Designer

Scott, I have never had the patience to wait a month or two to cure the epoxy before painting. I usually put on an epoxy primer before the top coat and have never had a problem with adhesion. Ideally it would be good to post cure the epoxy as it never totally cures at room temperatures. The high tech boats are usually put in an autoclave and post cured for several hours at around 140 deg. The dark color of your epoxyed hull could come close to that temp if left out in the sun for a day. As the strength of the sheathing is not an issue and epoxy paint will adhere to reasonably cured epoxy, the only reason that I can see to wait could be the potential to get some print-thru from the glass when the finished boat sits out in the sun and gets hot enough to post cure the epoxy under the paint causing shrinkage between the weave of the glass. This will be more apparent with colored hulls. For the bottom paint this should not be an issue. If you want to cut down on print thru, you could put the upside down boat outside on a sunny day and let one side bake and turn it around for the other side.

Eric, I was surprised by your post so I checked the inbox and found your e-mail. It had the little arrow showing that I had responded so I checked the sent items and can't find you anywhere. I will get a new e-mail out to you by tonight. My apologies for the lack of response, I have been having some trouble in this area ever since I downloaded the latest Microsoft patch that they said that we must do.

Scott, I wouldn't touch it with a barge pole. I played around with it when it first came out. It did not work as well as other good LPU's, there was very little gloss and it did not seem to hold up very well. My neighbor painted his 29 footer with it, it did not look great when it was finished and after a few years it looked awful. There is a clear coat that can be put over it but the test panels that I made discouraged me from going any further.

Hi Klaus, welcome to the forum. A couple of years ago a friend showed me your web site with the building of your boat, congratulations on a fine job. You make some good points and have some good experience to back it up, however I stand by my method. You can make the bow as strong as you like and if your painter is strong enough it is as reliable as the mechanical method. During my 15 years of voyaging I had plenty of opportunity to test it and it never failed. The most sensible thing to do is to carry the dinghy on board when offshore but for convenience we often pushed our luck. I found that if it got too rough I would just heave too and bring the dinghy over the lee side, but not always before it was put through some wild gyrations.

All of the experts say to put the bow eye low, but as Garry said, I don't see that it makes a lot of difference. I have seen bow eyes take a nick out of nice shiny topsides and did not want that to happen to me. I decided to just use a reinforced hole in the bow through which the painter passed, with a figure of eight stopper knot. It has worked perfectly for me for many years, it is cheap, reliable and it cannot leak into my floatation compartment. After about five years of full time use I noticed that the line was wearing at the hole, so I just cut 6" off and tied a new stopper knot. Using the hole through bow method requires that it be above the floatation, but I have not seen any problems while towing.

Two cuts with a hand saw and chisel the center out. Yes we do use hand tools.

Your problem might have been having the corners too sharp. 10 oz. glass does not like to be bent around tighter than a 1/4" radius, preferably larger. It will lift on one side or the other or both. Now that you have the problem, you can cut out the bubble, sand the glass around the bubble to a nice taper and glass in a patch and it will be just fine. It is also a good idea to monitor the glass till the epoxy kicks to avoid these surprises. Michel, there should have been no need to cut darts in the tape as the loose weave is specially designed to conform to compound curves. Before applying resin to the glass on outside curves you can rub your hands along the glass working it into shape, you will be surprised at how it will conform to compound shapes. If you are in the middle of wetting out the glass and feel that you need to cut a dart, go to the end of the tape and pull gently on the outside or middle fibers depending on which way it has to conform and you will see the problem area disappear. If the bubbles are small like yours it is fine to cut them out and fill as you did.

When I designed the connecting system for my nesting dinghys, I wanted to keep it simple, reliable, easy to build and inexpensive. It is very easy to make a complicated design, but hard to meet the above criteria. I think I came close. I am enjoying this discussion and the more we debate, the more we can learn. I think that most of the systems discussed will work if properly executed. I use a center bolt at the keel because I believe that there is more force in tension at times than your force diagram suggests. You are right that one of the nuts could come undone. If the wingnuts are tightened finger tight, the compression of the rubber grommets will put a lot of friction on the threads making that unlikely, but it could happen. One way to prevent the nuts from unwinding is to make one legged wingnuts and gravity will prevent them from unwinding. If one believes that the bolts could unwind through the nuts with all the friction of passing through the two bulkheads, then one could weld a leg off one side of the bolt head and again, use gravity.

