Thanks mate…
epoxy? i know epoxy is way better with wood , 2 resons i dont use it …
its a bit to flexy on some of the finer foils ,and coz it takes to long to set ,your forever chasing bubbles around ,where as the polyester snaps off and you can play with it till it sets making sure youve got no bubbles , epoxy you walk away ,when you come back you freak coz the wood bubbles and gases…
Hi Bert,
Beautiful fins!!!
I took a guitar making class recently, and for woods that gas and bubble the guitar maker would squeegie in a thick paste to plug the pores and gaps. For the back of the attached photo, which is Rosewood, the paste was colored black. My friend had a balsa wood board made awhile back with an exotic wood tail block that gassed under the cloth. Oh my!
When I made plywood fins for my backyard shape fish in the 70’s I used marine ply mahogany, what a wonderful smell! Not something that you get to experience with fiberglass…
Hi Bert, very nice job and very very good experience!
I am making some attempts to make my central longboard fin because I like classic longboard ('60) and here, in italy, isn’t eaasy to find some classic wooden fin to fit in my fin box.
Ok about shaping and foiling the fin but I have some trouble building the part of the fin that fit in the fin box in the surfboard, I want to use a fin box to avoid glassing the fin, (You know that longboarders like to try different kinds of fin!)I know I have to make the fin tab in fiberglass (where to put the screw) but I don’t how to make it.
Should you post some other pics about that or can you tell me some tricks? I’ll be very gratefull, I am exploring the web by weeks and never found a good instruction.Thanks!
yea ive done a few like that , big singles for fin boxes…
you get some regular fin panel and shave it down to about 6 layers of glass thinner than a fin box fin base thickness…then get your wooden fin foil it down then stick the fin panel peice to the bottom of your fin …
so you have a wooden fin with a fiberglass base that fits into the box then glass over the whole lot like your glassing the wooden fins ,so the the glass and resin cover either side of the fin and fibreglass base together …
im putting in a simple diagram i just did which will help explain it …
this is the way ive been making wooden fins for standard larger fin boxes…
if anyone else has other ways , that could help, much appreciated…
hope this helps…
regards
BERT
That instruction sequence is the best that I have seen on swaylock’s since I started following the board. It was surely no small project to put it together. For folks like me who are just getting in to shaping it is so nice to have pictures to see to know I’m doing it right.
Thank you for sharing your wisdom and experience. So many experts gusrd their secrets so their business doesnt suffer. I commend you for your generosity. Now I have no reason for not shaping some fins for my new board.
One question. Do you have to make any adjustments for longer fins in the 9" range to make them stronger? I couldnt tell how long the fins in the pics were.
Outstanding posts.
I wish you many great days of sure and future prosperity.
Terry
yea i usually run 3 layers of 6oz either side instead of 2 for thruster size fins…
regards
BERT
ps yea the fins was just my normal work routine , just handed the camera to one of my staff when a pic needed to be taken …
but it did take about 4 hours to put all the photos in order and write instructions…
Again thank you. You are too generous.
Terry
Thanks again.
But I don’t undestand why don’t shape the fin base within the rest of the fin and then foiling the tab to the right thickness and then glassing them.
Why do you use a concave line in the base of the fin?
The problem I am thinking is that if the glass of the fin have a little gap it will suck water inside causing swelling ao the wood and cracking of the glass around the fin box. Do you think this can happen really (because screw need a passage in the wood and I am thinking to make the fin base only with fiberglass)?
I’d like to make a fin like that of Jensen, see the link http://www.hollowsurfboards.com/fins.htm
but I have still problems with the tab.
Finally, do you put fiberglass aroung the tab or only glass?
I guess you put 6 layers.
Thanks again, you are the best source in the web!!!
Where do you shape?
Greetings from Italy!
those fins of jensens look wild ,yep you could do them like that no worries…
coz his are thicker just out side the box it would sit on the board and give more support,
the reason i put the fin panel section on the base is strength , but jensens look pretty solid at first glance…
regards
BERT
thanks, I’ll keep you informed! Bye.
I’ve just finished foiling my first fin and plan to glass it as you do Bert. My question is do I flatten the trailing and leading edges (the trailing edge is quite sharp) for the glassing or can I leave it as it is. Just nott too sure what to do. It’s partially shaped at the base for a box system.
thanks
Hicksy
my trailing edges are pretty sharp…but usually my leading edge is blunt , so it will allow for the build up of glass and rovings on the leading edge to complete the foil…
regards
BERT
Thanks for that Bert, I’ll post my finished fin here. Should be fun doing this, I got soooo much satisfaction shaping this one. The base for the box system should be easier now that you’ve clued us in somewhat ;-))
cheers
Hicksy
To avoid bubbles in the glass layer, first seal the wood with a thin coat of epoxy only. You may/will still get bubbles, but these can then be sanded out. The next layer (with glass) will adhere just fine to the sealing layer and should not have any problems with bubbles due to outgassing.
retroman
I know this is kind of an off the subject response, but I have this balsa lumber in my rafters and I was thinking of making a boogie board style thingie. Do I have to glass it or just seal the wood with epoxy?
daddio
You could go either way. Using fiberglass cloth means it will be much stronger, of course, but also weigh a bit more.
For that size board (body board/paipo), as long as you glue up your blank properly it should be strong enough with or without fiberglass (unless you plan to put it under some extreme stress, like 10’ Pipeline!). The board will flex more without fb. You could use marine epoxy (rather than carpenter’s glue) to glue up the blank which should make it strong enough to withstand most any kind of abuse.
I built a boogie for my wife out of leftover balsa pieces and I didn’t use fb cloth. It works just fine but she only uses it in smaller beach break type waves.
If your balsa has been sitting around for a while it will have ‘case-hardened’. You will have to completely remove this outer layer and get down to good fresh wood. If you don’t the epoxy/resin/glue will adhere only to this layer which will separate from the wood underneath and peel off under stress.
Could you post a picture of this creation? - pretty please…
Hello Retroman, have you noticed balsa ‘case hardening’ under clear glass? I have noticed that clear glass has a tendency to delaminate from the balsa after a lot of use, taking a layer of balsa with it. I haven’t noticed this with opaque finishes over balsa and wondered if it might be UV affecting the timber.
Hey Roy,
I’m no expert on this subject but from what i understand ‘case hardening’ is due to exposure to the air, not UV (that’s not to say, however, that UV will not affect the balsa and glass).
I’ve only been making balsa boards for about 6-7 months and have yet to experience a delamination, although I have read that can be a problem with polyester resin, which is rather brittle to begin with and thus does not flex with the board (just like foam, this will lead to delams). I use epoxy, which is flexier and has much better adhesion properties, and also first apply a sealing layer.
I did have a shaped board that I left sitting in my garage, unsealed, for several weeks. It case hardened to the point where a layer of balsa would come off easily with masking tape! I have also noticed that pieces of scrap balsa left lying around tend to become rather dry and brittle after a while.
The solid keel fins are Phillipines mahogany. The plywood fins have a polycarbonate core with birch plywood glued together with marine epoxy. The large fin is a polycarbonate. These fins will all be glassed with epoxy providing for optimal flex and strength. The vice is a great little Brink & Cotton hobby bench vice. Can be adjusted to most any angle and has a suction base. Extremely handy and versatile.
