Clay Fins and Tails my Way

I know there are many, many artists who can do mermaid (or dragon) fins and tails much better than me.  They can also write a better tutorial.  But, I said I’d do this for my friends and here goes.

I use a mixture of Fimo clay for all my sculpts but, for the most part, I have used pure Fimo translucent (number 00) for fins and tails or spines on dragons.  The older formula of translucent usually bakes with a series of circles that adds to the look of the fins if left a very light color.  If the circles are not desired, either the Genesis heat set oils or any acrylic will cover the inner texture.  I have yet to use the new translucent formula, so I don’t know if the same characteristic appears in the newer clay.  If you prefer, use the same color clay as the body of your sculpt; just make sure the clay is well conditioned as the clay is much easier to maneuver and shape without cracking.  

This sculpting technique should be workable with any brand of polymer clay; but, since I don’t work with the other clays, I can’t vouch for the results.  Test first to see if the same strength applies to other brands before adding fins to your work.  The Fimo clay is very strong and has enough pliability to bend slightly instead of breaking – after baking properly.  Although I can attest to the strength of fins made ‘my way’, I would NOT trust a fin or tail in a support position for the sculpt body.

If you are not accustomed to working with thin sheets of clay, I would recommend some practice with scrap clay.  My experience was gained when I worked with mending or altering porcelain figurines and many of the techniques of porcelain work transfer well to clay figures.

The tools I use can vary but the main selection include:

I work on a large marble floor tile but use whatever work surface you are prefer.  The following instructions are for the fins, spines or tail only, the sculpted body should already be baked to the manufacturer instructions.  The particular sculpt in this tutorial is a merman with Genesis heat set oil (green) already baked to the under tail section, then scales were applied and baked again before I began adding crown or fins.  I did not take pictures of the crown but it was made in the same manner as the tail fin, only using a thinner piece of clay and a tiny spaghetti clay edging. 

All hardening to the fins was done with the Genesis heat gun after each section was complete, then the final baking was done as a full bake in the oven.

PLEASE NOTE THAT ALL MEASUREMENTS STATED ARE FOR SCULPTS THAT WOULD MEASURE LESS THAN 7 INCHES TALL IF STANDING.  The merman used in the photos would be 6 ½” tall from the top of his head to the bottom of his feet (if he had feet).  Smaller sculpts would take thinner strips of clay and larger pieces would probably need more thickness. 

Roll a piece of clay to the size of your thumb – again, please make sure the clay is well conditioned; place the cylinder on your work surface and roll out to a thickness of 1/16^th inch.  I used my clay roller but, use a pasta machine if you choose. 

Using the Exacto knife, cut away the uneven edges and divide the remaining strip into two long strips – each approximately ½” wide.  This will be more than enough to make both arm fins, both side fins and the upper back spine fin.

For the arm fins, cut two angled pieces approximately 1&1/4” long from the longer section – cut both these pieces at the same time so they are the same size.  Choose how you wish the fin to ‘grow’ from the arm – I placed Triton’s fin from his knuckles, around the wrist to the outer edge of his arm and almost to the elbow.  Place a VERY thin track of Fimo liquid where the fin is to be applied.

Carefully lay one of the clay strips along the line of Fimo liquid, tapered edge toward the fingers.  The clay strip lays almost flat toward my right hand (left hand if you’re a lefty).  Using the #6 metal knitting needle, start at the knuckle end and begin to press the fin clay onto the arm flesh.  I know we’re not supposed to ‘move’ clay with our tools but with the fins this has to be done.  Gently press the bottom edges of the fin clay onto the arm, pushing from the body of the fin toward the edge attached to the arm.  Don’t go too far up the side of the fin or your clay will become too thin and a hole will develop between the fin and arm.  It only takes a small amount of fin clay to make adhesion.  Work all the way down the fin in this manner until you have the whole fin slightly attached on one side.  I had my clay a little too long for Triton’s arm and had to snip off the elbow end with scissors.  Clean off any tiny lumps of clay squeezed out by the application motion – either use the Exacto or the knitting needle and add a thin coat of Fimo liquid to further smooth the joining.

Lay your index finger along the arm as close to the fin as possible.  Gently raise the fin along your finger and repeat the process of attaching the fin the same as with the first side.  This raises the fin perpendicular to the arm.  Clean off any tiny lumps and smooth as with the first side.  Check both sides of the fin to be sure there are no holes along the joining of fin and arm – or any spots where there are sections that have become too thin.  If there are very tiny holes along the joining, use the same technique as the general application to attach the fin, closing the hole.  If there are too many loose sections – or a section that is too thin – remove the fin, clean all fresh clay & liquid Fimo and try again.  It’s better to retry than to attempt too much repair. 

 Once the fin has been attached & the joining seam is smoothed start to ‘texture’ the fin.  Again place your finger along the opposite side of the fin for support – place the knitting needle a little more than half way down the depth of the fin and pull it gently toward the outer edge of the fin – gently.  This makes the fin slightly thinner along the outer edge and gives an erratic look to the fin edge. Do this all along the length of the fin.  Repeat the same process with the other side of the fin.  Be very careful when texturing the fin, if you pull too hard you will detach the fin from the arm and will either have to reseal the fin back to the arm or start over.  Once the texturing has been completed on both sides, use the knitting needle to ‘push’ the outer edge of the fin to one side or the other to give a ‘wavy’ appearance.  The fin can be left straight if you desire but I believe the waving adds strength to the fin structure.

