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-   -   Matte Clearcoat for carbon fiber (http://www.bikeforums.net/bicycle-mechanics/935366-matte-clearcoat-carbon-fiber.html)

BoSoxYacht 02-23-14 09:38 AM

Matte Clearcoat for carbon fiber
 
Does anyone have a product recommendation for a rattle can matte clearcoat to be used on bare carbon fiber?

Kopsis 02-23-14 01:24 PM

I haven't personally used it, but I've heard nothing but good reviews:

http://www.eastwood.com/2k-aero-spray-matte-clear.html

http://www.eastwood.com/media/catalo...e95/p43047.jpg

FBinNY 02-23-14 01:26 PM

Before using any kind of clearcoat on a CF frame, check for compatibility with the existing outer coat.

BoSoxYacht 02-23-14 02:59 PM

Quote:

Originally Posted by FBinNY (Post 16519957)
Before using any kind of clearcoat on a CF frame, check for compatibility with the existing outer coat.

Thanks, but this frame is down to bare carbon. The clearcoat that was on the frame had flaked off down to bare carbon on most of the frame, and the rest of it was sanded bare.

I'd like to do a matte clear finish, but may go with a matte black paint(whichever will adhere better & be more durable).

BoSoxYacht 02-23-14 03:11 PM

Quote:

Originally Posted by Kopsis (Post 16519946)
I haven't personally used it, but I've heard nothing but good reviews:

http://www.eastwood.com/2k-aero-spray-matte-clear.html

http://www.eastwood.com/media/catalo...e95/p43047.jpg

Thanks for the suggestion. I look into the product, but from what I've seen, this looks like what I was hoping to find.

FBinNY 02-23-14 03:40 PM

Quote:

Originally Posted by BoSoxYacht (Post 16520184)
Thanks, but this frame is down to bare carbon. The clearcoat that was on the frame had flaked off down to bare carbon on most of the frame, and the rest of it was sanded bare.
.

This makes my post even more relevant. There's no such as pure carbon. CF frames are made the same way as fiberglass boats. Yhere are sheets of woven carbon fiber laid into a composite resin which forms a matrix holding them stable. While it's the CF which provides the mechanical strength, it's the matrix material that makes it possible. So if the solvent in the paint damages the matrix material, it can compromise the frame.

BoSoxYacht 02-23-14 07:34 PM

Quote:

Originally Posted by FBinNY (Post 16520272)
This makes my post even more relevant. There's no such as pure carbon. CF frames are made the same way as fiberglass boats. Yhere are sheets of woven carbon fiber laid into a composite resin which forms a matrix holding them stable. While it's the CF which provides the mechanical strength, it's the matrix material that makes it possible. So if the solvent in the paint damages the matrix material, it can compromise the frame.

I'd love to hear more about your experience with CF.

I'm new to CF refinishing, but have 10 years of Fiberglass/boat repair experience.

Please explain the difference, or post a link that will help me become better educated about it.

BoSoxYacht 02-23-14 07:40 PM

Quote:

Originally Posted by FBinNY (Post 16520272)
This makes my post even more relevant. There's no such as pure carbon. CF frames are made the same way as fiberglass boats.

I have to say BS.

Clearcoat on a CF frame, and the way boats are made are two very different processes.

FBinNY 02-23-14 09:06 PM

Have it your way. There are plenty of videos show how carbon fiber structures are laid up from sheet CF and resin. Though not identical, there are plenty of parallels to how fiberglass structures are laid up from sheet and resin (which was the point).

In any case, it's not how the parts are made, but the specific resin used, and it's compatibility with the solvents in your paint. I'm not saying you'll have problems, just that since you don't know which resin was used, you should check with the manufacturer about solvent vulnerability.

But of course, feel free to disregard.

BoSoxYacht 02-23-14 09:18 PM

Quote:

Originally Posted by FBinNY (Post 16521094)
Have it your way. There are plenty of videos show how carbon fiber structures are laid up from sheet CF and resin. Though not identical, there are plenty of parallels to how fiberglass structures are laid up from sheet and resin (which was the point).

In any case, it's not how the parts are made, but the specific resin used, and it's compatibility with the solvents in your paint. I'm not saying you'll have problems, just that since you don't know which resin was used, you should check with the manufacturer about solvent vulnerability.

But of course, feel free to disregard.

Some of what you are saying is true, but your boat construction comparison is far from accurate.

AB@WDW 02-23-14 10:08 PM

Quote:

Originally Posted by BoSoxYacht (Post 16521126)
Some of what you are saying is true, but your boat construction comparison is far from accurate.

So, BoSox, please enlighten us. How the heck DO you make a fiberglass boat without suspending the glass fibers in a reason matrix as FB described?

Because that's EXACTLY how I laid up the fiberglass when I helped my friend build his boat. And that's exactly how I laid up the carbon fiber when I built a racecar in college.

