Introduction: Anchor Weight for Fishing Boat

I've got a present from my family: an inflatable fishing boat. They made me very happy. Only thing I had to do before the first trip was to collect the regulated accessories. I could collect them quickly, except the anchor. I want to use it only on lakes, so I needed any type of anchor, but in regulated weight compared to the loaded boat.

Unfortunately I found new anchors in very high price, and found no (useable) used ones. I turned to my friends with my questions, and they told me a 10-15 kg stone or piece of iron can do the job, and these are accepted in case of inspection.

I went around to buy a piece of iron thing, but all of them were too sharp to use them in an inflatable boat. So I went on an alternative: concrete block. Such type what is used in mooring, but in smaller size.

So this is a simple instructable of making anchor weights for a fishing boat (used on shallow lakes).


Step 1: Materials, Tools

Materials / tools:

  • concrete mix, 20kg
  • water
  • mixing box
  • shovel (or another tool for mixing, pouring concrete)
  • some recycled plastic tube, or used plastic bucket (*)
  • iron bars (2 x 50 cm, max 10mm diameter)
  • saw
  • file

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* I even heard of using a wellington as a mold.

Step 2: Preparing

I found a 20 cm diameter plastic tube around, and cut it in two.

I wanted to keep the concrete in the tube (not just as a mold), so I scratched their inner surface to create anchor points between plastic and concrete. (It is not necessary. I only thought it can help.)

I bent the iron bars with help of an iron tube. See shape on pics

I also get two pieces of wood, to keep the bended irons in their place.


Step 3: Mixing, Pouring Concrete

Then I mixed the concrete mix and the water well, until it was homogenous.

I poured the concrete into the tubes, then placed the bent bars into their place, and fixed them with wood pieces.

I let them cured overnight under plastic cover. Then I removed the wood pieces.

I kept the concrete wet and under the plastic cover in the next 7 days.

Step 4: Finishing

The anchor weights were ready for finishing after a week.

I simply used a piece of wood to measure the height of surplus tube from inside and copied it to outside. Then I connected the marked dots to a line.

I sawed the plastic slightly beside of the line to avoid cutting into the concrete.

Finally I made fillets around the sharp corners with a file.

Step 5: How to Use

It can be obvious, but it wasn't for me, so for those who are similar to me in this:

Anchoring in shallow water

You need to use two anchors to anchor a boat good in shallow water (less then 3 meter). One for the front and one for the back.

First drop the back anchor at least 6 meters behind where you want to anchor the boat.

Then troll forward about 3 meters past where you want the boat anchored. Keep letting out rope from the back. Then drop the front anchor.

Then, pull the boat backwards with the anchor rope in the back while letting out rope in the front. Once both anchors are out and the back anchor is far behind the boat and the front anchor is far in front of the boat, tie off both ropes tight and the boat is stationary.

Comments

author
cowboyathome (author)2015-12-19

I remember back in 1972 when my parents bought a resort in Wisconsin. Half the boats had these for anchors. They never did pull free from the "Tube" which were actually coffee cans. As the anchors where lost, my parents replaced them with purchased boat anchors.

author
dwinn2 (author)2015-08-22

iron dumbell weights work great for anchors and ive found that theyre quite a bit cheaper than boat anchors

author
Jobar007 (author)2015-06-17

You could have drilled a hole across the tube and put rebar through the tube itself. That would have prevented the concrete from pulling free of the tube.

Well done. I like this idea a lot. I've seen buckets and tin cans used for this purpose, but not a PVC pipe. I like that idea as the PVC is less marring for a hull than concrete.

author
Korvinst (author)Jobar0072015-06-25

Thanks

The concrete swollen slightly, so - till now - I cannot imagine that the concrete core would ever go free from tube.

Yes, the main goal was to protect the hull.

author
rayfinn (author)2015-06-22

Clever Idea. About how much do the anchors weigh?

author
Korvinst (author)rayfinn2015-06-25

Each is about 12 kg / 26 lbs.
I tested them on a shallow lake on a windy day. They work great. They were dragged a bit, but then sank into muck and the boat was solid. It was hard (but not impossible) to make them free later. I think they are in ideal weight for me and the boat and the lake.

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Bio: When I was young I enjoyed and immersed my Grandpa' DIY world. He was a metalwork enthusiast. He couldn't get into this profession, as ... More »
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