Author Topic: How do you hand-shape concaves so they are smooth & uniform like the Tomo Evo?  (Read 6380 times)

magentawave

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How do you guys shape concaves, and especially elaborate quad concaves like this Tomo Evo? I can see how it would be easier to do channels. Do you shape a piece of wood so its curved and then contact cement sandpaper to it?
« Last Edit: March 31, 2015, 12:26:28 PM by magentawave »
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

Biggreen

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I'm amazed by the fin boxes centered in the channel "lines" in those pics.  I'll bet that's no small feat to deal with.

Some of those channels look great for a piece of PVC pipe with sandpaper glued to them. I have 2" and 4" PVC with 60 grit glued to them, plus a V-shaped wood block with 60 grit glued to it. Come to think of it, I have all kinds of blocks with sandpaper glued to them.

I'm ready to see your design Magenta!
And I like the look of that yellow board in your pic. I may just try and adapt that.  Hmmm, I have a piece of foam.....

Biggreen

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Hey! Not that it's of any import to this thread, but I just noticed that all 5 fin boxes on that yellow board are 0 degree cant FCS II boxes.....interesting. Of course the center would be, but the sides...

Anyone have any ideas/input? Doesn't JP do the same?  Please....those in the know...

Sorry Magenta, to digress from your question.

magentawave

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Biggreen - Yeah, I thought it was a really cool looking board too. Kind of a softer Tomo. I'm pretty sure this is the first outline I'm going to settle on - except I'm going with an asymmetric tail.

I haven't started my build yet because of time and also because I've had a few breakthroughs with my sup surfing lately which makes me think I'm ready to move down in volume.

I'm not sure about cant, but the two front boxes look toed-in a bit but the back boxes are parallel to the center line. Yes, the JP Surf has no toe for the front fins too. There is a good video on Vimeo where that aussie explains this. It's faster but stiffer without toe. I noticed how the two back boxes saddle the concave too. Wouldn't that require a lot of grinding to make the in-side of those boxes conform to the concave? I didn't think you could do that with Future boxes??

Is there a piece of PVC or ABS pipe big enough to do the big concaves on this board? How would you do them?
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

PonoBill

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I use cardboard tubes.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

supsurf-tw

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First you want to tape off the outside line of the concaves. This prevents the tools from  "coloring outside the lines" so to speak. The concaves are shaped with various things with sandpaper glued on. I have several that have handles on them of varying diameters.
Boards:

 
8-10 x 31 Egg
8-11 X 32 Double wing Fangtail Tom Whitaker
8-6 X 30 1\2  Inbetweener Tom Whitaker
8-4 x 30 Hyper quad Tom Whitaker (wife's now)
8-4 X 31 1\4.  Round (wide) Diamond Tail Quad Tom Whitaker
 9-4 X 30 1\2. Swallow Stinger Quad Tom Whitaker (ex wifes now)
10-0 Brusurf for teach

magentawave

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Even one of the concaves in a double concave could easily be 12" wide on a sup - which would require a huge tube. But what would you use to shape really wide concaves, like a single concave that spans most of the width of a 30" wide board?
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

supsurf-tw

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Even one of the concaves in a double concave could easily be 12" wide on a sup - which would require a huge tube. But what would you use to shape really wide concaves, like a single concave that spans most of the width of a 30" wide board?
I use my planer and then finish up with a tool that is 24' wide with a slight curve and handles on the top. I have probably 5 concave tools for varying applications
Boards:

 
8-10 x 31 Egg
8-11 X 32 Double wing Fangtail Tom Whitaker
8-6 X 30 1\2  Inbetweener Tom Whitaker
8-4 x 30 Hyper quad Tom Whitaker (wife's now)
8-4 X 31 1\4.  Round (wide) Diamond Tail Quad Tom Whitaker
 9-4 X 30 1\2. Swallow Stinger Quad Tom Whitaker (ex wifes now)
10-0 Brusurf for teach

magentawave

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I don't suppose you'd want to show us a photo of that tool, would you?  :)

Even one of the concaves in a double concave could easily be 12" wide on a sup - which would require a huge tube. But what would you use to shape really wide concaves, like a single concave that spans most of the width of a 30" wide board?
I use my planer and then finish up with a tool that is 24' wide with a slight curve and handles on the top. I have probably 5 concave tools for varying applications
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

supsurf-tw

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I don't suppose you'd want to show us a photo of that tool, would you?  :)

 

I'll be in my shaping room tomorrow and will snap a pic for you
Boards:

 
8-10 x 31 Egg
8-11 X 32 Double wing Fangtail Tom Whitaker
8-6 X 30 1\2  Inbetweener Tom Whitaker
8-4 x 30 Hyper quad Tom Whitaker (wife's now)
8-4 X 31 1\4.  Round (wide) Diamond Tail Quad Tom Whitaker
 9-4 X 30 1\2. Swallow Stinger Quad Tom Whitaker (ex wifes now)
10-0 Brusurf for teach

55NSup

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I'm sure he means 24 in wide, nog 24 ft.

supsurf-tw

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I'm sure he means 24 in wide, nog 24 ft.
Yeah I hit the wrong key. Just kike you hitting the g instead of the t
Boards:

 
8-10 x 31 Egg
8-11 X 32 Double wing Fangtail Tom Whitaker
8-6 X 30 1\2  Inbetweener Tom Whitaker
8-4 x 30 Hyper quad Tom Whitaker (wife's now)
8-4 X 31 1\4.  Round (wide) Diamond Tail Quad Tom Whitaker
 9-4 X 30 1\2. Swallow Stinger Quad Tom Whitaker (ex wifes now)
10-0 Brusurf for teach

Jradtke

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Shape a piece of scrap foam, glue sand paper to foam.  Or find another object / material that matches the concave you want to achieve.  Use tape to frame the area you are shaping to prevent round off and to keep lines sharp.  Finally use good lighting and a straight edge to check symmetry.   

magentawave

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How would you blend the little double concaves out the tail into the single concave? I guess you would have to shape the double concaves first but how would you blend them into the single? (I wish I could look at one of these boards but they won't be in the shop here until at least June.)

Shape a piece of scrap foam, glue sand paper to foam.  Or find another object / material that matches the concave you want to achieve.  Use tape to frame the area you are shaping to prevent round off and to keep lines sharp.  Finally use good lighting and a straight edge to check symmetry.
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

supsurf-tw

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How would you blend the little double concaves out the tail into the single concave? I guess you would have to shape the double concaves first but how would you blend them into the single? (I wish I could look at one of these boards but they won't be in the shop here until at least June.)

Shape a piece of scrap foam, glue sand paper to foam.  Or find another object / material that matches the concave you want to achieve.  Use tape to frame the area you are shaping to prevent round off and to keep lines sharp.  Finally use good lighting and a straight edge to check symmetry.
You want to shape your single first (rough) then start your doubles at the deepest point of where you want them. You now blend from deep to nothing at the single. When the board's roughed out, you fine sand with a foam pad and blend all bottom curves together
Boards:

 
8-10 x 31 Egg
8-11 X 32 Double wing Fangtail Tom Whitaker
8-6 X 30 1\2  Inbetweener Tom Whitaker
8-4 x 30 Hyper quad Tom Whitaker (wife's now)
8-4 X 31 1\4.  Round (wide) Diamond Tail Quad Tom Whitaker
 9-4 X 30 1\2. Swallow Stinger Quad Tom Whitaker (ex wifes now)
10-0 Brusurf for teach

 


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