The ONLY difference between a fiberglass structure and a carbon fiber structure is the material that the fibers are made of. They are both made of layers of fibers suspended in a resin matrix. Of course for both, there are nearly infinite combinations of cloth types, or loose strands, and types of resin, and techniques for doing the lay up. But in the end, they're all just fibers in resin. That's all FB was saying.

Back to the OP, FB was right on. There are so many resins out there, and so many chemicals in rattle cans, you can easily happen upon a combination that will cause a bad chemical reaction with the very structure of your frame. A chat with your frame manufacturer would be wise.

-Andy

kelsodeez 02-23-14 10:29 PM

wow, some anger in this thread haha. what FBinNY said is completely 100% accurate. they impregnate the carbon fiber sheets with resin, and in case you didnt pay attention in sex ed, impregnate means to puts your goo inside of.

most resins are okay to use with polyurethane clear coatings. i cant speak much to any of the newer waterborne formulas, but ive sprayed over many resins with the proper prep work without issue other than having to flatten everything out because of rogue air bubbles in the resin.
i cant help you with any aerosol options, but if you have access to an hvlp spray gun and an air compressor, get a product made by PPG called "flex n flat". ive used it numerous times on carbon fiber to make it look just like dry carbon, which is the look i assume you are going for.

BoSoxYacht 02-23-14 11:47 PM

Quote:

Originally Posted by kelsodeez (Post 16521273)
wow, some anger in this thread haha.

no anger coming from me, it's all from the boat building "experts".:rolleyes:

FTR, most boats are not clearcoated the way that CF bicycles are. If you think they are, it's clear that you don't know as much as you think you do about modern boatbuilding.
Quote:

Originally Posted by kelsodeez (Post 16521273)
i cant help you with any aerosol options, but if you have access to an hvlp spray gun and an air compressor, get a product made by PPG called "flex n flat". ive used it numerous times on carbon fiber to make it look just like dry carbon, which is the look i assume you are going for.

Thank you

Fidelista 02-24-14 05:59 AM

Fibreglass boats are often painted (hull and topsides) with no problems. Most clear coats are just paint without pigment. FB is quite correct in his post...fibreglass boats and carbon fibre bikes are indeed built in a similar manner.
I finished my shipwrights apprenticeship 38 years ago. I really couldn't count the number of fibreglass boats I've painted.
You will probably get a poor finish from a rattle can. It's unlikely that a rattle can finish will be as durable as the original finish. A two pack finish from a professional spray painter would be better, obviously.Two pack will go over carbon fibre quite well and won't damage the resin.

Andrew R Stewart 02-24-14 09:21 AM

http://www.velocipedesalon.com/forum...archid=4926106

This is a link to another forum which tends to have a more professional frame builder membership then this forum's sibling across the hall does. The link is to a search for "carbon fiber building". there are many threads found. In these you'll read about how many carbon fiber frame builders do their thing. Sorry there's nothing about boat building though :). Andy.

Kopsis 02-24-14 04:12 PM

Quote:

Originally Posted by Fidelista (Post 16521688)
It's unlikely that a rattle can finish will be as durable as the original finish. A two pack finish from a professional spray painter would be better, obviously.Two pack will go over carbon fibre quite well and won't damage the resin.

The Eastwood product I linked to is a two part catalyzed polyurethane clear -- fundamentally the same as what the "pros" use (including the same warnings to use a proper respirator because of the isocyanates). It comes in a special two compartment can. You puncture a seal between the two compartments when ready to spray and mix the paint and hardener. I've used the high-gloss version from another vendor and the results are fantastic. It's been on my commuter (which spends it's days locked to a bike rack outdoors) for 18 months and looks as good as the day I sprayed it (when I occasionally wash off the layer of grime). Of course with any paint job, the results are heavily dependent on the prep. But with some skill and patience, you can get amazing results from a rattle-can repaint.

leob1 02-25-14 11:01 AM

[QUOTE=kelsodeez;16521273 , and in case you didnt pay attention in sex ed, impregnate means to puts your goo inside of.
[/QUOTE]

Best line in a long time!

ultraman6970 02-26-14 11:36 AM

If you really want to mess this up use a clear coat that is not polyurethane based.

If you want to do it right, you have to put 3 or 4 coats of car polyurethane clear coat and then sand with 600 grit to get it dull, second option is to add a flat agent to the coat and will dry and cure with the effect you want.

Good luck.

02Giant 02-26-14 12:57 PM

Quote:

Originally Posted by ultraman6970 (Post 16529202)
If you really want to mess this up use a clear coat that is not polyurethane based.

If you want to do it right, you have to put 3 or 4 coats of car polyurethane clear coat and then sand with 600 grit to get it dull, second option is to add a flat agent to the coat and will dry and cure with the effect you want.

Good luck.

Sanding a clear coat is not the same thing as a "matte clear", completely different appearance.

ultraman6970 02-26-14 11:17 PM

I know is not the same but is the cheap way to get a matte finish :P


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