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Thread: Fairing a boat as you go verses following the plan. Building a whitehall

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    Default Fairing a boat as you go verses following the plan. Building a whitehall

    Hello everyone, I'm looking for a little input and suggestions on a boat called the Catherine, designed by Richard Kohlin. Mr Kohlin calls it' Built in the Whitehall tradition '. It is Lapstrake, WRC planking,14 feet long and it is a very nice boat. Mr. Kohlin has done a sufficient job in the illustrated book that even I can follow most of it. That is except for the gaps in knowledge that I struggle with because of my lack of experience. This is my third boat to build. Each boat has gotten harder as I have challenged myself. This boat has been very challenging to say the least. The suggestions I am seeking are not relegated to just this boat but to all small boats built in traditional way, especially by novice like me.

    The problem,
    The boat is being built upside down and there are 7 molds, not including the transom and stem. The directions have very minor lofting as Mr. Kohlin gives you most everything you need to know. For example,the 4th mold has all the measurments. I built the mold and put all measurements on it. All the way down from the keel to the sheer for the plank landings. I did run battens ( 9 battens representing 9 planks ) I ran the battens from stem to transom with the 4th mold and its measurments as the mid way point on the boat. Therefore I had three points that I knew where my batten was to land; on the transom, the stem and on the specified spot on the 4th mold.

    So looking at the profile of the boat there are three points in which the batten needs to hit. The transom, based on his specifed measurment, the stem and its specified measurement and mold 4 and its specified measuremts. I assume everything given in his book is right. But as I have now started to put on the 2nd broad on I feel that the boat planks don't look very fair. That is not because the planks are not laying flat, that has been ok except trying to get them to lay flat on the mold. I have had some difficulty with that on mold 6 and 7, but more concerning, looking at the planks from either the stem or the transom down the length of the boat the edges of the plank to the eye do not have nice curve to them. Yes they curve but not real smoothly. There are no abrupt areas on the plank do to my hand planing, the planks just don't have the pizzaz or alot of shape. at least it seems that way to me. I do assume there is a possiblity it is deceptive looking at the planking upside down, or perhaps it doesn't look shapely because it seems there is quite a bit of a long flat run in the garboard and first broad from stem to stern. And of course it could be that I have simply not done a good job in building the molds or cutting out the planks.

    Now that I am at the 2nd Broad I have opportunity to add just alittle more shape to the plank but it would require not landing on the 4th mold where it is specied. In essence I would be ignornig the measurment given my Mr. Kohlin and try to fair the boat by eye. Because of my in- experience If I do that and I turn the boat up right will I have found I really messed up. Should I have stuck to his measurments no matter what and not decided to just use my eye for most of the rest of the boat. If I don't use his measurements on this plank it will probably run that way thru all the other planks to the sheer. None of the planks will hit the mark he indicated. The planks may land a quarter or three eights off from his given mark. Is that a big deal if it gives more shape to the plank ? Is being off the mark a catastrophe ? That is my concern as a novice boat builder.

    Advice and suggestions would be appreciated.
    Thanks Mac

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Put your battens back on and view the boat from every direction and adjust them until all the battens run fair every which way you look at it. Also check that the plank widths on the intermediate moulds progress evenly, with no sudden change in width.
    Photos would be helpful. You will get better advice if we can see what you are seeing.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    A photo or two would be helpful as it's hard to know what you mean by a "nice curve".

    It can be deceptive looking at the plank edges, especially the first few. This is because we are used to looking at boats as a 3-dimensional surface; and when we do look at them as 2-dimensional surfaces, they are very specific – waterlines, buttocks, sections and diagonals.

    The run of a plank doesn't follow any of these 2-dimensional lines, so we do see an unexpected curve in the mind's eye. This is especially true when building the first strip planked skin of a cold-moulded hull – the strips follow completely different lines from those we are used to looking at, so often appear unfair, or not very nice curves. When the surface gets more complete, these "unfair" lines disappear as we start to see the complete surface.

    If the planks are laying easily on the moulds and meeting the three datum points the designer has given, and you had no trouble with the trial battens laying fair to the datum marks, it sounds to me as if they are just fine. You say you had a bit of trouble with getting them to lay flat on moulds six and seven – was this because of the necessary twist as they approach the bow? In which case that is normal.

