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Tom Lathrop

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Everything posted by Tom Lathrop

  1. Jack, Have you posted photos of your new sprits'l? How do you find it handling? Is it slow in stays? How do you run and handle the mainsheet? Tom
  2. not to mention zero tolerance policices on weapons to include such ridiculous rules as to ban leatherman tools! It comes as quite a shock to me too Ray. On the "weapon" thing, when I was a boy, only the class sissy would not have a jacknife in his pocket at all times. Nowadays my shop knife hangs on my belt almost always. Sometimes when I go into the city (New Bern, at 25K+ counts as a city around here), I find myself being looked at in a shunned kind of way. Then I realize they are looking at the sheath knife and imagining all the nasty things a knife can do. When asked, I explain why the knife is so useful to me and why it is there instead of in my pocket. I get enough epoxy on my pants anyway without reaching pox covered hands or gloves into my pocket to retreive a folding knife and open it.
  3. Howard, You're welcome to my shop anytime. Let me see if I remember the tools and steps used in making the buchering knives. It was around 60 years ago, so give me some slack. The main work was done in metalworking shop at school. They did not plan on everybody going to college in those days, so vocational training was the norm. I had to break the sawblades into lengths short enough to take to school on the bus and can't remember exactly how that was done with no vice or grinding tools. At school, I drew the pattern to the customer's order and scored with a grinding wheel. The grinder was a big belt driven 8" job with no guards of any kind mounted on a post so there was complete freedom to move a workpiece around. I mounted the scored piece in a vice, told everone to step back and swung away. Then back at the grinder, the knife was roughed out and the edge roughly shaped but not sharpened. We did have a blowtorch kind of forge/kiln?, so I wrapped the blade in a wet rag and stuck the shank into the forge to soften it for drilling rivet holes. Back to he grinder for final edge shaping and then making the oak handle and riveting with sections of brazing rod. Final sharpening with files and stone. They weren't beautiful but could go through meat and small bones with one swing. If that sounds crude, it was. OSHA, NIOSH and interfering school administrators were far into the future. Dangerous, perhaps, but my shop teacher took his job seriously and showed us how to do each task in a safe way based on then current practice. I think we used goggles on some tasks but am not certain. I now have stationary and portable grinders, vices, clamps of all kinds, files, plus the usual assortment of other woodshop tools but when we did not have such things, we made do with what was there. I also made fur mittens for my sisters from rabbits that I caught and tanned the skins. This is starting to get long and maudlin so, as Forrest Gump said, "That's all I have to say about that".
  4. Yes Howard, it's often less expensive in time and labor to buy some things rather than to make them. You miss out on the pleasure of making something special for only the investment of time and labor though. Several years ago, I made 5 or 6 knives and only put a handle on the one that is now in my belt sheath. The rest are wrapped up in a drawer. Funny thing is, I don't consider that a waste of time now. That's partly why we are here. Otherwise we would all be buying used plastic boats which are usually cheaper than the ones we build.
  5. Charlie, I have made scrapers from old circular saw blades. They are too hard for any normal kind of sawing. I've not tried your chisel idea for breaking them out. Here is one method that does work on just about any blade up to 1/8" thick. Lay out the profile with a marker pen and grind a shallow groove on the line. Chuck the blade in a vice with the waste part exposed. Put on your safety goggles and hang a towel or other cloth to catch the flying pieces. Strike the waste piece with a hammer and it will break off fairly easily. Don't let anyone you like very much stand near while you are swinging the hammer since these pieces fly off at a prodigous velocity. You then need to grind the rough edge to your shape. As Charlie mentioned, if you are going to use the tool as a finish scraper, the sides near the edge will need to be smoothed since many saw blades will have some machine grooves there. If you want it for rough work, leave the machine grooves intact. About a million years ago I made and sold hog butchering knives from old crosscut saw blades this way for spending money. I also make scraper blades from old or broken Japanese saws. They are thin and flexible and I have them in several shapes. They are great on convex or concave curved surfaces like a strip canoe where normal scrapers are useless. I usually put a radius on most of the corners to avoid gouging.
  6. Ray, I did not mean to imply that the foil would not work to prevent condensation. Apparently it does not take a lot of insulation to do that. I have had one of those boats that have all interior hull surfaces covered on the inside with a synthetic carpet material. While we thought it ugly and tore much of it out, it did seem to prevent condensation. The information I gave related to instructions from the manufacturer on installation of multiple layer reflective foil insulation used in homes for a long time. They require minimum spacing on both sides for maximum effect. It makes engineering sense to me. Any flexible closed cell foam placed in the overhead between the hull and liner might work as well as the foil material.
