making a clear sight lens in carbon fiber tank

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#1

Hell all,

I am brand new to this site and am attempting my first fiberglass and carbon fiber project.

I have a tank that I have made out of fiberglass and clear epoxy, and I was surprised my the clarity of the epoxy when I was done. This started me considering when I am doing the overlay of carbon fiber to leave a section (about 1" dia. circle) out of the carbon fiber to make a sight lens to check fill level.

This made me wonder how best to accomplish this. I haven’t layed any carbon fiber yet, and don’t know if I cut a circle out of the twill before laying how well it would hold together without fraying. Or if it would be best to lay the entire piece, and hole saw through it, and re-seal with epoxy, forming the lens.

How would you go about it?

Any suggestions would be appreciated. And sorry if any of this is out of line for this forum, section of the forum. Like I said, brand new.

Thanks again.

#2

Are you aware that laminating resin without fibre reinforcement is very weak? Not sure if that matters, but just thought it should be mentioned.

#3

You would likely get some fraying with trying to cut the hole in the carbon material before overlaying it on your fibre glass part.

Maybe you could do what is called green trimming where you would just do the full carbon skin and then wait the appropriate time until the resin is firm enough but not cured (maybe 2-4 hours) to cut through with a sharp knife. Use a circular template disc and just cut around it, then peel out the circle piece. Maybe then another resin coat to finish the surface and get some clarity again?