Bonzer Project

tryin something different this time with a tiny little fish bonzer. This is the first time trying one and i am a little confused on how my concave and fin lay out should be. First things first, the board is an egg 5’7 x 20 3/4 with a 16 inch tail that comes to a rounded pin and i am going to do a three fin set up and make my own fins. I have already shaped out the board except for the bottom, and made it a little thicker than I would to make up for the lost foam in the concaves


I understand that i need to have the concave go in an hourglass shape inbetween the fins and then out the tail. But what about from the fin to the rail? should the area be left flat or have its own concave so it is almost like a tripple concave board?


I have no idea where to set my fins and what size to make. I know I need to have them at 18 degrees but how far forward should I set them and how much toe should I have? I checked the archives and found a 5 fin set up but thats it. Still not sure if i am going to do glass in or fin box for the back.

I attatched a sketch of what i was thinking of if i am not being clear (though my drawing is that of a two year old. Many mahalos for the help

Give it a day or so, and LeeDD will come and piss on this post for you…tell you how he last rode them in 1970whatever and blah blah blah … [Don’t worry though…by his own admission, Lee hasn’t shaped a board since 1977 , so what he talks about is through the haze of ‘back in the daze’ memory … ]

Me, personally, I’m making one soon , and can’t wait ! … I’M stoked, even if some ‘grumpy old men’ aren’t !! Don’t let ANYONE stop you enjoying experimenting …EVER !! [That’s MY motto !]

It will be good to exchange notes on ours [maybe by ‘p.m.’ , so no interference]

good on ya mate…GO for it !


check out

if you look through all THAT info, photos, and video, you’ll get all the knowledge you need …direct from the inventors / creators of the ‘Bonzer’ ! How GOOD is THAT !!!

As a ‘teaser’ , here’s an example from that site…the rear view of the 3 fin’s concave … [ Obviously, they have the 5 finner shots, too !]

thanks for the vote of confidence chip from the pictures on the site it looks like I could do a shallow single concave through the whole board and then add the doubles

I will post some pics when I am finished so you can see how frankenstein turns out

This is only me, but …for what it’s worth …finbox for the back, if you leave enough foam on the stringer.

So, then you can move your fin forward or back.

My “Stubbie” is the same dimensions as your board , and could EASILY have three or four fcs plugs put in [each side] for the runners .

Or, since the rails are ‘chunky’ [technical board design term ] , I could even put in fins unlimited [oz equivalent] boxes on each rail , and make canted runners for the finboxes .

…which would be fun , because then I could also play around with side thruster and twin fins as well. The board could then become a single stubbie, twin stubbie, thruster stubbie , 2 +1 stubbie, and a bonzer stubbie…

WHAT did 'ZoSurf ’ say ? "Infinite options, infinite fun " ? [or something like that !]


more shots, from the campbells…

[used without permission] to hopefully illustrate the concaves they played with during the 70s… I LOVE that website !!

GREAT photos, and history, of the ‘Bonzer’ design !]

here’s a 1972 example…



The above one was apparently shaped following a visit to fluid foils [jim pollard the oz channel bottoms man , along with al byrne [a kiwi, originally] and colin smith ]


Skeletor, here’s another one [ resurrected from another 3 fin bonzer thread from the archives] …a shot from ‘Australian Longboarding’ mag…thanks Josh !]

…enjoy !!

( fairly radical concaves, eh ? this was an aussie made one from 1973, apparently… )

dimensions of this one : -


I will be at Hicksy’s tomorrow and the next day. See what results, eh ? …

[could be a frankenstein here too, methinks !]

i think this looks awesome. Make sure you let us know how it turns out, this is a board i would be intersted in shaping one day so make sure you post all you learn. Cheers.


thanks mate !

I can’t speak for Skeletor…his may well turn out much better / sooner than mine !

But me, I’m a pleb, who has always had a fascination with different designs, some of which I couldn’t get hold of first time around [living in Australia, and never having seen the boards, having no money… and being around only 10 years old at the time]

But , having seen Shwuz do the 5 finner, and the fat peguin , [and having made a single fin stubbie, a ‘stinger’ and a fish or three myself] , if I don’t at least attempt the 3 fin bonzer I’ve been wanting to make ever since I can remember…if I don’t try it, I’ll never know.

I liked the ‘’ bonzer bottom ‘’ single fin I had for a while, THAT’S for sure !!


p.s. - Also, THANKS to those who have 'p.m.'ed me , expressing their interest … I hope you ALL make one, and enjoy them immensely !!! [and post them on this thread…

share the stoke !

those pics are helping a lot for once you can actually see concave in a picture. Chip Mahalo for all the responses and posts. She ain’t goin to be pretty, but she’ll ride. decided to do it when in all my stoney luck I droped a paint can on the nose of a blank and dinged it beyond all recognition.

still need some help on fin placement though

Anybody following this thread might want to see this:

Campbell Bros 7’0" 5-fin bonzer for sale in San Jose, CA.

