Been through the search function, read what is out there but doesn’t cut it.
Anyway, I have been putting off this project for a while now and I have all the materials and want to get started. The main part that I’m having trouble with
is how to tackle the carbon fiber rails that I want to incorporate. How does one effectively wrap the rails with carbon fiber material? Do you cut the finish rail
line when the resin is gel’d out like a regular cut lap?
Any info on the actual lay up process and tips/tricks that sort of stuff to make this less painful would be great.
Mask off a double inlay, laminate rails, cut when the cloth gets slightly crunchy (past gell) it’s easier when firmer. It’s a bit easier to paint on the resin with a brush then use your squeegee to clean them out. Simple stuff really.
Whatever method you choose..make sure you wet it out properly..do a test panel first so you know your saturation is adequete before you squeegee it out or it will be dry and a disaster in the making!!
The board i am riding is sixteen years old..it has a extruded styro foam blankwith a single layer uni-directional glass stringer and carbon fibre flexible rails!
Made by me and is a copy of 5 previous boards dating back to 1969...however the others are polyester,..i still have the oridginal which ..lol..is in better condition to this one. I will try and work out how to load a pic from my phone, Bear with me please!
Here’s my cut and paste from the wmd thread (thanks for the reminder, chrisp):
I’ve used a couple of methods for doing carbon rails, a combo of the
two would probably work best. First thing, even though it’s cheaper to
buy full-width carbon cloth and cut it to width, it’s messy as hell and
not worth the trouble. 4" graphite tape is the call. On regular
rails (no flutes, e-wings, etc) I pre-stretch my cloth over the rail
with a million little bits of tape to make sure it’s perfectly
stretched and flat. This is particularly nice at the nose and tail where it has to make tight corners. I do one rail at a time. After getting it good
and wetted out with a brush, I put saran-wrap all over it to get a nice
shiny finish.
Another good thing about the saranwrap, it allows you to “work” the cloth a bit. plain weave carbon cloth has lots of holes in it, so when you lay it down you’ll often get a bunch of white spots showing through the cloth. To get that nice checkerboard effect of pure carbon, you can rub the cloth once it’s wetted out and covered with the saran wrap. Usually just a couple of wiggles with a fingertip on problem areas will get the fibers to spread out enough to cover up holes in the cloth.
Vac bagging is probably the best way to get a good resin/cloth ratio and bonding, but I’ve never been happy with the finish I’ve gotten when bagging carbon rails
shwuz is on the money. I used the saran wrap and had super results. Steps: sealed the rails with micro/epoxy (peanut butter consistency), waited till tacky (30 min (fast hardener @ 75 degrees F)), wetted the carbon tape (3") first on a wet out surface, rolled it up, unrolled on the rail, then covered with saran wrap, pulled wrinkles by gently tensioning the wrap on both sides, taped, and went on with the board rail facing up. I ended up using around 27-32 grams of epoxy per rail on a 6’ and 6’9" respectively. two notes- 1. don’t finger rub the wetted carbon on the rail “too much,” it will loose the pattern a bit and “blurr” 2. If you want a perfect pattern and are lacking in glass weave manipulation like me, tape the carbon tape in place with the pattern perfect, then wet it out with a brush. Thanks to all. I’m having lots of fun.
To avoid white spots showing through on a recent bellyboard I sprayed the spackled EPS blank with black water base paint. I glassed the bottom and rails with carbon and left a generous overlap (freelap) which was ground smooth before a prefab deck skin was vacuumed over the feathered edges of carbon.
If you’re doing a prefab skin top and bottom, you don’t even need to use masking tape or cut the laplines… just grind the freelaps and vacuum the skins. The skins might leave a bit of a step along the edge but you could smear some clear epoxy over the steps (baste) before doing the outer glass. By the time you glass the outside top and bottom, the laps should fill in any leftover step.
In my opinion, the hardest part is doing the outer glass without frothing the resin and leaving a ghostly mess over the carbon.
chrisp, I did do one rail at a time. The plastic wrap worked best starting the nose and rolling to the tail. The standard kitchen width is 12" wide allowing about 4" on each side beyond the carbon tape edge. There is roughly a half inch overlap at the nose and tail. Also, the carbon tape is great, but I placed some masking tape on it where I cut it when dry. It comes apart very easily. Once wetted out on the table it stayed together very well. Keep having fun.
Learned an ugly carbon fiber lesson yesterday. After laminating on the deck and bottom bamboo veneer with overlap on the carbon rails, I opted to post cure the compsand 24 hours later. The board was still in the bag (clear plastic) and I opted to just leave it in the sun thinking that with the ambiet air temp around 70 F, it would get up to around 130 F like in Hawaii. I neglected to consider that I had always used an opaque plastic. Upon returning to the board 6 hours later, the carbon rail facing the sun looked odd. Turns out the sun on the black carbon combined with the “global warming” effect of trapping the radiation created temps melted the EPS under the carbon. I’m guessing it got well over 140 F. Now when I cut the board in half (multi piece baggage board) I’ll have to fill the vacated space with pour foam and hope that the expansion will make the rail tight again. Lesson learned.
Also, I’ll hence forth vac on the bamboo veneer at around 7 psi. The 2# EPS foam got crushed a bit at 13 psi.
What kind of carbon fiber should be used for carbon rails? I found a 25cm wide roll of 200g/m2 plain carbon fiber. Would it do the jobb? Or should it be multidirectional?