Framebuilders - Post-flux removal steel oxidation?

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mudboy
01-05-11, 07:07 PM
I did all the braze-one on my frame last night, and since there was flux at some point on the frame from head to tail, I decided that a hot water soak in the tub was called for. All tubes that don't intersect with the BB (plus the head tube, natch) are sealed.

Soaked the frame for a bit, worked any remaining flux loose with a brass wire brush, and then dried it off and left it for a bit. There's now oxidation (very light rust) inside the BB shell and along the lug lines...is there a secret to how to de-flux frames without getting rust? Any easy way to remove the rust?

Thanks

Pete


moto367
01-06-11, 10:21 AM
Naval Jelly is good for removing rust. As far as the other part of your question, sorry but I'm just getting into framebuilding myself so I don't have an answer.

mudboy
01-06-11, 10:29 AM
It's not deep rust at all, it's just like a film, so I think Naval Jelly would be overkill.


moto367
01-06-11, 11:14 AM
steel whool

unterhausen
01-06-11, 11:28 AM
first off, it's nothing to worry about. It isn't going to get worse, so you can just leave it for the last step before paint. In fact, you can usually wipe it off with a wet rag.

I have found that if I leave something soaking in hot water for as little time as it takes to get rid of the flux, I generally don't get rust. Actually, removing rust is one of the things that flux does. If I'm lazy and leave something overnight or longer, I get rust. I'm sure there are ways of avoiding rust chemically, but I'm not sure it's worth it. In hot water, silver flux comes off quickly, the better bronze fluxes take a little longer. If you are going to leave a frame unpainted for a year, then you might want to use one of the corrosion prevention chemicals, paint places have them. Check with your painter first though.

mudboy
01-06-11, 12:24 PM
It'll be headed to Fresh Frame shortly after I finish up. I'll not worry about it for now, though I was planning on bringing it to school and show it to my creative writing class as an example of being proud of your work, warts and all :)

tuz
01-06-11, 01:58 PM
I think it was Falanx who suggested in another thread that diluting some molasses into the water will help prevent the steel from rusting. I tried it some time ago.... seemed to work! I'll try it again soon.

unterhausen
01-06-11, 02:48 PM
well, if you are going to take it to class, wipe it down and leave the rust that stays behind.

schooner
01-07-11, 03:37 PM
If you are worried about the looks of it, a little steel wool or sandpaper would take it right off. Otherwise, it will not be a big deal as your painter will take it off with whatever his surface treatment is prior to priming the bike.

stanridgespeed
01-11-11, 06:03 AM
Im with unter. You're painting the frame soon. Don't worry about it. The film you're seeing wont harm the metal structurally. I use the green brillo pads you can by at the grocery to cut the film off right before paint or have it media blasted.