Page 34 of 36 FirstFirst ... 24333435 ... LastLast
Results 1,156 to 1,190 of 1246

Thread: Building Arabella (An Atkin Ingrid)

  1. #1156
    Join Date
    Jan 2009
    Location
    se pa (Bristol PA)
    Posts
    3,192

    Default

    I'm sure I missed it if it was mentioned just wondering about the decision to have square rivets.
    Denise, Bristol PA, Oday30, Anchor Yacht Club, On tidal Delaware River. my current project; http://forum.woodenboat.com/showthre...0-Ducker-Resto

  2. #1157
    Join Date
    Mar 2015
    Location
    Granby, Massachusetts
    Posts
    361

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by DeniseO30 View Post
    I'm sure I missed it if it was mentioned just wondering about the decision to have square rivets.

    Once we decided to go with copper rivets over silicon bronze screws (Atkin specified galvanized boat nails but we were never going to go that route) we had to find a source.


    We spoke several times each with Chip at Faering Design, the folks at Jamestown Distributors, R&W Rope and Rigging among a few others about sourcing rivets.
    Chip at Faering and the folks at R&W both said that square rivets would be stronger and last longer but they were not sure they could get them anymore. They all looked for a manufacturer, one of the guys from R&W was in Europe meeting with manufactures for something else and asked around there as well with no luck.

    The biggest rivet any of them could come up with was 4" long, round and 3/16" diameter. The 3/16" round rivets seemed too small to join 1-1/4" planks to 2-1/2" square frames, Chip said he would recommend 1/4" square rivets if they could be found or made and that seemed much more appropriately sized.

    We went so far as to spend half a day calling every rivet producer/ distributor we could find in the States and a few over seas and we found several that could/would make the rivets in round but not square and most wanted $3k or more just to tool up to do the job.

    Making them became the best option and the copper could easily be had in squares or rounds so we bought the squares. It would have been a bit over $7k to buy the 3/16" round rivets or $1,600 to buy the stock for the 1/4" square that weight almost exactly twice as much as the 3/16" round. So we got twice the rivet for a fraction of the price and we figured with the $5+k we saved we could figure out how to head and point them. Even considering our time we are coming out ahead.

    The reasons we have been given for using square are as follows. I'd take them with a grain of salt, this is just what we have been told, I've got 0 evidence to back any of it up but conceptually it makes sense to us.

    - The square peg in the round hole cannot rotate at all, supposedly this helps with the longevity
    - They grip better than round ones because of the corners biting in
    - They are more difficult to bend. This is the one that sold me the most. Assuming the rivets go in with the corners randomly angled no matter how you load the planks/hull it will be trying to bend a lot of rivets from corner to corner. Basically the square shanks resist a shear load much better assuming the corners are all pointed in different directions.

    So for us making them round or square was of no real difference in terms of production and the points people made about the square shanks made sense.

    Maybe some folks have some insights into the pros and cons of square or round rivets they would feel like sharing =)


    Screws would have obviously been the easier and faster option but I really like that the copper rivets essentially become a bolt with heads on both ends. The screws going into but not through the inner split frame spooks me. I know it's done all the time and the boats are fine and last a good long time but I personally just don't really like it. If the frames were not split then screws likely would have been the order of the day for ease and speed.
    ACORN TO ARABELLA
    For additional info on this project:

    www.acorntoarabella.com
    https://www.youtube.com/channel/UCAi...WB1xCp6uuUo0VA

  3. #1158
    Join Date
    Jan 2009
    Location
    se pa (Bristol PA)
    Posts
    3,192

    Default

    Thank you for the explanation.

    Re Spock: "logical; flawlessly logical"
    😃
    Denise, Bristol PA, Oday30, Anchor Yacht Club, On tidal Delaware River. my current project; http://forum.woodenboat.com/showthre...0-Ducker-Resto

  4. #1159
    Join Date
    Sep 2017
    Location
    Denmark
    Posts
    31

    Default Re: Building Arabella (An Atkin Ingrid)

    Toplicht in Germany have 4mm square 4 inch rivets and 5mm(almost ¼") 5". But they are expensive and its way more cool that you make them yourself. Enjoy your posts; thank you.

  5. #1160
    Join Date
    Sep 2010
    Location
    Bainbridge Island WA
    Posts
    2,706

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by sdenette View Post
    I've used a palm nailer before, we plan to get an air powered rivet peener but one for driving them as well might be nice. Thanks for the suggestion! It is amazing what a lot of taps can do, same concept with the impact drivers.


