Rust on steel frames

[old_fat_and_slow]

I realize there probably are not too many metallurgists on board, but I'd like to know others opinions, even if based primarily on anecdotal evidence alone.

If you have mild to medium rust that has developed on a steel frame what is your preference for dealing with it?

a.) Leave it alone, apply WD-40 (or whatever periodiodically to inhibit surface oxidation) and let it do it's cancerous corrosive thing, and eventually replace the tube if necessary and repaint the entire frame.

b.) Lumpectomy, that is, sand the crap out of the rust until you remove all the surface oxidation and the internal pitting. You've removed the cancer, but now you're left with a tube that has a small to medium divot resulting from the operation. You've also created some collateral damage to the the area adjacent to the rust. You've also weakened the area by removing some of the material, and created a mild stress raiser. Refinish the area as best you can with touch-up paint or spray paint.

c.) Sand the surface oxidation only, and apply some kind of rust converter/inhibitor. Refinish the area with touch-up paint or spray paint.
(Editorial/opinion only: Does this crap really work? I can't see how something applied to the surface of the metal can actually penetrate the steel at the microscopic level and stop the corrosion. At best this stuff probably just treats the surface, and inhibits further surface oxidation only, but the internal corrosion is still active, and the tube will eventually break similar to the untreated case.)

d.) ??

What's your preference? If you're a metallurgist or chemist, your input would be most welcome. (If tempted, please save the smarmy ... "that's why I ride alternative frame material _______, so I don't have to deal with this" comments to yourself. :rolleyes:

Thanks.

Fatty

[Pete Serotta]

Really depends: If outside surface rust than clean it and touchup. If coming to the outside of tube from the inside that is bad and depending on where it is on frame will determine plan of action.

[old_fat_and_slow]

Outside rust, can't just really "be cleaned up".

If you sand the surface oxidation off, you will see dark spots below where the oxidation formed. This is the top of corrosion pits where the corrosion has eaten down into the tube. To fully remove the rust, you must continue sanding until the dark specks go away, and the sanded area is one uniform color.

If you just sand the surface oxidation, you are just sugar coating the problem, and kicking the can down the road, (that is, putting today's problem off until the rust re-appears, months or years later.)

[Fixed]

i am going to send my merckx to tom kellogg and have him redo ( refresh ) the whole frame
in the mean time i wipe down with an oily rag
cheers

[schneiderrd]

The purpose of cleaning the existing rust off is so that you can get paint to stick to the metal. If you can get down to "bare metal" a good paint job will prevent oxygen from coming in contact with the steel thus preventing further corrosion. Understand that any coating (paint) needs to be maintained as any chips or perforations of the coating will allow oxygen to come in contact with the steel and start the corrosion process all over again. If the rust is so deep that you have to remove a lot of metal to get down to bare steel you could compromise the strength of the tubing.

[AngryScientist]

if it were my frame, this is my take on it:

remove the rust, period. sand until you are down to bare, clean metal. it is not until you do this that you know how far the rust has actually penetrated, and that's exactly what i want to know.

after that it's a judgement call, if you really had to gouge into the tubing to remove the rust, it can be repaired by a competent welder by building the area back up. if it's really not too deep, a 2-part body filler to smooth out the area, followed by an etching primer followed by a top coat are the way to go.

unless you've got serious rust issues, the second case is very likely.

how about some pictures?

[old_fat_and_slow]

Whah hell boy... Ah gots me'n a rusted-out ol' Allis Chalmers sittin' out in tha pasture hind tha' ol' barn over yonder. Been thar pert near 80 years, ah reckon. Rusted all tah hell, an she ain't fell in two, yet.

What tha hell yah frettin' over'n a few tiny li'l specks a rust fer?

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Yeah, yeah, fanks for that anecdotal gem there Farmer Brown.

