Marking carbon fiber cloth

[RunningBeer]

Hi Boat Builders, I am interested to know what is used out there to mark carbon cloth before cutting. As I get older my black felt pen approach isn't serving me well for seeing. All help is greatly appreciated. R.B.

[Prodrvr]

I just use 1/4" 3M masking tape laid out where I need to cut, then cut down the center of the tape.

[fweasel]

I just use 1/4" 3M masking tape laid out where I need to cut, then cut down the center of the tape.

Ditto. Last time I used a piece stripe tape that had some flex to it. I draw on the tape with a sharpie if the template is a more complex shape.

[Bigford]

You could have your wife pick up blue marking chalk
From Michaels or a.c moore

[martin]

Use the tape method where you cut along the middle of the tape, you leave the tape on the cloth after cutting as this stops the carbon fraying at the edges. Lay the carbon with the taped side down when laying in the boat so the tape isn't visible.

[ray schrauwen]

I don't advise doing this but I found out by accident that when you lay epoxy down over the leftover tape, if the tape is on top the adhesive will come loose and you can take the tape out if you are very careful.

Again, I found this out by accident! It's just an FYI.

[jmack]

The best way to lay up composites such as carbon is to place a length of thin plastic sheet on a cutting board, then place your oversized piece of carbon on the plastic and wet it out using rollers so you do not distort the carbon, after the carbon is wet enough with the epoxy place some paper toweling over the top and use a roller to remove excess resin, then remove the paper toweling, place another piece of plastic film over the lay up this is called a carrier, then use an accurate template to cut the laminate including the top and bottom plastic film using a very sharp or new blade, remove the film on the side of the laminate to go in place on the surface you intend to reinforce, once you are satisfied with the placement then remove the other plastic film or carrier as it is normally referred to as, here is a video showing the process. https://www.youtube.com/watch?v=2LgqpFxTcAc

[Prodrvr]

I just made it through half of that video. I'd say that procedure goes in the f-that file.

[jmack]

I just made it through half of that video. I'd say that procedure goes in the f-that file.

Sorry about that Prodrvr I should have said to watch only the first 3 minutes, the idea of wetting out the laminate between two pieces of film then using a template and a sharp cutting knife to create a carrier and transfer onto the job with clean cut edges no frayed bits, gives a clean professional look that some people are after.
Cheers.

[Prodrvr]

Using tape with a template, or no template, yields the same results. We're not cutting diamonds here. The method you linked the video is fine if you choose to create more work for yourself.

[ray schrauwen]

Using tape with a template, or no template, yields the same results. We're not cutting diamonds here. The method you linked the video is fine if you choose to create more work for yourself.

Close. It's carbon.

[Prodrvr]

[REDLINE1]

Testers makes a 1/16" wide masking tape that works nice

[RunningBeer]

Ha ha Bigford, your wife must be slightly more enthusiastic about boat building than mine. I'm liking the 'tape cut halfway method' from Martin (uk) to avoid the cloth falling apart. Just as an aside, where I buy my cloth there is two different types of weave. One holds together better but won't bend sharply as easily. The other weave forms and holds down with the resin nicely, but falls apart easily. Thanks for the tips everyone . R.B.

[kfxguy]

I use modeling pin strip or masking tape that's 1/4 wide. Cut down the middle. You have a 1/8" piece of tape left and lay it face down. This is the easiest way to do it and the only way I do it. I use harbor freight .99 scissors to cut it. They don't last long but neither does a pair of $30 composite cutting scissors. It's easier to grab another pair than to resharpen them. Plus if you do this enough epoxy will find its way on your scissors and ruining a .99 pair is easier on the wallet than ruining a $30 pair. No need to make this complicated when it can be very easy.