Anybody following this thread might want to see this:

Campbell Bros 7’0" 5-fin bonzer for sale in San Jose, CA.

Too late on that one guys. I bought it this morning! I’ll let you know how it surfs once I give it a shot. If you guys want pictures I can take some: it’s really easy to feel the concaves and you can see them if the angle is right. Not as extreem as some of the boards I’ve seen on here.


Campbell Bros 7’0" 5-fin bonzer for sale in San Jose, CA.

If you guys want pictures I can take some…

…yes, please !

I’d REALLY like to see a tail to nose view , and a side on view, showing the runners , concave in between, and the back fin …if it’s not too much trouble…that would be GREAT, thanks Mar man !

  cheers ! 


I took some pics but man, it’s hard to make the concave visible on a clear board on a cloudy day. Hopefully you can see something from this and I’ll try to take better pictures later if you need them. A dozen pics on this page:

nice board there… yeah it is hard to take a good picture of those concaves without the proper lighting…

I like to use the clear side fin/runners on my boards. they look to cool.

thanks Mar and Ben !

…always good to see a few concaves and fin configuration / placement shots !

Yes, AREN’T concaves a bit difficult to photograph sometimes ?? …sidelighting needed, I reckon, to really accentuate the curves .

Same with LOOKING at them …sometimes standing the board on it’s rail and looking across is the best way to see them .

Mar, Ben …I’m curious …any chance you could measure how deep those concaves are at the very end of the tail, and also a foot up ?

thanks guys !


p.s. - Ben , is THAT the board you’re selling ? [ WHY, if you don’t mind me asking ? …you can ‘p.m’. me, if you prefer…cheers !]

Hey MaraboutSlim,

Have fun with that board. I’ll bring my bonzer up and we’ll go surf Pacifica soon.

At the bottom of this page:

is a fantastically garish rainbow and dolphin festooned 3 fin bonzer - you can get a good idea of the fin placements as interprted by Mike Eaton. I just bought a 20 year old 7’10" 3 fin bonzer by him and in the few go-outs that I’ve taken it on, I’ve gotten compliments on the template and had some great waves. Maybe put a long finbox in the center for more adjustment possibilities.

Hey MaraboutSlim,

Have fun with that board. I’ll bring my bonzer up and we’ll go surf Pacifica soon.

Sounds like a plan! There should still be plenty of waves to come this winter. If it’d just stop raining so the water stays clean I’d be happy…

‘Skeletor’, okay if we share this thread, as we are BOTH doing ‘first time’ “Bonzer” projects ?

…Thanks mate !!

okay…I hope no lines through my words THIS time [could be a lengthy post ?]

Template used [as a rough guide] : -

the " Bob Cooper double concave 6’4 single fin " of mine


Tuesday, after watching how to do the rail bands on ‘Shaping101’ , the board was shaped , and the rails done .

Bottom thinned [thickness 2 1/2"]

“Concaves” done with a sanding block … [no, I haven’t measured them yet]

Dimensions of shape

14.25 x 6’5 x 20 x 2 1/2 x 14.5 [tail more rounded and wider than the Cooper’s]

to be continued… [in case of “line attack” on this post]



Hicksy’s 7 y.o. twins went ballistic , handing me the following coloured spraycans…

yellow, red, blue, black…

At Grant’s suggestion, I had sprayed the ‘concaves’ [hahaha] with blue paint, just to give an idea where to sand to.

When the kids saw that, it was " what colour are you going to spray the rest of it ?" , etc.

After they’d FINALLY gone to bed, I flipped it over and sprayed the deck…yellow, blue , and red [tail to nose]

The next morning I glassed the bottom…


I mixed a small batch for the concaves. Glad I did . [ It took me somewhere between 20-40 minutes , I think ?]

Then I glassed the rest of the boards’ bottom, then the rails.

[…guess what colour all those 4 colours became ?]

The deck , at least , stayed yellow, blue, and red, when I glassed it …nice ‘rainbow’ shades where the colours overlapped, too.

The board is now filler [‘hot’] coated , and awaiting fin boxes and a legrope plug / ‘leash’ loop.

It’s at Hicksy’s curing for a week or so until I get some boxes for it…and some rollers, so I can layup some fibreglass bonzer runners for it…

okay, that’s all for now. No photos until it’s sanded [and, hopefully, looking worthy of a photo ?!]

cheers !