SuperSix EVO frame stripping

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charirider
Posts: 263
Joined: Tue Apr 13, 2021 3:00 am

by charirider

Hi fellow weightweenies.

Recently I've decided to strip my SuperSix Evo 2nd gen frame to bare carbon with only sandpaper and elbow greese.
Completed fork at the moment.
Started with #320 grit wet sanding to remove clearcoat and paint, then #600 and #800 wet sending to smooth things up, then coated with Aerospace 303. Results could be observed in the attached photo.

Now the frame that is in question.

1) I really REALLY tired of sanding with 320 grit, thinking about shifting down to #240 on the frame. Is it ok?

2) Also, I have a question for pro strippers here:
What to do with FRONT derailleur mount; I mean, how to you sand around it without scratching the anodizing? The bastard is riveted to the frame, so I have 2 options here:
- remove rivet heads, push rivet body inside the frame then remove the debris, cover 3 holes with rubber grommets, as I am not using front derailleur anyway (1x fan here)
- use masking tape and do micro sanding around it; in this case which micro sanding tool should I use?

Thanks fot your suggestions!
Attachments
E224C3D0-AB35-4535-94AE-375E18C6AF5E.jpeg
2018 Cannondale SuperSix EVO 2 rim size 56 (raw stripped) 6.9kg
2014 Bridgestone Anchor CX6 Equipe size 55 (cyclocross) 9.8kg

jfranci3
Posts: 1572
Joined: Tue Jul 26, 2016 5:21 pm

by jfranci3

Use paint stripper. You'll get waves in the tube finish with sandpaper. You'll notice it on the longer tube. Plus you don't want to score the resin.

by Weenie


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Discodan
Posts: 406
Joined: Mon Oct 16, 2017 2:55 am
Location: Sydney

by Discodan

My understanding was the paint stripper can attach the resin and effect the structural integrity of the carbon so I'd be cautious. I've sanded frames back before and agree it's really tedious, you should have no issues using 240 but be cautious as soon as you get through the top layer of paint. Most people who's done this a bit prefer using a sharp blade or knife to scrape the paint off rather than sanding; I've never tried it myself but may be worth a little research. It would also let you get into the nooks and crannies like your FD mount

AZR3
Posts: 998
Joined: Wed Sep 12, 2012 9:00 pm
Location: Az USA

by AZR3

I tried carbo lift and it was a pain and didn't do much. I then moved to sandpaper and worked but took a while. I then read about people using a razor blade, hold it perpendicular to the surface and drag it and watch it peel the paint off. I sanded the fork on my Evo and then used the razor on the frame, the razor was much faster.

charirider
Posts: 263
Joined: Tue Apr 13, 2021 3:00 am

by charirider

AZR3 wrote:
Tue May 24, 2022 3:53 am
I tried carbo lift and it was a pain and didn't do much. I then moved to sandpaper and worked but took a while. I then read about people using a razor blade, hold it perpendicular to the surface and drag it and watch it peel the paint off. I sanded the fork on my Evo and then used the razor on the frame, the razor was much faster.
I also read about razor blade/stanley knife, but I'm a bit scared to try it, dont want to cut into the composite layer.
Sanding is safe, you could control pressure and place where paint is, so you won't damage carbon composite too much
jfranci3 wrote:
Tue May 24, 2022 3:05 am
Use paint stripper. You'll get waves in the tube finish with sandpaper. You'll notice it on the longer tube. Plus you don't want to score the resin.
Discodan wrote:
Tue May 24, 2022 3:48 am
My understanding was the paint stripper can attach the resin and effect the structural integrity of the carbon so I'd be cautious. I've sanded frames back before and agree it's really tedious, you should have no issues using 240 but be cautious as soon as you get through the top layer of paint. Most people who's done this a bit prefer using a sharp blade or knife to scrape the paint off rather than sanding; I've never tried it myself but may be worth a little research. It would also let you get into the nooks and crannies like your FD mount
I have considered this option, but put it aside after reading mixed comments on carbonlift.
About "scoring the resin", folks here are sanding their frames to remove weight, and they are "scoring the resin" as far as I understand.
Where this "resin" is supposed to be? Between paint primer and carbon? I thought carbon is impregnated with resin itself...
Under paintjob there is also some filler, so it's hard to tell if there is some resin before it's bare carbon. I do saw black "dust" while doing finish wet sanding with #600 and #800 sandpaper, but with such fine grit you cant remove any considerable amount of material anyway.
Also, boutique frames like parlee and appleman come without any finish, or they are coating their frames with "resin"?
2018 Cannondale SuperSix EVO 2 rim size 56 (raw stripped) 6.9kg
2014 Bridgestone Anchor CX6 Equipe size 55 (cyclocross) 9.8kg

charirider
Posts: 263
Joined: Tue Apr 13, 2021 3:00 am

by charirider

To the main question of this topic, how I suppose to remove material around bottle caage bosses and front derailleut mounting plate?
What tool for micro sanding could I use in this places?
2018 Cannondale SuperSix EVO 2 rim size 56 (raw stripped) 6.9kg
2014 Bridgestone Anchor CX6 Equipe size 55 (cyclocross) 9.8kg