  7. Metal reflective foils have been in use for many years. To get the greatest positive effect from this material, it must have air space on each side and some way for the reflected heat to get out of the system. If the foil is in contact with another layer, much of the "reflected" heat will transfer by conduction to that other layer and the advantage is largely lost. There ain't no free lunch. The claim on the website that most heat gain is from radiated sources is true but only under a narrow set of conditions. In a boat overhead with the foil contacting both hull and liner, a lot of the effect will be lost. It still may be worth using this foil, but don't expect the results they claim in most cases. There are other foils with closed cell foam in the center which would be more durable since bubble wrap is subject to popping if hit, as every kid among us knows.
  8. A CB trunk, CB and pin built to Graham's plans is very strong and has no reason to ever leak. Never heard of one giving any trouble. Adding unnecessary weight to a small sailboat is something that I could never do. There are always better solutions.
  9. I have hit stuff with a high aspect CB and know of many others who have done so. The only broken board that I know of is when a guy ran aground in a soft bottom with a CB that had a broken lift cable. In having the boat towed off, they twisted the boat around and broke the poor thing off. It is not difficult to make a small cruiser CB sufficently strong to handle any reasonable incident. The superior performance and extra space in the cabin makes the choice simple for me. How much extra performance? I have no idea and that would not be the deciding factor for me in a cruiser.
  10. Howard, What do you consider to be the advantages of a low aspect CB? Unless the board is to be ballasted, the lifting moment is not very great for the high aspect kind. Other than sailing performance, the major advantage of the high aspect CB is that it interferes much less with the boat interior. For a small cruising boat this can be a major concern.
  11. Greg, I have converted an old battery as a plug with wire and clips to a car battery. Now, the drill can work with either a good battery or in the car or boat for trips. For Jason: I have "rejuvinated" some batteries with current pulses with mixed success. Some seem to be completely restored and some will not hold a charge very long. Some have leaky or otherwise bad cells which have to be replaced with like cells from other to make one good battery that can be restored. Some battery cases have to be cut apart and some are can be unscrewed. Even though I can often be successful, I'd probably be interested in using your service.
  12. Graham, are you picking on Jim again? By the way, I was back in Bonner Bay again yesterday. Having sailed a Bay River Skiff in company with other, presumably faster boats, I think the positive attributes of a cat ketch far outweigh any, often negligable, speed advantages of the sloop rig. For the general use that most of these boats are intended, there is just no better rig.
  13. Scott, Looks like a good job. One question that occurs to me is the strength of the pin bolt. It looks kind of small, especially regarding the point Graham brings up about shock loads caused by hitting the stops. Even in Indiana, I'd be concerned about stainless and aluminum being close to each other although the nylon bushing may adequately separate them. Nylon may be a bit soft for a bushing. Delrin would be better.
  14. It depends on what you want the sheath to do. For stiffness, glass is much better than the synthetics like Dynel, Xynole or polypropylene Vectra. For abrasion resistance, these synthetics are far better. Kevlar is the king but very expensive and difficult to use. I made objective tests of abrasion and peel strength of fabrics several years ago and there is an article of these tests in an old Boatbuilder magazine. A single layer of Xynole is a bit more than 6 times as abrasion resistant than 9oz glass cloth, both saturated and covered with epoxy. On a per thickness basis the difference is about 2.4 times. Vectra and Dynel are similar to Xynole in abrasion. For peel strength, Xynole is by far the best, Vectra is next and glass is not quite as good as Vectra. Dynel failled all attempts to peel it because it broke at the peel line every time. I have had fir plywood to check through Dynel after years of use but never through any of the others. Based on my experience, I would never use Dynel for anything.
  15. Charlie, I have been using my own version of this WEST brush for many years. I found that roller section could slip from the notch and that the lower part could contact the work. I cut the stick to fit the inside radius and hot melt glue it. When finished, just tear it off and mount another one.
