Originally Posted by
francophile
Want to find out? Dab a little Naval Jelly on it for 10 minutes, then remove it. It's paint-safe if not left on for more than an hour or two. Remove it. Is it gone? If so, it's probably rust.
Thanks! I almost got some naval jelly last night but ended up getting CLR since I've got to work on lime deposits in our bathrooms also. If CLR and additional sanding doesn't work, I'll get some naval jelly. Maybe overdoing it for a non-enthusiast, non-collectible bike but it still has some sentimental value.