Dinged my disc and there is a little hole what kind of epoxy would work? Does it have to be carbon fiber specific? Can any plastic epoxy work? The hole/dine is about 1/16 of a inch if that. But would like to seal so it does not get bigger.
It would help to know if your disc was made with epoxy, or polyester, but most epoxy might work for the repair. If you’re just filling a dent, you should have plenty of surface area to rough up and get the epoxy to stick. Unless it catches on something, the hole probably won’t expand. You could just put electrical tape or a sticker over it.
Carbon fiber layup is pretty much never done with polyester as far as I know; just epoxy resin. But that doesn’t matter in this case; if the hole is so small as 1/16" you can use pretty much any filler (Bondo even…)
If you insist to use epoxy I would recommend West Marine 105 epoxy with 205 hardener.
As another poster said, West System is the biz when it comes to epoxy.
Thanks guys will check their website in morning.
I’m not sure how your disc is constructed, but I’d wager the inside surface of carbon fiber is rough and unfinished, at least more so than the gel coated exterior.
I’d try taping over the whole, and injecting a button of epoxy through the tape with a syringe, setting the disc up on something and attacking it from below.
You could then just peel off the tape when it’s set.
It would likely yield a better repair, structurally and cosmetically.
It is a zipp sub9 the little piece is still there in dented in a bit so the hole really only has three sides. Your way sounds like it will work. But if I do it right side up and can view it then put apiece of tape over it after I epoxy won’t I get the same finished surface after it has cured?
Not sure I understand what you’re asking, but the tape is just to make sure no epoxy will get on the outside of the disc.
flush with the hole and on the inside only.
best source for carbon repair supplies is aircraft spruce & co.
Dinged my disc and there is a little hole what kind of epoxy would work? Does it have to be carbon fiber specific? Can any plastic epoxy work? The hole/dine is about 1/16 of a inch if that. But would like to seal so it does not get bigger.
This site is a great resource for anyone contemplating repair or construction using composites. You’ll even find howto books:
http://www.aircraftspruce.com/menus/cm/index.html
I agree you need to know about what kind of construction your disk is made of. Adhesives are either polyester or epoxy, thermo-set, thermo-cure. or room temperature. Use a compatible adhesive.
For a repair this small, you can use any filler. If you don’t already have it, an epoxy glue, putty, or filler from the hardware store or bondo (polyester filler) from the automotive store should work fine. You can add talc if you find a putty-like consistency easier to work with and the product you bought is not viscous. You can use a putty knife/spreader to get the filler flush. You can also tape over or tape a piece of plastic over to ensure smoothness, but again, this is a very small hole.
Epoxy is also able to be sand papered. If you use 400+ and spend time you wont ruin the surrounds. I’m in the process of mending a ding to my tranny and this method worked well and only affected the epoxy and not the surrounding paint
And if you want to make your ‘home brew’ epoxy filler look really discreet and have an old cut off section of stem or seat post you can use a 600 grit sanding block to generate some carbon black powder to use to thicken the paste. Be sure to use a dust mask though.
Sounds good I have heard the little carbon fiber dust particles are like little daggers that dig into the lungs like asbestos.
I know that the raw cloth in its “un laminated” and glued format can be a bit nasty as the fibres are quite thin and hurt like a bas***d if you get them stuck in your skin. My understanding is that once glued/laminated and then sanded it is more of a fine powder than sharp fibre. Hence why I always work outside with a dust mask and treat in the same way as the compressed fibre board or MDF for DIY projects. However if we have any composite engineers on the forum who could clarify, all the better.
That said it does give a fantastic finish if bonding 2 pieces of carbon together at angles. A small bead along the joint when allowed to settle gives a high gloss dark smooth joint.
I remember blowing some fiber dust off my steerer tube while getting fit at Elite bikes. Dave gave me a stern reprimand ;0( he is such a meanie. < insert pink.
Tut Tut! :o) I would certainly be paying a lot more attention if I worked with the stuff on a regular basis but (fingers crossed) using a bit of basic common senses and respect seems to have been ok so far. Many years ago the first time I cut and sanded some laminated sheet without a dust mask I had black snot for the following 24 hours hence the use of a dust mask ever since.
I always make sure that cut edges are clean and smooth. The other trick that I use is to run a wet finger over some thin superglue to seal the edge. That is very much a try it at your own peril technique though as if you don’t pay attention, stop, finger too dry, not enough glue etc etc etc you can end up losing some skin if your digit gets stuck to whatever you are making!! :o)
CFRP dust is classed as HazMat. Much like asbestos or fiberglass, the powder is actually very small fibers. These can and will get stuck in your lungs, and can cause scarring and damage over time.
The best way to avoid any issues, is simply to wet the area with water to keep the dust down. A little water won’t hurt anything and is easy to clean up.
Thank you sir. So keep the dust down and treat with respect is the order of the day.
I always rinse things (including my hands) off in a bucket of cold water before moving back inside. Good tip on sanding wet too, thanks.
Roger
So, good point regarding washing your hands. Don’t rub your hands at first, since that can drive the fibers into your skin. Instead either dunk your hands and wiggle them about or let the flow of water wash the material off your hands. Then gently start to rub the skin. I learned this the hard way when I was making stained glass and was covered with glass dust, and ended up with a paw full of glass slivers. (!) I found the technique works really well with CFRP & Fiberglass, too.
I would avoid immersing the parts(dunking). Spray is ok, but dunking can get water in to crevices that can be hard to dry. A small but important difference.
I’ll shut up now.