 I harden each fin after completion with the Genesis heat gun.  The fins are quite thin and a thorough application from the heat gun will cure the fins enough that they are already very strong – though the whole sculpt needs to be baked fully after all fins are finished.  Setting each fin with the heat gun allows handling while working on additional fins without misshaping the one already completed.

 The side fins and back spine fin are done in the same manner as the arm fins, just using a larger triangle of clay.  If you desire, a wire armature can be added to the longest parts of the side fins or spine.  If you do this, either a wire should be taken into account during the initial sculpting process of the body or a hole must be drilled for the wire; the clay can be attached as per the instructions for the tail fin edges.  I haven’t used wire on Triton since he is so small.  On the larger dragon, Sneekers (photo at end of tutorial), I did use spine wires on his head to give support for the taller spine; other than that the application was the same as for Triton.

Clay for the tail is worked up in the same manner as the other fins; I used a thickness of approximately 1/8^th inch for Triton.  The flattened clay should be larger than you intend to make the tail – the shadow is of the carry strap on the camera, not a color in the clay.  Decide what shape you wish for the tail and make a rough cutout with the Exacto, keeping the cutout slightly larger than the wire armature of the tail.  The tail should have wire armature on each side at a minimum, Triton has three because of the triple point design I used.  The wires were coated with a thin film of Gem-Tac glue and allowed to dry thoroughly prior to the application of any clay.   You can either use the design of two wires (Charis has two – photo at end of tutorial) or as many as you wish, just remember that the more wires used, the thicker the tail will be on completion.

After cutting out the tail shape use a fairly large rounded wooden tool to shape the ribbed look of a fish tail.  Start about ½” from the tail/body joining area; press down gently and draw the tool toward the outer end edge of the fin.  I stopped the pattern where the middle wire would lay and began again on the other side.  Carefully lift the clay away from your work surface and turn it over.  Repeat the rib process as with the opposite side.  Try to keep the patterning as equal as possible for a full ribbed effect – thinner portions the same on both sides.  Don’t worry if the patterns don’t match exactly, it isn’t critical and offset ribbing can add strength to the tail.

Add a VERY  thin coat of liquid Fimo to the bottom joining area of the body (ankles) and an even thinner coat along the armature wires.  Carefully pick up the tail shape and lay it across the wire armature of the tail fin.  Gently press the clay along the armature wires to support the tail shape.  Either use your fingertips or one of the sculpting tools to press the raw clay against the baked body and smooth out the shape where the tail joins the body.  Clean out any scales that were covered in the process.  Shape the joining around each side but leave the under side until later. 

There should be just enough excess clay left beyond the armature wire to wrap around and cover the wire: trim with embroidery scissors prior to wrapping the wire.

Turn your sculpt so that the bottom side of the tail is toward you – make sure you support the tail with your hand as it will still be loose and can fall away from the armature at this point.  Wrap the small excess clay around the armature wire, starting at the tail junction and working toward the outer edge of the fin.  Repeat this with the other side of the fin. 

Press the center spine into the clay and taper the end to a point – also taper the outer spine ends into a point.  For those of you who like to add curled wire ends (usually jeweled), make sure to allow for the extra length when you add the armature to your sculpt.

Cut a very thin, long and narrow strip of clay to add to the bottom side of the center armature wire.  Add a minute amount of Fimo liquid to the wire and press the strip along the length of the wire.  (This is where thickness will come in if you have multiple armature wires in the tail.) 

Starting at the tail/fin joining point, begin to smooth the armature cover clay with the metal knitting needle.  Use strokes that begin at the base of the tail and work toward the outer edges of the fin.  Smooth the outer armature wrapping in the same manner.  Once the clay is thoroughly adhered to itself further smooth with a larger tool or your finger.  A small amount of baby oil or hand lotion on a small brush will help smooth the joinings.  I used the larger wooden sculpting tool to smooth even further – the baby oil made it glide quite easily along the fin.  Shape the fin with curves to add grace to the fin.  Bake with the heat gun until hardened.  Those of you who don’t have a heat gun will need to bake the sculpt in the oven between fin applications.  Baking after this point in the tail structure is critical, if the clay is underbaked it will crack if you wish to add the support fins to the top and/or bottom of the tailfin.  If you don’t use the heat gun to harden the tail, I would recommend supporting the weight of the tail with cotton quilt batting.  I don’t know if the structure would sag but there is that possibility.  Once the tail has been hardened thoroughly, either with the heat gun or by baking, it will not alter in shape during further curing in the oven. 

The following pictures depict the addition of body spines on the top and bottom of Triton.  Application of these two fins are done in the same manner as the arm fins but care needs to be taken when working over the tail.  If the tail has not been cured thoroughly, it will crack from applied pressure when attaching the spine fins – if cured thoroughly the tail structure is quite sturdy.  I still support the structure with my hand – either working over my fingers or over the top side of my hand. 

After all ribbing and smoothing is compete, bake your sculpt fully.  I sincerely hope this tutorial is helpful to those who don’t already know the process.  I know there are other techniques for sculpting fins, perhaps better than the one I’ve explained.  All I can say is that this technique works for me and the fins and spines I’ve done in this manner are strong and are holding up over time.  I’m sure rough handling would cause cracks and breaks but no more so than with any other delicate part of our fae creations – it’s certainly stronger than the fantasy film and may last longer over time.

 The following pictures are those of completed sculpts using the process described in this tutorial.