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[Nick-R]

So I have carried out some flotation tests on my Billings Nordkap.  The good news is that the hull is watertight but will need some ballast.  Experimentation suggests I need around 1.2 kilos less the weight of gear - motor, battery, etc.  this is split roughly 500g towards the stern and 650g further forward.  Once the deck is fixed in place, I lose easy access to the forward spaces so need to get this right now and whatever I use for ballast needs to be fixed in place.


Back in the day, I was able to source sheet lead from friends working in local shipyards but sadly these days and the shipyards are long gone!  What do people use for ballast nowadays?   I have looked at fishing weights on Amazon but these seem quite expensive to get enough weight at sizes required, not mention awkward shapes.  I toyed with the idea of sand in bags but have dismissed that as not very practical.  What do you use?

[T888]

I use lead flashing which you can get from Amazon or B&Q. Or Google lead Flashing

[derekwarner]

Nick....lead shot from a GunSmith store  ............[same idea as your sand bags, but about 7 times heavier]

Can be placed in Glingwrap or plastic bags and uniformly dispersed...... can also be encased with epoxy resin [rembering the epoxy resin is also a dense {heavy} medium

Derek

[Backerther]

Hi
I used 4 pieces of lead ingots for main ballasts totaling to about 10kgs in my HMS Fencer 1/96.
They are surely expensive, instead very effective to keep a good balance and stability on the water
due to their flat and low ingots. I laid the ingots less than about 1"high from the bottom of hull.
One of the characteristics of the aircraft carriers (both real one and the model) has been said to be top-heavy.
But these lead ingots got my Fencer to improve remarkably her stability than ever before as seen in the video. 


See the video below;


https://www.youtube.com/watch?v=4f-fI3S6f1E&t=5s

[Nick-R]

Thanks to all for responses especially backerther!  I searched online for fishing weights, lead weights, sheet lead, lead flashing, etc but not for lead ingots.  When I do, lo and behold, there they are, reasonably priced on EBay!  I can buy 4 x 450g soft lead ingots for £7.50 and these should easily cut into appropriate sizes/weights for placement low down in the model.


Cheers again!


PS. very nice Fencer model!

[Geoff]

As an alternative, concrete is pretty good as well. A dry mix can be spooned in and pushed into shape. If you need to remove it line the hull with clingfilm and insert a screw-eye into the wet mix. The clingfilm stops it sticking to the hull. Once dry if you paint it in varnish of a water mix with pva glue it stops any future dust.


Concrete is good because it has a higher centre of gravity than lead. It all depends on the model but if there is too much weight low down you get great stability but too much "bobbing" which is unrealistic.


Cheers


Geoff

[Backerther]

For more information on the specific gravity of various metals supposed to be suitable and available for model boat ballast;
From the heaviest;

1;lead(Pb)...11.3        very expensive     less space and large stability in the hull, easy to cut but harmful !!
2;copper(Cu)...8.9      a bit expensive
3;brass........8.4         a bit expensive
4;iron(Fe)....7.8         not so expensive
5;aluminum（Al)...2.7    a bit expensive as being light   


concrete.....2.3-2.4                         

[NickelBelter]

I use steel bar stock from the scraps bin at work, cutting little lengths to fit between the frames inside the hull.  I've also bought BBs to mix with epoxy and pour into tighter areas. 

[Nick-R]

For more information on the specific gravity of various metals supposed to be suitable and available for model boat ballast;
From the heaviest;

1;lead(Pb)...11.3        very expensive     less space and large stability in the hull, easy to cut but harmful !!
2;copper(Cu)...8.9      a bit expensive
3;brass........8.4         a bit expensive
4;iron(Fe)....7.8         not so expensive
5;aluminum（Al)...2.7    a bit expensive as being light   


concrete.....2.3-2.4                       

Face mask and rubber gloves when cutting lead is de rigour!

