Building RYD-16.9 Rocky - Hull 21

Discussion in 'Boatbuilding' started by John Theunissen, Aug 5, 2017.

  1. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 467, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Many design simple combings and other things with easy to make bits, but I've always done rounded combings and stuff, simply because once you learn how to bend stuff, there's no need to live with boring. I've bent a lot of stuff over the years and developed plenty of techniques and preferences too. Sometimes you break something, but it happens to the best of us. It's the heat that really does the deed. Moisture just keeps the cellular structure from collapsing during the bend. My two go to tools are a standard heat gun and the steamer any more. I do have two different length traditional steamers, fed by a metal 5 gallon gas can over a campfire kettle cooker, but they don't get used very often any more.

    On your forward sections, steam the concave side first and if it's still fighting you, steam the other side too. I'll bet just steaming the concave side will be enough.
     
  2. John Theunissen
    Joined: Aug 2017
    Posts: 46
    Likes: 4, Points: 8
    Location: Melbourne, Australia

    John Theunissen Junior Member

    Greetings,
    Slow progress due to other commitments. Last weekend my cousin and I had a go at applying a sanding sealer coat on the hull using 6” plastic straight line scrapers. We mixed in some fumed silica and that worked quite well. Took us a fair bit longer than expected so only progressed about 2/3 along the length of the hull. It’s one of those times where you wish you had acquired some plastering skills (as you can see from the imperfections (my side) after sanding back the high points on the first image). I had another go at filling in the “troughs” today and it looks much better (second image) but I guess the result will only be evident when I sand it back with the long board. Next time I’ll perhaps try the recommended technique of using a notched trowel for the first layer.

    Paul, I’ve acquired a steamer as you suggested but haven’t tried it out yet - perhaps next weekend, but it’s becoming really busy at this time of the year. It’s all about priorities, and the boatbuilding tends to take a backseat when there other things that need doing.

    Regards, John T.
     

    Attached Files:

  3. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 467, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    What are you using as a "sanding sealer"? What I use is a neat coating of epoxy, to lock down what's there and seal the surface. This assumes she's reasonably fair first (you've already focused on seams and lap joints, etc.). If not, I long board the whole hull to identify obvious highs and lows. I knock down the highs and fill the lows (fairing compound like QuikFair) then long board again to see how good things got filled. Once the surface is close, then a building/blocking primer is applied, unless areas around high spots wore through the sealing coat (straight epoxy). If this is the case I'll touch-up those areas, or consider another whole boat sealing coat.

    With this prep done, the whole hull is "dusted" with primer and "blocked" with a long board and moderate paper, again to further identify highs and lows, which should be pretty sallow at this point. Usually, it just requires a few more rounds of filling with bulking primer, typically only in areas that need it. Once this is completed it should be pretty darn fair and I apply a final coat of primer as a continuous base for a top coat.

    FWIW, fairing and smoothing operations are not pleasant, no zen, just elbow pain and tedious motions, until it's right. Most eventually toss up their hands and say close enough, then wish they hadn't given up after the shiny stuff goes on. To be honest, it's tough for a novice to get a fair and smooth hull on their first few projects.

    I don't like the notched trowel method, because it's very difficult to sand down, inside the the notches, which has me wondering how good a bond you get, with unsanded fairing compound, which tends to be shiny when not sanded. Now this technique does help identify highs and lows well, but you apply a gallon of filler and sand off 80%, which is time and materials waste that I also don't like too. I haven't tested the notched bond thing yet, but it might be worth it, just to see where it'll fail and/or to change my "models" of the method.
     
  4. John Theunissen
    Joined: Aug 2017
    Posts: 46
    Likes: 4, Points: 8
    Location: Melbourne, Australia

    John Theunissen Junior Member

    Hi Paul,
    Thanks for your advice. I used the wrong terminology when I mentioned “sanding sealer” - what a am doing is applying the sanding compound to then fair the hull. I did use a longboard for most of the initial sanding (before applying the “fix-up” coat) but in the areas near the bow I used a smaller sanding block because of the curves. For the sanding compound I’m using the Botecote epoxy mixed with their sanding filler and some fumed silica.

    I tend to agree with you on the notched trowel approach so will not be using that. Regarding the perfectly faired finish, there’s no chance of me persevering to that extent, but I would like it to look reasonable.
     
