Bead and Cove Router Bits - Where to buy in USA?

Discussion in 'Boatbuilding' started by CatBuilder, Dec 18, 2010.

  1. SamSam
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    SamSam Senior Member

    Don't take this wrong, but you'd best be careful. You don't have the experience to go fast on this expensive project. My opinion is that a lot of those mold are too thin on one side and some are too thin on both sides. Some that are too thin on one side would have been alright if you had shifted the cutout to leave equal amounts on both sides, the ones that are too thin on both sides should have had been extended first with a piece in the center or one end and then the cutout made leaving enough on both ends. All the molds would then be lined up using reference marks instead of the ends of the mold.

    The advantages to doing the vertical sheets vs bead and coved strips are obvious still, but you've lost a lot of the advantage by going ahead and cutting the mold stations.

    You don't want to put short sticks between the stations. You'd have to measure and cut them pretty much individually. You'd have to put two fasteners in each end to keep them from twisting, that would be 4 fasteners at each station for each batten. They would warp and twist and sag being only supported on the ends. You would never get them aligned up in a fair plane to begin with.

    With long battens, it would take one fastener per station, they would span multiple stations and remain fair while being stronger.

    It would be 10 times faster than individual pieces also, except you now have to add in the process of either recutting the whole outline of the mold and then putting strips wherever you want, or holding the strips in place, marking the molds and then cutting notches to set the battens in.

    If you cut notches, they really don't have to be squared up things with two straight sides where the batten fits in snugly. The only part that counts is where the batten sits, so instead of multiple cuts with a saber saw and possible chisel work, one wider swooping cut could be made where you rapidly slope in to the bottom, cut the bottom carefully and then rapidly slope out the other side leaving a flatbottom notch with rough, random sides. If you cut too deep the battens can be shimmed with playing cards or that sort of stuff before fastening.

    Sister in junk like hoytedow suggests to beef the frames up, along with longitudinals on the outside. Home Depot or Lowes sells this for less than $300 Way faster and easier than screws and doesn't shift stuff around like hammering..

    .[​IMG]

    But now again you have war whoops take on it to think about.

    Here's something else. If you have to screw into the foam from the outside to hold it in place, is there enough room under your mold to get in there and do it?
     
  2. wardd
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    wardd Senior Member

    one thing may that may be useful is to measure every station from the same datum and not from one to the next to eliminate accumulating errors
     
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  3. SamSam
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    SamSam Senior Member

    I think you are talking about individual sticks between the stations and saying figure out what what the length should technically be according to plans and then cutting them all the same length.

    Error could come into play in that that station material may not be a uniform thickness. Error could come into play in that a slightly long stick would add up to accumulated error after 24 (?) stations.

    Another drawback to individual sticks is that even if you got them in there perfectly, if those stations swell even the slightest with the humidity, that will be a bunch of accumulated error with nowhere to go but lengthwise. With long battens sitting on the stations, the stations can swell individually and not effect the length (and fairness) of the mold.
     
  4. War Whoop
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    War Whoop Senior Member

    The advantage with long battens or the bead and cove is the fairing aspect,like I said the planks pretty much want to be fair like a long batten, following the golden rule of boatbuilding where a fair line overrules a given dimension so if it floats in a frame notch so be it.

    Even in the computer cut material one sees where the electronic spline does not match nature like the modulus of a good ole piece of clear fir or a metal batten.
     
  5. SamSam
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    SamSam Senior Member

    But don't you still have to fair the whole thing to eliminate the flats of the separate foam planks?
     
  6. War Whoop
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    War Whoop Senior Member


    If you work out the plank width so they follow the radius well, it is no problem.
     
  7. TeddyDiver
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    TeddyDiver Gollywobbler

    They are plain sawn boards... In boatbuilding and carpentry quarter sawn is the standard. For stripboards and alike it's also practical to use larger plainsawn timber (like 2x5 sawn to 7/8 x 1 3/4's) to get the orientation right.

    another thing..
    Concur with WW
    "the golden rule of boatbuilding where a fair line overrules a given dimension so if it floats in a frame notch so be it."
     