User avatar
Lucendi
Posts: 643
Joined: Fri Jul 19, 2019 10:37 pm
Location: Sweden

by Lucendi

I like to remove most of the paint using the knife scraping method. And then get the rest of the paint and filler off with wet sanding.

You could leave some paint around the derailleur braze and bottle cage rivnuts.

When you are all done, I suggest clearcoating everything. I used a plastic adhesion promoter and a 2K polyurethane clearcoat and was very happy with the results. It added like 5 grams to the entire frame and fork.

Maddie
Posts: 1532
Joined: Tue Oct 17, 2017 5:44 am

by Maddie

I wouldn't use pain stripper, too risky for me. Like others said, knife scraping and then sanding with 350, 600 and 800 grit. Remove the FD hanger. It makes sanding in that area so much easier and with 1x you won't be using the FD anyway.

Steve Curtis
Posts: 1314
Joined: Thu Jul 31, 2008 12:20 pm
Location: Hampshire UK, Dublin Ireland and Geneva Switzerland.

by Steve Curtis

Lucendi wrote:
Tue May 24, 2022 7:50 am
I like to remove most of the paint using the knife scraping method. And then get the rest of the paint and filler off with wet sanding.

You could leave some paint around the derailleur braze and bottle cage rivnuts.

When you are all done, I suggest clearcoating everything. I used a plastic adhesion promoter and a 2K polyurethane clearcoat and was very happy with the results. It added like 5 grams to the entire frame and fork.
As Lucendi says.
This is the best method. I think it's 13 frames I've done now, and this is bar far the best way for good results.
303 is garbage and does not help with UV. Projects farms did some testing, and found this offered very little protection against sunlight.

I also found it was terrible when I used it on my car's soft top.

Spraymax 2k clear is the best available clear coat, but it's toxic stuff. It does give very good results though.

For sanding the tight spots I use a dremel and a buff. There are a few different "grits", so pick the right one for the task. Ie, rougher for paint and medium/ fine for the final finish.

charirider
Posts: 263
Joined: Tue Apr 13, 2021 3:00 am

by charirider

Maddie wrote:
Tue May 24, 2022 8:16 am
I wouldn't use pain stripper, too risky for me. Like others said, knife scraping and then sanding with 350, 600 and 800 grit. Remove the FD hanger. It makes sanding in that area so much easier and with 1x you won't be using the FD anyway.
Thanks, I think this is the best solution.
I will order a replacement anyway, if I want to go 2x in the future.
Also, I am thinking about removing chainstay guard plate, no such thing on new c-dales.
2018 Cannondale SuperSix EVO 2 rim size 56 (raw stripped) 6.9kg
2014 Bridgestone Anchor CX6 Equipe size 55 (cyclocross) 9.8kg

jfranci3
Posts: 1572
Joined: Tue Jul 26, 2016 5:21 pm

by jfranci3

Discodan wrote:
Tue May 24, 2022 3:48 am
My understanding was the paint stripper can attach the resin and effect the structural integrity of the carbon so I'd be cautious. I've sanded frames back before and agree it's really tedious, you should have no issues using 240 but be cautious as soon as you get through the top layer of paint. Most people who's done this a bit prefer using a sharp blade or knife to scrape the paint off rather than sanding; I've never tried it myself but may be worth a little research. It would also let you get into the nooks and crannies like your FD mount
Planes get paint stripped all the time. Just use the right stuff. https://www.rustoleum.com/en/product-ca ... ft-remover Just make sure it is epoxy/resin OK. Epoxy is pretty impentriable.... hense the Jurassic Park plot.
Spraymax 2k clear is the best available clear coat, but it's toxic stuff. It does give very good results though.
I did this to a set of rims. It's OK for handlebars, but scratches up after a couple of years or comes off. It's not hard enough to hand either.
About "scoring the resin", folks here are sanding their frames to remove weight, and they are "scoring the resin" as far as I understand.
Where this "resin" is supposed to be? Between paint primer and carbon? I thought carbon is impregnated with resin itself...
You're thinking about carbon as the primary ingrediant. CF is more of a case where the resin is there with as much carbon fibres packed in as possible. Kinda like pancake or bread mix, it maybe mostly flour but it's a bunch of flour in water. The CF is there to strengthen the Resin, not the other way around. CF is basically a really strong string.


