Proper sanding steps?

Discuss light weight issues concerning road bikes & parts.
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Fourthbook
Posts: 256
Joined: Fri Sep 30, 2011 2:11 pm
Location: Columbus, Ohio

by Fourthbook

How much of a noticeable edge is there between areas where you've scraped-off all the clear coat versus areas you've left untouched: ie if you only want to remove some of the CC and underlying decals but leave other decals, etc., is there a striking difference in sheen etc. even after you wax the worked area? Can you remove the CC in spots and not create a 'patchy' look?
Wilier Cento1 SR
13.10 lbs (5.95 kgs) w/Enve 3.4-Tune 70/170 & Conti Competitions tubulars
12.53 lbs (5.68 kgs) w/FarSports 24-Extralite & Vittoria CX EVO II tubulars

by Weenie


gumgardner
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Joined: Sat Jan 06, 2007 9:47 pm
Location: Pittsburgh

by gumgardner

It all depends on how thick the clear coat is, but you can blend it very easily. This may be hard to explain but here goes...if the ledge of the clear and area that has no clear coat is running left to right, I take the blade and hold it perpendicular to the ledge and scrape it towards me that way. It's too difficult to go up and down over the ledge. You'll end up making more of a bump. You have to go side to side.


Clear coated area
--------ledge---------- |||||| blade --->>scrape until it blends
Bare carbon

cep111
Posts: 95
Joined: Sun Nov 20, 2011 9:50 pm

by cep111

I have learned something here! It also sounds like the 303 protectant is easy to find, any marine dealer .....


philhul
Posts: 129
Joined: Sat Apr 30, 2011 1:08 pm
Location: Newcastle, UK

by philhul

I think I might have a go on my saddle. It's fairly light and comfortable but it bugs me that it doesn't really fit into my stealth build.

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BmanX
Posts: 3844
Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

Just removed the RED from my SRAM red levers. Taped off the shifter and left the red part exposed. Used some 120, 400, then 800. Finished it off by adding some clear nail polish on the exposed area to match up with the clear on the upper part of the lever.

I have stripped down 3 pairs of cranks and the razor blade is the best way to strip at first but if you want a very good finish I would take some 1000 wet/dry sandpaper to them. Also do 2-3 coats with a very light wet sand between.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

HillRPete
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Joined: Tue Apr 12, 2011 8:08 am
Location: Pedal Square

by HillRPete

Sorry I'm a bit late to the game, and this is only somewhat related.

I'd like to change my bike's colour scheme in minimally invasive ways, replacing silver highlights with blue ones. That includes like 5mm wide lines. Could anyone offer advice on how to go about that? Go for partial paint removal, or would it be better to mask the pattern, and put foundation and colour on top of the existing one?

Thanks.

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eliflap-scalpel
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Location: italy
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by eliflap-scalpel

a Flash 29er high modulus frame can be "bladed" ?
http://eliflap.it/

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Genshammer
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Location: Escondido, CA
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by Genshammer

If you are going to sand your frame to the bare carbon, you really need to put some kind of UV protectant on the entire frame. Whether it's an automotive grade clearcoat or otherwise, if you don't UV protect it, over time the sunlight will begin to degrade the resin system, weakening the structural integrity of the frame.

That being said, if you are going to shoot the frame with matte or gloss clear, you don't need to use any finer than 320 grit. Clearcoat has a harder time adhering to anything finer than 400 grit. If you insist on doing a raw frame with no clear, then I guess wet sanding with 1000 or 1200 will make it come out super smooth, but I wouldn't recommend it. You really need some kind of UV protectant on the frame.

I usually start out with 150 grit on a sanding wheel to get the clear off, hand sand the lugs/joints, then step up to 220 then 320. Clean the frame really well with acetone, then shoot the clear over it. Comes out looking pimp! We also use the same procedure for cranks, handlebars, etc etc. You can see examples of our repair and finish work at the links below.

Sincerely,
Kurt Gensheimer
CarbonFrameRepair.com
Your source for quality, professional carbon fiber bicycle repair
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eliflap-scalpel
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Joined: Sun May 25, 2008 10:12 pm
Location: italy
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by eliflap-scalpel

i sanded 3 years ago a mtb frame

no protective clear coat

no issues ... and that frame was really used in the ... :mrgreen: "right" way ...
http://eliflap.it/

nickf
Posts: 537
Joined: Sat Mar 06, 2010 10:34 pm

by nickf

Just started sanding my sram noir mountain cranks. So far the razor blade trick is working well. Non drive side is done and will finish up the drive side in a couple days. I hit the nds arm with 400 grit, then 1000 grit. Nice smooth finish. Only thing im not crazy about is that the finish is now more of a gray color. I like the metallic sheen it has but wish it would have come out darker. Will that 303 sealer darken the finish up a bit? Or I might hit it with a flat clear.

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gumgardner
Posts: 3553
Joined: Sat Jan 06, 2007 9:47 pm
Location: Pittsburgh

by gumgardner

That's the color of carbon. Companies often darken the fiber or add a ton of clear coat to make it appear darker to hide imperfections.

BmanX
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Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

I think once you apply the clear coat everything will be back to normal. I always do three light coats of clear with a light wet sand between the first two coats. Looks great when done. I bake the parts in the oven for a short time as well to help with the curing of the clear.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

CarlTroy
Posts: 346
Joined: Sat Feb 13, 2010 2:59 pm

by CarlTroy

I would love to be able to put my frame in the oven when finished with the sanding :)
I guess current ovens are simply not up to the task

by Weenie


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Mr.Hyde
Posts: 124
Joined: Fri Sep 05, 2008 1:03 am

by Mr.Hyde

Genshammer wrote:If you are going to sand your frame to the bare carbon, you really need to put some kind of UV protectant on the entire frame. Whether it's an automotive grade clearcoat or otherwise, if you don't UV protect it, over time the sunlight will begin to degrade the resin system, weakening the structural integrity of the frame.


:lol:

You don't need UV protection on CF-EP-laminates. The fibres are intransparent for UV light, so the matrix won't geht any damange below the first fibre. You might get some yellowing on the outside of your part, but there is no significant loss in structural integrity :wink:

That might be different for GF or AF, because laminates made from these fibres are transparent or translucent.

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