My first attempts at fin box bonzer runners and fin[s]

back fins …pre base-moulding…

right on Chip!!!

Ride the Single keel yet?

I really want to see a pic of your dog next to the fin, Maybe see what his opinion of it is!!!

Keep on keepin on…

Hey quick off topic question…

What type of cars are those in " MAD MAX"?

Mad Max’s car, “The Interceptor” was a Ford Falcon XB Coupe…

Returning you to normal transmission…

Paul is referring to THIS FIN … 12" [!] base, 6" depth, red tinted fibreglass …a BEAUTY !!!

[Paul VERY kindly GAVE it to me …THANKS HEAPS , mate ! [ figuring , I guess , that I am 'old school single fin ’ enough to actually get quite a bit of use out of it . And I will , don’t worry… WHEN / if the WAVES eventually arrive !! [I just hope the tab stays intact !!]

At the moment , though …er no , no waves. Hicksy reckons it should go in my bonzer…

It’s on the Bob Cooper 6’4 …waiting…lurking…breathing quietly in the corner…getting psyched .

Okay , I’ll take it up to the “Hickster’s” and let “Rex” [hicksy’s dog , actually] give it the once over [but not lifting his leg] .

Regarding the movie ?

I dunno … [but the board in “Mad Wax” was a Byrne …and RCJ’s was a ‘Nirvana’ , if that’s any help !! ]


I would hope , if “Mad Max” was an aussie movie, that the cars would have been Holdens … hq’s, or fc’ s, or eh 's, or premiers or kingswoods ! [wasn’t that a biker’s movie mainly …or was that ‘stone’ ?

I mainly watch surf movies , monty python , roy and hg and for septic wit , the simpsons and [occassionally] ‘south park’ . … I’m pretty “cultured”, eh ? (Chicks hate me… they’re always telling me to ‘grow up’ [whatever THAT means!] …and sh*t like that ! )

[okay …now, after sidetracking myself]…

For anyone who is interested …

Why four tabs have broken on my runners […before they even made it into the ocean !! ]

  1. first pair , I thought I could lay 'wax paper '/ greaseproof paper inside the fin box, pour resin in , and when gelled , lift out a perfect finbox base . Think again . As I discovered , the stuff crinkles . When resin hits the gathered up [crinkled] bit , part of the fin’s base is missed . Result ? incomplete tab ! [in my case]

  2. the one with the nail stuck in it ? [d’oh !! ]

Kinda obvious but …don’t mix too hot a brew , go indoors , eat half a litre of icecream… and forget about the finbox !

result ? Couldn’t extract the bl**** y thing without …yep…you guessed it !

  1. straw in resin , while resin setting . Lift out just as it gels . result ? straw too big , hole too wide [double d’oh!]

[idea 3 is good though, thanks… ? ‘Shwuz’…I think it was ? who I first read this from at ‘surfer’ perhaps ? ]

I’ve since discovered that the six packs of fruit juice [kiddies’ school-lunch type things] we get here in the land of Oz have about the right sized diameter [?radius? I always get those two mixed up !] for a fin box screw.

Okay …that’s the hole / tab deal …

So …now …the actual ‘Goo for the mould?’

I used ‘general purpose’ resin . [I NEEDED to finely chop glass cloth also . And , possibly, milled glass [the powdered stuff] too. ]

I did the latter two on the single fins [still in the box at hicksy’s]. Plus , I pigmented the bases of THOSE green , to try to compliment the greenish fin colour.

Why I need help / info on the mould material for the base ?

…because so far , I’ve been moulding all these failed attempts in $6-12 aus finboxes , then when it’s gelled , labouriously GRINDING the box off the bases.

…time consuming , expensive… and I 'm sure, UNNECCESSARY ! [And not that accurate , either]

Solution ?!

…I’m open to suggestions guys !! [for the third time now…]

I’m thinking plaster . Mould release agent .

And / or silicon …you still need mould release agent [wax?] for that too, I guess?

I like being able to put them in from above [so , especially with single back fins , I can get them ‘straight’ ie: 90 degrees to the box.

And with the runners , I can , as in the first photo in this post , tape them together , to get both THEIR angles the same , too !

okay…thanks for your attention …any help , suggestions , ideas , easier ways of doing all this would / will be MOST appreciated , believe me !!

I’ll do some fins for people with fin boxes when I start getting this wired . [don’t worry , good finmakers …I won’t be taking away any of your customers , THAT’S for sure ! This is a fun and “convenience” [ ? well , not really “convenient” YET !!] only project for me . ]


Chip, I think the problem is in the moulding. When I make box fins, I just lay up the whole thing a little thicker than the box will be, including the base that goes into the box. Then profile & foil the fin, with the base in a vise. Next, profile the base, with the curved part for the screw plate and the rounded corner where the pin goes. Drill both holes - screw hole & split pin hole - with teeny tiny bits first working your way up to bigger ones until you get where you want them so the glass doesn’t split. And lastly, cut/grind/sand the base to the thickness it needs to be to go into the box. Leaving the extra thickness on there until last also helps the glass not split when you’re drilling it.

For your runners with the built-in cant, lay them up over something tilted. I’d get a little piece of sheet metal and just hammer it over the edge of a table to get a nice straight line. Tape down wax paper & lay up your fins right there.

thanks benny !

that’s good stuff …I hadn’t thought of METAL ! Good idea …that was the only thing stopping me laying them up as I do with all my “straight” fins !!



I mainly watch surf movies , monty python , roy and hg and for septic wit , the simpsons and [occassionally] ‘south park’ . … I’m pretty “cultured”, eh ? (Chicks hate me… they’re always telling me to ‘grow up’ [whatever THAT means!] …and sh*t like that ! )

hahaha clasic!