    All set to bend the bronze, it's a bit crude but it is fast to operate and very easily bends 3/8" steel so the bronze wings should not be difficult to bend. If we need to we can make the lever arm much longer =)



    That is quite impressive.

    I think in practice you will find that a head with a radius closer to the final curve will give you a better finished piece. What you have here will give you a series of facets that will have to be worked out or lived with.
    Steve

    Boats, like whiskey, are all good.
    R.D Culler

  6. #1161
    Join Date
    Oct 2015
    Location
    Kiel, Germany
    Posts
    199

    Default Re: Building Arabella (An Atkin Ingrid)

    So here's where I'm at with regards to floor design.
    All modelled floors.jpg

    I counted the following numbers:

    • 21 under the sole,
    • 5 engine bearers,
    • and 8 in the bow and stern,

    for a total of 34 floors

    I modelled seven floors based on frame 6 from the scantling drawing. Four for comparison:

    • Steve's mockup,
    • as drawn by Atkin,
    • a sawn frame according to Dave Gerr's Elements of Boat Strength (EoBS) scantling rule
    • and a metal floor to the same rule.

    Based on those I modelled three possible floor designs that I'm calling:

    • Full length flanges,
    • Corner knees,
    • and sole bearer knees.


    Comparison
    Input.jpg

    Immediatlely obvious is the fast difference in molding between Atkin at 5'' and EoBS at 12.5''. Now, Gerr is firmly in the camp of never notch the frames into the keel, so the argument can be made that the comparison should take the frame pocket into account. That comes out to about 9.5''. So even then, for my money the floors as drawn are undersized.

    Stopping the frames short of the keel does allow for sizeable limber holes right against the hull planking, which looks pretty much ideal to me.

    The metal floor is sided 1/6 of the sawn floor and reduced to 40% of the molding amidships. Which comes out to 3/8'' and 5''.

    Let's look at the three floors I modelled as a proposal. These take into account the design constraints already in place for Arabella:

    • Frames are notched into the keel,
    • frames are split,
    • and the plank fasteners also fasten the floors to the frame.


    Flanges full length
    flanges full length.jpg

    This is what I would do, or close to. Welded flanges all the way up the arms that tie in the sole bearer as a structural member with two bolts a side. The limber holes out in the corners are as good as we're going to get with the frames notched in. This design uses about 72'' of the 2 ¼'' flat bar, for a total of 1512'' for the 21 sole bearer floors alone. Which is, unsurprisingly, a lot more than Steve has ordered. So now for my two compromise designs.

    Corner knees
    corner knees.jpg
    These knees ease the hard spot in the mockup that sparked this whole discussion. They also double the weld length of the connection between the crossplate and the arms, compensating for the limber hole out in the corner that would otherwise seriously weaken the floor.

    Why the keel flange opposite the arms up the frame? With the arms disconnected from the flange by the limber, it frees us up to have the keel bolt holes in a part of the keel where the crossection is not reduced by the keel notches.

    The two knees nest on about 12'' of flat bar, and by nesting all of them on the same flat bar you can almost eliminate the waste, so one floor effectively uses about 13'' of flatbar.

    Sole bearer knees
    sole bearer knees.jpg
    These knees again tie in the sole bearer into what becomes essentially a composite floor comparable to the EoBS sawn floor. The hard spot previously discussed is geometrically still there, but less critical because the point where the shell is only supported by the frame is moved up to the sole bearer connection.

    Why a one sided connection, not two tabs sandwiching the sole bearer as Steve descriebed previously? I feel the material is better used in providing enough meat for two holes a side. Simplistically: one bolt is a hinge, two resist a bending moment. But more importantly, a bolted connection like this is propperly designed to utilise the bolts in tension. The flanges are stopped from sliding against each other by the friction from the surface pressure, not by the bolts in shear. But with the sole bearer sandwiched between two tabs that surface pressure is dependent on a propper fit, and it may also disappear down the line if by wood shrinking, but the bolt not coming loose alerting us to that fact. It also eases manufacture because the holes can be prebored and don't have to line up with the second tab after welding. And the weld is not obstructed by the other tab.

    A minus point definitely is the reduced weld length connecting the arms to the crossplate compared to the EoBS metal floor and the corner knee compromise design. Combining both corner knees and sole bearer knees effectively uses the same amount of material as the full length flanges, so it's a no go. The limber on the centerline as in the mockup looks preferable here.

    In conclusion, I would use the corner knees design in the bow and stern and the sole bearer knees design under the sole, probably with a central limber hole, or limber holes in the corner, but with the arms connected to the keel flange.
    Last edited by MoritzSchwarzer; 03-14-2019 at 03:11 PM.

