Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Difference between rust and pitting? Pitting can not be restored?

Search
Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Difference between rust and pitting? Pitting can not be restored?

Thread Tools
 
Search this Thread
 
Old 05-11-15 | 01:13 PM
  #1  
Thread Starter
Senior Member
 
Joined: Jul 2013
Posts: 99
Likes: 0
Difference between rust and pitting? Pitting can not be restored?

What is the difference between rust and pitting? Is there a visual or other way to tell? Is there any kind of "test kit" that can tell you if it is just rust or pitting?

If something is indeed pitted, I assume there is no way to restore?

Lastly, does the spray on re chroming work? I saw this on a video of Jay Lenos garage and it looks like it worked? Does anyone know the name of said product, cost and if it indeed works or not?
davey67 is offline  
Reply
Old 05-11-15 | 01:22 PM
  #2  
Banned
 
Joined: May 2015
Posts: 118
Likes: 2
From: Socal
Pitting:



It can be filled, what are you dealing with?
FRANK CANNON is offline  
Reply
Old 05-11-15 | 02:07 PM
  #3  
rmfnla's Avatar
Senior Member
 
Joined: May 2005
Posts: 6,301
Likes: 14
From: La La Land (We love it!)

Bikes: Gilmour road, Curtlo road; both steel (of course)

Pitting is essentially deeper rust, rust that has been allowed to progress beyond the surface stage.

The only real cure is to either fill in the pits or polish them away.

Don't know about spray-on chroming but it sounds like some form of paint and probably will look like it...
__________________
Today, I believe my jurisdiction ends here...
rmfnla is offline  
Reply
Old 05-11-15 | 02:31 PM
  #4  
dsbrantjr's Avatar
Senior Member
15 Anniversary
 
Joined: Sep 2010
Posts: 8,327
Likes: 1,108
From: Roswell, GA

Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta

They are the same thing. The iron in the steel turns into iron oxide. Whether is is called rust or pitting is only a matter of degree/semantics, the metal cannot be restored in either case.
dsbrantjr is offline  
Reply
Old 05-11-15 | 02:51 PM
  #5  
rmfnla's Avatar
Senior Member
 
Joined: May 2005
Posts: 6,301
Likes: 14
From: La La Land (We love it!)

Bikes: Gilmour road, Curtlo road; both steel (of course)

[QUOTE=dsbrantjr;17795994]They are the same thing. The iron in the steel turns into iron oxide. Whether is is called rust or pitting is only a matter of degree/semantics, the metal cannot be restored in either case.[/QUOTE

Sure it can.

Small pits can be filed out; large ones can be filled in by small spot welds and then ground smooth...
__________________
Today, I believe my jurisdiction ends here...
rmfnla is offline  
Reply
Old 05-11-15 | 03:05 PM
  #6  
Senior Member
Titanium Club Membership
15 Anniversary
 
Joined: Apr 2009
Posts: 39,897
Likes: 3,864
From: New Rochelle, NY

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Pitting describes the effect, and rusting the cause. Generally they're talking about the same issue, and the difference is the degree or depth of rust.

Others may also be referring to pitting from other causes, such as from chemical etching, or some people may intend a precise meaning, ie. pitting to mean deep pockmarks or dots (acne on steel) vs a broad area of rust, of any depth.

You also see people refer to pitting when describing plated steel, where you'll see rust dots (pits) because of the porosity of the plating. This type of pitting was classic on chrome auto bumpers for decades. Either way, it's all rust.

In any case, you can remove rust, but neither rust nor pitting are reversible. Once the steel is gone, it's gone for good.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Reply
Old 05-11-15 | 03:07 PM
  #7  
AnkleWork's Avatar
Senior Member
10 Anniversary
 
Joined: Jan 2013
Posts: 3,702
Likes: 105
From: Llano Estacado

Bikes: old clunker

Originally Posted by davey67
. . . Is there a visual or other way to tell? . . .
Yes, if you see rust, then you know there is pitting.


Originally Posted by davey67
. . . If something is indeed pitted, I assume there is no way to restore? . . .
Do you? There's always welding then grinding back to shape; remelting the steel and forming into replacement material, and other ways.


Originally Posted by davey67
. . . Lastly, does the spray on re chroming work? I saw this on a video of Jay Lenos garage and it looks like it worked? Does anyone know the name of said product, cost and if it indeed works or not?
Post which one you ask about and I'll tell you if it works.
AnkleWork is offline  
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
davey67
Bicycle Mechanics
2
09-16-14 12:46 PM
riggyk
Bicycle Mechanics
3
05-12-13 09:09 PM
micmat
Classic & Vintage
1
03-15-12 09:40 AM
vins0010
Bicycle Mechanics
1
11-23-10 03:38 AM
sjpitts
Classic & Vintage
6
03-04-10 08:08 PM

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.