plans for arch / davit ?

[rossny]

Does anyone know of a source for plans or drawings to fabricate an arch / davit for a sailboat ? The weight and wind force ( of the solar panels and dingy)should be considered along with the steel structure itself. Is there a book on the subject ? Will I need to consult a marine architect or engineer ? I need to fabricate and weld myself to conserve money. Thanks...

[Delancey]

I could be wrong, but I am pretty sure the answer to all your questions is no and I doubt highly you will successfully conserve money by fabricating yourself unless you already have welding experience.

I am pretty sure of all of this because if you had experience welding I doubt you would be asking these questions.

If you did, you would just copy the size of the tubing, plates, and connections that someone else used for a similar size arch that hasn't already failed. Not trying to be a jerk. A pro would just copy an existing design or modify to suit their needs.

Welding isn't rocket science, it's just melting a small amount of metal and using it to stick different bits of metal together. The problem is that it is skill that takes time and/or money to acquire which sounds contrary to your objective.

[Delancey]

Try again.

I would suggest you go and look at some other arches. Pay attention to the size of the tubing, plate thicknesses, and how the connections are made. As long as you can making something as strong as has been proven elsewhere you're good to go.

Easiest way to understand how it will affect stability on the boat is to do a mock-up and test the righting moment. Cheaper than paying for engineering.

[landonshaw]

I would pay a good welder and you describe what you want and he give you a few options. Each boat and project is unique. That is the fun in having a project.


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[Bulawayo]

......and determine the all the functions / use of the arch. Shall it also be used to pull your dinghy up (as davits)? Think about adding eyes to attach all manner of things to it in the future. Do you want to include a plate for a stern light? Or a cockpit light etc? We always include (now) an outlet for a shower head as well as a plunger tap having seen this on another boat several years ago. Make sure you include leaders when installing the arch such that you can pull through your wiring for the electrics. We have never consulted anyone else - rather we know what we want and get it fabricated. Welding stainless is not difficult but getting a nice finish is not so easy - at least for me! Best advice is to look at the same boat as yours and see what their design is and whether it meets with your criteria. Regardless, look at as many other arches as you can before committing. Laern fromwhat others have done and what they wished they had done. If doing yourself, consider how you shall bend the tubing unless you are going to weld every angle. Also consider how & where you shall mount the arch - is any reinforcement required?

[roland stockham]

Depending on your boat (ie looks) you can do a very nice one in epoxy ply if that suits your skill set

[Cadence]

Originally Posted by rossny

Does anyone know of a source for plans or drawings to fabricate an arch / davit for a sailboat ? The weight and wind force ( of the solar panels and dingy)should be considered along with the steel structure itself. Is there a book on the subject ? Will I need to consult a marine architect or engineer ? I need to fabricate and weld myself to conserve money. Thanks...

Find a machine shop with an owner 80ish and has done marine work. Just bring a rough drawing. They have probably been there done that.

[valhalla360]

If you are doing it in stainless, make sure you know how to weld stainless or it will rust at the joints.

I designed ours but had a stainless guy weld it up. It's basically simple truss design and making sure you have solid attachment points to secure the base to.

As long as the dimensions are close, you can probably get away with copying an existing davit.

If you don't have welding experience, a wood/epoxy design may be more suitable for DIY. If you have good skills finishing (I don't), you can make a very nice design.

[mserafi1]

Check out fishonsports.com and see what they provide for the do it yourselfers. I'm going to do the same thing you're thinking about by using one of their arches with davits to mount panels and hang my dingy. I think there's some room for customization, but the basic arches are pretty flexible.

Blue Skies

[jmtindle3]

I put a pre made dingy davit and solar panel arch on my Jeanneau 39 just last year. I was going to have one custom made. Prices were crazy. I contacted Garhauer Marine and bought one with a few changes. Came out perfect. It holds a 10 4 rib 9.8 tahatsu engine and a 150 watt solor panel. Their number is 909 985 9993 ask for mike. If you would like some pictures or have any questions send to jtindle3@aol.com

[Madehn]

so i designed my own then built a mock up using PVC pipe-- decided to overbuild it on the assumption that heavier material would not cost that much more and might come in handy-- ended up with a great arch and davit combination that is very sturdy- used 1.5 inch thick wall stainless tubing. i went to a machine shop guy that speacializes in stainless steel kitchens-- gave him plenty of time and was precise in my measurements- he did a great job at 25% of the price that the local Marine Stainless guy wanted-- no it does not look quite as good as the Marine Guy's but it is close.

[dgz3]

You're certainly correct about wanting to build it yourself. The cost of a custom fabricated arch is likely to run into thousands of dollars. But the skills needed to cut, bend and weld material, not to mention the time it might take is also considerable.
You may want to consider buying something used. I live in Florida, and there are, literally, tons of this stuff laying around in boatyards, marine salvage centers, craigslist, etc. Something that came off someone's go fast boat or sport fisherman might be just right for your needs with only a little cutting and fabricating to adapt it. All you have to do is find it before it goes to the recycler or land fill. The fact that it may come already festooned with antenna mounting tabs, lights, radar platforms and rod holders is a bonus!
I once asked a local marine engineer/fabricator to build a combination stem head fitting/anchor roller for my 30 Arpege. After a week of studying on it, his estimate was $4500. I laughed in his face. He came down to $3000. A month later I bought a custom fabbed anchor roller off a 50 foot trawler for $35 at a nautical flea market, drilled a few holes in it and bolted it on. Ten years and three hurricanes later it's still working and looking great.
Someone else suggested molding your own from fiberglass and epoxy. That would certainly be doable if you have time and a place to do it. It wouldn't be terribly difficult to mock up exactly what you want in plywood, PVC, and bondo and create a mold or form to layup glass and epoxy on.
Good luck.

[hpeer]

Four years ago I tabbed our arch. I don't use it as da its, but I could.

I took a high quality side shot of the boat from a couple of hundred feet. Reduce parallax. I then sketched the hull shape in an el cheaper CAD program. I drew the arch on the hull, messed with it until I got it right.

I printed the angles out and used them to make my cuts.

I made the arch out of schedule 40 electrical conduit, heavy wall, hot dipped galvanized. The bends were of standard 90° elbows. I made it in the basement and took it to the boat and assembled it. I then welded it to our steel deck, on reinforced pads I had welded down. I then welded the couplings up.

Been 4,000 miles and it's doing fine. Paint does not want to stick to the zinc, but I'll live with it.

Cost? Maybe $300.

[Captain Bill 3]

Contact Annapolis Marine Fabrcaters, in Annapolis, MD. Owners name is Olver, not Oliver

[Capt Doug]

Forget all the BS welding steel (wtf) I helped my nephew install a aluminum arch that has to large solar panels, will lift a heavy dinghy and has plenty of options for add on's. Talk to the people at FISHONSPORTS.COM no welding, you will spend much less than other options.