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PostPosted: Sat Aug 11, 2012 4:13 pm 
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Joined: Fri Aug 10, 2012 10:24 am
Posts: 4
Location: Simi Valley California
I would like to.
This would be a trailer boat.
I am an accomplished welder/fabricator so that should not be an issue.
Room to build is ample and enclosed.
Inboard diesel/electric hybrid. Steam power would be considered.

Anyone local to LA build one even from ply/glass?


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PostPosted: Wed Aug 22, 2012 3:02 pm 
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Joined: Thu Feb 11, 2010 4:15 am
Posts: 23
I have considered steam for a while now- wood is 15 times less than the cost of fuel..but has drawbacks..such as weight and bulkiness.
I was also thinking of using a D.E. system. But this gets complicated - especially for a tug which requires varying degrees of loading on the engine. You will lose 10% of your power due to energy losses through the system...if your going to build a tug- and can weld- steel should be your first choice--it allows the vessel to be more "stiff" in a seaway and wont roll as much since the weight of the steel slows the motion down- compared to wood.

...now if you use a boiler--keep in mind the weight of a vertical boiler full of water. if you use a boat that is going to see a good chop-remember this boilers extra weight will throw off the stability. I personally like steam...would you be using the D.E. system to gain range and cut fuel costs?? or are there other factors?...how far along in the build are you?
keep in touch im doing the fred murphy in steel...mig welded.


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PostPosted: Thu Aug 23, 2012 1:13 am 
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Joined: Fri Aug 10, 2012 10:24 am
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Location: Simi Valley California
I am leaning more toward a full electric power system.


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PostPosted: Tue Aug 28, 2012 8:27 am 
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Joined: Thu Feb 11, 2010 4:15 am
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CragRat wrote:
I am leaning more toward a full electric power system.

would youb be charging your batts offshore? If so- you will need to have small motors or only run the boat for a few minutes -of course you could go with golf cart batts- they are good for this application...what size motor did you have in mind??
D&D motors are good.. to be honest I looked into this considerably. In the end the complexity of it outweighed the advantages- the problem was the battery run time and the hp of the engines- i was looking at using big engines- like two 10 hp @ 70 ft pounds of torque each geared 2:1. They would be powerful but cannot run more than a minute at that capacity. for cruising--you dont need two nor do you need a powerful one- but you wont be able to tow much. if anything...however--for cruising--if you have a way to charge the batts onboard-- you will greatly increase the range and beauty of a quiet ride.

if i may ask- whats your plan what engines? hp?...torque- how many amps what size controller?? etc..very interested... :D

Doug


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PostPosted: Thu Aug 30, 2012 1:04 am 
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Joined: Fri Aug 10, 2012 10:24 am
Posts: 4
Location: Simi Valley California
Not sure yet about what motors. I have just started looking into the golf cart stuff.
I have decided that building the frames will be done with a water jet, i used a triangulation method on the full size plans to transfer everything to AutoCAD.
I am all about planning right now. There is another project in my shop that needs to get done first (72' Chevy Luv 4x4, tube frame / cage, 350 TBI Chevy, 39' wheels etc. )


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PostPosted: Sat Sep 01, 2012 10:59 pm 
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Joined: Thu Jan 24, 2008 11:36 am
Posts: 343
Location: Kenai, Alaska
I'd like to make some remarks about building this design in steel, and to extend these to include electric propulsion.

Preface:
I hope the boat turns out well, and you're able to make a fine, clean, smooth hull that satisfies your goals and provides enjoyable times on the water for you and your family. I hope that your estimates of the effort and skills are as simple as your post seems to imply you think they are?

Welding metal boats:
With that said, general welding is not the best training for building a welded metal boat. The problem is primarily using general fabrication experience to attempt to imply an ability to successfully build with long seamed panels of very slightly curving, but almost flat panels. 99% of all 'welders' I've watched do a pretty poor job of their first dozen or so boats.

I include myself in that completely, I figured that because I could weld pipe "I can build a lousy ole boat!". I'd say things finally smoothed out after the first couple of dozen boats- but they didn't get completely smooth for another hundred hulls.

I think you should give some very serious thought (and practice) to boat building as it compares to 'welding' overall?

Thin metal hulls are not easily created into fair, clean and smooth shapes using the skills developed making structural welds or even pipe welding skills. Yes, a steel weld is a skill in itself, but as pipe is somewhat more involved than a structural fillet (!) so too, is metal boat building a bit more involved than fabrication 'welding'.

I hope you will give more research and concentration to your preparation to weld your hull than your apparent dismissal of that skill?
CragRat wrote:
I am an accomplished welder/fabricator so that should not be an issue.


Regarding electric propulsion:
The idea does not scale down below a hundred foot of LOA. That is; small electrical storage and conversion systems are so inefficient that they cannot 'cruise' in boat less than many tonnes so the idea for a 16'er would only be functional if you 'plug in' the little boat between one to two hour rides in calm water.