  16. Graham's shop is about 2 feet higher than mine so he had no problem.
  17. Captain, I am back on this morning. Ophelia was much like Shakespear's Ophelia in Hamlet. Born under abnormal circumstances, extremely fickle in her intentions and more powerful than appearances would show. Her "eye" was 60 miles in diameter with 85-90 mph wind in the eyewall and even further out. The average level 2 or 3 hurricane might not have winds that strong at the same distance. The worse thing about her was that she just sat on the NC coast and moved only one eye diameter in about 24 hours at 3mph or less. Neither Graham, Mike nor I had any real damage from this one, mainly due to the wind direction for Graham and I and higher ground for Mike. I had about 6 or 7 inches in my shop and storeroom which was much less than I expected and have only messy clean up to do and no loss of equipment. Overall, the damage from Ophelia seems to be less than expected although I suspect that the "beach nourishment" program at Atlantic beach and nearby areas was rendered completely irrelevant. The fat lady has not even come on stage yet so we are holding our applause.
  18. I'm sure you know that the air is full of tiny spores looking for a place to land and multiply. We breathe them and don't know the difference. Let a twig die and immediately some spores take action. They need some water, oxygen and a reasonable temperature range to do their thing and don't do well in deserts, deep freeze places or other places where one or the other of the necesaries are not available. Water vapor penetrating wood is not a rot problem unless the spores are there and alive and oxygen also has a way to be there or get there. Fungicides are poisons that kill and keep on killing rot spores. We used to slap on Cuprinol or Woodlife before painting our boats before epoxy became prevalent and might ought to do that again, provided that epoxy adhesion is not affected. I find no argument between epoxy covering and paint. Epoxy is paint, just a little different and better except for solar degradation. For me, sealing exposed plywood with epoxy is a no brainer. Adding fabric just makes the protection better. In the 60's epoxy paints were available from many marine paint manufacturers. The chalking issue probably did it in although it is still available and I use it for many parts of a boat. I know of no other paint that can touch epoxy paint for toughness, sealing and long life. One boat that I built in 1994 was reported by its owner a couple years ago as beginning to need some paint work. You can read about this much traveled boat "Loon" on Graham's web site. Rot spores are not a bad thing. Think about how the world would look if nothing rotted. We would be living in our own landfill. Entropy lives Added for Howard, I think you have a better handle on the plywood thing than many who have been around the various forums for a long time. One thing is that this particular forum is almost all related to plywood boats and does not attract the nay sayers that pop on other woodenboat forums. I have 24 foot planing power cruiser with 1/2" Okoume on the bottom. I have hit at least one significant deadhead while planing. This occured about 30% aft of the bow where the deadrise is about 20 degrees. Only damage I can find is a chip in the boot top paint. This boat is sheathed with Xynole which I consider the best of fabrics for this purpose.
  19. Ditto what Graham said. A few years ago Graham decided to add some more ballast to the boat he describes by cutting out a section in the plywood keel and inserting a plug of lead. After whacking out the wood, there was absolutely no sign of any degradation, rot or otherwise. His original Catspaw dinghy is still in great condition after extensive offshore and inshore use. I see many small plywood racing sailboats that are 40 or more years old and still in sailing condition. Almost all wood needs some kind of protection to endure long in the marine environment. Denigration of plywood by the plank on frame crowd is often no more than an attempt to create an aura of uniqueness about themselves. For the home builder, plywood is hard to match for its broad and useful set of characteristics. Rot requires water and free oxygen, deny either of these and rot has a hard time making a foothold. The idea that you should epoxy only one side of planking to let the wood breathe makes no engineering sense. Wood is DEAD, it doesn't need to take a breath, at least it should be really dead before you put in your plywood boat. The best results I have seen for longivity are when all surfaces have been well coated with epoxy. I am most definitely not talking about large timbers that can see a lot of dimensional movement. Fabric sheathing adds another layer of protection in that it toughens the surface. Glass is good but for abrasion resistance, the synthetic materials like Vectra polypropylene, Xynole polyester and Kevlar are far better, in that order. In my tests, Dynel comes out poorly. If A/B exterior fir plywood of the quality available at most local builder's supply houses 40 years ago were still around, it would be a good choice for low cost boatbuilding. The stuff I see now is, for the most part, pretty disgusting and I never see the A/B grade anyway. I have used the BS6566 grade imported plywood with good results although admit that BS1088 is a better and safer choice when money is not a factor.
  20. Tom Lathrop


    Mike, How thick are the vertical planks and how wide are the caulked gaps? I'm sure you know why I'm asking.
  21. Tom Lathrop


    Mike, the peak appears to bee quite a bit lower and further aft. The foot is longer also? I expect this will give more weather helm and give it more feel in the light stuff. The snotter also appears to be lowered to make up the diference in the peak height. Gotta get down there and sail it since the changes.
  22. That looks like it will work just fine. The boat will be slow though and where will you sit :?:
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