Topic: Ballast? (Read 7486 times)

tizdaz · « **on:** January 10, 2019, 02:11:10 am »

Hi guys
At the mo im using my SLA batterys for ballast, each battery weighs around 13kg & i have 4 in the hull atm but i still need around another 15-20kg ballast, i was thinking of using lead shots mixed with epoxy but theyre expensive (would cost around £70+ for 15-20kg!!) other thing i was looking at was Ankle Weights (those used for exercising!) as some of them have removable weights, cost about £15 for 10kg, but does anyone else have any other suggestions?
cheers

Plastic - RIP · « **Reply #1 on:** January 10, 2019, 05:49:42 am »

You can get bags of concrete from Wickes for a fiver - and you can mould that into whatever shapes you want - it it's inside a plastic bag then it can be removable - you can also put a handle into it for lifting.

Also, look for people selling weights sets on ebay - most people just want them gone if you're prepared to collect.

Just how big is this boat? 1:1?

coch y bonddu · « **Reply #2 on:** January 10, 2019, 07:30:41 am »

5 feet TID TUG Daz why not simply get hold of a builder and get hold of some lead off cuts

Dave

Skimmer Fan · « **Reply #3 on:** January 10, 2019, 07:38:22 am »

tidtaz
Would these be of any use.
https://www.mightonproducts.com/products/sash-window-hardware/sash-weights/lead-weights

coch y bonddu · « **Reply #4 on:** January 10, 2019, 08:17:21 am »

Maybe that's why I use a 12v car batt and 2 other batts as well[size=78%] [/size]

Dave

Allnightin · « **Reply #5 on:** January 10, 2019, 08:54:42 am »

I used empty plastic 2 litre milk containers filled with gravel in my 1/32nd HMS Gloucester.

Very cheap, convenient to handle and quick to lift in and out when lightening the hull before lifting from the water

Klunk · « **Reply #6 on:** January 10, 2019, 09:04:28 am »

I have old lead flashing that i recast into strips 60mm x 15mm x 5mm. I can then line the bottom of the him and till mould them to shape. held in place with silicon. just be careful melting and pouring the lead. no water anywhere near molten lead!

tizdaz · « **Reply #7 on:** January 10, 2019, 06:52:13 pm »

Cheers for info guys some good suggestions, i wanted to use smaller 12v SLA batterys instead of a car battery as i can then also use the batterys in future smaller builds where a car battery would be too large. But like i say some good suggestions so will have a look a think 🤔 cheers guys!

tizdaz · « **Reply #8 on:** February 22, 2019, 02:58:57 am »

hi again ^^
ok ive had a good think, lead shot weight is just out of the question due to price, concrete i would need alot so would take up too much space, but my other alternative is Steel Shot which ive read isnt that much lighter than lead, but much cheaper?

What is the best & cheapest method to make a mould out of the steel shot? What i mean is... I want to place them into different sections of my hull to even the weight out, im thinking of placing a plastic bag on the surface of where i want to put them, then basically pour some sort of glue over them so they all stick together & make a solid piece of weight, doing this will give me a mould that will be pretty much the exact shape so i can remove/place with ease for ease of transportation with no messing. But im not sure what method is best to use for sticking the shots together to make the mould? Would the cheap PVA glue do the job if i just poured it over the shots when in place & then just wait until it sets?
Any suggestions/advice appreciated as always ^^

Klunk · « **Reply #9 on:** February 22, 2019, 03:06:18 am »

shame you cannot weight till Mayhem. could have bought you some lead along so you recast it

Klunk · « **Reply #10 on:** February 22, 2019, 03:06:45 am »

ps that's not a spelling mistake!

tigertiger · « **Reply #11 on:** February 22, 2019, 03:58:00 am »

One method I have used for filling a space with shot is to put epoxy resin into a bag, and add some shot. Swill it around to cover the shot, and then add more shot, swill around and repeat.

Variation on the theme,

Using a heavy duty plastic bag, and you can place it where you want, it will settle and your hull will act as a mold. You can also set some form of handle into the mix to be able to lift it in/out when set.