  7. #1162
    Join Date
    Feb 2002
    Location
    Shubenacadie NS
    Posts
    4,431

    Default Re: Building Arabella (An Atkin Ingrid)

    So given a clean slate to work with, stopping the frames above the keel would be your preferred method? How does one hold the heels above the keel while bending? jigs, clamps and a longer than finished length of timber? I suspect it eliminates the tightest curve but would that not create a hard spot of it's own? Or would the floor account for that?
    Daniel
    If one advances confidently in the direction of his dreams, and endeavors to live the life which he has imagined, he will meet with a success unexpected in common hours.
    -Henry David Thoreau-

  8. #1163
    Join Date
    Oct 2015
    Location
    Kiel, Germany
    Posts
    199

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by Sailor View Post
    So given a clean slate to work with, stopping the frames above the keel would be your preferred method? How does one hold the heels above the keel while bending? jigs, clamps and a longer than finished length of timber? I suspect it eliminates the tightest curve but would that not create a hard spot of it's own? Or would the floor account for that?
    Daniel
    Yup, I'd not bother with the notches and fit floors that reach up higher, making up for the difference in what in a metal hull I would call bracket length: the weld length of the bracket connecting the shell stiffener to the keel. Or in wood: the overlap between the frame and the floor. With a solid bracket connection that transfers the momentum of the heeled hull against the ballast keel, the last few inches of frame down in the bilge are neither here nor there.

    Frame notches or not is one of those cultural divides in boatbuilding and there is good arguments and autorities on both sides. Herreshoffs both Nat and L. Francis, Lürssen, Fassmer, Pardey and Gerr are con, MacIntosh, both Atkins', Gartside and Garden are pro. Good boats were and are built either way, and the best way to not have rot, notches or not, is keeping up on the maintenance.

  9. #1164
    Join Date
    Oct 2015
    Location
    Kiel, Germany
    Posts
    199

    Default Re: Building Arabella (An Atkin Ingrid)

    At the risk of shouting into the void, let's talk about weld preparation and geometry. Which is what separates welding from „hot-gluing“. It's the equivalent of propper joinery: dovetails and mortise and tenon versus butt joints and glued endgrain.

    What's it about? Thinking about weld pools, penetration, crossections and ultimatively: bevels. All old stuff long figured out by our predecessors and intimately familiar to anybody with a welding certificate. But this forum being hosted by WoodenBoat and not Metal Boatbuilding, it might be new to some and hopefully helpful.


    Aside from your basic fillet weld, this is the weld type that the mockup was built with. Which is fine for a mockup, but not a propper structural joint. Easy to see why: the distance between the welds is to big, and the weld pool on the opposite side of the fillet has no good way to penetrate down, which leaves us with a lot of metal in the middle that's unmelted and not connected. And after grinding the exess off, there is not much metal left that holds this joint together.

    And to make things worse, the inside edge of a weld triangle is considered a structural weak point. Basically a built in tear waiting to expand. "Root mistake," translated a bit freely. Once the undersized weld on the outside has let go, the fillet will follow soon after.


    Now, the easiest way to make this a propper joint is to make space for a second fillet. Let the flange overhang, weld two equal sized fillets. This is a standard welded girder, if you need an asymmetrical flange for one of many reasons. The unconnected metal in the middle and the two root mistakes are tolerated, the fillets are sized to account for that.

    But for Arabella, this alone won't do. The keel flange gets bolted to the wood keel, the arms riveted to the frames and planking. And especially on the arms we want all the room to land those fasteners we can get. No inches to waste on two fillets and an overhang. Which brings us to corner connections.


    If you look closely at the previous post, this is actually the connection that I modelled in the 3D floor comparison. An offset corner. We use those extensively in exterior steel, namely accommodation work where overhangs are verboten because surfaces have to be crisp and tidy. Covered in filler, sanded, painted and polished to a mirror finish. It's easy to manufacture and fill over. The second fillet welds over the root, eliminating the root mistake. But it's not a structural joint. It's difficult to lay down a substantial fillet because the „walls“ of the trench are flimsy, and it's easy to grind off too much material in the quest to round it over.

    Enter the Single HV. Single sided, half v-seam

    Now this takes some weld preparation. Namely, grinding a bevel on the web, 40° to 45° degrees according to taste. In a perfect world, you'd bevel this to a pinpoint, but for easier manufacture and to make sure you're not grinding away your web height, or straight edge, leave two millimeter proud. 1/12'' for you imperials.

