Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Classic & Vintage (https://www.bikeforums.net/classic-vintage/)
-   -   Rust around bottom bracket (https://www.bikeforums.net/classic-vintage/1224954-rust-around-bottom-bracket.html)

b dub 03-03-21 08:38 AM

Rust around bottom bracket
 
I’ve been cleaning up this 1983 Nishiki Cresta.

pictures before.
https://cimg2.ibsrv.net/gimg/bikefor...e244f4b25.jpeg
https://cimg4.ibsrv.net/gimg/bikefor...3118e3b08.jpeg


I have soaked the entire frame in Evapo rust for about a day and a half.


https://cimg9.ibsrv.net/gimg/bikefor...122baa22b.jpeg
https://cimg2.ibsrv.net/gimg/bikefor...6187566c6.jpeg


Then I dipped just the bottom bracket in a smaller bucket with the Evapo rust for one more night.

This is what it looks now.

https://cimg5.ibsrv.net/gimg/bikefor...fa83a3390.jpeg
https://cimg0.ibsrv.net/gimg/bikefor...9871b98d3.jpeg

What should I do next? I’m not too concerned about the paint since this area will be mostly covered up by the crank. Carefully sand it? What should I apply on the exposed spots?

xiaoman1 03-03-21 08:51 AM

^^^^ It looks like just flaking paint...I would sand off the flaking paint, primer and find a spray color at an automotive parts store and spray away. :thumb:
Best, Ben

b dub 03-03-21 09:17 AM


Originally Posted by xiaoman1 (Post 21950009)
^^^^ It looks like just flaking paint...I would sand off the flaking paint, primer and find a spray color at an automotive parts store and spray away. :thumb:
Best, Ben

Thank you!!! I'm on it.

randyjawa 03-03-21 09:20 AM

Were I faced with the situation, I would clean/sand the offending areas and then apply nail polish in as close a match as I could find(brush is included in the polish bottle). That should do a bit to satisfy the eye and to protect against oxidation.

There are times, of course, when more attention should be paid, not just to the outside, but also to the inside...
https://cimg1.ibsrv.net/gimg/bikefor...2633a8f3fb.jpg

Johno59 03-03-21 09:41 AM

Remove flakes first
 
You should wire brush all the loose paint / rust off before you apply evaporust. If left too long evaporust will attack the paint. Follow the instructions on the tin. Many suppliers claim a primer isn't needed but I seriously have doubts about that.

oneclick 03-03-21 10:25 AM


Originally Posted by randyjawa (Post 21950062)
There are times, of course, when more attention should be paid, not just to the outside, but also to the inside...

The mouse I found *was* inside - in a frame I bought the seat had been out and it (long since dead) fell out the bb shell after the axle came out.

Spaghetti Legs 03-03-21 10:40 AM

I, too, would have removed the bubbled chipped paint before the evaporust treatment. At this point though, it still looks good, and just finish the job as recommended above. This is a great example for people who are afraid of buying a steel bike because it will apparently rust away to dust. Your bike is 38 years old and has many years of good life in front of it. I like the bath tub!

b dub 03-03-21 10:51 AM


Originally Posted by Johno59 (Post 21950101)
You should wire brush all the loose paint / rust off before you apply evaporust. If left too long evaporust will attack the paint. Follow the instructions on the tin. Many suppliers claim a primer isn't needed but I seriously have doubts about that.

I thought I followed the instructions but I guess I didn't.
I will remove the flakes, sand it, then just dip it in Evapo rust again.

AJI125 03-03-21 10:59 AM


Originally Posted by b dub (Post 21950227)
I thought I followed the instructions but I guess I didn't.
I will remove the flakes, sand it, then just dip it in Evapo rust again.

Good plan. After a few hours soak, remove and maybe scrub with like a nylon brush to remove any loose black Evaporust stuff. I found I needed multiple soaks/treatments for some pitting, as the black surface coating seemed to slow/stop the reaction and it didn't really remove all the rust. I soaked overnight on each tube and found the remaining rust pits when I was done soaking. At that point I just used Naval Jelly in several applications to get the rest off.
If you don't care about color match, I used some black rust reformer primer. I could only find in spray, so I sprayed into a small glass jar to use for brushing on. Seemed to work ok, put on several light coats then sanded after a couple days drying time. Took the sanding like a champ. Then I top coated with some Duplicolor lacquer touch up paint that was a close match, but that stuff already flaked/chipped in spots as others have experienced too.

b dub 03-03-21 11:03 AM


Originally Posted by AJI125 (Post 21950246)
Good plan. After a few hours soak, remove and maybe scrub with like a nylon brush to remove any loose black Evaporust stuff. I found I needed multiple soaks/treatments for some pitting, as the black surface coating seemed to slow/stop the reaction and it didn't really remove all the rust. I soaked overnight on each tube and found the remaining rust pits when I was done soaking. At that point I just used Naval Jelly in several applications to get the rest off.
If you don't care about color match, I used some black rust reformer primer. I could only find in spray, so I sprayed into a small glass jar to use for brushing on. Seemed to work ok, put on several light coats then sanded after a couple days drying time. Took the sanding like a champ. Then I top coated with some Duplicolor lacquer touch up paint that was a close match, but that stuff already flaked/chipped in spots as others have experienced too.

Just another example why I love this forum. Thanks for your suggestions. I will report a follow up shortly.


All times are GMT -6. The time now is 08:37 PM.


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