Steve, That problem with the bulkhead was only on the S11N and it came about when I upgraded that plan recently. You are building a S10N, and I checked the plan before writing this, your plan measurements are correct. If your keel line is not completely fair, it may be because you did not draw the center seam completely tight, or your CL measurements/cutting were slightly off. The trouble with the centerline is that any errors are multiplied X 2, for instance if one of your measurements was 1/8" off and matched the other bottom to the first bottom then your CL would be off by 1/4". There is an old saying in the boatbuilding business, "let the batten be the boss". When you have wired up the boat, if there are any hollows or bumps they should be tweaked/adjusted out. Such as: if it dishes at the bulkhead, ease it away until it is sweet; if there is a bump just behind the bulkhead let the wires go and run a jigsaw up and down the seam to ease it out a bit and then re-tie it. This is, of course, academic to you at this point, but it may be helpful to others who have not yet reached your point. You asked how it will affect your boat's performance. Probably not much. We've seen boats come out all sorts of ways - (within reason) and they still seem to perform fine. I wouldn't worry.

You don't really need to glass the inside center seam. I do it because it is the easiest way to hold the bottom halves together to transition from the ties to the keel batten installed. If the center seam was just filleted it would most likely crack the fillet when you apply enough force to spring the keel batten into place.

Rob, Here is how we do our clew. It is just webbing passed through the clew grommet and sewn on the back side. The middle of the webbing is folded once or twice depending on thichness of webbing and sewn and then passed through the grommet forming an eye and sewn to the sail. With the end of the sprit shaped like an old fashioned tent pole it is just a simple matter to poke the pin end of the sprit into the webbing eye. It has just enough movement and flexibility to allow the sail to align itself to what ever direction is required with out being loose. Keep up the sailing stories. [attachment over 4 years old deleted by admin]

Alexander, Sorry to hear about your accident. I will answer you here instead of by e-mail so that it might help someone else. If only the front 3" broke off the bottom forward you can put it back on with glass tape on both sides and let it cure. I know that you decided not to use the butterfly method because of limited space, but I can't emphasise enough, how important it is to go back to the butterfly method. The S12 is the easiest of the spindrifts to fold up. We currently wire the 2 halves all the way around the centerline to the sheer with the insides face to face and just open it up like a book. The reason that it works so well is that the maximum load is, as you found out, is at chine forward and the extra length of the sides gives you lots of leverage and you don't even notice the strain at the chine bow area. As a bonus the butterfly method gives you a nicer looking bow, as it is hard to avoid a bump or unfair bow profile putting it together your way. It is so easy to fair the bow area to a sweet curve after you join the bottom to the sides and before folding. As frustrating as you feel right now (believe me I have been there many times before) just piece the bottom back together and join the sides to the bottom forward and you will have a nice hull in no time. If the wires did not pull too much wood away when it blew, you may be able to drill new holes and the epoxy will fix it when you fillet and tape. I don't know how limited your tight space is but it does not take up that much extra space to butterfly it.

Here is a picture of Anders Holstrom's CS20 #48 "Spray". He reads the forum and if you will give him a little encouragement I am sure that he will come on. He has an online album at http://foto.spray.se The directions are in swedish but after a bit of fumbling around I got it to work. Imagine sailing that boat around those fiords in summer. Maybe we could arrange a swap with these boats in all these wonderful places? Trade a week of sailing his boat over there for him sailing our boat for a week over here. [attachment over 4 years old deleted by admin]

The stability curve is for the shallow draft version built to plan. It would be misleading to give the most optimistic version. Naturally it would improve the range of stability if you deepened the draft using the same ballast lowered.

Bill finished the boat by christmas before his annual trip to Florida. The boat is just waiting for me to rig and test sail her. I have been using the weather as an excuse. I hope to be sailing her within a month. She turned out very nice and I'm really excited about the design. [attachment over 4 years old deleted by admin]

Styge, I would prefer that you stick with 6061 T6 for the lower section, or go up to the next gauge .125". The boats with the 1/8" wall thickness sure have nice sail shape. Your boat will have two strikes against it, it is heavier and you are going to put more sail on it.