    Line up in place, tack on the root side and take it to the welding table. Take a single root pass. Persuade pack into square with a few gentle whacks. Flip over, lay down a pass in the half-V. Repeat whacking as necessary. Maybe another fillet pass, then fill the half-V. Leave to cool. Once you get the hang of it, you can anticipate the leaning over on the hot side by whacking while the thing is still just tacked.

    In return for your troubles, you get a solid structural joint: a crossection almost equivalent to a standard angle iron. The fillet weld penetrates deeply enough to melt the inside corner of the root weld, so there is no root mistake or unconnected metal and there is enough meat to round over the outer edge without endangering the crosssection.

    This is the joint I would use to weld up these floors. Definitely for the arms. The keel flange might work with a double sided fillet geometry wise, but in that case I would definitely prefer a double half V over simple fillets. This is not the place for butt joints and pocket screws, so to speak.

    We could go into ceramic weld backing and single sided welding, but hey it's only 30 some floors. No need to throw the kitchen sink at it.

    Oh, and after watching the last video: Please Steve, for the love of all that is holy, and to save you from the youtube commentariat: never dunk a weld into ice or water to cool it down. Not on a piece that you expect to hold anything, anyway. I've retained enough from my metalurgy courses to cringe, my welding instructor would have groaned, and my professor would have probably cursed you out something long and colorful.
    Last edited by MoritzSchwarzer; 03-15-2019 at 07:44 PM.

  10. #1165
    Join Date
    Mar 2015
    Location
    Granby, Massachusetts
    Posts
    361

    Default Re: Building Arabella (An Atkin Ingrid)

    Wow

    Thanks for all the info!! You are not shouting into the void =)
    I always read and consider what folks have to say, I may not take the advice but it does not mean I did not hear it, consider it and likely research it more.

    In terms of welding what you described was pretty much the plan. The lions share of the welding I do is not very critical so I typically don't bother with too much weld prep but the bronze floors are a very different story!

    The vertical plate we will put on the bandsaw and neatly nip the corners off before welding like you described for the V seam. The wings hit the baseplate at varying angles so some seem like they will need little to no grinding/cutting as there are almost equal V's on either side where the wings meet the edge of the base plate so I can fill them in easily and have the welds overlap so there is no un-welded metal. Each wing angle is different though so some will absolutely need a little shaping but I think a lot will not.

    I also have acetone to clean the metal before we weld to remove any oil or other residue.

    For the design of the floors that you mocked up that makes sense. I think we will put the sole beam on the inside of the floor timbers, on top of the bronze floors though. Will keep everything a little more lined up in the bilge and they will be less in the way when accessing the bolts holding the bronze floors down.

    The ones for the stem and stern make sense for the stem but no so much for the stern since we need to attach the engine beds to the floors. We will make the ones in the stem and midship and likely tackle the stern ones last. We might need to purchase a bit more bronze for those and I have some more thinking to do on those as well.
    The thought right now is to build them like the midship ones but with a bronze bar/angle iron where the sole beam would be (it's narrow back there so it's not a ton of bronze to make that happen). I could notch the bronze bar and add supports or weld on top of the angle iron. Either way ideally making essentially dovetailed pockets in each floor for the engine beds to nestle into. If I do that they would be hard pressed to move fore/aft and it would all lock together very well back there. But like I said I have to mull that one over a bit more and figure out exactly where the engine beds need to sit.


    We started fabricating the first floor yesterday, we got the baseplate roughed out and one of the wings bent to shape. The crazy lever powered bender I made works well, it's just going to take some practice to get the correct twist and curve to the wings. We have been going very slowly and methodically on the first one, trying to get a good system down so we can fire them all out.

    So far I am very very happy with how the floor is coming out and I think once we get into the groove of assembly I don't think it will take too long to get them all made.

    Hopefully by the end of today we will have our first bronze floor ready for critique =)
    ACORN TO ARABELLA
    For additional info on this project:

    www.acorntoarabella.com
    https://www.youtube.com/channel/UCAi...WB1xCp6uuUo0VA

  11. #1166
    Join Date
    Mar 2015
    Location
    Granby, Massachusetts
    Posts
    361

    Default Re: Building Arabella (An Atkin Ingrid)

    Also I know that a weld should not be quenched like I did and YouTube has properly flipped out about it but since that floor with never see any weight on it and Alix was waiting on getting the shot of it in the boat I dunked it to expedite things. The bronze floors will be allowed to cool slowly as would any other load bearing piece!

