Crab legs.  You wont believe how much of my fly tying life has been spent wrestling elastic and other materials trying to get the perfect leg.  Ive never been satisfied.  Knotting gives me the wrong direction, Chenelle doesnt give enough movement, etc.

I found this SBS online when searching realistic crabs and it blew my mind.  Its brilliant.  Not just the moulding and moulding material, but the use of a soldering iron and wax is genius.


Latex is a wonderful tying material, you can make all sorts of incredibly lifelike flies with it. Liquid latex caught my attention when I stumbled across a lovely looking crab fly on the Internet, apparently liquid latex was used to make the legs, so I started searching. It turned out that latex was not used in that particular case, but searching the web revealed that latex had been used” in some excellent patterns.

I immediately sourced some liquid latex from Victoria and had it sent up. But the question is how does one exactly use this stuff? The method most people seemed to use for latex crab flies was dead simple, simply print out a diagram of a crab or whatever you want to copy into latex and lay a sheet of glass over the design and inject the latex into the shape you want. I tried this method, but found it clumsy and rather two-dimensional.

What I needed was a much better way to make accurate crab fly parts. I sat down and thought about it and remembered metalwork class in high school. We used dental wax to make objects which were then cast into brass. Dental wax (it’s used for making palatal impressions) is perfect for latex moulding too. It’s translucent pink, which means you can trace designs through it, it doesn’t crumble and it comes in sheets ready to use! So head down to the local dental surgery and ask for the following, or at least where to source them:

    • A few sheets of dental wax used to make palatal impressions
    • Curved, plastic tipped syringes. These are commonly used to flush abscesses after surgery.

This should not set you back much at all, in fact the nurse handed me the wax and syringes for free!

You may find hard objects around the house like skewers and the like, but to make life so much easier, I suggest going to the newsagent or craft shop and buying a cheap craft multi-tool. Mine came with blades and three different heads: a spike, curved tool and ballpoint tool. It set me back around nine dollars. No big drama.

To build the crab fly…

You can now print out a design from the web, or go freehand. Use the tools to gouge nd press out your crab fly design. You would want to go as deep into the wax as possible, I like to almost break through. If you are worried about the tool coming out the other side, you can simply put another layer of wax underneath.


Once your design is finished you can fill it with latex. Using the syringe, fill the mould. Any excess latex can be easily removed with a cotton bud or folded tissue. The latex should take about 5-20 minutes to set, depending on how much you have used and air circulation. To speed up the setting process you can put the mould in front of a fan. Do not put it in the sun or near a source of heat!

The latex will go a clear yellowish colour when set. You can then lift it from the wax and make some fantastic flies with it – not just a crab fly!

Latex accepts ink from permanent markers with ease, it bonds with superglue very well and it can be tied onto a fly using a thicker thread such as flat-waxed nylon.

I have found it is best to leave the latex to fully cure for a couple of days before use, as the bottle I bought has a habit of going white when wet if put in the water within 48 hours. This is apparently not normal. Also, store the crab fly in a cool, dark area, not touching others.

How is that!

link back!:

Peter Coetzee

Peter Coetzee

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One Response

  1. Unimaginable heights of OCD! Obsessive cab disorder. Saw my first two roosterfish in the surf wash today, both fish were over 25 kilos, chasin meter long needlefish! My five inch EP fly was dwarfed. The hunt continues…

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