Tim, I just looked it up for you and it is a bit convoluted. I positioned the center thwart at 115 3/8" aft of the bow measured horizontally. The back of the trunk starts 1/2" forward of the aft end of the center thwart which is 11 1/4". Like I said convoluted. The obvious thing would be to give you a distance back from the forward bulkhead, which I was reluctant use as I was concerned that it might not be put in accurately and throw everything off. I expect to be folding out a CS17 next week and I will spend some time on the plan and make it clearer. I hope this helps.

The fire hose that we use for fenders is 1 1/2". It is 2 layers of 2 ply nylon and neoprene. When the fire hose is worn out you can usually get it for nothing. The hose is flat and you can split it in two by cutting it down both edges. Throw the outside cover away because it is dirty and worn, inside it is clean and pristine. Because you cut it in two you now have two fenders. The new generation of fire hose is plastic (I think it is PVC) and is usually coloured, ours are yellow, they are much lighter and easier to use than the older white hose. We have not worn any out yet so I have not had the opportunity to open them up to see if they will work as fenders. There are two pictures, one with the commercial $5. 00 + per foot fender which was glued in place using Sika polyurethane and the other is fire hose nailed top and bottom with bronze ring nails. The gunwales under the fire hose were made from pressure treated pine to prevent them from rotting from water ingress around the nails. Both fenders work very well, the commercial one being heavier. If one wants to preserve the varnished gunwales as has been mentioned earlier, then the rope fender will look very shippy but it will not fender as well. [attachment over 4 years old deleted by admin]

A couple of weeks ago while visiting Heritage Boatworks, where they are building my sport fisherman, they were planing 8' long scarfs in 1/2" ply in about 2 - 3 minutes using the John Henry scarfing jig. The quality was good and they were well satisfied with it. You would need to do a lot of scarfing to justify the cost though.

Greg, No it is not. Yes they are 4' wide scarfs. Gary, With the loose part of the scarf removed and filled and a layer of tape over the joint it will be just fine. You may have noted that I said to use construction grade plastic, thin plastics like Saran Wrap have an incredible ability to get sucked into the glue joints so should be avoided at all cost.

When I need to scarf, I stack up my sheets and use an electric plane to remove the bulk of the wood and then fine tune it with a hand plane. In my boatbuilding class I encourage my students to hand plane the lot. The first lesson is sharpening and tuning the plane. By the time they have planed all their scarfs they have developed proficiency with the plane. If one is going to do much boatbuilding you better know how to use a plane. There is no tool that can handle all the bevels and adjustments and fitting of the various parts on a boat as accurately and quickly as a plane or spokeshave. Like Tom, I have sandwiched the scarfs between 1 x 6's screwed together with very good success. The jig in the picture is the one that we use in the class. It has clamped hundreds of scarfs by now. It consists of a 4 x 6 on the under side, a 2 x 6 on top of the ply, on top of that is a 4 x 6 sitting on 2 x 2 spacers at each end. The whole lot is clamped together with 4 pipe clamps and 3 pairs of wedges are driven in tight from opposite sides. There is construction grade plastic release used between and outside of each scarf. We always use a small brad at each end of each scarf to keep the alignment as the a glue joint becomes very slippery when lubricated with epoxy. All that pressure might seem excessive but you need to overcome resistance to force all of the pieces to be straight and true and get adequate pressure in the middle of the sheet. [attachment over 4 years old deleted by admin]

When installing the gunwales it is necessary to take advantage of leverage when you bend by starting with the hardest bend and bending toward the softer bend or straighter area. Since the area of maximum bend is at the bow, you should clamp your gunwales at the bow and bend them towards the stern. One mistake sometimes made is to try to fit the guwales tight/parallel to the boat when you attach at the bow. Just clamp them at the bow and let them angle out where they will. Also, I like to add a screw through the gunwale into the bow transom stiffener in ADDITION to the clamp. This allows you to get the gunwale exactly back in the same position for your glueing as for the dry run. It is necessary to to bend both gunwales at the same time. Now you can use the leverage and bring both gunwales together at the stern. You might need a little help if the gunwales are wider than your arms can reach. It's good to have help when installing the gunwales. The way to do it is. Attaching the bow and having one person hold the transom ends (which you left long of course for this purpose). As the person at the transom pulls in the assistant clamps each side as the gunwales touch along from bow to stern. As this is happening you are forcing the gunwale to follow the sheer. Once you have done this as a dry run, you do the same thing with the epoxy. There is a lot of curvature in the mini because it is a curvaceous small boat, so there is a fair amount of bending in the gunwales. The 3/4" X 1 1/2" is a little larger than necessary but it is a stock size. If you have clear straight grained stock you can rip it down to to 3/4" X 1 1/4". As for laminating, you should be able to get around in 1 piece. There is about 1 5/16" edge bend which is easily attainable in this size stock and length when done as described above. A last suggestion - I like to let the ends of the gunwale stand up about 3/16" above the sheer in this size boat . It gives the gunwales a lighter visual feeling without any loss of strength. While I agree, the rope fendering looks more "shippy", it still leaves the corners a bit exposed and able to bite the mother ship. The firehose fendering covers it top, edges and bottom, so no matter how it hits the boat, the motherboat is protected (and the mini too!). The fire hose does not use foam under it like the commercial stuff. It is stiff enough to have the right amount of cushioning without the foam.