    Believe it or not I am a tiny bit smarter than I look =) haha


    Thanks again for all the useful info!
    ACORN TO ARABELLA
    For additional info on this project:

    www.acorntoarabella.com
    https://www.youtube.com/channel/UCAi...WB1xCp6uuUo0VA

  12. #1167
    Join Date
    Oct 2015
    Location
    Kiel, Germany
    Posts
    199

    Default Re: Building Arabella (An Atkin Ingrid)

    You're welcome, Steve. It fits neatly in between modelling a 27'' Bob Baker schooner and drawing up scantlings for it.
    Hah, yeah.Quenching welds. I expected the youtube crowd to have a field day with that one. Sorry, dude. How many have told you to please wear solid active air filter masks for welding the bronze?

    With regards to the engine bearer floors... Thats a bit trickier. Tackling them last sounds like a good plan. Also more involved to modell, since by rights I think I'd need to modell the actual shape of the hull there, at least roughly. Have you figured out what engine you're going to use? And at the same shaft angle as drawn?

  13. #1168
    Join Date
    Apr 1999
    Location
    Now, there's a long story...
    Posts
    1,579

    Default Re: Building Arabella (An Atkin Ingrid)

    I‘m asking out of complete ignorance:

    You mention that the floors will create a slight „dam“ that you can mitigate by either beveling the base, or by building it up so you can cut it out.

    Why not simply inset it into the wood, so it lies flush? I understand you may not want to reduce the keel scantling, but wouldn‘t bolting bronze in its place make up for any weakening? It‘s only a half inch, and you could bed the floors in tar.

    Am I completely lost on this one?
    Heute ist so ein schöne Tag...

  14. #1169
    Join Date
    Mar 2015
    Location
    Granby, Massachusetts
    Posts
    361

    Default Re: Building Arabella (An Atkin Ingrid)

    The fruits of our labor yesterday and today.
    Now that we have one in the bag and the minor kinks worked out we can get to making the rest of the midship ones production style. Should be able to crank out a couple a day.

    The welds ain't the prettiest but we did a lot of testing on some offcuts and with 1 pass on 1 side we had to beat them with a big hammer and cold chisel to break the welds. I would be flabbergasted if the welds let go on the finished floors.


    ACORN TO ARABELLA
    For additional info on this project:

    www.acorntoarabella.com
    https://www.youtube.com/channel/UCAi...WB1xCp6uuUo0VA

  15. #1170
    Join Date
    Mar 2015
    Location
    Granby, Massachusetts
    Posts
    361

    Default Re: Building Arabella (An Atkin Ingrid)

    After welding. The splatter on the keel looks bad but it's totally superficial, a light sand and it will all be gone. It'd just from doing the tacks in place, we need to get a couple welding blankets or some hunks of leather to put on the keel for future floors.

    They were tacked in place then moved to the welding table for the actual welding.








    ACORN TO ARABELLA
    For additional info on this project:

    www.acorntoarabella.com
    https://www.youtube.com/channel/UCAi...WB1xCp6uuUo0VA

  16. #1171
    Join Date
    May 2016
    Location
    Ottawa, Canada
    Posts
    227

    Default Re: Building Arabella (An Atkin Ingrid)

    Hey,

    From a welding sort of person... did you do some test coupons to bend test / cut a cross section and check for defects ? It's worth the effort to make sure the welding setup is good.

    Cheers,
    MArk

  17. #1172
    Join Date
    Feb 2002
    Location
    Shubenacadie NS
    Posts
    4,431

    Default Re: Building Arabella (An Atkin Ingrid)

    Looks awesome guys. Looking forward to seeing more of your work.

    Moritzshwarzer,
    Would a better solution be to cast them given all the issues that can come up with improper welding technique? Lin and Larry cast theirs. The shape of the hull allowed Larry to make a handful of patterns and then grind out the outside face so it mated to the hull. A few patterns provided enough variation in shape that he was able to cast all the floors he needed and modify the ones that were pretty close so they were spot on. No welding required. Is cast not as strong as welded? I know little about metal so figure I'd ask. I'm following this very closely as I intend on building at some point and will benefit from the information provided.
    Thanks,
    Daniel
    If one advances confidently in the direction of his dreams, and endeavors to live the life which he has imagined, he will meet with a success unexpected in common hours.
    -Henry David Thoreau-

  18. #1173
    Join Date
    Jul 2010
    Location
    northeast Ohio
    Posts
    1,770

    Default Re: Building Arabella (An Atkin Ingrid)

    I like the idea of your floors having this upper cross piece - in bronze or wood though-bolted to a tab welded on.


