Oxalic Acid Bath Help

[Bike from the Dead]

Hi guys,

So, I’d been doing some research on oxalic acid baths for removing rust and shining up paint on old bikes, and I decided that I wanted to give it a try on some of my bike projects. I think I know what supplies I need, and I think I understand the process, but I’ve found that there’s a bit of conflicting information on how to do an oxalic acid bath.

Here’s what I’ve basically learned so far:

Supplies I’ll want to do an oxalic acid bath:
1. Oxalic acid/wood bleach (I got 2 12oz tubs from Ace Hardware)

2. 1-2 kiddie pools big enough to fit my bike parts in

3. Gloves

4. Simple Green or vinegar to remove any grease and dirt from parts before the bath

5. Tooth brushes to remove yellow film from parts during bath

6. Soap and water to wash off parts after bath (Would Dawn work?)

7. Air compressor for drying

8. Rust inhibitor to spray inside of frame and forks after bath

9. Wax to protect paint/chrome/steel from rusting again (I’ve heard a few folks recommend Johnson’s paste wax, but I don’t know of any stores that carry it. Would automotive wax work?)

10. Scotch Brite no-scratch pads to wipe off parts after bath

11. Micro-fiber cloths for waxing

The process as I understand it:
1. Disassemble bike

2. Clean off any dirt and grease from any parts using either Simple Green or vinegar, depending on whether or not the part is chrome?

3. Once all parts are cleaned, place in kiddie pool full of warm water. I’ll be doing this when the weather is warm and sunny out, so I take it that I’ll just have to let the water warm up on its own.

4. Mix at least a couple tablespoons of oxalic acid into water. It’s okay if the solution is weak, as more OA can be added if needed.

5. According to some, this is when you pull out a 6-pack of beer and start drinking. Given that I don’t drink, I’ll substitute this step with lemonade or something.

6. After a few hours, a yellow film should develop on the submerged parts. Remove yellow film with toothbrush while sitting in the solution.

7. After all rust and yellow film appears to have been removed, gently wash off parts with soap, water and pads. (Seriously though, what kind of soap do I use?)

8. Dry parts with air compressor and a micro-fiber cloth

9. Spray inside of frame and forks with rust inhibitor. Wipe it off if it gets on the outside of the frame and forks. Allow it to dry.

10. Gently wax parts with micro-fiber cloth and reassemble.

11. Take your shiny rust-free bike for a ride!

Okay, now that that’s out of the way, here’s where I get a little lost:

1. So it’s fine for the wheels to be put in the oxalic acid bath whether they’re chrome or painted, but the spokes, spoke nipples, hubs and axles are not okay to place in the bath?

2. Is it okay to dump the used solution into my lawn, or not? Some say it’s fine if I pour some additional water over the spot, others say don’t do it at all but don’t say how to dispose of it, some even just dump it without doing anything else. So, which is it?

3. What kind of soap do I use to wash off the bike parts after I take them out of the bath? I know some stuff doesn’t react well with the oxalic acid, but how do I know which kind of soap to use?

4. Does it matter what kind of wax I use to preserve the finish from rusting further, and how would you apply it? I don’t have a buffing tool, but I have micro-fiber cloths. What sort of wax would you recommend that I could find at Walmart?

I had originally given up on doing an oxalic acid bath on my bikes when I decided that I wouldn’t risk my health or others’ health by getting the few remaining supplies I needed after the coronavirus was officially declared a pandemic in the U.S. However, since my parents still plan on going to Walmart and a few other places at this time, and had offered to get the last few supplies I need to finish some of my bikes, I’m going to go ahead and move forward with this. I’m still worried about getting sick, so I’m staying home regardless, but just because I’m staying home doesn’t mean I can’t go do some work on my bikes out in the yard.

So, what do you guys think? Do I pretty much have the whole list of supplies and steps down right, or is there something I missed? Any help or advice is greatly appreciated.