The "code" that you are referring to is the ABYC (American Boat and Yacht Council). It is a the basis for the safety standards for most of the world many countries adopted it in whole, such as Australia and I think Canada and in the EU, the ISO standards were plagiarized from it! We became members 20 years ago. Their standards are very sensible and are adopted after working with the USCG. NFPA, ASTM, UL, USGregs, among other organizations, and of course members of the industry etc...They are constantly updating and revising as new materials and techniques are introduced. The book of standards is large and heavy and you get updates several times a year. While the standards are voluntary in this country, the insurance industry has adopted the ABYC as their standard, so if a boat does not meet the ABYC it may not be able to get insurance. We have been surveying boats for 20 years to this standard. It is probably not worth the money for an individual amateur small boat builder to join the ABYC as it is quite expensive and most of the standards are outside the scope of the needs of the home builder. If you are building a cruising boat you SHOULD join for at least one year and get the book of standards. However the ABYC does offer an electrical section only made for the professional marine electrician, individual builder, or boat owner who wants to do his own work. I will synopsize part of what the standard concerning solder says: 8.15.15: / 9.17.12.8...joining...must be able to withstand a tensile force equal to the value shown in .... then in 8.15.19: Solder shall not be the sole means of mechanical connection in any circuit.... The main problem with solder is that it creates a rigid point and in a boat that is not a good thing. I've seen vibration do a lot of negative things to both electrical and plumbing systems on a boat. Just to quickly touch on some of the other issues that were raised - yes there is a marine wire. No it is not just expensive house wiring, it is really different and much better. It is tin coated and has heavier waterproof insulation and yet maintains flexibility. Yes there are standards for the color coding on a boat and no they are not the same as for a house. RV etc... I think marine wiring is worth every cent and would never use anything else. While here, let me just make a comment or two based on my years of observation about boat wiring. DO NOT ever use wire nuts. Keep your AC and DC sides wired correctly and separate. Never use the incorrect outlets for AC/DC. Electrical parts, even marine are relatively cheap in the scheme of things - a fire which destroys your boat is NOT. For those who would like to have the ABYC electrical guides for AC and/or DC, you can contact the ABYC at: www.abycinc.org We could go on and on on this subject, but won't bore everyone to sleep! Those that are interested can get the standards and if it doesn't apply, you can wake up now! :roll:

Tim, I'm sorry that you had trouble with going 3D. There have been too many of these boats built for the method not to be valid. Normally we don't have trouble folding a boat up, but occasionally it happens. The reasons are many fold. Plywood's resistance to bending can differ from sheet to sheet, the epoxy not being fully cured (as you mentioned) and rough handling, which is hard to avoid while working alone. On our CD we covered that problem with this picture and text. Perhaps it was too subtle for you to have caught? Usually if a problem is going to occur, you will notice some whitening of the glass especially at the aft end and at the seam. If you screw through a pad of 3/8" plywood from the outside to a similar pad on the inside, you will take the load off of the glass tape and you should have no further problems. The advantages of this method are many, beside being quicker you usually end up with a prettier bow. I had to down size this picture to fit on the forum so I hope that it is clear. [attachment over 4 years old deleted by admin]

I too was surprised by the amount of resin that Scott used. The bottom has 94 sq. ft. plus overlaps, using Gougeon's formula for 10 oz. cloth which allows for three fill coats and 15% waste worked out to 1.5 gallons. The foto's of the glassed bottom look good, so who are we to argue over success and progress.