I know blakesteah made mention of using RR epoxy for fins, so hopefully he will see this, and/or GL himself…
I am looking to lay down sheets of fiberglass and RR epoxy to make some fins (lots of experimental ideas in my noggin) and have two questions:
what sort of material should I put down to lay the first layer (regular PE resins don’t stick to smooth plastic, so I have used that before… but I recall, from using RR epoxy to repair epoxy boards, that RR epoxy gets a more stubborn grip on plastic, and I dont want to get to the point of peeling up my built-up sheets to find I can’t!) upon? I was thinking wax paper, but my plan is to lay down a large section so I can cut multiple fins, using a grinder, from one big piece (thinking something as big as 2x4 feet), so I would not want any seams from where pieces of paper overlap. Maybe a pane of window glass?
For those who have done this before, how many layers or 6-oz glass will approximate the thickness of an FCS tab?
Poly-vinyl alcohol (PVA) release agent (.e.g. RAM Plastilease 512-B, RAM Chemicals, Div. of Whittaker Corp., 210 E Alondra Blvd. Gardena, CA…or any decent fiberglass/resin supply place) painted (brushed) or sprayed (one properly applied coat should do, but if you feel better use multiple coats for insurance–and it won’t run if thin coats) on a smooth surface (e.g. a glass plate, sheet of Formica, etc.).
Alternatively: Wax glass first (e.g. Johnson’s carnuba floor wax), then spray (several thin coats, brush or heavy coats generally don’t work as wax causes the PVA to bead) with PVA for an even easier release.
After removing the part, the PVA skin can be peeled off whichever surface it is adhering to…and/or washed/wiped off with water.
Can’t help you with the fin layup schedule as I always make composite ones.
Wax paper or a pane of glass will work fine,I have used both. I use wood cores so not sure about the # of layers. I know bert berger has a fin thread going that I believe had the(fcs tab) info on it…I want to say 32 layers but someone will answer…
Wax paper is fine just a little extra work is all.
25 to 27 layers of 6oz will be just about right for FCS box thickness. Do a small panel first so you don’t invest too much material in you initial outing with the material.
I use wax paper, you can wax a piece of plastic or glass first using floor wax (as MTBs suggestion).
I’d reckon Halcyon’s right on for the num layers, its about 0.01 inches per layer, and FCS tabs need to be 0.250 inches thick. It is easy to build up, or sand down, a tab though, so I wouldn’t sweat it too much.
The epoxy is a little different. You don’t need to be aggressive with the squeegee. Just be patient, the epoxy takes a little time to wet the glass. Then roll it out, and add another layer or two.
And by all means use the epoxy at 60 degrees F or warmer.
And use mixing cups that are pre-labelled. Fill to the first line with resin, to the second line with hardener. 2 to 1.
If you use Additive F I recommend an area with good ventilation. If not, you could do it in your living room.
As always, resin will get on just about everything, the floor, your clothes, etc, be prepared.
please let me know how you go, Hackey ! [send / post photos if possible!]
After my boards, that is MY next project , too ! … you took the question right out of my mouth mate !
Here in Oz, I will be using West System epoxy. Can anyone out there (Bert ?) tell me any differences / pitfalls to watch out for, laying up panels with this stuff ?
…cheers !
ben [aka “chip”]
p.s. - the F.C.S. tabbed fins I’ve made [with polyester resin] in the past have been 30-33 layers of 5oz flatweave, just for a comparison. And, 50 layers 5oz flatweave for finbox single fins [I lay up and laminate 5-6 layers at a time]
Thanks guys, you all rock! Can’t wait to start on these projects.
One last question (I hope!): have you guys ever laid multiple layers down at once, or should I do the “one layer, let cure, next layer, let cure… etc etc etc”? I would think trying to rush through multiple wet layers at once could be trickier, but faster.
Chip- West Systems epoxy, in my experience, cannot hold a match to RR epoxy regarding sanding. WS epoxy seems to be mushy and leaves shiny bumpy buildup on the sanding paper. Plus the stuff gives me a headache (from the fumes). BUT there are multiple versions of WS, and I have not tried them all, so my perspective is not necessarily a complete representation.
I always go the entire layup at once. 1-2 layers down, wet out carefully, let epoxy wet glass, roll, on to next layers.
If you want multiple colors, you need to let a layer cure before adding another layer.
Its also useful using a different middle layer to help with foiling, lately I’ve been using carbon fiber (although it dominates the color scheme of the fin, making pigment much darker).
I used the West Sys for some ding repairs (some extensive) before I started in with the Tap. It takes 2+ days to set hard enough to sand with out leaving gunk, then sands as easily as industrial grade diamonds, and then turns yellow in about a month. Stay away, if at all possible.
As to RR vs. Tap, I haven’t tried RR. I’m sure, especially with the famous Additive F, its a super product since it is made specifically for surfboards. But the Tap stuff with the Type B Medium hardener is almost exactly the same price. I think the 1.5 gallon RR kit (2:1) is about $85. The Tap Medium is 4:1 and a gallon of epoxy resin is $62 and a quart of the hardener is $19. I’ve had very good results with it. They might ship to Aus., ya never know…
When you say “roll”, what sort of roller are you using? I’m presuming you are trying to squeeze excess resin out of the cloth to prevent pooling and bumps, so I am assuming you are using something like a firm rubber cylinder?
A metal fiberglass roller is essential for getting solid resin intergrity when stacking fin panels. Once you’ve spread the resin about with a squeegee it’s time to get the roller out and get rid of all the air.
A metal fiberglass roller is essential for getting solid resin intergrity when stacking fin panels. Once you've spread the resin about with a squeegee it's time to get the roller out and get rid of all the air.
Rich, the fins I’ve made, I used a 4" taping knife’s edge to press the middle first and work towards the ends to get out the bubbles. Kind of jabbing it in every 1/8" to work it along. Probably every 8-10 layers. Is the roller that much better? Worth buying? Or will the tape knife work just as well. The roller sounds hard to clean…
My experience with glassing was in firberglass roofs and decks. Those steel rollers were the only thing that would get the air out on large surfaces. We used to soak them in acetone and everyonce in a while you would have to take them apart and scrub them with acetone.
They look like a steel paint roller with raised ridges every 1/16 to 1/8 inch depending on the size roller bought.
The small / thin (4’ x 1/2" dia.) ones would be good for fins I imagine.
