Composites Central


Reply
Old 07-01-2014, 07:13 PM   #1
bl1tzk1213g

New Member
 
Join Date: Jul 2014
Location: Murrieta, CA USA
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts



Default Carbon Fiber crack repair

Greetings! I am not a carbon maker myself just seeking some help to people who I think would know most about them though!

I bought a carbon roof, overall condition is okay, just some minor set back that is not noticeable in a few feet. Up close you can see 1 large crack on the side, and small ones all the around the roof. My problem is the long crack, it seems like it has gone through all the way down to the carbon itself. Is there a way to fill the crack? Do you just sand it and hope the clear coat can get through or do I need resin? How do you spray the clear? Do you sand first, then buff, then respray the clear? Here are some pics

LONG CRACK







Here's a sample of the crack that goes around the roof. Seems like these are sandable then buffable





Here's a big crack but I believe weather trim will cover this part but might as well fix it.

bl1tzk1213g is offline   Reply With Quote
Old 07-03-2014, 07:23 AM   #2
Michiel

Composites Expert
 
Join Date: Jul 2012
Location: Netherlands
Posts: 454
Thanks: 8
Thanked 45 Times in 35 Posts



Default

As far as I can see it's the clear coat that's cracked. Sand it back and paint a new clear. I can't see or it's a real crack on the last picture. Be carefull with sanding the clear down that you don't damage the carbon fiber. If you have no experience with this and you don't want to screw up your carbon roof bring it to a specialist.
Michiel is offline   Reply With Quote
Old 07-03-2014, 08:52 AM   #3
bl1tzk1213g

New Member
 
Join Date: Jul 2014
Location: Murrieta, CA USA
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts



Default

Ny saying "be careful not to damage your CARBON FIBER" do you mean down to the fiber cloth themselves or just to the epoxy resin of the carbon fiber? How can i tell if i'm sanding the clear coat or the epoxy resin already?
bl1tzk1213g is offline   Reply With Quote
Old 07-03-2014, 02:51 PM   #4
canyon

Administrator
Site Admin
Composites Expert
 
Join Date: Jan 2010
Location: Orange/La County
Posts: 1,262
Thanks: 58
Thanked 119 Times in 79 Posts



Default

He means be careful you're not sanding the fibers themselves. I don't know how to effectively describe this on a forum but you can tell you're getting close to the fibers when they start looking "dry".

I know my explanation isn't that good. Hopefully someone posts in this thread and gives a better one!
__________________
Someday I'll be a pro. But today I'm getting there one step at at time.
canyon is offline   Reply With Quote
Old 07-03-2014, 07:41 PM   #5
HCD

Member
 
Join Date: Mar 2012
Location: Florida , USA
Posts: 50
Thanks: 0
Thanked 6 Times in 6 Posts



Default

If dry sanding , you'll see the weave pattern begin to distort when you're about to burn through the fibers .

If wet sanding , you'll see the carbon grit load up on the sandpaper . Just check it frequently and keep wiping it down with a clean sponge . Either way I would try to repair it installed so that the pressure you're applying on it doesn't damage it more . It's hard to tell how thick it is from the pic or how sturdy it may be .
HCD is offline   Reply With Quote
Old 07-04-2014, 12:53 AM   #6
Hanaldo

Composites Expert
 
Join Date: Feb 2014
Location: Australia, WA
Posts: 745
Thanks: 1
Thanked 157 Times in 138 Posts



Default

Yeh if you're wet sanding, the dirty water will be a milky sort of white until you go through to the carbon, where the water will start to go grey.
Hanaldo is offline   Reply With Quote
Old 07-04-2014, 09:18 PM   #7
Livernois514

Member
 
Join Date: Feb 2012
Location: Montréal
Posts: 30
Thanks: 1
Thanked 7 Times in 5 Posts



Send a message via MSN to Livernois514
Default

Carbon fiber/Kevlar race kayak Repair:

OR! You can sand even make a small groove (cut in bevel) into the crack and make a epoxy putty with bubble glass powder,graphite powder,fiber glass powderr and aerosil/cabosil/fume silicia. You can heat the putty with a heat gun to increase the polymerization. Fill up the crack and put a small release demold film and tape the release film with a masking tape. Et voila! The crack is filled up with a simple super strength epoxy putty

Last edited by Livernois514; 07-04-2014 at 09:24 PM.
Livernois514 is offline   Reply With Quote
Old 07-05-2014, 08:31 AM   #8
Michiel

Composites Expert
 
Join Date: Jul 2012
Location: Netherlands
Posts: 454
Thanks: 8
Thanked 45 Times in 35 Posts



Default

Quote:
Originally Posted by Livernois514 View Post
Carbon fiber/Kevlar race kayak Repair: How to Repair a Damaged Composite Canoe or Kayak - Carbon/Kevlar Fibre - YouTube

OR! You can sand even make a small groove (cut in bevel) into the crack and make a epoxy putty with bubble glass powder,graphite powder,fiber glass powderr and aerosil/cabosil/fume silicia. You can heat the putty with a heat gun to increase the polymerization. Fill up the crack and put a small release demold film and tape the release film with a masking tape. Et voila! The crack is filled up with a simple super strength epoxy putty
That's not a good solution for this and will make it even worse.
This are coating cracks and not in the product itself.
Michiel is offline   Reply With Quote
Old 07-05-2014, 09:12 AM   #9
bl1tzk1213g

New Member
 
Join Date: Jul 2014
Location: Murrieta, CA USA
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts



Default

Quote:
Originally Posted by Michiel View Post
That's not a good solution for this and will make it even worse.
This are coating cracks and not in the product itself.
Helped me get an idea though . I will sand it a little see if the cracks go away, if not, i will have to dremel the cracks a little bit and fill it with resin see if it seeps all the way down
bl1tzk1213g is offline   Reply With Quote
Old 07-05-2014, 01:16 PM   #10
HCD

Member
 
Join Date: Mar 2012
Location: Florida , USA
Posts: 50
Thanks: 0
Thanked 6 Times in 6 Posts



Default

If you have enough mil thickness to dremel into the crack and not cut through the carbon fabric below , it is going to eventually crack again anyway . The strength of a composite is in the proper fabric/resin ratio and excess pooled resin above that offers no benefits . Those spots are always the first to show surface blemishes and damage since they are the weakest areas in the composite matrix .
HCD is offline   Reply With Quote
Reply

Bookmarks

Tags
carbon, crack, fiber, repair

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -8. The time now is 04:01 AM.
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

Inactive Reminders By Icora Web Design