    Unless I was very unhappy with the shape, I would lay another two planks before making any adjustments. By that time the 3-dimensional surface will be starting to appear and you can get a better idea of the planking as a whole.

    Having said that, adjusting a plank by about ľ" isn't so much – but be aware that it will tend to be cumulative so the following plank adjustments may want to get more severe, to the point where the plank widths start to get cranky.

    Cheers -- George
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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    I can relate to the lines looking rather flat when viewed upside down....
    I was concerned at this stage that there was a problem.
    In the end it all worked out quite well...
    There may be () slight discrepancies in my plank widths in places, but I'll never tell...

    I marked all the plank landings for each plank and closely adhered to those as I planked. Some minor adjustments were needed here and there.

    I'm also an amateur builder.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Have you checked all of the dimensions from station to station and confirmed they are correct?
    Do the battens lay fair against the molds? Are you happy with the curves of the battens? You can fiddle with them here and there but be wary of drastic changes.
    If all the conditions are met and the dimensions are correct, trust the design and the designer.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    If your line off was fair, then you are likely making a mistake in spiling your planks.

    Jeff

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Attachment 87790Attachment 87791Attachment 87792
    Hello to those that responded to my questions. Here are a few pictures but I don't know if they will help from my original questions. It took me a while to figure out how to get the pictures on.
    My measurements have been checked multiple times. I'm feeling a little better now that I ran the battens in a couple of places. There is no drastic changes in the plank but there is some small ones. But, being inexperienced I am only guessing what is drastic and what isn't. That is where I get lost sometimes. Trying to make a judgment call on something that may bother me as being not right. I have also decided the advice given to move ahead with at least two more planks. That may help me get a better view of things.
    The planks actually are starting to lift off molds 6 and 7. Those planks are near the transom not the stem. Of course I have another question and any further thoughts to the original questions would be welcomed. I am building the boat upside down, clenched nail. I thought it would be beneficial to flip the boat over near the last strake or at the sheer before I put it on. It would certainly help nailing as things are bit crowed and I could get a good look at the boat for fairness. Its difficult to do to me upside down.
    Any thoughts.
    Thx. Everyone, MacCatherine pic.jpgCatherine pictures.jpgCatherine.jpg

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    lifting how far off the molds? 1/8"? 3/4"? If you clamp them down do they spring up at the next ones?

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    It is a bit late to tell you, but file this away for the next build.
    Professional boat builders always build clinker boats the right way up. Even carved Whitehalls were built right way up.
    It is far easier to clench the lands. In fact, it allows you to leave clenching until all planks are hung.
    Far easier to check for fairness and for symmetry.
    You do not need to turn a floppy hull and set it up again for timbering out.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Ok, I wont turn it over when I only have a plank or two left, but it sure is tempting.

    The planks at old 6 and 7 are about 3/8" above the mold. There is a little movement on the plank over mold 5 and 4 when I press on the plank while it is over mold 6 and 7. Less than 1/4".
    The planks at mold 1 and 2 also have the plank raising a bit over the mold. ( 3'8 " ) I understand that is not unusual but not sure if that is good, or what I van do with it now.

    Always grateful for everyone's help.
    Mac

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    From the photos, the planks look to be running pretty fair to me.

    Remember, in the days of clinker dinghy building, it was quite common to build with just the transom, a midship mould and the hog/stem backbone set up. So you wouldn't really know much else anyway!

    I don't think I would worry too much about the planks not laying hard on all the moulds. If it were glued ply lapstrake and the moulds were frames, then you would be pulling them down on to the frames. But with traditional clinker, as long as everything is looking fair it's not unreasonable to let the planks depart from the moulds a bit. And planking with different timber species would probably produce slightly different results, depending also somewhat on how the planking timber is cut (through-&-through, quarter sawn etc) and where in the log a plank comes from.

    Cheers -- George
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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    And as Nick says – best built the right way up!

