Hard top dodger

[Russell]

I have begun patterning my new dodger. I have opted to go for a hard top with california style cloth side curtains. I have a mock up of the top done and will build the fibreglass mold tommorow and start layup. Pictures to come.

[tmsc]

Russell,

Its funny that your are doing that. I have been thinking about doing the same with my 33. Was thinking of using the existing frame and using door skin to make a form for the top then laying it up over the form.

[Russell]

Russell,

Its funny that your are doing that. I have been thinking about doing the same with my 33. Was thinking of using the existing frame and using door skin to make a form for the top then laying it up over the form.

I had originally considered doing it that way, but I never liked the shape of the existing dodger. So I used a piece of 1/4 ply pressed against the cockpit bulkhead to trace the curve of the cabin top to make my pattern for the curve I want, then used that to cut 3 pieces of 3/4" ply for the base of my mold. I cut another peice of 1/4" ply for the shape pattern, a slight curve on the front, the sides have a slight flare back ( the front width matching the handrails on cabin top and the aft width a bit inboard of the coaming width). Thats where I am at now, today I will use another piece of 1/4" to fasten to the bases of the mold, then place my shape pattern on top of that and trace the shape onto the mold with a sharpie.

My big debate right now is layup. I got some marine grade douglas fir for the coring. I originally was going to use a modern coring, like coosa, but the way I want to attach the canvas side panals is with awning track and sheet metal screws, to avoid oodles of fasteners being thrubolted and looking poor. But sheet metal screws will bite much better into a good wood core (and will be from underneath, I dont think wet core will be an issue). I was thinking of 2 layers of glass, 1 layer of 1/4 fir, 1 layer of glass, 1 layer of fir, 2 layers of glass. But lugging the pattern, which is made of 1/4 ply, back and forth to the boat yesterday, has me thinking more about overall weight if doing it that way. So I am debating a core of just 1 layer of 1/4 fir and maybe 3 layers of glass on each side, which I think should still be stiff enough. So the layup will be: 1 layer finish cloth, 2 layers bi axel, 1 layer 1/4" fir, 2 layers bi axel, 1 layer finish cloth.

I will be putting conduit inside the dodger as well, there will be a hole on the aft part under side leading into the conduit for a LED cockpit light, and a hole in the forward side underneigh where I will eventually put a pod to house my insturments (which will be done another year, but conduit will be in place for it), with both conduits leading to a hole where one of the support struts is so wire can be hidden and lead down into the boat for wiring.

Support struts will be 1 1/4" SS tubing with feet welded on, 2 forward ones going to the cabin top and 2 aft ones to the coaming, I dont want to use typical dodger frame hardware, as all those pivoting points wont give the ridigity I want. This is the only part of the process I cant do myself and likely the one that will take the longest as most fabricators around here are so busy building large projects. I did look into a cheap harbor freight TIG welder, as I do think it would be fun to learn to weld and do it myself, but getting into cutting tools and pipe benders and such the cost got to be a bit much for a single project (and those are not tools I can take with me on the boat).

There will also be 2 side handrails on the top of the dodger and an aft handrail. Fortunately these can be bought off the shelf in various sizes, pre bent with thru bolt studs welded on.

[Steve Laume]

Russell, here is a link to one of Nick's videos. This guy has been designing and building some very complex and beautifully shaped forms out of wood and glass for a long time now. He has a whole series of videos that may be helpful for the project you are doing.

http://www.youtube.com/watch?v=csrYyZBq ... 8DE4A600BD

Have you considered making the supports out of glass or carbon reinforced wood? This would give you much more freedom in your design and eliminate the need for the ability to work with stainless tubing.

This is a project I can't put off much longer and I will be watching what you do very carefully. I started to make up forms last year but didn't get to the point that I was ready to tackle the entire project. My canvas is dictating that this will be the year.

One of the things I want to do is make up a sealed combing along the cabin top. Lots of water leaks in under the canvas and tends to get annoying. The part of the design that I am struggling with is how to transition from the curve along the cabin top to incorporate the cockpit combing. It would be easy to stay with the lines of the cabin trunk but that would dump all the water into the cockpit.

I would plan on a red light and reading lights on both sides where we tend to sit. I have also thought about an aux speaker and an overhead map or book pocket. Hand rails would be one of the greatest benefits aside from creating a drier sheltered area. A boom gallows could also be incorporated.

Did you consider using lexan instead of canvas curtains for part of the enclosure?

When you are a carpenter, everything looks like it should be made of wood, Steve.

[Russell]

Russell, here is a link to one of Nick's videos. This guy has been designing and building some very complex and beautifully shaped forms out of wood and glass for a long time now. He has a whole series of videos that may be helpful for the project you are doing.

http://www.youtube.com/watch?v=csrYyZBq ... 8DE4A600BD

Have you considered making the supports out of glass or carbon reinforced wood? This would give you much more freedom in your design and eliminate the need for the ability to work with stainless tubing.

This is a project I can't put off much longer and I will be watching what you do very carefully. I started to make up forms last year but didn't get to the point that I was ready to tackle the entire project. My canvas is dictating that this will be the year.

One of the things I want to do is make up a sealed combing along the cabin top. Lots of water leaks in under the canvas and tends to get annoying. The part of the design that I am struggling with is how to transition from the curve along the cabin top to incorporate the cockpit combing. It would be easy to stay with the lines of the cabin trunk but that would dump all the water into the cockpit.

I would plan on a red light and reading lights on both sides where we tend to sit. I have also thought about an aux speaker and an overhead map or book pocket. Hand rails would be one of the greatest benefits aside from creating a drier sheltered area. A boom gallows could also be incorporated.

