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Old 01-18-2019, 01:57 PM   #41
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Hey, I'm reading them. Thanks for posting and keeping us updated
Thanks for the comment. I was starting to think about the old adage "When you are chatting in a bar, you're amiable. When you look around and your alone, you're a drunk."
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Old 01-20-2019, 10:39 PM   #42
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Cool project! Keep the pics coming!
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Old 01-20-2019, 11:25 PM   #43
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Yes, thanks for the pics too
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Old 01-22-2019, 02:06 PM   #44
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Thanks for posting your build, I am very keenly following.
I don't know if you stated this already, but what are the fuel tanks made of? Capacity?
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Old 01-22-2019, 02:48 PM   #45
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A question for the moderators. I normally open the site to "general discussions" and, after browsing those, look to the right side of the page to the "Trawler Discussions" column. I assumed any new discussions would show up there. I've not seen this thread show up there so I'm curious if I have my thinking wrong. I, only now, stumbled upon it. What goes into the Trawler Discussions column?
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Old 01-22-2019, 02:50 PM   #46
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A question for the moderators. I normally open the site to "general discussions" and, after browsing those, look to the right side of the page to the "Trawler Discussions" column. I assumed any new discussions would show up there. I've not seen this thread show up there so I'm curious if I have my thinking wrong. I, only now, stumbled upon it. What goes into the Trawler Discussions column?

Click the "New Posts" link in the top red bar. It will show you unread posts.
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Old 01-22-2019, 03:19 PM   #47
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I don't know if you stated this already, but what are the fuel tanks made of? Capacity?
Leeman, thanks for the question. The fuel tanks are aluminum. They are separate tanks (NOT integral to the hull) and are 150 gal each (two total). I considered all sorts of increasingly complicated fuel plumbing arrangements with different polishing systems, and ultimately settled on the most simple answer: two tanks, each with single draw and return and no separate polishing system.

The builder pushed for smaller tanks to keep weight under control, I wanted larger tanks just to brag about my range. Ultimately I settled on tankage that would give me a good combination of range at slower speeds but reasonable fuel turnover at higher cruising speeds. Since my cruising area is east coast, primarily Chesapeake Bay, I'm not as concerned about how much range I can get. If I were building a Bahama boat or I was in the PNW - I'd reconsider that.
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Old 01-22-2019, 06:30 PM   #48
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Click the "New Posts" link in the top red bar. It will show you unread posts.
I started a new thread as I still don't comprehend the Trawler discussion sidebar.
Why does this discussion not shown up there?
The OP was wondering if anyone was following and I wasn't for the above reason.
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Old 01-22-2019, 06:33 PM   #49
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Leeman, thanks for the question. The fuel tanks are aluminum. They are separate tanks (NOT integral to the hull) and are 150 gal each (two total). I considered all sorts of increasingly complicated fuel plumbing arrangements with different polishing systems, and ultimately settled on the most simple answer: two tanks, each with single draw and return and no separate polishing system.

The builder pushed for smaller tanks to keep weight under control, I wanted larger tanks just to brag about my range. Ultimately I settled on tankage that would give me a good combination of range at slower speeds but reasonable fuel turnover at higher cruising speeds. Since my cruising area is east coast, primarily Chesapeake Bay, I'm not as concerned about how much range I can get. If I were building a Bahama boat or I was in the PNW - I'd reconsider that.
Thanks, you answered all my questions, although what would you feel the maximum tankage might be?
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Old 01-22-2019, 08:00 PM   #50
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Looks great...THanks for the photos.
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Old 01-23-2019, 08:36 AM   #51
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Hey Gene, hope all is going well! Have you decided to pull the trigger on an aluminum cat yet? You might want to hold off and see if mine floats upright. Delivery is expected in May/June time frame. If you are still thinking about it you'd be welcome to come down and take a look.

