OK so I love the Bonzer setup but never had the 1k for a shortboard but I got my shop! So anybody got a thread or tips on shaping one of these crazy bottoms I think I have the fin placement guide somwhere. I would love some tips on shaping concave in general. The board wil be a 5’8 x 20.5 x 2.35 round pin egg. I usuall make this board as a quad but wanted something different. Thanks ahead of time for you knowlege!
If you do a search under Bonzer on here there are some posts which have a fin template diagram based on the 5 fin bonzer. That should be a start. I just ordered a Cambell bonzer (Bumblebee) as a gift to myself for my 50th birthday in December, but they are pricey.
Heres a post with the template http://www2.swaylocks.com/node/1023182
Thnaks for the links tons of info but the pics on the dif threads are gone :(. Well I will prob just butcher a great shapers design, again…
Beware of the bonzer fin placement diagram. It fails to show that the Brothers use a 1/2 overlap of the two sets of runners.
I’m working on my second bonzer. It helps to have felt up some Brothers bonzers. The single is very subtle, the doubles fairly pronounced. I shape in the single first, just a hair over 1/16" starting about where the nose rocker kick starts to flatten (above the center point). After that is shaped in, I shape the doubles running out of the single (I’m always thinking/envisioning the flow of water). I made the doubles a hair over 1/8", about 3/16". I think the Brother’s doubles may be deeper. I have the fin positions marked before shaping the concaves. I use a surform with a few deep cuts at the center of the concave and then fair outwards from there, cutting 45 degrees, criss crossing the concave. I put in the “flute” between the runner last and mine is very subtle. I imagine it might be negated when I glass on the runners. Finally I smooth things out with a foam covered sanding block.
concaves with veneer skins bagged on.
Mind you , I’m a home builder/hack, not a Campbell Brother’s approved shaper…
That pic is worth a thousand words, thanks!
Looks pretty good. I would have “flared” the main channels toward the rails a little more, in front of the fins rather than have em aim toward the center. You are on the right track.
Thanks Ace. Coming from someone who has shaped as many bonzers as just about anyone…
Girvin, you’ve probably already checked this, but if you haven’t, enjoy- Surfy Surfy: bonzer
Some more picts from Surfysurfy which show off the concaves nicely
I don’t know about GH and others , but Malcolm puts vee in the tail before cutting the concaves, even though it’s not that fashionable at the moment. He has his reasons , presumably.
I use a little sureform with a curve for the main channel, and 60 grip paper wrapped around a piece of broom handle for the side channel. As a cheat I mark out the shape of the channels with masking tape. I also put around 1/4" vee in before the channels.
The rails should have sharp edges from the start of the fins to the tail.
The Lokbox bonzer diagram is for lokbox only and shows finbox positions and not fin positions. Here is a general fin layout diagram.
Girvin ya gotta watch this
some snippets of shaping room footage of MC cuttin the concaves plus a lot more
Burnsie , you are the Man.
Your bonzer bottom should be anatomically designed, or so I was told by a certain brother in Haleiwa.
You stand at the tail of the board, with the tail pressed against your belly. Extend your hands, and that is where the concave should start. Shape your hands so that they are like a butterfly (thumbs together), and the heel of your hands will define the width of the concave. As you pull your hands toward your body, along the bottom of the board, the angle of your hands will naturally change, and the profile of the heel of your hand will naturally widen on the bottom of the board, just as the concave on a bonzer bottom does.
…not in all the situations the back side runners overlap the front ones
not 1/4 nor 1/2
i guess this means our gut instinct about personal board-building specs is far more accurate than rulers & protractors. thanks for this validation!
Thanks guys I am still a little uneasy baout it but I will give it a go soon.
can you explain please Reverb?
…mainly is to mimic the glass ons…
…Not to hijack but what exactly is the benefit of the bonzer style design? In what type of waves and scenarios does this design excel? I am familiar with the design but I don’t have an understanding of how it works or the riding characteristics of these boards.