  5. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 467, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    In stead of a block, use a smaller longboard, maybe one with a slightly more flexible board. 1/8" (3 mm) acrylic sheet or plywood makes a pretty flexible board, that you can attach some blocks to to hold the paper. Fairing is all about technique and if you do it enough, you'll get pretty good at it, depending how long your elbows hold up.
     
  6. John Theunissen
    Joined: Aug 2017
    Posts: 46
    Likes: 4, Points: 8
    Location: Melbourne, Australia

    John Theunissen Junior Member

    D2DE2E1A-681B-4ECF-A305-6F69A2B477E4.jpeg Fairing the hull is hard work! The sanding is going to take ages....time to inspan my sons during the holiday break if they are willing.
     
  7. John Theunissen
    Joined: Aug 2017
    Posts: 46
    Likes: 4, Points: 8
    Location: Melbourne, Australia

    John Theunissen Junior Member

    Greetings Everyone,
    Well, three months have past since my last post - during which we had my daughter’s wedding and an extended trip to South Africa, with the result that I was only able to rejoin boat building activities in February.

    “Fairing” certainly has to be one of those activities that requires dogged perseverance. I started off determined to use the homemade longboards almost exclusively - well that didn’t last very long. I found that a combination of an electric orbital sander and the longboard was more efficient...and then I discovered that a pneumatic sanding pad is an even more effective tool, and less prone to “bite”. My plastering skills are woeful, so my progress has generally been two steps forward and one step back. Anyway, I think the end of this activity is in sight, one more weekend ought to do it. Here are a couple of pictures - doesn’t look much different from the previous ones but I can guarantee there is a lot of hard work in -between. The different colours on the hull are because I ran out of the Bote Cote sanding filler compound and then used a microballoon mix which is whiter in colour.
    Next time around I’m going to invest in one of those pneumatic tools with a flexible spring steel “longboard” type of construction.
    Regards, John T. 4216E18D-793A-40B8-BB4D-E72940FD85BA.jpeg 1443975D-402C-4D40-8390-1DEBF6F7C152.jpeg
     
    Angélique likes this.
  8. TANSL
    Joined: Sep 2011
    Posts: 5,349
    Likes: 136, Points: 73, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    It is convenient to do a lot more "fairing" in the plans to avoid doing so much "fairing" in situ. IMO
     
    Last edited: Mar 12, 2018
  9. Angélique
    Joined: Feb 2009
    Posts: 2,382
    Likes: 196, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Once again you show yourself as a very bad reader, and as the master of uninformed opinions by ignorance.

    John clearly indicated that he's in a steep learning curve* about this process, which isn't due to the plans, nevertheless John is doing well.

    * Steeply going up in boatbuilding knowledge, skills and tooling, that is.

    Congrats John, it's looking good, and thanks for sharing about the learning curve, from which info I'm learning too, but without having to do the hard work myself. :)
     
    Last edited: Mar 12, 2018
  10. John Theunissen
    Joined: Aug 2017
    Posts: 46
    Likes: 4, Points: 8
    Location: Melbourne, Australia

    John Theunissen Junior Member

    Hello,
    Thanks Angelique for your encouragement, it is much appreciated!
    I am intrigued to understand how one can avoid “fairing” in the plans - Rocky is a taped seam construction and unless one rebates the area where the seams lie, then there will always be fairing required.
    In my case, almost all of the fairing effort is due to my poor construction technique - I perhaps didn’t have a couple of the molds exactly right and when torturing the plywood to make the shape in the bow section, I introduced some irregularities between the port and starboard sides as well as a pinch point where I had used a tie-down strap.
    Anyway, its all part of the enjoyment and boatbuilding is a very rewarding pastime.
    Regards, John T.
     
  11. TANSL
    Joined: Sep 2011
    Posts: 5,349
    Likes: 136, Points: 73, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    @John Theunissen, I have never questioned your good doing. I am not who to do it. I was just thinking that sometimes the plans are not smooth enough. The body lines plan for calculating naval architecture does not need to be as detailed as the body lines plan for construction. In the shipyards there is usually, there used to be, an expert in charge of making that definitive "fairing" to create building information. And he was a person of great professional category.
    A hull, it is my opinion, should not be fixed more than for the final aesthetic touches.
    Yur way of working, perhaps, has given reasons, I do not know, to need to smooth the hull a little more but I attributed the problem to the drawings because, perhaps, they were not as good as they should be.
     
