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ezl74

As noted above, you really need a naval architect to help you with this, not just "someone who can draw in autocad".

Since you'll really need a General Arrangement (GA) dwg of you proposed finished 'design'. Then once that has been done, a weights and centres review, to establish the total weight of the boat and its lcg. Then draw a rough lines plan. From the lines plan input into a stability program...this to ascertain whether your boat is at level trim..ie is the lcg in-line with the lcb?..then once you have gone around the houses a bit on that to satisfy your layout (your first attempt wont be correct, it is an iterative process) last step is to determine the resistance at varying speeds. This will tell you what speed you can expect from your new boat with your proposed engine layout and power.

Straight forward to do, but requires knowledge, and sadly money too, if you are not able/qualified yourself. I would not trust someone who can "just draw" a boat...nor someone who keeps saying things like "oooohh..ya...done it this way before, been doing it for years" each time you question them. That just indicates ignorance and they are only doing what they have always done without any understanding why.

It is a case of having to spend, but spend wisely now...

 

Thanks for your input. I know that I need somebody to go over this project and it needs to be done rite. I know that the money spent will pay off in the end with a better boat and far less frustration through out the project. Now my question is how do I find that person?

 

Why not look at the SNAME directory for someone who is registered and local to you, since you'll need someone who can be hands on, face to face with you to thrash out your ideas....much better than via email, when the project is so personal to you.

 

I will do that . I hope I can find someone in my area. Thanks

 

You have made up your mind that it is the most economic way of doing things and lash back at anyone that offers sensible advise. It is cheaper and better to build a new boat. I design, build and repair boats. What you are planning on doing is first take a boat apart and then build one piecemeal and attach it to what's left. In this post you are asking for validation not good sense advice.

 

I think it would be possible to perform such major surgery and bring it in cheaper then a new build, but it will be a difficult job.

At this point it might be helpful to see the hull form, to get an idea how far the chines need to move, how much displacement we're working with, etc.

Of course this type of job will require the boat be essentially gutted, the whole of the bottom removed, frames, longitudinal, everything, the chines cut and moved, new structural elements added then the new plate slapped on. Just supporting a project like this while it's bottom is missing will prove a challenge, but doable, especially if you could roll her over and work down hand.

With the exception of equipment and topsides, you're building a new boat, just salvaging some effort and materials. Not the easiest way of doing things, but possible.

Post an image of the hull, preferable a lines drawing so we can have a look see at what you've got. Secondly, what are the goals of such an endeavor?

 

How about welding a double bottom with an extension that serves as a swim platform and where the outboards attach?

 

Hi everybody. Well my project is getting closer to the construction phase. I took some advice and went to the NA professional website and found a person to do the project. We are currently in the 4th revision and getting very close. It has been a very inforative and long process but well worth it. I feel I have gained a lot of knowledge that will pay off in the construction phase. Contrary to some opinions I still belive strongly that this is the best way to build my boat because of some special needs I have. Throughout the design process I have been privileged to talk to many knowledgeable builders,designers, NA,and boaters. Many varried opinions with one general consent. Lots of work!! I say what better way to learn.

 

Having been a Marinette owner for many years...with a 32' Express hull in the yard and a 32' Sedan in the water..and an aluminum boatbuilder too:

The way the Marinette hulls are built..overall scantlings, stringers, stiffeners, etc etc..make the hulls fairly easy to lengthen. But to effect a complete change to the underwater lines is a much greater challenge indeed. I'm not afraid to say that I wouldn't know how to accomplish that without scrapping the entire existing hull below the chines and replacing it with a new bottom altogether; frames, stringers, skin..the whole nine yards.

At that point..to me anyway..there is so little left of the original hull (and you said you aren't even going to keep the superstructure even) that I can't see how it would be cheaper or better than starting from scratch with a new build using one of the many aluminum kit makers out there that will send you stacks of aluminum sheets on pallets with all parts already cut out and ready to weld.

The last aluminum boat I built from CNC-cut aluminum was a 43' trimaran. Even as complicated a hull shape as that was, it was quite easy and quick to build the hull...it was the outfitting that took all the time.

A key feature of the Marinette hull, as with many/most aluminum hulls, is the maximum use of developable surfaces. To achieve that goal AND at the same time end up with a hull that is stable and performs well..that is not a trivial matter and requires someone skilled in the art.

Just my .02

 

For me, as for many others, the journey is often the thing, the destination merely a place to think about the next trip. I wish you success and hope you enjoy the ride!

 

I should also add: Make sure you keep us posted on the project. As a long-time Marinette owner meself..it will be interesting to see what you come up with.

 

Thanks for the insight. Throughout this project I have had opinions on both sides. Some say scrap it some say rebuild it. Throughtout this project I have looked to a couple key people, one of them being the owner of Marinette Yachts(John). As one would expect he is also a NA. In his opinion this is a very do-able project and offers me free consult on occasion. Along with Johns opinion I also have a NA-ME graduate student who has done most of the desighn work including new stability test and structural calcs. That said I will procede with some reserve pending qualified revision. It seems in this industry there are very few "new designs" that set president. It also seems the many designs have sunk. More than anything though I see the majority are somewhere in the middle. Good by some boaters standards bad to others. Some people purchase a Crestliner or Alumacraft and thik they are the "best" boat ever made. Personally I would not own one. I own a simi-custome Aluminum Charbered Boat, it is a good boat. Very well built and tough as heck, but nearly useless to me. I have spoke with 3 different kit designers and have come up quite short in all 3 attempts. I have combed the used boat adds for years and come up short. I guess to sum this up is I have done a lot of homework and consulted qualified people I think this is the best path to take. I do look forward to chatting more and will post photos and give honest results of the project when complete. For now if you have any building tips or advice please share it. I love to here what other people have done with aluminum boats. Thanks

 

Thanks Terry. Well said. Many people lack vision.

 

About 15 years ago or more, I worked with an Australian NA outfit that had a really nice portfolio of aluminum vessel designs, all packaged up and ready to be sent to any aluminum supplier that provides CNC cutting services (rare then, but many do now). The venture did not really take off as they expected it would. Your experience and need seems to indicate that there is still a niche unfilled in that area.

 

LOL..perhaps that is true..but being a Marinette owner and scratch-build aluinum boat builder both..I have to admit my 'vision', or lack thereof, has more to do with my experience (the time and money involved building and/or modifying any aluminum hull) than anything else. Heck, the 32 Marinette in the yard right now has a perfectly good hull except for some dock damage on one corner of the transom; a very easy repair for us...but I'm scrapping the hull after the engines are pulled, having already stripped everything else out of it. Or, more correctly, its going to be sunk in a quarry owned by an outfit that trains rescue divers.