Did you consider using lexan instead of canvas curtains for part of the enclosure?

When you are a carpenter, everything looks like it should be made of wood, Steve.

Steve, I did consider doing a coaming on the cabin roof, but decided to put that off for another year. Since i do my own sewing it wont be a big deal to redo or modify the canvas to accomidate it down the road.

I did consider doing the supports out of wood, and am still debating it. I am going to make mockup supports as patterns to give the fabricator, and at that point i might find myself thinking wood is adequate, the problem will still be though attachment on the ends, you cant weld wood or glass to an attachment base, and both have to be pretty thick for solid attachment, unless I actually glassed the whole structure permanently to the cabin top, which is possible, but I think I still want it to be removable.

I actually will be using lexan for the windows, with canvas boarder (for cosmetics). Makrolon AR2 060 gauge, rather then straglass, You can glue this to canvas or sew it. You cant roll it up like strataglass, but it can still bend to form curves for a nice look and each panel will be removable, the Markralon is the reason I am going for California style rather then traditional style. Its MUCH clearer and does not suffer from ripples, and will last much longer. The canvas itsself will probably be Stamoid rather then subrella, they make Sand color which matches my Subrella Linen color nicely, and Tenera thread. The whole setup should last 3 or 4 times longer then a typical Dodger. The Markalon wont scratch as easy as strataglass, AR stands for abrasion reisstant, its Lexan with a coating on it, it has UV inhibitors in it as well to reducing yellowing with time, but I will make a cover for each panel to help it last a long time.

[tmsc]

Russell,

Keep it coming..... Will be interested in how it comes together. You may inspire me to get off my posterior and do it myself.

[Steve Laume]

If you make up a combing with a flange it could be screwed or bolted to the boat with some sort of sealant under the joint.

I would not want to have it permanently attached to the boat, Steve.

[K Chiswell]

Russell, I would think a 1/4 core would be plenty stiff. I recently finished a strip canoe where the core started out 1/4 thick but after sanding it was closer to 3/16. With a single layer of 6oz cloth inside and out, it is nice and stiff. It is an 18ft boat with a 3ft beam and the center of the boat is pretty flat, so it is dependent on the buildup for stiffness, not the curves of the hull.

[Russell]

Russell, I would think a 1/4 core would be plenty stiff. I recently finished a strip canoe where the core started out 1/4 thick but after sanding it was closer to 3/16. With a single layer of 6oz cloth inside and out, it is nice and stiff. It is an 18ft boat with a 3ft beam and the center of the boat is pretty flat, so it is dependent on the buildup for stiffness, not the curves of the hull.

That is my thinking, I decided I am going to do only 1/4 core, what I will do is lay down the finish cloth, biaxel, core, then biaxel, and pop it out of the mold before laying on the final finish cloth, and test its stiffness, from there I can add to the layup if needed, it will be rigid enough that it wont need the mold anymore anyway. I do want to be able to put all of my weight on it with very little flex, but its not like it needs to put up with a traveler mounted on top of it.

I finished building the mold today, I had hoped to get some layup done, but it was getting late by the time I finished building it, took a lot more time then anticipated, lots of measuring and double checking to make sure the form was uniform. Forgot to bring my iPad to take photos, will bring it tommorow morning to take a photo of the mold before I start layup though.

[Russell]

I just snapped some photos, waiting for the mold release to cure so thought i would post them while i wait.

Here are the patterns for the dodger, and the small one below is the coachroof curve.


Here is the mold constructed. I glued down formica on top of it, a tip from a friend who has done a lot of this, to make it release very easy without having to saturate the plywood mold with epoxy and fare it..

[Russell]

First round of layup, a layer of finish cloth and a layer of biaxel:



Preparing coring for laminating tommorow:

[hilbert]

I have been experimenting with FRP profiles as supports, for a large solar panel in lieu of a bimini.


It is easier to take risks with a project boat.

[Russell]

Wow Jonathan, I like it! Though I would suggest having something under the solar panals to keep that pesky rain off of you that will drip between the panels, a simple peice of canvas with common sense fasteners that can roll up when you dont need it (they are easy to install into fabric without special tools). Some friends of mine who have been cruising full time for nearly 20 years on their Ontario 32 made a similar setup, but they put a peice of 1/2" ply between the gallows and aft support and just coated it with epoxy (no glass), it wasnt pretty but it was effective and could be taken down by removing a couple thru bolts for hurricanes.

I have followed your various other projects, and you certainly have been doing some cool stuff. I dont think I ever caught anywhere though what you plan to do with the boat when you launch it? You seem to have some long term cruising in mind based on what you have been doing to the boat.

[hilbert]

I dont think I ever caught anywhere though what you plan to do with the boat when you launch it?

I would like to do some blue water sailing.
I doubt the boat is as enamored of the prospect, as it is resisting mightily.
Anyway, working on the boat has kept me thinking and moving.

[Russell]

I took the hard top out of the mold today to trim it, came out easy and the glass looks pretty good.



I trimmed off the excess and its starting to look like what its supposed to.



Then it went back into the mold for me to add another layer of core, this is just edge core, to save weight I decided I didnt want a full two layers of 1/4" coring, but I did want the edges, where various hardware is going to be attached, to be a bit thicker, so I am putting 4" wide strips of coring around the edges.



Once this is cured, I will take it out to the boat for dry fitting and making all my measurements for the support tubing to give to the metal fabricator. Then back to the shop to round over the edges, then a final layer of 4 oz finish cloth, and glass tape around the edges. Then faring then finally painting, still a lot of work left to do.