  12. Angélique
    Joined: Feb 2009
    Posts: 2,382
    Likes: 196, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Right, you don't know.

    Unfortunately you've just proved again it's like I've said before, you're the master of uninformed opinions and suggestions, since you haven't seen the plans.

    Below you can see the opinion of someone who has actually seen the Rocky plans...

    Ken, Rocky #1:
    ‘‘ A week or so ago I received a large tube of plans from Riccelli Yacht Design. Very impressive, just short of 40 pages, many of which are near full blueprint size. Very thorough, very detailed, very well done I must say! ’’

    See also Andrew's line below his Rocky #3 pictures, this is after having seen the plans, and in fact in the process effectively building from them.

    Andrew, Rocky #3:
    ‘‘ How cool is Paul Riccelli? So helpful with amazingly detailed email responses to any of my questions. I highly recommend building one of his designs. ’’

    Note these are all amateur builds, learning the trade while they go, and partly they're so good because of the good plans, and PAR's excellent guidance, the rest comes from their own determination and the build knowledge and skills they already had, which they further develop during construction.
     
    Last edited: Mar 16, 2018
  13. Angélique
    Joined: Feb 2009
    Posts: 2,382
    Likes: 196, Points: 63, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Hi Paul, how you're doing ?

    Long time no see on these forums, not really that long, but meaning for your usual doing, hope all goes well, and hope to see you posting here again soon . . :)

    All the best !
     
    Last edited: Mar 16, 2018
    PAR likes this.
  14. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 467, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    In my assembly guide for this design (like many others) I try to convince folks the value of fairing pre and post sheathing and to get it fairly close, if only to save some effort when working just below the finish coats. Fairing can be a bit of an art form, especially if you get good at it. It's also tedious, time consuming and most eventually end up having their elbows tell them when the project is "fair enough".

    I will state that orbital tools (DA's ROS's), etc.) are for smoothing, much more so than fairing, so you'll make a the job go much slower if using these tools. Inline sanders, now this is a fairing tool, as are hand drawn fairing boards, if a little slower. I've used 1/4 sheet "jitterbug" style of sanders with a piece of 1/8" acrylic sheeting attached as a reasonably well cutting long board, too. I have one I made some years ago with two 1/4 sheet jitterbug sanders attached (one at each end) and it work good, though can be "confusing" on the hands with the weird consolations.

    In the end, I find most try to focus on material removal, rather then the process of fairing. The crosshatch pattern the is key to getting it fair, regardless of how much material you plow though. Once you get goo at it, you'll find you remove a whole lot less material, before getting a uniform crosshatch pattern to appear. Focus on the crosshatch pattern, nothing else. Fill the hollows, knock down the high spots and think a little at a time, instead of getting greedy (like I do sometimes). Honesty, with some time (and elbows cursing at you), you eventually find you can make quick swipes across the surface, see the most obvious defects and go right back and fix them.

    The new pup looks cute too . . .
     

  15. John Theunissen
    Joined: Aug 2017
    Posts: 46
    Likes: 4, Points: 8
    Location: Melbourne, Australia

    John Theunissen Junior Member

    Hi Paul,
    Thanks for your wisdom in this. You are so right to focus on this task, bit-by-bit. One of my work colleagues also suggested to take pictures, even if it is just the section of the hull that you have been working on, to reinforce the fact that one is making progress. The pneumatic sander I was using was the “jitterbug” type, but I didn’t have a longer board attached to it. The tool that I will use next time around is something like the “flexisander” range. I’m nearly done, so hope to finish the fairing this weekend. The hull is not perfect, but then neither am I, so it should be ok.
    My plan after that is to coat the hull with two coats of epoxy and then to paint it before finishing and fitting the keel plank and the skeg (using the modified design drawing that you sent me). What is the best means to “attach” the keel plank to the hull aside from the s/s bolts? I seem to recall from your notes that one shouldn’t epoxy the plank to the hull, rather use a flexible waterproof caulking type of product so that it can be removed if damaged later in life.
    Regards, John T.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.