Hi all
I said I would post the followup on casting the fish. This will help the beginners.
Here goes. First I seal the dried plaster molds with 3 thin coats of shellac. Make sure it is thin or u will loose detail. I thin my shellac with mentholated spirits. I let the first coat dry before applying the second and third coats. U can spray it on or brush it on. If u brush it on, just check for bristles, it could ruin ur cast.
I do this with the body, fins and mouthplug.
After the shellac has dried I apply the wax. I let the first coat settle before buffing it. I appply 3 coats with buffing in between coats. I do this with all the mold pieces. I use what they call Ramwax.
After the buffing I put on the PVA mold release. U can spray it on with a touch-up gun or brush it on. I prefer to brush it on as I have better control of the amount I put on. Again if u brush it on check for bristles.
I do this with all the mold pieces.
After the PvA has dried U can start with the casting.
I start with the fins. As this is going to be a competition quality cast I opted for using clear gellcoat. I want transparency as well as flexability. U can use Finmagic for this as well. I use about 1% catalyst with the gellcoat. Make sure u don't add to much catalyst as it will definitely discolour ur clear gellcoat.
I apply the gellcoat in the deep impression side of the mold. Fill it to the rim. Brush it over to the edges of the fins. Brush it over the other side of the mold. Make sure that u cover the fins properly as not to have any air trapped in the fins.
Put the shallow part of the mold on top of the deep part and press the two halves together. Make sure that ur mold is properly slotted into place and press the excess gelcoat out. I do this to get the thinnest possible fins. I clamp the 2 sides together as to keep the sides properly closed, it also helps to press out more of the gelcoat.
After the gellcoat has set I split the 2 halves removing the fins from the mold. U just wash and trim the fins and U are ready to go.
As u can see the fins are transparent and flexible. The advantage of using theclear gellcoat is that u can heat the fins with hot water or a hairdrier and put it in the position u want.
I then start with the body and the mouthplug. I first put on the gellcoat to pull the detail of the mold. For this I use white gellcoat.
I don't put any on the fins as I will put clear gellcoat on the fins when I join the 2 halves. I also put white gellcoat over the mouthplug.
When the gellcoat is starting to set, it still has to be a bit tacky, I start to laminate the halves with the resin and chop. I put the block in and let the halves cure.
When the resin has started to kick I trim the excess chop from the mold and testfit the 2 pieces to check if they have a tight fit.
I then apply the clear gellcoat over the fins and sides of the mold. Make sure it is properly covered. I also pour a little bit in the cavity.
I put the 2 sides together and press down on the mold to get all the excess gelcoat out, and clamp the 2 sides together.
I then rotate the mold to get the seams sealed with the gellcoat that I poured inside the cavity.
After the gellcoat has set I split the 2 sides and remove the blank from the mold. U just wash the release of with soap and hot water. I also split the mouthplug and remove it from the mold. I usually fit the 2 halves of the mouthplug togeteher and pull a rubber mold from it.
As u can see the fins on the body are seethrough. I get maximum detail from a fish by using this method.
I hope this can help some beginners. As I said i'm not an expert but this works for me.
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