Hi, I’m cleaning and fixing our buoys and I’m looking for ideas on what to use as weights for RC buoys. I use divers buoys as mark as they are easy to transport and won’t damage the boat during a contact.

So far I’ve been using old shackles that the yacht club used to attached club marks and cardinals (2 or 3 were perfect depending on their size) but they’re becoming very rusty and I’m looking for something else to replace them. we’re on a budget or should I say very little of it so we try to recycle stuff we can use as weight.


lead dive weights are great sicne the lead won’t rust. 1/2 liter soda bottle filled with concrete would probably work as well. Nice thing about putting it inside the bottle would be the bottle would help “encasulate” the concrete… here in the states a 50lb bag of “just add water” concrete mix is about 10 bucks…

the shackles could still be used if you were to paint them or dip them in some sort of rubber coating to stop the rusting.

I have a smelter and use a small cupcake mold to make our lead marker weights. they are about a kilo in wieght… and I drill a hole through the center for the line to pass through.

the biggest issue is that with lead, you get more bang for the buck IE most dense for the smallest space. anything less dense and it takes up more space to store…

Have you though about going to a metal recycler and seeing if they are willing to sell you lead? maybe they can even melt and pour into a mold of your own size/shape. take an old steel cupcake mold usually about 6-9 cakes and have the recycler pour the molten lead into the molds. quick way to get 6-9 weights… and potentially pretty cheap…

Thanks Marc, I have already dipped the shackles in a rust treatment paint after having cleaned them with a steal brush. Worked for the last 2 years but sea water and seems to have chipped the coat off and enabled the rust to come back. Some are still salvageable but I need more weight.

sorry what is a cupcake mold ? is it a steel tray with 6 or 9 holes for cupcakes ?

I like the idea of the concrete in a bottle - not sure the price here but shouldn’t be expensive. Lead is a good idea too but not confident handling lead… (melting it to pour in a mould)- was thinking of little plastic pots and pouring concrete in it and inserting a hook before it sets but I prefer the water bottle- don’t know why I didn’t think of that I’ll go with that first and see how it goes… any old concrete will do or is it better to use a particular more resistant to sea water ?


if you were able to take this pan to the metal recycler and have him pour it. takes the risk out of handling it on your end… you’d need the recycler to insert a screw eye into the mold as its poured, other wise you’ll have to drill a hole in the lead. to accept a screw eye. Keep in mind that handling lead can be safe. disposable rubber gloves. and drilling lead is fine sicne you aren’t creating a dust, just some “chips and chunks” which can be swept up… after you don’e rattle can of primer that way you can “handle it” pond side with out having to worry about handling lead…

the hardest part about the concrete would be getting it into the bottle… Some concretes uses larger aggregate material, which would make it hard to get everything into the bottle. I guess if you cut the top off the bottle and then embed the screw eye into the pour…

I guess you could always use plaster of paris since it is a much finer blend I guess the end weight would be the same I’d bet the plaster of paris is much more expensive than concrete…

another option…go to a home improvement type store and get some copper pipe with two caps. solder one end on the pipe. and fillthe pipe with sand. drill a hole in the oother cap, put a screw eye in the end and then solder the cap on…

Not sure if you are referring to permanent buoys or just temporary ones.

In our local pond there are a few permanent markers. WHoever did them used concrete buildiong blocks as anchors.

The blocks used are the large ones with a couple of holes and a web in the middle - use some galvanised chain from buoy to brick, loop chain around web in the brick and secure with a galvanized shackle - lasts forever…
Some pictures and dimensions in this link

While this is an Australian product (and I believe you are in US?) I would imagine there would be a similar product available in your area.

Also the price is pretty right…

Hi, no I’m looking for temporary ones. we sail in different places but all from yacht clubs so we can only leave the marks for the duration of our sailing. The shackles were free and worked very well for a good 3 years now but they become very rusty now and leave rust flakes everywhere and since we often use rescue boats that the club put at our disposal I want to keep their boat clean and the weight easy and safe to handle.

no I’m in in Dublin USA, though I believe there are about 15 Dublin in the World, I’m in Dublin Ireland.

In one of the dinghy club I was member of when I race fireball they made up the weight by pouring concrete into a tyre by blocking the opening at one end by a circular wood plank. Worked well by too heavy for what I’m looking for but a potential solution for people who are looking for a cheap weight for semi-permanent marks.


Can’t you keep it simple and use a brick. “Engineering Bricks” as they are known have holes going through them.


Thanks Mark - yeah ok I thought it was something else cos here we tend to use rubberised trays for the cup cake - unless I can find some bakery somewhere that uses these styles of trays but only seen rubberised one so far.

The silicone type trays should work fine for lead. You might have to support it, but lead is fairly low temp for a metal and can be poured into silicone molds. there are even silicones that are designed for foundry work.

We use the concrete in a plastic drink bottle, after cutting the narrow top off. Bend a piece of wire, preferably stainless, but a coat hanger works too, into a u shape, with an additional 90* bend in each leg, and stick it down in the concrete before it hardens. Use this to tie off too.

We use waterski marks from Overton’s at about $6 each. We attach a short length of chain to them with a pulley at the end. Then we use a heavy anchor and another lighter one at the other end of the line after running it through the pulley. The heavy one sits on the bottom and the lighter one keeps the line tight and vertical so no one snags a keel on it. So far it has worked for us in 6’ to 35’ of water.

I have used the silicone trays as well…but they won’t last forever… the silicone trays are also good for mixing up epoxy. once the epoxy hardens, just pop it out…

I figured the metal trays are much easier to find and probably cheaper…

same as I set them up - 3 shackle for the main weight and one lighter one as a traveller going up and down on the rope attached to the main weight as we sail in the sea with tides. works well in varying water level to keep the line straight. - will try the water bottle filled with concrete.


Quick update on these buoys… I found a ready mix concrete bag in our local hardware store. they had ready mix bags of cement and concrete. I decided to go for the concrete cos I thought it would be heavier and tougher then the cement ! bought a 20 Kg bag for €6.95. Brilliant !!!

I then decided to use milk bottles. 2l bottle. I find their plastic is tough enough to keep the concrete in without breaking after a few days dropped in the water and pulled out. Time will tell ! The BIG advantage I saw was it has a handle so it would make it much easier to handle.

I have bolts with a loop at the end witch I sink gently in the mix before it sets (c10mins) and to ensure pull resistance I put a big washer and a bolt at the bottom of the thread.

first one I did I respected the recommendation of filling with half way with water then poor the concrete mix but I found that the water was coming out as was pooring the concrete mix so for the second bottle I didn’t fill half way but less and added water as I poored the concrete in, steering the mix in the bottle so it would mix more with the water instead of simply sinking to the bottom of the bottle so we’ll see what will work in time…

Have not tried them yet but they look heavy enough - I’ll have to “play” a bit more with the pooring to get a more homogeneous mix with the water. Sorry didn’t take pics yet but might come later.

Thx all for your advices.