    Here's a couple of videos of traditional clinker dinghy building. Just three moulds for this boat, which is a 12', fairly heavy smack dinghy.

    https://www.youtube.com/watch?v=TpF44MPSJ_g&t=372s

    https://www.youtube.com/watch?v=ZX3cCZit828

    Cheers -- George
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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Thank you for the info. and the videos. Needless to say I'm learning alot . My wife ask me if I'm still having fun. Yes, but depends on the day

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    A fair curve beats all.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    That is about how it's going. Now to train my eye to see a fair curve and be happy with it.
    Thx.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Quote Originally Posted by Peerie Maa View Post
    It is a bit late to tell you, but file this away for the next build.
    Professional boat builders always build clinker boats the right way up. Even carved Whitehalls were built right way up.
    It is far easier to clench the lands. In fact, it allows you to leave clenching until all planks are hung.
    Far easier to check for fairness and for symmetry.
    You do not need to turn a floppy hull and set it up again for timbering out.
    Not all lapstrake / clinker boats are built upside down, even by professionals. It's not a necessity to build the boat upright. I do note that you said "were built" and I said "are built" so there's definitely more history on your side than there are current builds underway. That math will always be true.

    Quote Originally Posted by willin woodworks View Post
    A fair curve beats all.
    My experience while planking lapstrake boats is that now and again you end up ever so slightly shimming a station mold (on both sides) in order to get a nice fair line. Sometimes the designer's own eye doesn't quite test out true once you're using actual lumber or plywood. That's life. It's just a little boat.

    I'd agree that if it looks pretty & fair, then it is pretty & fair. ("Pretty fair" isn't quite good enough, though.) There comes a moment when your line off and lap lines just "feel" satisfactory from all angles (including upside down) and then you just gotta forge ahead.
    Quote Originally Posted by James McMullen View Post
    Yeadon is right, of course.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Quote Originally Posted by Mackey View Post

    The problem,(snip) I assume everything given in his book is right.
    Don't assume that, there is a reason once a boat gets lofted the first time you go back and make sure everything agrees before proceeding. Small Boats Monthly had an article a few years back about this design, you might reach out to those builders and see what they discovered.

    As I discovered the hard way on my first build, it does not take much "offness" in a plank spiling to really mess things up. I didn't account for the gains as the planks dove into the stem and fought the planks as they wanted to lift off the molds (sound familiar?) until I figured out where I went wrong. Fix those broads now, any unfairness is far more likely to be compounded than reduced if you go forward without a clear resolution.
    Steve

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Thank you

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall



    I do not see any gains there, but rather looks like the planks are just butted together at the transom...
    Is that what the designer is calling for?
    Doesn't seem right to me....
    Also, have you beveled the laps yet?
    That will also make a difference in the way the planks lay.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Yes there are gains. The designer said to finish the aft gains after the plank is attached. The second broad in the picture is not fastened yet, so the gain is only cut in about 1/16th of an inch. I will finish it when plank is fastened to the transom. Yes the laps are beveled and I did look closely at that because the planks were lifting slightly above the mold.
    Thanks for asking. Mackey

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    It isn't essential to use gains at the transom and it saves a good deal of time and effort if you don't.This sot of thing has been normal in the Merlin rocket class for a very long time.




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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Very nice. I think I'm to deep with the gains to turn back. thx

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    The normal way of planking a clinker boat is to do it right side up. Every plank is made a bit wider than it's finished width so you can use a hatchet to adjust the upper edge to a fair curve after nailing the plank in place. The upper edge is planed smooth to remove the axe mark and to tweak the curve a bit to get it even fairer. Then the next plank is shaped and hung.
    I am absolutely not a boatbulder but this is how I have seen it being done and been told by boatbuilders to do it should I ever build a boat.

    To me those gains look weak. Esentially the land is rebated down to zero thickness. Some boatbuilders use rebates instead of just rolling the bevel of the land but then the land of each plank is rebated to half it's thickness leaving some material to hold the aftermost nail (or rivet).
    Joggling the transom and letting the planks overlap at their full thickness like it is done on those sail dinghies is another way of doing it. Not common but sometimes seen.
    Amateur living on the western coast of Finland

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    I am also quite concerned about the lack of gains. I’m not understanding the part about finishing them off after the plank is hung,… you can’t.

    As to laying right on all the molds, unless it is a class boat (dependent on precise measurements in order to compete) the planks often won’t hit all the molds just right. When boats were wood, and before boat building became “boutiquey” a fair curve and looking good was far more important than hitting every mold.

