I did a search (a quick one at that) for a similar topic, but didn't find a whole lot. Anyways, I have a Peugeot PGN10 Galibier (1986) that was very well kept on the outside. No dings, no chips, only some scratches (surface, these don't reach the metal) on the paint. Well, the fork was bent and the seatpost was stuck, but otherwise it was in great shape.

Now the main question, The internal rust isn't horrible, the seat tube was rusted, but it's not flaky. however, I am worried about one of the chainstays, because the rust is showing up around the vent holes and some of the flaky rust is sliding around and falling into the bottom bracket and vent holes. But it's only one side. Is this something to worry about? Perhaps the longevity of the frame is lessened by good factor? And is this something that could be replaced in the future?

And a picture:


Just the frame, it is currently built as a singlespeed (don't kill me It's just what I prefer, it didn't come with all the original components either).

Many thanks in advance

Buy a cheap plastic kiddie pool and some oxylitic (think that's how it's spelled) acid and submerge the frame in the solution. It will kill the rust completely. As long as there are no obvios thin areas or perferations due to the rust you should be good to go!
Good luck!
Oh yeah...please don't cut off the derail hanger or any braze ons pretty please

Ah, I see. I will have to look up on that o:

But, don't worry, I am leaving the bike to be 100% converted back if it needs to. Well.. 90%... The fork is not original, I have the original, but it's got a bent steerer

After looking up rust killers, apparently oxalic acid isn't very effective, but I did find this. It's supposed to work decently well, but it's also 23 dollars a gallon. I suppose I could funnel it through the bottom bracket and seal off the vent holes.

After looking up rust killers, apparently oxalic acid isn't very effective

Funny as this seems to be the chemical of choice for most fellow board members!

Wrong.

I have treated about 20 bikes in the last year.

Do a search on oxalic, lots of threads out there, be sure to sort by relevance.

Oxalic acid is a great rust remover. It isn't a rust preventative. Two different problems - two different solutions. (This is also a good general theory of problem solving.

One of these days I'm going to buy a completely TIG welded steel frame and fork and have the whole damn frame parkerized (phosphoric acid treatment, AKA pickling) and flip rust the finger for the rest of my life.

Certain surface treatments, especially ones which aggressively etch the surface such as parkerizing, may make the frame more susceptible to fatigue.

Pickling is different from parkerizing.

Sorry, I didn't do the search on oxalic on here, but through google, and I probably was quick to jump to conclusions with not a whole lot of resources.

But from what I've read, diluted oxalic acid bath and then a baking-soda rinse to neutralize. But one thing I'm not too clear on, how strong should the bath solution be? I think I read in one of the threads that 2 pounds per kiddie pool and then leave the frame in for less than 24 hours?

leed: that sounds like too strong a solution. i used maybe a 1/4 of a relatively small bottle.

whatever you do, make sure you check the pool for leaks first. and do it OUTSIDE :-)

WHAT HE SAID.

I took his advice about the Oxalic Acid and the kiddie pool
I even keep a covered bucket for for an overnight parts wash.

lovely stuff oxalic acid...used for bleaching wood
I got it at the paint store for $7 per pound of crystals.
makes a bath about as strong as vinegar
so you can stick your hand in it.

Welp, I think I'll try 1 pound to a tub, I guess.

With the history of Parkerizing not causing firearms and military hardware to fail, I pretty much trust it.

You are right, pickling isn't parkerizing.

Firearms may undergo as many stress cycles in their lifetime as a bike frame would undergo in a few long afternoons, though.