The Ship Model Forum

Another good idea is to use threadlocking pastes like Loctite or Molycote. In my opinion Loctite is far better...

http://www.loctiteproducts.com/threadlockers.shtml


http://www.dowcorning.com/applications/ ... px?R=948EN
http://www.dowcorning.com/applications/ ... px?R=185EN

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NIKOS (NICK)
ΜΕΓΑ ΤΟ ΤΗΣ ΘΑΛΑΣΣΗΣ ΚΡΑΤΟΣ
(GREAT IS THE NATION THAT MASTERS THE SEAS)

Joe, GT... You guys are the best. I've always been a safety man. Hell, I'd wear a belt AND suspenders if the wife wouldn't leave me for it! So, I'm definitely gonna secure these props. Probably with loctite and a set screw.
Thanks so much!

OK... I'm in a goofy mood this morning. As a child and roaming the decks of the Conyngham, I remember there being an old 10 foot John boat. It was leaned against the base of the aft stack just forward of the SPG-51s. Back then I thought, WOW, this is cool. It was cool because my Uncle Chuck (the CPO that took me over to the base to play on the Cony) had one just like it which he used to shove in the back of his pickup. He'd then take it and me to Rudy Inlet or any number of other small bodies of water in the area and we'd go fishing. Well... My Cony had to have one.





Here's where it gets goofy...

I decided "Hey, it's a model boat. I may as well put it in a test tank and ballast her to the water line!"
Guess what? She needs no ballast! I got lucky! HAHAHAHAHAHAHA. Oh god, please help me! I need a life!

GOOFY????......no bro your just as goofy as the rest of us.. ....locktite is ok...but if you ever need to replace the shafts it a real bear to remove.....the setscrew is better without the hassle.... ......joe

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http://www.48thfleet.com

Its little details like that make models come alive and mean something. Nothing goofy about it all man. Keep up the great work!

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Drawing Board:
1/700 Whiff USS Leyte and escorts 1984
1/700 Whiff USN Modernized CAs 1984
1/700 Whiff ASW Showdown - FFs vs SSGN 1984

Slipway:
1/700 Whiff USN ASW Hunter Killer Group Dio 1984

chris,

Seems to me you have it bassackwards - you're supposed to start out with the simple builds and then proceed to the hard ones!

Your model is beautiful! It will be the queen of the fleet when she is underway.

Phil

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A collision at sea will ruin your entire day. Aristotle

sorry for rattling your crib son......any progerss????....joe

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http://www.48thfleet.com

whats the status on the good ship conyngham? hope you got the prop staying on issue resolved. take care!

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On the drawing board: 1/72 Iowa Class Battleship
On the slip ways: Tamiya 1/350 Missouri BB63
In the hanger: 1/144 Tu-26 Backfire B And a F-105F

Hey gang...

Well, I've been away from the ship for about a week... Other projects, "honey-do's" and what not.

I'm having an issue with ballast. Looks like I built the top half too heavy. I was optimistic but as of right this minute, I don't know what I'm gonna do. Without the top structure in place the hull rests in the water beautifully and even rights herself. Which is puzzling because back when I first "tanked" her in the neighbors hot tub, the top structure was roughed in and on and she was true in the water aside from being a little light in the bow.

Now, with the top half attached she lists hard to port and wants to capsize. Granted, I haven't fully applied the ballast, I've merely been trying to get her to set in the water true. At this point it looks like she's gonna be too unstable in the water to RC unless I take drastic measures.

I just don't know where I went wrong. The hull weighs WAY more than the upper structure. And with about 22 pounds placed in her hull (evenly spread with half the weight split in two and placed on the waterline inside) she settles into her waterline beautifully. But if I let go of her as she sets there she wants to roll over. Take the top off and she's fine. I've tried moving weight around and well... Then she wants to roll the other way.