[AngryScientist]

Whah hell boy... Ah gots me'n a rusted-out ol' Allis Chalmers sittin' out in tha pasture hind tha' ol' barn over yonder. Been thar pert near 80 years, ah reckon. Rusted all tah hell, an she ain't fell in two, yet.

What tha hell yah frettin' over'n a few tiny li'l specks a rust fer?

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Yeah, yeah, fanks for that anecdotal gem there Farmer Brown.

huh? was that directed at my advice?

[ckamp]

I obtained frame which was rusted inside and out, not just basic surface rust either. If you scrape at it, you will dent and scratch the good metal underneath, you also may over-sand it and remove paint that you want to keep.

The best product I have used is this (Purchased at Lee Valley):
http://www.evaporust.ca/

I sealed all openings of the rusted frame and poured this in, let it sit, and it removed it all. For the outside of the frame, a soaked paper towel of this stuff wrapped in some seran wrap removed it as well. Very easy, does not damage or fade the paint.

Biodegradable, non toxic, non corrosive.

Finish by spraying the bare metal with Boeing T9 or Frame-saver.

In my opinion you would be foolish to do anything else.

Good luck.

[old_fat_and_slow]

huh? was that directed at my advice?


@AngryScientist,

No. (Sorry if I gave that impression.)

Just trying to inject a little levity into the thread. Sorry if that's poor form responding to my own thread.

Very sorry if I came across as mocking you or your post in anyway.

[AngryScientist]

no worries, just checking, sometimes i'm a bit longwinded. :beer:

[Bob Loblaw]

I used to do Volkswagens, notorious rusters. VW experts swear by this stuff:

http://www.por15.com/

Allegedly it stops rust cold, bonds to it, encapsulates it, and strengthens it, and you can sand it and paint over it. Depending on how bad the rust is and how important the frame is to you, you might think about it.

Personally, on my winter beater which is constantly exposed to rain and road salt, I just sand off the rust (well..wirebrush attached to a drill), and spray on rustoleum primer and then enamel. Works fine so far.

BL

[retrofit]

I've treated both internal and external rust on frames and components with oxlic acid, more commonly known as wood bleach which can be found at most hardware stores. No sand paper required. If you search the Classic and Vintage subforum of bikeforums.net you will find plenty of threads on the use of OA to remove rust. After rust removal apply touch up paint, or if internal, treat with Frame Saver or Boeshield T-9.

[130R]

for the inside i used

http://xkeresto.files.wordpress.com/2008/04/2676-evapo-rust.jpg

i did it during winter break.

i plugged up the both sides of the bb, both sides of the ht, and the st. i used a funnel to put the evapo-rust in the bb cable guide hole.

i filled it so that all the tubes were immersed in solution and closed the hole. i let it sit for 3 days to make sure all that rust crap was gone and then i drained it.

all the dead rust came out.

i let it dry for 2 days then i applied

http://www.cswestbikes.com/catalog/jpwiegleframesaver.jpg

let that dry for 3 days

then i assembled it back up

and then now it looks new again

for effect:

http://farm6.static.flickr.com/5096/5389256711_17db5f416e_z.jpg

[Peter P.]

Lots of great solutions here.

What you do to the frame depends on whether the frame is a keeper or not.

If the frame is worth repairing and the rust is confined to one tube, you could let it go, hoping it will eat through and justify a restoration. Or, by sanding down to remove the rust you thin the tube, possibly weakening the frame and shortening its life, you're either closer to the restoration or closer to dumping that frame and getting something new.

It appears to me that taking a chance on a home repair with one of the methods above is not a bad idea, and a learning experience, too. Either it works or it puts you closer a repaint, restoration, or a new frame.

For what it's worth, my daily rider has severe rust under the top tube and actual holes in it. I'm letting it go in the hope it will fail, justifying a new frame. I KNOW sanding away the rust would all but eliminate the top tube! The frame is 26 years old and not worth much, although it's served me well.

[Louis]

For what it's worth, my daily rider has severe rust under the top tube and actual holes in it.

Carbon wrap will take care of that for you.