Rachel, I like that plan. Can you let us know how it works out?
I’ve been using a thin hacksaw blade and some increasingly calloused thumbs, followed by careful sanding. Just got a rounded surform, may get a round rasp or rat-tail file, but if that 1/4" drill bit method works, that’d be perfect.
Rachel---That is a great idea. As far as the comment that the drill bit would slip off to one side; that is easily solved by drilling a smaller pilot hole. The only problem that I can think of is that you may want to drill the hole at a slight angle to blend with your eventual rail contour off the tail. Drilling a hole is a common carpenter trick before taking a power saw to plywood, siding etc. and pilot holes always make drilling a larger hole easier.
Or use a pre drilled piece of sheet , wood or plastic, as a guide for the bit - clamped or held in place by a glamorous assistant.
I’ll try it on my upcoming build - what a pain it is cutting that swallow sorry fish tail.
not my saws mate. my chisels are kept in a draw. sharp. japanese saws are lying all over the place in piles of foam and wood dust. my father inlaw sends them over to me. they are about 10bucks in a hardware in tokyo. i was selling them to compsanders until they turned on me like rabid dogs
oh sweet jesus im a jeweller for godsake . i can saw pierce anything
the japanese saw is the tool for the job it cuts a perfect v notch in the stringer that doesnt require sanding or any other finishing. which is also the secret for piercing metal. its finished off the saw
saw pictured below is a hacksaw
for hacks
it only takes a few minutes as well. i might post a video on a fish im doing in the next few weeks
If you guys check the ''winterfish'' thread you'll find that a fish is now a roundtail so you don't need any special tools.
no. a fish is a aquatic creature with gills:)
Refraining from poking rabid dogs with sticks often avoids them turning on you 
where i come frome we just shoot them 
But who would be game enough to give you a gun?
when you a hack like me you need all the help you can get. this one turned out allright until i ruined acidentally using uv resin in a open garage. a beam of light cured a part half way through a resin swirl
im aplying for my license so i can discover the inner redneck and shoot some innocent animals
you only have to be 18 to get a slug gun.
This type of hack saw blade handle is great for just that purpose - cutting fish tails, not killing dogs and animals. You can use old broken blades and install them to cut on the push or pull stroke. The ‘teeth per inch’ dictate the use of the various blades but for cutting foam any old blade will do.
The hard part for me about shaping swallow tails isn’t so much cutting the outline as tapering the stringer in the notch. A dremel cut off wheel works for that. Just cut in to the stringer from each side and try to make the cuts meet right down the middle. A round file works good for knocking the rest down to size.
I’ve seen posts here that some guys use a utility knife and cut in to the stringer from either side.
By any method the trick lies in not F’ing up the foam on either side of the stringer.
http://www.rjtool.com/p-1378-hacksaw-blade-holder-cal-van-406.aspx
I have one good saw to cut all my outlines including butt cracks. I just cut bands like shaping a rail and clean up with surform. Wouldn’t work if you had concave crack but most don’t.
Question for you all; What if we leave the bands and don’t smooth the crack. Would it promote easier water release? Anybody do this already? Seems plausible as the crack is a huge curve and could potentially create drag.
[img_assist|nid=1048258|title=fishTailDiagram|desc=|link=none|align=left|width=610|height=640]
I use a fine-toothed Japanese pull saw (prefer the rigid-backed ones myself) and then a microplane small round rasp. Then work on the surrounding foam with the normal tools for foam – its getting the wood cut down right first that does the trick.
http://www.billabong.com/eu/surfboards/gallery.php Click the link and at the bottom right there are 2 boxes that say video, click the first one and you will see a fish being shaped from start to finish using a Japanese saw and wood chisel for the tail, second video shows a nice glassing, hot coat, finbox install, sanding and polishing. If these videos where posted before sorry for the repeat
Tom
Most of the sugestions here are fine - I use a hack saw blade and although someone on here said “Hacksaw blade is for steel not foam”, don’t worry it gets through foam pretty easily and cleanly and gives you enough movement to cut the arc in the tail that you need.
Tips:
cut it (most sugestions here are fine for tools) but cut about 3mm (1/16") outside the line of the tail
clean it up / square it up with a sanding block.
The important thing is to get the cut square so that you can get a clean outline when you shape the tail
Just to clarify - when I say square it up, I don’t mean shape it into a square tail
I mean that the cut is at 90 degrees to the deck or bottom of the board (whichever you square up with)… I square it up with the bottom as when you shape the tail down, you end up with only foam in the bottom section of the tail (ie. you foil the deck side of the tail down)…
If you don’t square it up, it may look OK when you have made the cut, but it will get a kink when you shape it down.
Other sugestions on here for cleaning up the butt crack (deep in the V of the tail) are also spot on - use either a round file, rat tail rasp / surform or a dremmil. Make the V at least big enough to run your finger down it as you need to remember that you have to glass it and then sand it… get too fancy with fine V and the glassing / sanding become a pain in the A$$
Excellent advice Cam! For the record my good friend gave me a Japanese fine tooth saw that was given to him from a friend in Japan - I am stoked! Thank you everyone for all the input. Swaylocks does it again!