There must be a dramatic offset to the weight of the structure yet finite enough to have to ballast this thing out by measuring and adding or subtracting a few ounces here and there. It's the only thing I can figure. I built it evenly. Granted, I went by the drawings and the deck equipment is placed as per drawings and photos.

Maybe I configured her a little too on the "Static display" side and less on the "RC" side of things. I really don't want to have to rebuild the structure. So, for right now and until I can get this figured out, she's gonna be a static display in the house.

I understand your frustration!

There are two things you can try. First, you have to lower the center of gravity. Use the densest ballast you can get (lead) and shape it to fit in the bilges. If all else fails you could create a removeable lead keel piece to fit under the hull when she is in the water.

The other thing is to look for ways to reduce topside weight. Drill lightening holes in interior structural frames, if possible. Keep in mind that small changes high up may have greater benefit than larger changes down lower. Start at the top looking for ways to reduce weight.

The tendency to list to one side could result from even a tiny off-center alignment of something high up - like the mast.

Whatever the outcome, you do have a beautiful static model, and you will have learned something about mass distribution in ships!

One thing you should be very cautious about. Even if you get the ship to float upright in the hot tub, it might be susceptible to cross winds on the open water. When you get her floating upright in the test tank, pull the model over until you have a list of maybe 20 degrees to one side, and release it. If it takes a long time and many side-to-side oscillations before it stabilizes upright again, it will be very susceptible to capsizing in a strong wind.

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A collision at sea will ruin your entire day. Aristotle

I can understand your frustration. Think of the model as the real ship. The method I have used is simple and it does work .Although as a note of caution top hamper on any model can be critical by way of weight or windage. I apply thin sheets of lead up the sides of the hull , just below the waterline , with weight along the keel this should allow the hull to sail up right with out producing a stiff ship. This is very evident in turns as it allows the hull to heel gently in the turns and then gently return to the upright. Too much weight in the keel can have a negative effect. Hope this helps and best of luck .
Dave Wooley

Hi Chris:

To Address your stability problems I would suggest the following remedies.

First of all. You have built a very nice looking model that I am sure will look very good on the pond, once the weight distribution is solved.

I would remove the ballast weights that you put in this model by whatever means that you can and then put a good portion of the weight back in the hull but just on either side of the keel, and no more then 1 inch above baseline, do not go with the others advice to separate the weights by any more margin then the thickness of the keel and by no means should you put the weights anywhere near the waterline. The area between the keel and the first stringer is the only area where the lead weights should be.

Next, carefully hollow out as much as you can the 5” gun mounts, MK-13 launcher base and the Asroc launcher As well as the MK-68 director could probably use some drilling underneath for weight control. What is the missile magazine under the MK-13 made of?
You may be able to remove some material from the stacks and I did not see what the actual structure construction was made from but have another look up inside the structures and see where you can drill some lightening holes.
The steel mesh you used for the railings would have been lighter if the stanchions were made of .040" brass wire and the rails were made of .020" brass wire from K&S.

What batteries are you using for this?

I would not consider the drop down keel as for one it will look rather retarded and you will still have to remove weight from the model to compensate for it.

I noticed that she was listing a bit to port when you did the early float test in the hot tub.

What you are going through now is the reason I have always advocated builders running first sea trial long before the model is even in the first paint stage. When drastic weight reduction is required I would even drill material out of the bow and stern blocks for this model to remove material above the waterline.

Recently we started the process to make up cast sonar domes and hull fairings for the DDG-2, DLG-6 and DD-931 class ships and I have found that the sonar domes on the DDG-2 class (DDG-15 drawings) are the same size. Although the shape of the dome itself changed from the early version from the1950’s, the footprint of the dome did not change.

Your ship came out very well.