[Backerther]

And..I covered whole ingot fully with the heat-shrunk film for RC plane followed by painting
for a better appearance as well as my good health and easy handling of the harmful stuff.
I also applied non-slip rubber to it for a secure sitting on the deck inside the hull.

[Nick-R]

That is belt and braces! 


Nordkap is though a plank on frame construction and there is only around 5cm between the frames.  This makes it fairly easy to prevent movement fore and aft plus the hull shape naturally stops side to side movement but for good measure, I will epoxy the lead in place.  This is particularly necessary towards the bow as once the deck is fixed, there is virtually no access to forward areas of the hull.

[dodgy geezer]

If you have the room for a lighter ballast, water in cheap plastic containers has the huge benefit that you don't need to carry it to and from the lake...

[1967Brutus]

Lead sheets in rolls of up to 5 kilo can be bought in most stores for DIY home renovation. At least where I am... They use it for rainproofing roof ridges and chimneys and such...

In general: most people put their ballast "as low as possible" in the hull and sometimes that absolutly is necessary, but in my experience it is sometimes more effective to place the ballast as far as possible to the sides, rather than as low as possible: this increases roll-axis inertia which gives the model a much steadier appearance. With  ballast as low as possible often boats become a bit "bouncy" on the roll axis.
Both my boats (Borkum and Alexandra) have their ballast in the sides at approximately waterline height. Borkum is rather wide and still a bit bouncy, but Alexandra is pretty steady with the waves coming in from abeam.

[ColinB]

Hi Nick-R.
I have just started putting ballast in my Nordkap which is almost complete. I got thin lead strips from my mate who is both builder and fisherman.
Cutting the 6mm strips into 45mm lengths they drop nicely on the keel and between the frames. With tweezers I can slip some through the fore hatches. I will fix them down with some plasticine.


Thanks for the heads up about about side ballast Brutus. 

[roycv]

I ballasted a boat a few years ago with plated 2 pence coins.  I rolled them up in papre tube and glued it and slipped them in place.  So my models have a small investment inside earning its keep!
Roy

[AndyR]

Scuba diving lead shot weight pouches are good.
They come in a variety of sizes and the shot is already bagged up.
You can also get the shot loose

Usually about £7  a kilogram

[ColinB]

I ballasted a boat a few years ago with plated 2 pence coins.  I rolled them up in papre tube and glued it and slipped them in place.  So my models have a small investment inside earning its keep!
Roy

Reminds me of the story our much travelled History teacher told us at school in the 60s.
He said the government of an Arab state had issued low value coins with a hole in the middle and within a year they had all disappeared, so they minted another batch and they quickly disappeared also.


On investigation it was discovered that the dhow makers were using them as washers on their boats as they were cheaper than washers.

[AndyR]

A 2p coin weighs 7.2 grams


So a kilogram would cost you £140

[roycv]

OOps'  There are 140 2p coins in weight in a kilogram.  That comes to £2.80, not a bad investment and what with the UK almost going without coins now, they may even increase in value due to rarity!
Roy

[AndyR]

oops yes, didn't times by two lol

[1967Brutus]

Hi Nick-R.
I have just started putting ballast in my Nordkap which is almost complete. I got thin lead strips from my mate who is both builder and fisherman.
Cutting the 6mm strips into 45mm lengths they drop nicely on the keel and between the frames. With tweezers I can slip some through the fore hatches. I will fix them down with some plasticine.


Thanks for the heads up about about side ballast Brutus. 

Here's the proof of the concept:

https://www.youtube.com/watch?v=WF1iqISsdQo

Waves close to freeboard height, as exactly abeam as I could manage, and because wave frequency and natural rolling frequency are wide apart, there is barely any rolling at all...

Same boat, same ballast condition, torquerolling on the irregularities of the engine for comparison:

https://www.youtube.com/watch?v=t8S6NmNbQz4

[ColinB]

Amazing! 

[chas]

Excellent proof, it's nice to learn something new.