Chippy61, ever give thought of using a little marine plywood 1/8 or 1/4 inch and then layed up cut/foil/drill/reglass/gloss=lighter cheaper nicer looking, maybe the sheetmetal and half wood, save the weight of the resign besides the cost of the stuff. The latest keels i’ve done are just 3ply door cover plywood that i used for templates, and glassed 2-3 layer of direct s glass left overs first foil only one side then the other flat side, trim/sand/etc ive done mostly glass ons but adding several more layer to each side for a box set up wouldn’t be that hard mate…Lived in Woomera SA. three yrs, no surf there, not even water, thats where I got the neckname gonzo, all the kids new me a gonz or gonzo, you’al love the nicknames, we need more of that stuff, makes life funner.

Another brain fart, the glass rope or the huge weave and unweave the stuff, supper strong stuff, easy to add girth.

Hi Gonzo !

welcome to ANOTHER Aussie ?! Plenty here now !

…woomera eh ? that would suck for a surfer . [ I went to school at BATHURST for three and a half years [shithouse being that far from the ocean, eh !]

Yep , I’ve done plywood , foam core, solid glass , polycarb reshaped …still need to sort the angle though when doing runners . So far , the laying up on metal and bending idea sounds a good one to try.

But , I’m still going to persevere with placing fins, at an angle , into [strong] ‘goo’ base, because the 50 layers of cloth for the layup method I’ve done in the past has proved more costly .

Doing the “moulded base” option , I’m using about 20-28 layers 4 or 6oz for the runners or fin [ie: doing it without a layed up base] . And about 200mls of gp resin in a 8-10" fin box [I can get 2 runners to a box]



here’s a pic of the Quad 5-fin I’ve ssen at my home break.

It’s by Greg Griffin a long time in-house shaper at Town and Country…

Funny I thought it was by local motion or by Cino Magallennas(?) (A T&C shaper too)

He has a post at the surfer mag forum…

The fins are hand made as well…

Pros can produce such clean lines its depressing. But I’m sure griffin’s thousands of boards under his belt…

funny you should mention / post that very photo …zo just received it tonight …too good to pass up for a fellow 5 finner !

I wish I could post at surfer sometimes , or some more of those people posted here, so I could contact them . I’d definately like to talk to Greg …‘foamdust’ [who should know ] pointed out Greg knows what he’s talking about .

Thanks for posting that here , bernie ! [I was nearly going to do the same myself ] . Now , if Greg also does Bonzer’s runners , I would indeed be VERY interested to talk to him !! [any ideas of how I could get in touch ?]

cheers !



Greg does Bonzer’s too…But I don’t know about doing campbell 5 finners though.

Pat Rawson’s the only one I knew of that’s doing them other than the Campbells here especially with Duncan around… I had an old 5-fin Davey Miller throw away in 93-94 sold it at the Kam swap meet a couple years later.

A surf buddy now rides Griffin Longboards and his son works at the T&C factory…

Next time I see him I’ll ask…

Griffin, Cino, and Pang are the shortboard gurus at T&C now although they probably all share templates.

Funny in that I haven’t bought a T&C labeled board in about 8 years And that when Jeff Johnson(?), Ned Mc Mahon and Gabe Garduque were shaping for them…

You should ask Foamdust too he’s got alot of old-time connections in the industry…

thanks for that info Bernie !

…“foamy” will be getting a pm soon.

Do ANY of these guys do the fu finboxes in their boards though ? [the guys at my surf supplies often have a bit of a chuckle …lucky he’s seen my boards , or the son might think I’m a windsurfer [“it’s mostly windsurfers we sell finboxes to nowadays” , says the dad . It’s true too]


Hey Chipfish61,

I’ve been doing ventral fins using boxes for a number of years. Since there are as many as 5 fin boxes used I found it beneficial to try to save weight. The F/U boxes are heavy for the ventral application, there are other options. I am submitting some pics of the latest customized system for the flexible ventral fins:

this board is super light. It is 6’4" and made with performance surfing in mind. Ventral fins

in these photos are polycarbonate plastic. I’ve tried fiberglass, carbon graphite, plexiglass,

foam sandwich, and polycarbonate. The contrasts in the “feel” of the same board is quite

astonishing. If you have any questions, please fire away. Thanks.

hi Plus One !

thanks for the shots .

How did you mould the base and angle the fins ?

…I assume it’s all moulded as one piece , not adding on the base to existing fins ? [what I’m doing ]

Do you have a shot showing the fin’s base , please ?

thanks !


I did it the way you did mate! The mold is vert and the fin is tilted (22 deg. in this case) and held with tape. I pour RR epoxy and wait a couple of hours. I disassemble the mold and trim the base to the profile with a small grinder.

The little black spot on the front of the base is from the set screw of the box.

We’ve done a bit of travel with it and it seems to hold up really well. The only

failure was when one of the guys packed his boards in a hurry and left the fins

in the board. When we got home one of the fins was cracked. No problem,

just cut another out of the sheet and molded a base on it. Great for prototyping

as well…

I want a clear single fin for the moonrocket. How do you do those, they look sooo unreal!!!



Not sure how to do a single fin Hicksy,

But those ventrals are made from 1/8" thick sheet (3mm?) and it’s flat, that is, I only round the leading edge and slightly foil the trailing edge.

I imagine that you could either purchase 1/2" pieces from the Plastics shop’s “cut off bin” and then hand-foil the thing. Then just go progressively finer grits until you reach 1000 grit, then use polish compounds… ?

Thanks for the info +1s8pr

Never thought of that.

Is it just perspex or is it kevlar or some other exotic material.