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W.L. Upshaw
The Scale Shipyard

World's Largest Supplier of Large Scale Warship Hulls and Fittings
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Hi Lee without sounding any note of disagreement with your conclusion, that ballast near the waterline is inadvisable I can only observe the fact that I have found after many years of experience that if you concentrate the weight low in the keel then you will produce a stiff ship. A small amount around the bilge to just below the WL improves stability in the roll . I do agree with you that the weight should be limited to the area amidships here the batteries can be part of the ballast but as you say ballasting trials are best conducted prior to any painting. In fact I'll factor in the ballast /running power trials as one operation before completing the superstructure. Vic Smeed one time editor of Model Boats magazine well known for his scale ship designs in the 50s 60s always increased the draft to allow the model to sit deeper in the water whilst retaining the same water line slightly increasing the margin for additional ballast. This worked well but departed from the true scale of the hull and has since fell out of favor as a means to improve model stability . I guess all hulls behave differently and are ballasted accordingly with a bit of old fashioned trial and error . Good to hear from you by the way and a good disscussion on a good topic .
Dave Wooley

G'day Chris,
Had a look back thru the build 2 remind myself how you built superstructure and weapons. I suggest use some kitchen scales (digital if ya got em) and weigh superstructure components 2 see if you have a heavy item (rear 5" mount and Asroc maybe??) up high. I helped ballast a 1/72 Perry (aussie variant) a few weeks back and we had same problem hull floated fine without superstructure on, but was very unstable with it in place. Similar TF72 Adams class models should weigh in at approx. 28lbs fully ballasted. with the Aussie Perry I helped setup We ended up putting a long length of lead flashing( from plumbing supplies) folded as narrow as possible along full length of keel on centerline, get your batteries as low as you can as well it all helps.

Best of Luck

Bruce

Ps Maybe stick some lead in your sonar domes?? ( If you hollowed em out)

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building:
1/72 RC USS LONG BEACH CGN9
1/72 RC USS CALIFORNIA CGN36
1/72 RC USS SAIPAN LHA2
1/72 RC USS JOHN PAUL JONES DDG53
1/72 RC USS SHARK SSN591
1/72 RC USS SEAWOLF SSN21
1/72 RC USS ALBANY CG10

I looked through your posts and noticed something else that is contributing to the problem, although perhaps not much. The sonar domes are solid wood. Wood floats. Because these are below the keel the effect is maximized. These are lifting the bow, and that has a bad influence upon stability.

It isn't something I would want to do, but if you can drill out some of the wood in the sonar domes and replace it with ballast - lead - it would help stability. Of course, too much ballast will leave her too heavy at the bow.

It is a beautiful model, and I have been waiting to see pictures of it on the water. Hope you solve the problem!

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A collision at sea will ruin your entire day. Aristotle

any narrow beamed ship is going to roll!!....for years i've placed the ballast to the water line and on the keel.....sure your ship will be stable with out the superstructure but when you start adding the superstructure and other details the rolling begins.....the real ship rolls.....your model will to..... ......joe

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http://www.48thfleet.com

Any luck with her Mate??

Cheers Bruce

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building:
1/72 RC USS LONG BEACH CGN9
1/72 RC USS CALIFORNIA CGN36
1/72 RC USS SAIPAN LHA2
1/72 RC USS JOHN PAUL JONES DDG53
1/72 RC USS SHARK SSN591
1/72 RC USS SEAWOLF SSN21
1/72 RC USS ALBANY CG10

any good news to report good sir?

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On the drawing board: 1/72 Iowa Class Battleship
On the slip ways: Tamiya 1/350 Missouri BB63
In the hanger: 1/144 Tu-26 Backfire B And a F-105F

Chris,

Any news? It is a beautiful model, and there are a lot of us waiting to see how it turns out.

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A collision at sea will ruin your entire day. Aristotle

hope your still working on this awesome ship. its been sometime since an update has been established. take care!

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On the drawing board: 1/72 Iowa Class Battleship
On the slip ways: Tamiya 1/350 Missouri BB63
In the hanger: 1/144 Tu-26 Backfire B And a F-105F

I just found this build and it is out of this world.

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If you are not living on the edge then you are taking up to much space