The "score" or small cut, just give a place for a crack to form. You're making a weak spot, maybe with other micro-cracks, maybe cutting a bunch carbon fibers in a row. This weak spot might cause a micro fold of nearby fibers on compression, weaking them too. Probably not a big deal on the fork, where everything is thick, but on the downtube and top tube there's maybe a little risk with a decent size score. Generally, you don't want to score any high performance thing metal or otherwise, because thats where it will fail. The higher the performance of the part, the higher the risk.
Something like this
Image

charirider
Posts: 263
Joined: Tue Apr 13, 2021 3:00 am

by charirider

Thanks!
Will not try to sand too much into composit)
Decided not to lower grit to 240 and use 320 as a minimum, because it gave good results on fork without any noticeable scratches.
Also, removing front derailleur mount which is riveted down is a real pain in the ass, ended up ordering a dremel with cutting disc to cut rivet heads off.
2018 Cannondale SuperSix EVO 2 rim size 56 (raw stripped) 6.9kg
2014 Bridgestone Anchor CX6 Equipe size 55 (cyclocross) 9.8kg

Aeo
Posts: 668
Joined: Wed May 25, 2016 2:06 am

by Aeo

Check ETOE for rivnuts https://www.youtube.com/watch?v=kTVBzfgOEAU
Also has more videos about stripping paint
Giant TCR Adv Pro Disc '17 · BH Lynx Race Evo '19 · Seraph GR029 '21 · Canyon Inflite AL '14

Maddie
Posts: 1532
Joined: Tue Oct 17, 2017 5:44 am

by Maddie

jfranci3 wrote:
Wed May 25, 2022 2:41 pm
Discodan wrote:
Tue May 24, 2022 3:48 am
My understanding was the paint stripper can attach the resin and effect the structural integrity of the carbon so I'd be cautious. I've sanded frames back before and agree it's really tedious, you should have no issues using 240 but be cautious as soon as you get through the top layer of paint. Most people who's done this a bit prefer using a sharp blade or knife to scrape the paint off rather than sanding; I've never tried it myself but may be worth a little research. It would also let you get into the nooks and crannies like your FD mount
Planes get paint stripped all the time. Just use the right stuff. https://www.rustoleum.com/en/product-ca ... ft-remover Just make sure it is epoxy/resin OK. Epoxy is pretty impentriable.... hense the Jurassic Park plot.
You can't really compare planes to bike frames. While the outer shell of a plain will have dozens of layers, a bike frame has two or three in some places. I build a lot of carbon parts myself. And I did some testing with paint strippers. The stuff that is supposed to be OK on carbon just doesn't remove paint significantly. Maybe there is one, but I haven't found it. And the stuff that does remove paint, significantly weakenend for instance one of my OEM Venge seatposts to the point where I could bend it with my bare hands. The product you linked is definitely one of those that can weaken a frame. It's for metal, not carbon. It's supposed to remove epoxy paint so just imagine what it does to the epoxy laminate of a bike frame.

I believe there are two methods that are safe if done correctly. One is with knives and sandpaper starting from 350 grit. Or nutshell blasting. But you need someone who is experienced with carbon.
With paint strippers, you just don't know what happens beneath the surface...

charirider
Posts: 263
Joined: Tue Apr 13, 2021 3:00 am

by charirider

Decided to go 320-600-800 grit sandpaper way.
Messy, but safe and result is satisfying.
At the end ripped front derailleur mount and chainstay chain suck protector plate off. Easy 20g saved.
Fork done and 303 coated, frame, I'd say 1/4 done.
Also, ordered SS Nano styled light pink toptube and stearer tube waterslide decals.
When finished, will post weights. I think, nobody have posted 2017-2019 regular ss evo stripped weights yet...
Attachments
05B9AFA1-7934-4A0D-8244-E5C9B1D781C2.jpeg
B5F1ADB3-8413-4FE0-89EE-B39115797CEA.jpeg
2018 Cannondale SuperSix EVO 2 rim size 56 (raw stripped) 6.9kg
2014 Bridgestone Anchor CX6 Equipe size 55 (cyclocross) 9.8kg

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



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