Also, here are my sources for my earlier research, in case you’re interested:
https://vintageamericanbicycles.com/index.php/2019/07/25/saving-a-rust-bucket/
https://bmxmuseum.com/forums/viewtopic.php?id=351132
https://thecabe.com/forum/threads/oxalic-acid-on-paint.53809/
https://thecabe.com/forum/threads/oxalic-acid-bath-before-and-afters.64373/
https://thecabe.com/forum/threads/how-to-clean-rust-off-the-bike.14561/
https://thecabe.com/forum/threads/m...cid-to-water-for-a-bicycle-frame-bath.143259/
https://thecabe.com/forum/threads/another-oxalic-acid-bath.120503/
https://thecabe.com/forum/threads/oxalic-acid-bathing.119924/
https://thecabe.com/forum/threads/n...due-from-chrome-after-oxalic-acid-bath.85055/

 

[Lamont]

Good for you tackling this challenge with the Downtime !

1. (If / presuming disassembling hubs and axles etc before immersing ? ) Often chome on hub shells is very well preseved once your degrease.

2.

3. Some folks recommend a Baking Soda/water solution, followed by the a Mild dish soap. They key is to nuetralize the Ph level promptly.

4. Applying Wax by hand is fine. Also, and if you have a variable speed cordless hand drill , you can consider buying inexpensive buffer attachment that is great for tubes and detail areas , importantly allows you to stay clear of any remaining decals of hand painted striping areas. (use lower speed drill setting )
order two : one for polish , one for wax

$4 each ( shipping currently slow)
https://www.harborfreight.com/1-1-2-half-inch-x-2-inch-cylinder-buff-65000.html

For metal and chrome areas: you can also dw 40 sprayed as soon metals as dry , to protect as you work. have to work deliberately/ promptly ReRust happens quickly. later you can wipe of the dw 40 and apply NevrDull, metal polish to chrome (found in walmart in a silver tin)


Wax type: everyone has their favorites , and they all seem to be good, but i use Maquires Fine Cut Cleaning Polish ( fine cut, or Ultimate not coarse) , followed by car wax.
( pricey stuff / will cut into your stimulus check) I also like Turtle wax premium polishing compound (at walmart )
I experimented with auto Heavy duty Rubbing Compound: I dont recommend ; too coarse for many paint types and conditions .... can burn right through the paint , at least that happened to me, others may have different results/better technique)


I appreciate how complete and thoughtful your post is , and looking forward to others comments / experiences/ recommendations . good luck !

 

[New Mexico Brant]

Be careful with both red and blue paint as they can discolor (change color).

 

[rennfaron]

1. So it’s fine for the wheels to be put in the oxalic acid bath whether they’re chrome or painted, but the spokes, spoke nipples, hubs and axles are not okay to place in the bath?

2. Is it okay to dump the used solution into my lawn, or not? Some say it’s fine if I pour some additional water over the spot, others say don’t do it at all but don’t say how to dispose of it, some even just dump it without doing anything else. So, which is it?

3. What kind of soap do I use to wash off the bike parts after I take them out of the bath? I know some stuff doesn’t react well with the oxalic acid, but how do I know which kind of soap to use?

4. Does it matter what kind of wax I use to preserve the finish from rusting further, and how would you apply it? I don’t have a buffing tool, but I have micro-fiber cloths. What sort of wax would you recommend that I could find at Walmart?

I just put the chrome wheels in, grease, rust and dirt intact. I primarily did this to limit the amount of pre-scrubbing with the dirt and grease (limit amount of abrasion). The OA seemed to break down the grease. It does seem true that the grease does prevent some of the OA effectiveness below the area. What I did was let the wheel soak and came back a little later with a soft toothbrush and knocked the grease and dirt off. It came off without any force at all and just washed away. Then left the wheel back in there. The toothbrush worked well around all the spoke nipples and the grease + dirt came off easy. I also find that the OA dissolves a lot of the rust but in areas where there is more build up the toothbrush helps to knock off some layers of it so the OA can get the rest. As it sits in the bath I just go over it with a toothbrush as needed. You want to limit the amount of work you do to the surface. I would work the frame the same way. Tedious, yes.

I dumped the solution in a grass free area. I read that the OA originally was used to clean wood and is environmentally safe (ish?). I still dump baking soda in the mix, stir it up and then dump it. I then fill up some fresh water and mix in baking soda and let the part sit for a bit and then dump that. I don't spend much time on the neutralizing process as the acid is really mild.