Good luck in your quest!
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Old 01-23-2019, 08:49 AM   #52
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Thanks, you answered all my questions, although what would you feel the maximum tankage might be?
Leeman, I look at changes to aluminum boats as 3 level:
Minor changes that don't impact the cutting files and are taken care of in house or on the shop floor;
Material changes that require tweaks in the cutting files but don't impact the hull or major movements of weights, these are also done with in house engineers or outsourced at minimal cost.
Major revisions that require you to build essentially new cutting files.

Having said that, I think you could easily go to 175 - 200 gallons with only minor or maybe a few material changes and stay within my 38' footprint. You might be able to go larger but I'd have defer to the smart guys at US Workboats for that.

The first boat of this type I inspected had 2 x 200 gallon tanks and there was physical room for more, but it was a 42 foot hull. He had similar range at WOT as I will have because he had larger engines. You could probably fit even larger tanks in if you make them integral to the hull - then weight will likely be the limiting factor, not the space.

If you do a major revision you just need to set the volume of fuel and they can design the boat around that. But if you don't set some reasonable constraints, you'd obviously risk driving around in a freakishly large floating fuel tank.

As an aside, I set my water tankage and fuel tankage to give me a target number of autonomous days. If you increase your fuel tankage you would need to consider increasing your water tankage or add a watermaker. I suspect either of those would be easy fixes.
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Old 01-23-2019, 01:33 PM   #53
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I'm certainly reading....and enjoying....your posts. Please keep them up!
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Old 01-23-2019, 01:40 PM   #54
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Aluminium isn't regarded as a perfect choice for fuel tanks....did you consider going with plastic or some other material ? Or is there that being in an aluminum fabrication shop that material becomes the default for everything ?
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Old 01-23-2019, 02:10 PM   #55
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I'm not fully convinced you could get 3 boat builders together and come to a consensus on the perfect choice for fuel tanks. I would certainly be open to a proper plastic tank, but in this case, the ability to weld the precise shape to fit the available space and to weld the tank into place is a real benefit. Aluminum certainly isn't the default on everything - my water tank is plastic.

I have an aluminum tank on my current (wooden) boat and I've been happy with it despite the challenges of proper installation. But I think an aluminum tank makes a lot more sense on an aluminum boat. We have not gotten that far in the actual build, but if they propose a change to proper plastic tanks, I'd accept that in lieu of aluminum. I wouldn't accept any other material on this build even though there are well justified opinions of other materials being best.

Having said all that, all 3 of my prior boats had aluminum tanks. So maybe I am missing something.
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Old 01-29-2019, 10:21 AM   #56
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While Iím twiddling my thumbs waiting for my engines to be granted asylum in the US (see post 38) I thought Iíd philosophize. When I started looking at building a boat about 10 or 15 years ago, I couldnít get my brain around why they cost so much and frankly, I assumed everyone was wrong when they said you really can't get a good cruising boat cheap. Now Iím older, but not really any wiser, I figured Iíd share my experience in pricing out new build boats.

Iím technically not under a non-disclosure agreement with my current build, but since I adhere to the philosophy that gentlemen donít discuss women or the price of their boat, Iíll give you some real world numbers from research I did a couple years ago that never resulted in a contract.

First, I used to look at boats on a cost per foot basis. But anyone bothering to read this probably already knows that cost per foot is a poor metric because it ignores total volume. Cost per pound of dry displacement is more accurate because it accounts for all the "stuff" that went into the boat. It is of less use when comparing two different types or materials (aluminum costs more AND it is lighter - so you'd expect the cost per pound of an aluminum boat hull to be different than steel or fiberglass).

In the summer of 2017 I had a well-known NA develop study plans for an aluminum monohull new build. Hereís a sketch I did Ė it looked a little better when the NA was done with it, but Iím not really at liberty to show his product here. That boat was 38' x 12' and we estimated the weight at 19,500 lbs with a half load. It was to be powered by a single 160 hp John Deere. We estimated 10 to 12 knots cruising speed.