If you use 2hr epoxy and you will have plenty of time.

Antipodean · « **Reply #12 on:** February 22, 2019, 04:46:19 am »

Maybe get hold of your local tire shop and see what they do with the balance weights they take off wheels.
I grab them from my local shop by the pound and at a good price too and then melt them down and cast 5 lb ingots.

BrianB6 · « **Reply #13 on:** February 22, 2019, 08:47:31 am »

Just be careful of the fumes.

david48 · « **Reply #14 on:** February 23, 2019, 12:07:13 am »

I think you will have to make certain that the steel shot is well covered so that no moisture can get in or you will have a big blob of rust in no time .
Have you looked on shot gun cartridge loading sites , Mabey you know ,or not but shot comes in many sizes , so smaller the shot it will take up the space better .
Some where on here is a link to a shot supplier it might be less money , anyway you have spent a lot of time and effort on this project so using lead might be the best option to keep up with the rest of your work . Try your good local Builders merchant and ask for Code 4 lead flashing , it comes in rolls ,lead price varies week to week , wheel weights have metal in the to knock on to the rims so that's to get rid of and the ones for ally wheels are contaminated with the glue so as below fumes are a big no no
just may take on it ,but who am I
David

Buccaneer · « **Reply #15 on:** February 24, 2019, 09:20:47 pm »

Lead Flashing from a builders merchant has a specific gravity of 11, i.e. 1 cubic centimetre weighs 11 grams. Lead shot has a specific gravity of about 8.3, i.e. 1 cubic centimetre weighs about 8.3 grams. The details on lead shot are the same whatever the size of the shot. Using smaller shot will not get you more lead in. It is all to do with the mathematics of spheres, the ratio of space to filled volume is the same regardless of the size of the sphere. I noted this from a post on here a few years ago.

John

roycv · « **Reply #16 on:** February 25, 2019, 12:48:58 am »

Hi, I think someone else where on this forum worked out that lead shot in volume, etc had the same specific gravity of steel in bar form so that goes along with the previous thread.
regards

Roy

Captain Flack · « **Reply #17 on:** February 25, 2019, 01:30:50 pm »

You could use steel shoot mixed with a waterproof glue. I have it in the keel of my Fairwind. It hasn't gone rusty nor has it moved.

CGAux26 · « **Reply #18 on:** February 25, 2019, 02:13:25 pm »

I Googled it. Lead shot vs Steel shot. 11.1 grams/cc vs. 7.86 grams/cc.

tizdaz · « **Reply #19 on:** February 25, 2019, 02:28:58 pm »

Brilliant info, thanks guys, so steel aint too much lighter than lead, im going to pick it up on thursday so i can see exactly how much it is but going off info here i think should be good! Will let you know, thanks again guys 🙂

Netleyned · « **Reply #20 on:** February 25, 2019, 03:11:30 pm »

Nearly half the weight Steel to Lead.

Ned

CGAux26 · « **Reply #21 on:** February 25, 2019, 03:16:19 pm »

Yeah, doin' the math, lead is 41% more dense than steel. So using steel shot will require 41% more of the boat's volume to achieve the same ballast effect. May get crowded in there.

BTW, which is heavier a pound of feathers or a pound of lead?

tigertiger · « **Reply #22 on:** February 25, 2019, 03:25:46 pm »

Steel bar will be heavier per cubic cm, than shot. Square section bar can be laid parallel to each other, and stacked. A good coat of waterproof finish, be it epoxy resin or paint, should stop it from rusting.

Netleyned · « **Reply #23 on:** February 25, 2019, 03:36:17 pm »

Lead bar heavier and less space taken up and don't rust.

Ned

Tug Fanatic · « **Reply #24 on:** February 25, 2019, 05:14:06 pm »

Quote from: Netleyned on February 25, 2019, 03:36:17 pm

Lead bar heavier and less space taken up and don't rust.

Ned

Still a good idea to seal it as it is not nice stuff if you end up with any inside you.

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Author Topic: Ballast? (Read 7486 times)