I don't use soap. The OA seems to get everything off, so no reason to use soap. Maybe others found a need. (if there is enough grime left on the surface maybe some soap will help get this layer off).

Then once all that is done, dry it all off. For the paint, the OA bath is just to remove the rust and other stuff on the surface. That doesn't mean your paint comes out looking great. Like @Lamont said, you may need to work the paint and apply a fine cut polish to get the paint back. Then follow with a good car wax. I used mequiars ultimate liquid wax.

 

[vincev]

I would use 1 tablespoon per gallon.

 

[GTs58]

Johnson's Paste Wax is $8 at Lowes. If you use a car wax, paste or liquid that is white or light colored there is a good chance after waxing the white residue will stick in the small chips and cracks and it looks like crap on a Black or dark colored bike. Actually it looks like crap on any color. I believe this is why some say they use Johnsons. A good Carnauba wax is what I use.
The water/acid ratio is also something that everyone differs on. I like more OA in the mix reducing the soak time. Why do a weak mix and soak for up to 24 hours as the weak mix loses it's potency?

 

[New Mexico Brant]

I use a high concentration but only leave the parts in for 30 minutes to an hour usually (warm water works best). During the soak I physically brush or wipe the parts about every 10 minutes to aid the action. It is my preference to pull parts before all the rust is gone; they look more realistic that way. There are many people here that leave parts in too long and they get a certain dull/dead look to them.

 

[saladshooter]

This is the best advice. Leave a little rust. If not the results are totally unnatural and look "off". Don't just drop the parts in and come back in the morning. Keep an active eye on the progress.

I use a high concentration but only leave the parts in for 30 minutes to an hour usually (warm water works best). During the soak I physically brush or wipe the parts about every 10 minutes to aid the action. It is my preference to pull parts before all the rust is gone; they look more realistic that way. There are many people here that leave parts in too long and they get a certain dull/dead look to them.

 

[Rivnut]

Buying Wood Bleach is waaaaay more expensive than buying a 5 lb bag off Ebay. Wood bleach is about $7-$8 for 12 oz. A 5 lb bag (80 oz.) on Ebay is less than $20. It's not real scientific. Mix up a batch, throw in your parts, let them soak for a while, then rinse them off. Once the rust is off the part is good for a long time. But, I only use it on chrome; haven't has real good luck on painted surfaces. Either the original paint is good or the parts get stripped and repainted.

 

[Bike from the Dead]

Good for you tackling this challenge with the Downtime !

1. (If / presuming disassembling hubs and axles etc before immersing ? ) Often chome on hub shells is very well preseved once your degrease.

2.

3. Some folks recommend a Baking Soda/water solution, followed by the a Mild dish soap. They key is to nuetralize the Ph level promptly.

4. Applying Wax by hand is fine. Also, and if you have a variable speed cordless hand drill , you can consider buying inexpensive buffer attachment that is great for tubes and detail areas , importantly allows you to stay clear of any remaining decals of hand painted striping areas. (use lower speed drill setting )
order two : one for polish , one for wax

$4 each ( shipping currently slow)
https://www.harborfreight.com/1-1-2-half-inch-x-2-inch-cylinder-buff-65000.html

For metal and chrome areas: you can also dw 40 sprayed as soon metals as dry , to protect as you work. have to work deliberately/ promptly ReRust happens quickly. later you can wipe of the dw 40 and apply NevrDull, metal polish to chrome (found in walmart in a silver tin)


Wax type: everyone has their favorites , and they all seem to be good, but i use Maquires Fine Cut Cleaning Polish ( fine cut, or Ultimate not coarse) , followed by car wax.
( pricey stuff / will cut into your stimulus check) I also like Turtle wax premium polishing compound (at walmart )
I experimented with auto Heavy duty Rubbing Compound: I dont recommend ; too coarse for many paint types and conditions .... can burn right through the paint , at least that happened to me, others may have different results/better technique)


I appreciate how complete and thoughtful your post is , and looking forward to others comments / experiences/ recommendations . good luck !