I reached out to 5 well known aluminum boatbuilders and all the estimates came in around the same range (give or take $25K). Including the cost of design fees, NC cutting files and additional engineering costs (which totaled about $28,000 for a 1st time build), the best value came to $539,553 total or $27.67 per pound (that included all design costs). That bid was from an east coast builder that produced good, honest boats without a ďyacht-levelĒ finish.

One of the bidders on that job also had produced several semi-displacement catamarans and I looked at the specifications for a catamaran with a comparable level of finish that was under contract at the same time. That catamaran was 40' x 13' and had an estimated displacement of 25,000 pounds. Since the cutting plans and engineering for that boat were already in existence (this company had built several similar cats before) the total cost came in at $563,860 or $22.55 per pound. While this was almost $25,000 more than the monohull with similar length, it was a much better price per pound. And this boat had 2 x 225HP John Deere engines.

As an aside, at that time I was told these engines ran around $30,000 each with reverse gear Ė so at 1300 pounds an engine costs about $23 per pound; similar to the overall boat cost per pound average. Frankly, I suspect these 1300 pound JD engines costs less than 1300 pounds of high end teak and mahogany joinery.

So in the case of the cat, the old adage of catamaran hulls costing double because there are two hulls didnít hold true. I think the reality is builders often hedge their bets on a new design Ė so if you can build a boat that has been built before, you lower your risk of performance shortfalls and you lower the builderís risk of underestimating construction costs.

One more point of comparison: at the same time I was helping a friend develop specifications for a weekender lobster boat built on a Duffy 35 hull with a 2í extension in the cockpit. This boat had a shelter top and basic accommodations for two below. The final dimensions were going to be 37í x 12' - almost exactly the same as my initial aluminum monohull. We estimated the finished weight would be 15,000 and the cost to build this boat at a nice, but not luxurious, level of finish by a well-respected builder in Maryland would be around $450,000 including design costs. So thatís significantly cheaper than either of the two aluminum options on a dollar per foot basis, but the cost per pound was close to $30.00. So in the end, it was a cheaper boat but a worse value (from my perspective Ė everyone has their own tastes and requirements). For reference, that boat had a single 300 hp diesel if I recall correctly.

I used to read every source on boat construction costs that I could find and I appreciate the work of those folks who educated me. Hopefully this is useful information to someone. The most useful thing I got from reading otherís input is that boats really arenít cheap and just because it doesnít make sense that a simple boat costs more than the median house price doesnít mean itís not true.
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Old 02-04-2019, 11:29 AM   #57
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A few more update photos - The first two pictures give a hint of how the propeller pockets are shaped. They also exhibit that universal truth, there's precious few things you can't fix with either a hammer or WD-40.

The small pieces of plating inside the tunnel and on each hull are done first. This is the most time consuming part because the smaller the plates, the more linear feet of welding required.

I understand they will cover a lot more ground doing the fairly large pieces of hull plating on the exterior of each hull. Obviously, the more you can plan in the use of large, uninterrupted pieces of plating, the faster the welding. A disadvantage of aluminum is the skill of the welder must be much higher (than for steel) and I understand you have to have greater control of the environment. A benefit is that the welding tends to go faster than with steel.

The 3rd pic is obviously the house with overhead frames tacked in.

These photos were from last week. They are targeting a hull-flip date of Friday; but I'm trying to exhibit a little combat patience.
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Old 02-04-2019, 06:18 PM   #58
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Really interesting to watch!

Just for your information, our boat is aluminium too but uses the Strongall(TM) method (translated). Ours is 12mm hull and 6mm superstructure, minimal framing. I presume even more careful welding and skills are needed!
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Old 02-05-2019, 10:09 AM   #59
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I've heard of Strongall method, but have not inspected one. 12mm? Geez that's heavy!
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Old 02-05-2019, 07:44 PM   #60
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I'm not an expert, but it seems that while the individual panels are heavier (possibly much heavier!), there's few/no ribs and few joints which saves a lot of weight. In theory strongall should be stronger due to the thicker panels and fewer joints, and the various expedition-level boats appear to bear this out although I doubt anyone has run the same style boat into a reef or an iceberg to test the theory!
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