If your design statement includes a few hours at most of cruising, then back to a dock/trailer and then charging, that may work OK? But there is not enough displacement in this tiny hull to provide fuel,engine, batteries and drive to have a powered/electric system that provides for any range.

There is no means of propulsion in this size as cost effective and compact as gasoline. The physics of energy conversion and storage are just not available for this small a displacement until you scale the idea up to hundreds of tonnes of vessel.

The frames (if given in patterns?) should be re-faired in a digital or manual loft before cutting if you scaled them from offset tables, and if you got them from measurements from paper then I'd suggest you run splines through the erected model to fair the chine points so you don't have errors/hogs in the plate developments or the hull.

cheers,
Kevin Morin

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PostPosted: Wed Sep 05, 2012 1:24 pm 
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Joined: Fri Apr 22, 2005 11:56 am
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I am with Kevin on this. When I built my first boat I had spent years welding in nukes, refineries, chem plants, power plants welding all types of carbon, stainless and aluminum pipe. Had even been teaching welding for about 5 years. To this day I would love to buy my first few boats back and sell them for scrap metal prices. Whole different game compared to what I had done in the past.


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PostPosted: Wed Sep 05, 2012 3:29 pm 
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Joined: Sat Sep 22, 2007 9:49 am
Posts: 1141
Location: Colborne ON Can
But then again, I built a 34'steel sailboat with plate that rolled out at .100 instead of the 12 guage it was supposed to be, and was taught how to use the new mig welder by the company rep. When complete most people, even those who had meals onboard , didn't realize it was steel. Tho I still say I wasn't much of a welder, but I'm a helluva good grinder. :lol:
Incidently, after 15 years in salt water it still looks terrific.
Doug


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PostPosted: Wed Sep 05, 2012 3:36 pm 
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Joined: Thu Jan 24, 2008 11:36 am
Posts: 343
Location: Kenai, Alaska
slug, 'you were taught by the company rep' - so you might not have had to undo a career worth of contrary experiences in the welding trades?

Boat welding is not the same as structural or pipe, just a word from someone who's wrinkled some hulls after I already 'knew' how to weld.

Cheers,
Kevin Morin

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PostPosted: Wed Sep 05, 2012 4:31 pm 
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Joined: Sat Sep 22, 2007 9:49 am
Posts: 1141
Location: Colborne ON Can
Good point Kevin. Reminds me of an old friend of ours years ago who went go carting with a group of us. She had never driven a car, and she out perfomed the lot of us "trained" car drivers. We all had problems with the short steering :lol:
Doug


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PostPosted: Tue Nov 27, 2012 8:37 pm 
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Joined: Thu Feb 11, 2010 4:15 am
Posts: 23
im an amateur welder- and have built steel boats.. two- to be exact. the trick is knowing to weld in short sequences. its not rocket science. you can do it. the nice thing about a boat is that- you can do flat welds on the plates.. use skip welding- and good templates-- you'll be fine--it may not be perfect- but it will be nice looking--there are many who have never welded who built very fair boats after a bit of practice. do not get dsicouraged because pro welders discourage building in steel. if you want i can point you to large projects on the net who have never welded. one in particular is doing a 72 ft origami design and its turning out fine--and the guy has no welding experience till this-his first project. practice on some scrap--when the welds look nice and you can control the distortion a little using spacedwelds-- you'll be fine- no not perfect but it will be sufficient--btw- a tug should have a bit of distortion --its a work boat! not a america's cup contender.


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PostPosted: Tue Apr 30, 2013 6:14 pm 
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Joined: Sun Jan 31, 2010 6:25 pm
Posts: 24
Location: Cassville, Missouri (SW MO)
Hey guys, I guess My friend is right, I ask too many question sometimes, but I just have to ask...

"SLUG" made a reference that I may be having to deal with, but for a different reason...

Quote:
I built a 34'steel sailboat with plate that rolled out at .100 instead of the 12 guage it was supposed to be,


I am seeing I may have some issues getting a thickness of sheet, (11ga.) sheet for the hull of the Goliath. I am finding most places I've called hav 10,12,& 14 ga steel. 11 ga. is .119" and 12 ga. is just .015" less (.104"). I am wondering it the .015" will be ok, if I remember to insure the 457 lb. loss below is accounted for, in everything in the decks and above. I had planned to keep the cabin and finishings spartan and light anyway. I also thought to add increased tankage or other useable ballast below decks to make her sit right. And like "ELECTRIC TUG" said,
Quote:
-btw- a tug should have a bit of distortion --its a work boat! not a america's cup contender.


I also wondered if I substituted the upper most side sheet at the sheer line, with a 14 ga, still being .074" thick and not having to withstand full hull waterpressure. I have been doing some recent building with this thickness in cold rolled, and found it to be quite a solid surface, And structurally sound in a similar function. I have read and re-read all the comments here on altering a design. I guess I am searching for experience in this "avalibility work-around".
Dan

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Better, faster, cheaper. Only ever found 2 of the 3! (But still lookin.)

Built 4, repaired 30+, ...So many boats, ...so little time.


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