    You may have already said elsewhere...but what will you do in between the split frames? Bedding compound or something else?

  19. #1174
    Join Date
    Mar 2015
    Location
    Granby, Massachusetts
    Posts
    361

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by Mark0 View Post
    Hey,

    From a welding sort of person... did you do some test coupons to bend test / cut a cross section and check for defects ? It's worth the effort to make sure the welding setup is good.

    Cheers,
    MArk
    Absolutely!
    Much destruction happened before the first structural weld. Bent, broke, cut... Took a few runs to get the settings dialed and the gas right and once that was set the welds were bomber every time. A light root pass took a while with a sledge hammer and cold chisel to split. Once that happened every time, several times in a row we went for the real thing.
    Initially we got some bubbles in the weld and the penetration was not amazing, just took tweaking the gas, feed and amps a bit. Having someone tweak the feed rate while I laid beads helped us a lot, folks who said "frying bacon" was what we wanted to hear were about right.
    ACORN TO ARABELLA
    For additional info on this project:

    www.acorntoarabella.com
    https://www.youtube.com/channel/UCAi...WB1xCp6uuUo0VA

  20. #1175
    Join Date
    May 2000
    Location
    Conway, MA
    Posts
    5,502

    Default Re: Building Arabella (An Atkin Ingrid)

    Great!

  21. #1176
    Join Date
    Sep 2014
    Location
    Lexington, MA
    Posts
    269

    Default Re: Building Arabella (An Atkin Ingrid)

    Wow! Looks like you laid the whole limber hole discussion to rest.

    The wings look thoroughly flush with the ribs.

    It feels like a lot of visible progress is about to be made.

    Kenny
    Almost everything about boats involves so much more time and money than one anticipates that rational and accurate planning will deter even starting. Ian McColgin

  22. #1177
    Join Date
    Sep 2010
    Location
    Melbourne mostly, Australia
    Posts
    2,522

    Default Re: Building Arabella (An Atkin Ingrid)

    You’ve probably already thought of this but...Would it not be stronger with bolt tabs on the other side where the triangle bits are? So they get welded on two sides in effect bracing them. Bit fiddly doing up bolts but you’ll only need to do it once.

  23. #1178
    Join Date
    Mar 2015
    Location
    Granby, Massachusetts
    Posts
    361

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by andrewpatrol View Post
    You’ve probably already thought of this but...Would it not be stronger with bolt tabs on the other side where the triangle bits are? So they get welded on two sides in effect bracing them. Bit fiddly doing up bolts but you’ll only need to do it once.

    Folks on Facebook and Instagram are asking the same thing. The reason we put them on the other side is because of the pockets for the frames and the screws holding the frames in. If we put them between the frames we would need to put them inboard far enough to miss the screws and the frame pockets. This way they can be out by the edge where the load is and no worries about hitting anything when we put in the hanger bolts.

    On the stem/stern the plate will be a bit different and there will be a bolt on either side of the floor in the centerline since there is not enough room to put them next to each other.
    ACORN TO ARABELLA
    For additional info on this project:

    www.acorntoarabella.com
    https://www.youtube.com/channel/UCAi...WB1xCp6uuUo0VA

  24. #1179
    Join Date
    Oct 2015
    Location
    Kiel, Germany
    Posts
    199

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by sdenette View Post
    The fruits of our labor yesterday and today.
    I like it. Structurally, I'd be happier with a one piece keel flange and limbers in the corners, but either limber location is a compromise. Now, a last nitpick concerning weld prep:

    A V-seam below 40° opening is not ideal, you run the risk of producing voids, or having to crank the ampage too much to fill all the way in, which leads to burn in on the edges of the weld. Ugly Dimples.

    And maybe throw a welding prodection blanket on there before you tack. Not essential, but for neatness' sake.


    Quote Originally Posted by sdenette View Post
    Having someone tweak the feed rate while I laid beads helped us a lot, folks who said "frying bacon" was what we wanted to hear were about right.
    That's the way to do it. You can absolutely hear when a welder is dialed in right. A nice steady sizzle is what want.
    Last edited by MoritzSchwarzer; 03-17-2019 at 09:31 AM.

