starting sailing and made a small one mounted on the bow. Not the most accurate wind direction but better than yours and allowed great vision which showed wind changes well and was in the line of sight without looking at the sun or causing neck pain.
  6. Many years ago when I developed the idea of an impregnated synthetic piece of line on the leading edge of foils, keels, bows, etc., I did not consider using three lay line for this purpose. I always used braided Nylon or Dacron line with the thought that it would have greater non-directional strength and resist damage from blows better . I hope this line will be fine though if well impregnated and covered with sufficient sheathing.
  7. Neither website or email are working yet at 2100 today.
  8. Frank,  I'm trying to hit all available bases in getting my website back on line after being left out in the cold.

  9. Frank, I am still ambulatory, sort of. My email went kaput last Saturday and have not been able to get it working again. It may be that the problem you bring up may be the culprit as I use the website as my email, but I'm stuck not knowing . Will take the computer into New Bern this morning and have them fix that and another problem. Please hang on to my address while I gt this fixed. I don't remember getting a notice about this. Either I'm getting dumber or computers are getting more malicious as this used to be easy to manage.
  10. It looks like you did a very good job on the bow. The photos I gave show just about the limit of what can be done in achieving a deep knuckle on the bottom panel with plywood that survives this much bending. I wanted an extreme bow knuckle on this boat which resulted in getting up the learning curve. Graham has also had similar problems and has worked out how much bend he can have on the plans for amateurs to have success. We experienced some of the early plywood breakages with Graham years ago as we learned how much the wood can be forced.
  11. After having a couple of plywood failures (explosures really) in bending panels to difficult curves at the bow, I gave the problem a bit of thought. The photos attached show how a much more difficult shape was made in complete safety for the plywood. The side reinforcement battens are all in compression to the side panel and need only enough dry wall screws to hold them in position so the big bolts are unnecessary. A C-clamp or similar is the best thing to draw them together and allows plenty of adjustment as you go along. The piece added on the outside is to give the clamp a needed fixed place to draw the panels in with no slipping. This is the only piece that needs to be plenty strong to take the force. If you need a clamp at another place to even the bow shape, add another batten on both sides. The pictures should show everything well enough. Never had a problem since on much heavier plywood where stop gap measures almost always failed before. Good luck.......Tom Lathrop
  12. Paul has, sadly passed on but his words remain as clear as when written and will be forever so. Dories evoke some wisp of reverence in many boating souls but those that bear the name are most always significantly modified to hide their worse tendencies that made them especially useful to Banks fishermen and their masters. It's just a boat, crafted from common materials for a special purpose with some good boat design characteristics ignored in favor of those that were more important for the task. That later dreamers imbue the banks dory with magical properties is not the fault of the highly practical designers, builders or users of the originals.
  13. I'm happy to stand (or sit) aside and have other builders advise and work with you on planning and building a couple smaller boats before taking on the larger work of a Bluejacket 271. I think the BJ271 is just about the top of my desirable list for a small family cruising boat. The BJ28 has attracted more interest and builders though. One thing that impacts this decision is that there is at least one builder who is using the thinner plywood scantlings of the of the smaller boats for the build of a BJ28. This is perfectly acceptable as the thinner scantlings are plenty tough and strong enough as well as delivering a very little heavier boat than the BJ271. On the matter of using CAD and CNC for cutting out the hull panels is that, in my opinion, it offers little savings in time or effort. In my experience using CNC for the full size boat parts adds both time and effort to the task for a one off build. Building a large number of any design (or kits) utilizes advantages that CNC can have . It's pretty simple to build in the somewhat earlier method that Oyster advocates which is how almost all BJ's get built. Much of the questions about the procedure will be resolved in building of the smaller vessels and they will be a great help in that way as well ad useful in myriad other ways. Tom
  14. This beautiful boat is a credit to all those who contributed to her the dreaming, planning, design, and building in bringing her to the launch. Many boats suffer set backs in their realization and Rough Point is no exception as large bumps appeared in the road along the way to completion. Rough Point will take a proud place in the North Carolina fleet and look the part of her pedigree.
  15. Don, I sent you a note on your site.
  16. Don,  After my reply on your post about the transom, the thread died.  Since my suggestions are completely counter to the plan your took in repairing it, I expected some kickback.  Instead there has only been silence.  As an engineer, although not in structures, I am pretty certain that my thoughts on the forces involved are correct and that a knee as seen on many plans is the wrong way to handle this issue.


    Even if the transom were strong enough to transfer the force through the knee to the keel, the result would be a hollow or hook in the bottom just where it would do the most harm.  Such knees are a bad idea on a boat powered with an outboard.


