etherhuffer 

I agree that more dilute is better. A little elbow grease with weaker solution works well. Neutralizing with baking soda not a bad idea. But remember that when the rust is gone the underlying metal is happily waiting to oxidize. My solution to this on chrome is to immediately polish with Simichrome. Good product, repeat on chrome parts occasionally to keep them shiny.

spclark 

Reasonable approach. Another being simply to use a hard paste wax every so often to give the shiny bits a protective layer that prevents water vapor and oxygen from getting to the reactive iron underneath. That's the reaction you want to avoid, iron just loves marrying with oxygen to create rust.

tiger1964 

Someone on the forum mentioned Wolfgang's Metal Sealant some time ago, and I've been using it on chrome and aluminum parts for a while -- so far I' don't see any problems re-erupting. I do like shiny things to remain shiny.

spclark 

Never heard of THAT stuff 'till you posted this, thanks!

jonwvara 

This has been my experience, too, The "before" and "after" pictures look dramatic, but within a few years of normal use, you're pretty much back where you started (at least in my case, where I live in a relatively damp climate and store my bikes in a n unheated and non-climate-controlled shed). Maybe regularly wiping down the frame with Boeshield or some such would help, but I've never tried that. Waxing doesn't seem to prevent rust from recurring, at least in my experience. Bottom line, I doubt that I'll ever go to the effort of dipping another frame, either with OA--which I don't like for other reasons--or Evaporust, which I do like and continue to use for derusting components.

tiger1964 

Wow, in late 2020 it was only $19.99 per bottle. I am getting low, perhaps I need to shop around!

tiger1964 

Good info in this topic. Wish me luck! EDIT: Checking every 1/2 hour. Somewhere between 2 hours and 2.5 hours, somewhere have a tiny leak. This is going to be a mess! I wonder if there something better to line the box in? The spray version of Dip-it?

Classtime 

Two layers leaked

One layer good for 3 uses so far.
Mine leaked too. I’m using a piece of poly tarp now that works great.

bibliobob

+1. Super easy to make a paste and do spot applications.

oneclick 

I used 6 mil polythene sheet, it was good enough to last through quite a few frames.
You have to be a bit careful not to poke a hole in it with a pointy bike bit.
And out-of-doors is probably a good idea in any case.

tiger1964 

I got lucky and was able to empty the box and clean up before the OA damaged the tiles on my porch (unlike the last time I tried this ) Three cans of the rubberized undercoating arrive today and I'll coat the inside of the box and try again shortly. A friend suggested I could have tried the as-seen-on-TV Flex Seal product; probably not a bad idea.

If I keep the box long-term for future bikes, I think I need a petcock or sillcock to drain it once done -- scooping with a bucket was tedious and a lot of splash out, etc.

albrt 

Did an oxalic acid demo at the co-op tonight. That stuff is unbelievably good at making completely worthless chrome parts shine. The 11 ounce stamped-rolled-and-bashed Murray stem probably did not look that shiny when it was brand new.

It also works for nice chrome parts, but those aren't super common at the co-op.

obrentharris 

A word of caution. Don't dump the neutralizing baking soda into the acid bath while the frame is in the bath. The reaction that takes place may discolor paint and damage fragile decals.

Better to remove frame from bath, dump in baking soda, wait for reaction to subside, then return frame to bath to neutralizer the acid still remaining in frame tubes. Yes, I learned this lesson the hard way.

Brent

tiger1964 

It has been too cold for working outdoors in any case. Meanwhile, I sprayed all three cans of undercoating on the box -- no, IN the box. Then, working on something non-bike, I bought a quart of clear Flex Seal and only needed a little, so I am going to put a coat of that in the box too. Hoping to try it out in a few days.

Educate me on that? You put baking soda (how much per gallon?) in the water that already has the acid? Hmmm, I have a special challenge -- I am doing three frames, my plan was to dunk each one in succession in the same bath, I presume up to 24 hours (?); this would mean each bike would be out of the oxalic bath for up to 48 hours before I could re-immerse in a neutralizing bath. Bad idea? Alternatively, I re-mix the acid each time; I guess that means I'll be going through a lot more oxalic acid -- sure would not mind avoiding that.

obrentharris 

Baking soda is cheap. I use a whole box (8oz.?) in a frame bath. You will be fine letting the frames sit around for a day or two before purging them with baking soda. For extra protection you could run some fresh water into the tubes while waiting for the baking soda treatment.
Brent

spclark 

Any way you can rig up a scheme to have a plain water rinse for each frame (inside and out!) as you cycle each through your acid bath? That'd go along way to eliminating much of the carried-out acid solution. Or even prepping a bicarbonate solution (cheaper than oxalic acid) to do a cursory internal neutralization before setting each frame aside for a few days?

After all these baths it's A Good Idea I think to give each frame a decent rinse with plain water before proceeding with the next steps in your plan of action, then thorough dry-out. Gets rid of any remaining contaminants, leaves a clean surface for whatever you might have in mind for overcoating (lacquer inside, or oiling) before re-assembly.

tiger1964 

Reading a bunch of topics, not running into info on how long to leave the frame in the neutralizing bath. An hour? 24 hours? And I presume the "reaction" will be obvious in its appearance.

OK, two frames (and forks of course) have spent 24 hours each in the oxalic acid, and rinsed upon removal. Third one in there now -- and now it's lightly raining, not pleasant being out there but I'm "committed". So, once all three are done, I add a box of baking soda -- and how long each in that? And does that leave residue that I should remove with, say, soapy water?

And additional concern -- one frame is bare metal after soda blasting, and hope to take to a paint shop soon. Should I be worrying about "flash rust" or anything else, post-OA but pre-paint?

obrentharris 

I leave the frame in the baking soda bath for only a few minutes, then flush with clean water.

Yes, new rust is a concern after the OA treatment. My approach is to treat the dry frame with zinc phosphate and store it indoors until I can paint it. The product I use is POR 15 Metal Prep.
Brent

tiger1964 

Good info, thanks. Zinc phosphate, thanks for that, will get some ASAP. Hopefully no adverse impact with the guy who will do the actual painting.

obrentharris 

I don't know about powdercoat, but zinc phosphate is pretty common with quality wet paint jobs. I use either an epoxy primer or a two part urethane primer over it.
Brent

tiger1964 

In this case, it will be regular paint. Normally, I'd prefer powdercoat.

Today, the third frame came out, then the baking soda (yeah, it swirled/fizzed a bit, pretty obvious), then a short soak for each frame in that, then a cold-water rinse outside, then inside and a quick wipe down with microfibers to minimize drying on the frame. That took the last "film" off the frames, they look pretty good. Still awaiting the zinc phosphate. Meanwhile, frames in the house and the pellet stove on which can bring the humidity in the house down to about 30% so hopefully no flash rust.

Dang it, I swear there's still a little leakage from the soaking box despite the three cans of rubberized undercoating and then the coats of Flex-Seal. Not sure what I need to do the get a 100% leak-free vessel.

Still have some frame-prep steps, like Frame Saver and touch-up paint. Whew!