Be careful with both red and blue paint as they can discolor (change color).

I just put the chrome wheels in, grease, rust and dirt intact. I primarily did this to limit the amount of pre-scrubbing with the dirt and grease (limit amount of abrasion). The OA seemed to break down the grease. It does seem true that the grease does prevent some of the OA effectiveness below the area. What I did was let the wheel soak and came back a little later with a soft toothbrush and knocked the grease and dirt off. It came off without any force at all and just washed away. Then left the wheel back in there. The toothbrush worked well around all the spoke nipples and the grease + dirt came off easy. I also find that the OA dissolves a lot of the rust but in areas where there is more build up the toothbrush helps to knock off some layers of it so the OA can get the rest. As it sits in the bath I just go over it with a toothbrush as needed. You want to limit the amount of work you do to the surface. I would work the frame the same way. Tedious, yes.

I dumped the solution in a grass free area. I read that the OA originally was used to clean wood and is environmentally safe (ish?). I still dump baking soda in the mix, stir it up and then dump it. I then fill up some fresh water and mix in baking soda and let the part sit for a bit and then dump that. I don't spend much time on the neutralizing process as the acid is really mild.

I don't use soap. The OA seems to get everything off, so no reason to use soap. Maybe others found a need. (if there is enough grime left on the surface maybe some soap will help get this layer off).

Then once all that is done, dry it all off. For the paint, the OA bath is just to remove the rust and other stuff on the surface. That doesn't mean your paint comes out looking great. Like @Lamont said, you may need to work the paint and apply a fine cut polish to get the paint back. Then follow with a good car wax. I used mequiars ultimate liquid wax.

I would use 1 tablespoon per gallon.

Johnson's Paste Wax is $8 at Lowes. If you use a car wax, paste or liquid that is white or light colored there is a good chance after waxing the white residue will stick in the small chips and cracks and it looks like crap on a Black or dark colored bike. Actually it looks like crap on any color. I believe this is why some say they use Johnsons. A good Carnauba wax is what I use.
The water/acid ratio is also something that everyone differs on. I like more OA in the mix reducing the soak time. Why do a weak mix and soak for up to 24 hours as the weak mix loses it's potency?

I use a high concentration but only leave the parts in for 30 minutes to an hour usually (warm water works best). During the soak I physically brush or wipe the parts about every 10 minutes to aid the action. It is my preference to pull parts before all the rust is gone; they look more realistic that way. There are many people here that leave parts in too long and they get a certain dull/dead look to them.

This is the best advice. Leave a little rust. If not the results are totally unnatural and look "off". Don't just drop the parts in and come back in the morning. Keep an active eye on the progress.

Buying Wood Bleach is waaaaay more expensive than buying a 5 lb bag off Ebay. Wood bleach is about $7-$8 for 12 oz. A 5 lb bag (80 oz.) on Ebay is less than $20. It's not real scientific. Mix up a batch, throw in your parts, let them soak for a while, then rinse them off. Once the rust is off the part is good for a long time. But, I only use it on chrome; haven't has real good luck on painted surfaces. Either the original paint is good or the parts get stripped and repainted.

Wow! Thanks for all the tips and advice guys! I've got just a few more questions and comments before I get started, so I hope it's okay that I reply to all of you at once, rather than separately. Also, I should’ve mentioned that I’m fairly young and relatively new to the hobby, so I apologize if my questions/comments sound a bit elementary.

1. Ok, so on the oxalic acid bath itself, it seems that everyone has their own method on how to get the best results. With that being said, it looks like I’ll just have to experiment to find what method works best for me. I’ll update this post with my own method of doing an OA bath for each of the bikes I plan to try this on.

2. The main thing I’m getting lost on is what I do after the OA bath. I have no experience polishing/buffing paint, and from what I’ve heard it’s possible to actually destroy the paint if done improperly. The closest experience I’ve got is just using Maguire’s (sometimes waterless) wash & wax on my car with sponges and microfiber cloths. I want the paint to look right, but I’m afraid of messing up. Is there a “buffing/polishing paint for dummies” guide to restoring the finish on original bike paint? What would be the simplest and safest way for a newbie to bring the shine back to his bike?