So…
since those very helpful threads of George / PlusOneShaper’s [“moulding fin bases” ] …
HAS anyone else here had a go at doing it ??
I would be very interested to compare your results / findings / struggles , and of course… successes ! [hopefully !!]
…thanks !
ben
Hey Ben,
I saw that you came up with a new mold device. (Typical Aussie, always taking it to the next level). Would you be willing to show pics and maybe detail the set-up?
Thanks,
George
PS. My last two batches of runners were s!*t because I think my wood shrunk! (the wood on the mold).
hi George !
firstly , many thanks again for making this possible via your initial threads !
In terms of “modifying” the mould , the credit goes to Grant [“Hicksy”] for that !
Grant came up with the idea of using aluminium instead of wood [partly because of the wood shrinkage / sogginess / bowing issues , after repeated usages.]
Three strips of thin aluminium , hole drilled at each end for the screw and wingnut [screwed through a block of heavily taped aluminium], and insides taped with electrical tape . [we found that releases from the resin , whereas the masking tape used to stick to the resin .
The bottom strip of aluminium [the base] is also heavily taped inside and out [ie under the base ]…
here’s a photo …I hope it shows what you need to see .
[I really must write down the quantities of epoxy , hardener , and milled fibre used , as well as the temperature and time [day[s] ?] it took to harden completely …
okay , I hope this helps …
ben
We used 100mls of resin to fill the mould and 20gs of milled fibre.
Tape all inside parts and tape the base plate on (might suss out screwing the base plate on soon)
Too easy…
Hey Hicksy,
Nice set-up!
great tip about the electrical tape.
How’s the finished product look?
Got any close-ups of the bases?
George
hi George !!
Poor Hicksy’s been helping with the bases on my fins so far .
Soon , I’m sure, Grant , you’ll get a chance to do your own !!
Meanwhile , for your viewing pleasure [?] , George…
here’s the base on one of the twin keels I made for Luke . [They have now arrived on the other side of Australia… ]
Also , the base of the wood fin I made to match the [moulded bases] now F.C.S. tabbed wooden bonzer runners …
So far , I / we have used
general purpose resin for the above pictured wooden back fin / single fin ,
epoxy [for the wooden bonzer runners],
and polyester lam resin , with 5oz flatweave cloth , for Luke’s keels.
All of these also used 20-30mls [one medicine cup full ] of “milled fibre” [basically , the powdered fibreglass, like F.C.S. supplies to install their plugs] .
The yellow bonzer runners below had yellow pigment added to the base , so it all looked like one moulded bit …
The tab on one unfortunately broke , when it dropped on the garage floor [d’oh!!] …So, at some stage, they will be re-moulded [the bases] and pigmented again … from memory , these were made with general purpose resin.
I still have two other sets of bonzer runners waiting in the wings , to have bases moulded to them . And NUMEROUS twin fins and thruster fins and 2+1 setup “sidebites” [I think you guys call them ? ]
But , Grant needs to make some single fins first .
[And so do I ! …I will be interested to see how the 23 layer fin panel I made recently [including 2 layers of carbon fibre] will work as a thin single fin , once we have moulded the base for THAT !!
… I REALLY want to try a deeper , flexy single fin on my “stubbie” …should be FUN with the carbon fibre inlay , hopefully !
ben
Guys, that’s frickin’ fantastic! Totally pro; like I said you blokes took it to the next level.
Thought: similar to the way molded gel-coat parts are made, coat the inside of the mold with hot resin, then when tacky stick some (dry) 6 ounce cloth thus lining the mold. Next, fill the mold with the resin/milled fiber mixture and shove the fin in; could be very strong that way…
grant will be stoked to hear you say that , George. Look closely at the base of Luke’s keel …see something ?? [yep …Grant’s idea… ]
Now , we just wait on your report Luke , as to how the keels hold up .
It’s great to have a test pilot , mate ! [I definately want to make MYSELF a set now !]
ben
Hey P1S
I’m stoked you said that, I lined the base of the mould with 4oz so that it wraps around the bottom, folded it all over the outside of the mould and taped it down, poured in the resin and fibre and then put the fins and front screw hole in. The front screw holes were made from a piece of a straw, plugged at the end with Blue Tac and pushed into the resin mix. That way the hole is blocked at one end stopping resin filling it up and it will stick to the bottom of the mould.
Hey Hicksy,
I can see the cloth as described in the keel photo. Wondering how the performance will be (as far as holding together kind of performance) compared of milled fiber alone. Of course, “regular” fiberglass fins are similar to this so I would say this is a baseline to compare from…
G
Also came up with a jig to drill the back side hole for the pin. Used an old finbox that was cut in half (eg 10" box now a 5" box with an open end). Drill from the outside through the channel that the pin slides into all the way through the box.
Then all you have to do is put the fin into the box, line up where you want the hole and drill through the hole that’s already in the box, no measuring involved apart from the pin placement.
TFE
oh right yeah, thanks for mentioning that Grant . How could I have forgotten that ??
…SO important …wish I’d thought of that YEARS ago , after the numerous mis-placed holes I’ve drilled in single fins over the years !
[This jig saved me a LOT of hassle !!]
ben
“after the numerous mis-placed holes I’ve drilled”
Now that’s not too good is it Mr Chips…
Ha Ha, couldn’t resist it…
Hicksy,
looks like you’re set up for production! Of course, that first hole that’s in the 5 inch box must be spot-on.
Ben,
“…the numerous mis-placed holes I’ve drilled…” Never saved any of the Sheila’s numbers, did ya? lol
Shear prowess!!!
Like Grant, I also, could not resist. Ha!!
George
general purpose resin used …
Gents
Have you ever tried using a PolyUrathane casting resin for making fin boxes etc?
I am told it pours like water and goes off in mins.
I would really be interested in anyones experiencees
Hey BC, welcome aboard!
I tried Casting P/U about 9 or 10 years ago. It worked very well. I used opaque resin color and they came out pretty trick. Advantage was the lower shrink rate. Only problem was that I ran out and it was a sample. I always had poly and epoxy around so…
I’m looking forward to one day adding a moulded base to the two curved wood fins [tabs long since snapped] I made a few years ago .
Either fcs tabbing them , and using them in my fish , or finbox base them , and use them in my 6’5 three finboxed board. [ That’s the one with the “canyon bottom” !]
I really enjoyed the feel of the curved wood fins …for the whole three waves the tabs lasted on !!
[Yes , I made them too thin , and mostly wood ]. I was glad that they floated , because at least I still have the fins now !
ben
Cheers for running this trend Ben, you and Grant have done some good work here, and its helped shed a little light for me. feeling pritty inspired now, I’ll have to get myself down the hardware store tomorrow now.