    Just wondering how this was seen by you and others as I certainly did not mean to shut down an active thread...............Tom

  17. The basic problem here is that the transom is week in bending and the knee to the keel is not a good solution. I consider a knee on such boats to be the wrong way to go about it. It does not work against the forces properly that a transom gets from an outboard. Heresy, I think not. Analise the forces on the transom when an outboard is thrusting the boat. An outboard generates a force forward at the lower or propeller end and the same force is aft on the upper end of the transom and forward at the keel. A weak plywood transom like yours is opposite to what is needed to counteract these forces and the knee is useless. None of the outboard boats I have built in 60 or so years have had a knee and none have ever experienced a problem like yours or too many boats built from plans that specify such transom support. The keel of your boat is quite able to resist the forward force of an outboard without help and the weak (in bending) plywood upper transom is just what you don't need. The best method is to have a non-bending (lateral) upper transom that transfers the force to side decks, sides or adequate sheer structure. A strong board on the forward face of the upper transom that is adequately secured to decks and sides strong enough to take the force is the best method to cure your problem. I think the transom to keel knee is a left over from older boat construction and is not the most useful way for new boat and especially those with outboard power even though many designers specify them. There are several means of resisting transom deformation by transferring the transom twisting outboard forces to the boat structure. Strong and well secured knees between a stronger upper transom and the sheer structure can take care of thrust from small outboards in a way that resists this force. on a boat without side decks. Larger outboards with large such forces need more structure between the upper transom and the boat side structure.
  18. Most men in their 80's have trouble getting back in a capsized or swamped boat or one in dry conditions after expending the energy used in offshore conditions. Running or managing many races of relatively high level competitors who face far less energy requirements have shown this to be true. I've seen healthy and apparently active sailors need considerable help after a capsize in boats designed to allow this easily for younger sailors. Its easy to ruminate about what provisions need to be made to a boat and what equipment would allow the older sailor to get back a board and continue sailing. Such discussions should probably take place in very sober conditions and then tested out to see if it is practical or possible. I sailed well past my 80th year but, in practical moments, I knew that there were seriously degraded human issues to be dealt with. It has been rare that a serious accident or death has claimed a sailor over the 60 years of my involvement with sailboats but it has not been a non existent event. In each case, the cause of the loss has been determined only because it happened where other people were able to witness the event, ether directly or by evidence. In this case, that appears not to be possible and possible steps need to be studied and taken where possible, practical or useful. We all feel the loss of Jim Slauson acutely as we would feel the loss of any member of our sailing sport even though most of us may not have known him personally. As I read back over this note, it may seem a bit detached but I am unable to make it more meaningful than it is.
  19. Oh my. According to reports from Coast Guard, Sailorman is confirmed missing after they found the boat at sea but empty. At 88, 73 years old doesn't seem so old but memory tells me different, especially in those conditions. I join with all Watertribers in hoping for the best outcome. It's difficult to express true feelings for a fellow sailor in these circumstances but the real limits to our control come forward.
  20. I don't consider your advice as picking on the builder. Posts like this are far too frequent and good repair advice may not be what the builder needs. After all, the situation was apparent all along the way by the guy who did it. How do you expect the guy who allowed this to happen to follow good advice in rectifying it??. The proper way to deal with any resin situation is to make it right at each step and not leave globs to be cleaned up at the end. Like any of us, I am also guilty of not doing clean up along the way as well as I should and curse myself for having to work harder at the end. Never anything an order of magnitude this bad though. If the surface below the resin is anything as bad as is shown, it calls for a big effort to make it right. Otherwise, just ignore it and use the boat as is. If it's waterproof, it will still be a boat and the fish don't care.
  21. For a different purpose, I use "Squiding line", which is the same or similar to braided fishing line. Available in Dacron or nylon in a range of strengths and very strong.
  22. My friends were flown back to Melbourne on a Hercules aircraft but had to leave their car, gear and the boat behind. They will go back and pick up the boat and car later. Hope all works out well for them as the near term looks pretty safe and good. Future weather does not look too good for Australia according to long term weather reports. The current fire situation and weather were not a surprise and were predicted. It seems the Australian PM dismisses expert advice almost as well as our own leader.
  23. I'm in touch with a builder in Australia who is on vacation in eastern Victoria where evacuation is common. Many have been evacuated with some being taken by landing craft and other boats. They are OK as of now although nearby fire and smoke must be pretty bad. Travel by many roads is impossible to mobility is limited. Temperature is very high and, with a spark, stuff just explodes. We hope for the best as this is about as bad a weather event as can be imagined. My floods seem less severe after seeing this. Some pictures and video of an Island off the coast of Victoria. https://www.news.com.au/technology/e...86471fa20c88dd
  24. What I asked is clear. No opinions were offered from me. I did not ask anyone to evaluate the Australian builder I am using although they have many successful aluminum boats as well as provide extensive hands on training for prospective builders. I understand and stated that boats or kits shipping from Australia may too much for many in the USA. The questions were only related to what issues wooden boat builders might have with aluminum as a material.
  25. I posted this thread with the thought that wooden boat builders would have some thoughts about aluminum as a viable and practical material for a Bluejacket. So far, none have expressed any thoughts along those lines, such as: What are opinions of aluminum versus plywood as a boat material? That is, not regarding the obvious ones of building expertise or price. What are the issues in contemplating an aluminum boat for the average home builder? Which is more desirable aesthetically? Which would you rather own? Which is less maintenance? Anything else?
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.