  25. #1180
    Join Date
    Oct 2015
    Location
    Kiel, Germany
    Posts
    199

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by Sailor View Post
    Would a better solution be to cast them given all the issues that can come up with improper welding technique? Lin and Larry cast theirs. The shape of the hull allowed Larry to make a handful of patterns and then grind out the outside face so it mated to the hull. A few patterns provided enough variation in shape that he was able to cast all the floors he needed and modify the ones that were pretty close so they were spot on. No welding required. Is cast not as strong as welded? I know little about metal so figure I'd ask. I'm following this very closely as I intend on building at some point and will benefit from the information provided.
    Thanks,
    Daniel
    In short: no. This is normal engineering stuff, ironing out construction and manufacturing details. Casting comes with it's own set of particulars and design constraints.

    Material science wise, I'm a bit out of my depth on bronze. Given that it's an alloy primarily used for casting, I would say cast and welded are equal.The main difference is designing for castability. Taliesin is built with sawn frames to which the floors are bolted longitudinally. The floor is one flat part across with one flange to bolt into the keel. Quite a simple part, and with few critical tolerances. Because as you said, since the arms of the floor run past the frame, it does allow for the use of one casting for multiple stations, with some trimming against the planking. And the angle of the keel flange to the main plate can be adjusted with a bit of grinding, since there's enough material on the opposite side because of the draft required for the part to cast properly.

    Now, since Arabella's frames are split steam-bent, it makes sense to run the arms of the floor on top of the frame and use the plank fasteners to also attach the frame to the floor. But that makes the geometry a lot more complicated. You would have to provide a pattern for each floor, and the part itself would be a lot more involved to mold and cast. Plus with shrinkage, the angles of the arms might need a few trials to dial them in. Not talking about cost or logistics. Which is why for this build, welded is the way to go.

    Now for steel, welded would be better material-wise. Rolled mild steel has better engineering numbers than cast iron, and steel casting requires higher temperatures, heat treatment afterwards and shrinks twice as much.

  26. #1181
    Join Date
    Sep 2010
    Location
    Melbourne mostly, Australia
    Posts
    2,522

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by sdenette View Post
    Folks on Facebook and Instagram are asking the same thing. The reason we put them on the other side is because of the pockets for the frames and the screws holding the frames in. If we put them between the frames we would need to put them inboard far enough to miss the screws and the frame pockets. This way they can be out by the edge where the load is and no worries about hitting anything when we put in the hanger bolts.

    On the stem/stern the plate will be a bit different and there will be a bolt on either side of the floor in the centerline since there is not enough room to put them next to each other.
    Of course......Doh

  27. #1182
    Join Date
    Mar 2015
    Location
    Granby, Massachusetts
    Posts
    361

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by MoritzSchwarzer View Post
    I like it. Structurally, I'd be happier with a one piece keel flange and limbers in the corners, but either limber location is a compromise. Now, a last nitpick concerning weld prep:

    A V-seam below 40° opening is not ideal, you run the risk of producing voids, or having to crank the ampage too much to fill all the way in, which leads to burn in on the edges of the weld. Ugly Dimples.

    And maybe throw a welding prodection blanket on there before you tack. Not essential, but for neatness' sake.



    That's the way to do it. You can absolutely hear when a welder is dialed in right. A nice steady sizzle is what want.


    Hahaha!
    I was going to pull the wings and nip the corners like you described but we have a German guy helping a bit who
    is here in the U.S. until August doing some more schooling and
    was a professional metal worker there for a number of years, he told me not to bother with those that the angle was enough to get in there. When on the bench with the V facing upward it was easy to get the puddle back there but if it was any tighter I would absolutely open it up a bit.

    I have some old hunks of leather that we can throw down on the keel timber, the splatter from the bronze is much hotter than from steel! The marks on the keel are not deep, they will easily sand out but I don't really feel like sanding the whole centerline. lol


    So far welding the bronze had been pretty easy, the settings make the biggest difference, get those dialed and you are good to go.

    We welded the one floor just inside the garage with the doors open because it was quite windy outside and both Alix and I did not feel great afterwards. I'm not super worried about the one floor doing me any real harm but 37 more of them plus knees, chainplates… just might. Hitting pause on the bronze until we can get some good PPE. Thankfully a chap from Lincoln Electric saw our post about the getting the welder and said if we needed anything to let him know. I emailed yesterday asking if they would hook us up with a positive air pressure helmet, he is going to see what they have in the shop tomorrow but it's looking like they might have one they would be willing to give us. Fingers crossed!!! Those buggers are not cheap and after buying the bronze and welder we are pretty tapped for cash. It would make the rest of the bronze work worry free and we could also use it when we strip all the mahogany of it's finish. A drum sander attached to the festool and the helmet would make cleaning up Vick's lumber worry free if not a bit odd looking.