    In this picture you can see where the planking is a good couple of inches off on at least one mold. Look at the mold with the “P” painted on it. This is a 30+ foot Lapstrake Jersey sea skiff with only four stations. This shop built over 300 boats over 50+ years.
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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Quote Originally Posted by nedL View Post
    I am also quite concerned about the lack of gains. I’m not understanding the part about finishing them off after the plank is hung,… you can’t.

    .
    Yes you can, I have seen it done.
    Unless you are thinking that the gain is finished as the next plank is hung. You cut the gain on the top land and can also brow off the bevel on the boat if you work that way.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    I can add a couple of thoughts to this discussion...First the Thread Title: Fairing of lines begins 1) when the designer bends his curve, 2) When the loftsman lays down the offsets full size, and corrects them, 3) when the patterns are picked up and cut out and cut on bandsaw and planed ‘fair’, 4) the pattern is transferred to the mold stock or backbone pieces and ‘faired again’ on the bandsaw and by hand planing.
    Each step in this process that curve better be getting sweeter and ‘fairer’ or somebody is asleep.

    As far as the lapstrake planks not touching the molds at various stations, that could be from poor spilling of the plank pattern- meaning the pattern stock is being edge set a bit to not allow the upper edge of the plank to not touch the mold, OR, a lapstrake plank does not strictly follow the lofted lines due to the overlap of the plank edges, so an upper edge wanting to naturally lie a bit off the station mold is not a cause for concern(both port and Starboard strikes should show the same offset), and it shows the great need to be able to properly line off for lapstrake construction.

    During my Ancient(Viking) Boatbuilding instruction, it became very apparent how the fair line of the previous planks upper edge was affecting how the plank I was clamping and shoring into place was being dictated to. Hard to describe, but these boats were built without station molds, so the planking process was determine the ultimate shape of the boat. This shape was different in the various Districts of West- and North-Norway, but very repeatable.

    ...maybe a bit of thread drift here, sorry.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Thanks to everyone for their replies. I will continue to re-read all the info. sent my way.
    Mac

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Quote Originally Posted by Peerie Maa View Post
    Yes you can, I have seen it done.
    Unless you are thinking that the gain is finished as the next plank is hung. You cut the gain on the top land and can also brow off the bevel on the boat if you work that way.
    Nick, I understand what you are saying, and I completely agree.
    I should have been more clear. What I meant was that the gains canít be cut in between two or more planks that have already been hung.
    I donít see any gains here, either shiplap or beveled.
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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    The first broad is covering the garboard gain and the gains are cut in on the first broad. They are loosely covered by the 2nd broad that are not fastened. They do not have the gains cut in yet on the 2nd broad.
    Mac

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Something interesting...according to Gardner's description in his book, original carvel Whitehalls were initially built right way up on the stocks with the sheerstrake, strake below (usually clinker lapped) and then internal structure put in first...makes it alot easier to bevel things etc before planking down the topsides, then the boat was turned upside down and the bottom strakes fitted. Unusual but efficient. They did it both ways on the one boat!

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    That is interesting.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Quote Originally Posted by Mackey View Post
    The first broad is covering the garboard gain and the gains are cut in on the first broad. They are loosely covered by the 2nd broad that are not fastened. They do not have the gains cut in yet on the 2nd broad.
    Mac
    Ahh,Ö. Ok. Iím following what you are saying. I have just not seen gains done like that before, and none of my Lapstrake boats are built that way. Ö.. Interesting.
    Thank you for the explanation.

    I have always seen them where you can still see overlapping at the transom ( whether beveled or shiplap). Like this.
    Attached Images Attached Images
    Last edited by nedL; 06-14-2021 at 09:23 AM.

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Mac, your boat is built in a boatbuilding school here several times and there is a forum member, 'Dutchpp', who attended a course. He might be able to give more info. I like the boat very much and were often tempted to build her myself, made a few sails for her, and I think you are doing well. Frank
    www.oarandsail.nl

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    Default Re: Fairing a boat as you go verses following the plan. Building a whitehall

    Thank you for those thoughts. I enjoy the forum and it has helped me now and then. Sometimes I can get-lost in the overwhelming amount of help ( haha
    Overall I am grateful for everybody’s help and experience.
    Mac

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