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  8. CatBuilder

    CatBuilder Previous Member

    Ugh. This always happens on forums. :)

    One person says vertical (athwartships) planking would be best, the other says bead and cove. Both people have built boats this way and both people are good at what they do.

    War Whoop: What about having to sand the foam to get a round radius on a round hull? With the vertical strips, I have nothing to sand in many places and hundreds of feet less joining to do. I'm currently about 30" on center with my mold (seen above), so either way can work.

    I'm really wondering here... which uses less hours?
     
  9. War Whoop
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    War Whoop Senior Member


    Here: You have to modify your fixture for full sheets OK no problem, I would make the decision now and get on with it,As mentioned do you have room to fasten and release the foam from the bottom side? and we are not talking a lot of lumber here.

    The flip side is you have to process the planks and then glue them together.
     
  10. SamSam
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    SamSam Senior Member

    Oh, Ok, I just pulled that photo off the net to illustrate the bead and cove.

    Yes, quartersawn has some advantages, but I've never known it to be a matter of much concern with carpentry.

    Sure, the fair line is what you want, so if the batten is floating off the mold, you want to shim it before fastening so it doesn't get pulled unfair.
     
  11. AndrewK
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    AndrewK Senior Member

    CatBuilder, the battens MUST be full length, to make the notches attach a depth stop to a router, as already mentioned its the depth that is important not the length of the notch, make the notch oversize by 1/2" or so. Notching with a jigsaw or saber saw freehand is too difficult to get the depth exact as well as flat.

    Use scraps to reinforce the thin bits, or rip up a couple of sheets into 8" strips.
    Do not glue the extensions in the bilge ,you can glue the deck ones if you wish, self taping plaster board screws will do.
    Remember the bilge area you need to be able to remove to do the glass overlap.
     
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  12. TeddyDiver
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    TeddyDiver Gollywobbler

    :D Just flip a coin or anything if there's no other issue. If the coin ends on its side then you have a new problem.. you have to use both methods ;)
     
  13. CatBuilder

    CatBuilder Previous Member

    Yes, I found this out the hard way when I did one from the other the first time, then measured the overall length of the boat. It came up 3/4" short. Then, I measured every station from a table of distances I created from the bow (or zero station).

    SamSam: Will reply soon. I'm thinking about your posts...
     
  14. CatBuilder

    CatBuilder Previous Member

    I probably don't. The lowest part of the form where the battens would be (closest to the floor) is currently 14" from the ground... a nasty ground, I might add. You might sneak in there, except the 2x6 strongback is only 8" off the ground, on some concrete blocks to keep it off the floor, that floods sometimes.

    I could make the mold higher, but I'm having a really hard time reaching parts of it for layup as is.

    Guess this might narrow the choice, huh?
     

  15. CatBuilder

    CatBuilder Previous Member


    This all makes sense, thanks.

    I actually have plenty of left overs from cutting the stations, so that I can easily put enough sistered extenders on. Today, I was out getting some materials I needed. I will work on this soon.

    I had to keep my mold low to the ground so that I could both reach it (it's 8' wide, obviously) and so that I could lift the hulls out with a set of these when they are done:

    [​IMG]

    So, there are all kinds of restrictions and limitations at play here. Not fun. But I guess this may leave me to strip planking after all, since I can't get under my mold without raising it. If I did raise it, I wouldn't be able to lift the hulls out or even reach parts of it.

    Hope sanding the foam round doesn't suck too much!:eek:

    Another dumb question: Can I walk on the foam once it's glassed??

    As in... if I glass an easy, flat, topsides portion of the hull, can I stand on that when I need to reach the bilge and deck areas, or will it ruin the foam, the bond or something else?
     
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