    For cast verse welded

    We actually came very close to casting them and even went so far as to make a couple patterns. Figuring out the shape and twist of the frames was a real big challenge and the best route seemed to be to cast them oversize and CNC them down to spec. It was going to be a massive time consuming process and if they did not fit right we would be up the creek without a paddle.
    I did not consider welding them at first because there is just about no info out there about welding thick bronze, almost everything I could find was about brazing and anything addressing bronze was super vague. It seemed like casting was the only way to go. Then we met a bronze sculptor/ boat builder and he convinced us welding the floors was very possible.
    After talking to a lot of people and doing hours of research I have come to the conclusion that 1- very very very few people weld thick bronze. 2- those that do are inevitably experienced welders and the bronze is a cake walk for them so no need to write or post on the web about it.
    The bronze comes in so many sizes and shapes, cuts easily, can be bent/worked cold (within reason) and works very easily when heated, taps and threads nicely, so far it has been a dream to work with. I think for us welding them was the way to go and now that we know we can weld it and we have the parts bender, big press and a torch we can make just about anything. The wire is not cheap, nor is the machine (at least if you need to weld 1/2") but I think it will absolutely be worth it and gives us a lot of options. For sawn frames it would be even easier! Larry could have welded his floors in the time it took him to make the patterns.

    Only issue so far is dealing with the fumes but that is a very surmountable obstacle.
    ACORN TO ARABELLA
    For additional info on this project:

    www.acorntoarabella.com
    https://www.youtube.com/channel/UCAi...WB1xCp6uuUo0VA

  28. #1183
    Join Date
    Feb 2013
    Location
    Florida
    Posts
    126

    Default Re: Building Arabella (An Atkin Ingrid)

    For fumes you could also make a hood cabinet. Welding surface could be a galvanized trash bin turned over with bricks on it

  29. #1184
    Join Date
    Jan 2011
    Location
    Norwalk CT
    Posts
    1,070

    Default Re: Building Arabella (An Atkin Ingrid)

    Im f@&$ing impressed....

  30. #1185
    Join Date
    Apr 2015
    Location
    San Francisco, CA
    Posts
    253

    Default Re: Building Arabella (An Atkin Ingrid)

    This is fascinating. Can't wait to see how they all turn out.

  31. #1186
    Join Date
    Jan 2009
    Location
    se pa (Bristol PA)
    Posts
    3,192

    Default

    I'm sure they are but, I'll still ask, is each floor slightly different in size than the one next to it?

    Sent from my LG-M430 using Tapatalk
    Denise, Bristol PA, Oday30, Anchor Yacht Club, On tidal Delaware River. my current project; http://forum.woodenboat.com/showthre...0-Ducker-Resto

  32. #1187
    Join Date
    Mar 2015
    Location
    Granby, Massachusetts
    Posts
    361

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by DeniseO30 View Post
    I'm sure they are but, I'll still ask, is each floor slightly different in size than the one next to it?

    Sent from my LG-M430 using Tapatalk

    O yeah, every one is a different shape. We can use the same baseplate for many of them and the wings get cut to only a couple different lengths and the rounding at the tip is the same. The curve and twist of the wings as well as the vertical plate will all be different. Thankfully it's easy to pick up patterns and matching the curve/ twist is easier than one might think, just have to go slow and compare to the pattern often.
    ACORN TO ARABELLA
    For additional info on this project:

    www.acorntoarabella.com
    https://www.youtube.com/channel/UCAi...WB1xCp6uuUo0VA

  33. #1188
    Join Date
    Aug 2017
    Location
    Melb, Vic, Aus
    Posts
    438

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by MoritzSchwarzer View Post
    At the risk of shouting into the void.
    I have found your posts to be a fantastic contribution to this thread Moritz!
    No voids here. Thanks for the time you put into it.

  34. #1189
    Join Date
    Jan 2009
    Location
    se pa (Bristol PA)
    Posts
    3,192

    Default

    I never knew bronze could be welded I thought it was only for steel
    Denise, Bristol PA, Oday30, Anchor Yacht Club, On tidal Delaware River. my current project; http://forum.woodenboat.com/showthre...0-Ducker-Resto

  35. #1190
    Join Date
    Jun 2010
    Location
    PNW, an island west of Seattle
    Posts
    1,909

    Default Re: Building Arabella (An Atkin Ingrid)

    Quote Originally Posted by DeniseO30 View Post
    I never knew bronze could be welded I thought it was only for steel

    Artists/sculptors have been welding bronze for a long time.

    Jeff

Posting Permissions

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