Neutralizing vinegar

[1930]

Can someone tell me how much baking soda is required to neutralize the rust removing vinegar solution I have had some parts laying in.

Ive had a cylinder head and an intake manifold sitting in Vinegar for a few days, I pulled out the intake and it was very clean, Vinegar worked very well but the orange came back very quickly so I need to evidently give it a Baking soda bath.

Just dont know how much baking soda to use per gallon of water?

Is it just grocery store baking soda? Nuthin special about it?

[rusty]

as much as will dissolve in the water. You aren't trying to balance out the acid, you are reversing the PH, and baking soda is very weak.

Baking soda, not powder, yes, store kind.

It will still flash rush tho, it is the water as much as the acid, you need to dry it with alcohol and oil it immediately after you are done...

PS: The residue from baking soda is insoluable in water, so it'sa gonna make a mess ;P

PPS: At root temp, soluability is 94 grams per liter, 16 oz box is 454 grams...
So a box should be ok for a couple gallons...

[Bill Houghton]

It will still flash rust tho, it is the water as much as the acid, you need to dry it with alcohol and oil it immediately after you are done...

Concur.  I don't use baking soda, I just use lots of running water, pat dry, then hit it with lots of WD-40.  But my uses for vinegar soaks are mainly small hand tools, on which this method is feasible.  Larger components, it would be harder to use this approach.

[scottg]

For a cylinder head or manifold I'd just take it to the car wash.
 Blast the crap out of it with soap, then plain water.

 Get it dry and oiled as soon as possible. Too bad it ain't July along about now.....
    yours Scott

[bonneyman]

Baking soda is a weak base, but typical vinegar is like 5% acetic acid. That's also pretty weak.

Someone told me once about spraying aerosol brake cleaner down a gun barrel after shooting corrosive (i.e acidic) ammo. He said that doing that at the range would prevent rusting for at least a day until you could "really" clean it. I've never tried it, but, maybe you have some of that aerosol in your shop?

[1930]

as much as will dissolve in the water. You aren't trying to balance out the acid, you are reversing the PH, and baking soda is very weak.

Baking soda, not powder, yes, store kind.

It will still flash rush tho, it is the water as much as the acid, you need to dry it with alcohol and oil it immediately after you are done...

PS: The residue from baking soda is insoluable in water, so it'sa gonna make a mess ;P

PPS: At root temp, soluability is 94 grams per liter, 16 oz box is 454 grams...
So a box should be ok for a couple gallons...

Thanks Rusty, I am not clear on this however.....Baking soda, not powder, yes,...........You say not powder? Baking soda is powder ?


You said...........It will still flash rush tho, it is the water as much as the acid, you need to dry it with alcohol and oil it immediately after you are done..............

Yes this is an issue I need to deal with, I was hoping that a dunk in kerosine might stop the flash rusting ( after the baking soda dip ) As you know I have water outlets, fuel runners ect that cant be just wiped down because there is no access. Dunking this stuff in some exotic mix of fluids is sorta out of the question since that would put my budget over the top so any suggestions would be welcome.

[1930]

It will still flash rust tho, it is the water as much as the acid, you need to dry it with alcohol and oil it immediately after you are done...

Concur.  I don't use baking soda, I just use lots of running water, pat dry, then hit it with lots of WD-40.  But my uses for vinegar soaks are mainly small hand tools, on which this method is feasible.  Larger components, it would be harder to use this approach.

Thanks Bill, I dont have the ability to pat down, I am hoping that a dip in kerosine would do the trick.

 I guess I could scrounge up some diesel fuel if you think that would be better

[1930]

For a cylinder head or manifold I'd just take it to the car wash.
 Blast the crap out of it with soap, then plain water.

 Get it dry and oiled as soon as possible. Too bad it ain't July along about now.....
    yours Scott

I have a power washer at the house here and I am not afraid to use it :)

July is welcome around here for me.

[1930]

Baking soda is a weak base, but typical vinegar is like 5% acetic acid. That's also pretty weak.

Someone told me once about spraying aerosol brake cleaner down a gun barrel after shooting corrosive (i.e acidic) ammo. He said that doing that at the range would prevent rusting for at least a day until you could "really" clean it. I've never tried it, but, maybe you have some of that aerosol in your shop?

Cant imagine brake cleaner preventing rust on clean shiny metal but I do have plenty of that around here.

Ive had issues with the vinegar attacking a cast head.....badly. I do not consider straight vinegar as a weak acid any longer.

[1930]

Do I need to soak these parts in the baking soda solution and if so for how long? Maybe it needs to be neutralized in the solution which takes a specific amount of time?

The intake I pulled out a few days ago and then immediately soaked in Kerosine started rusting again in the Kerosine if thats believable.

Looks like it was never soaked to remove the rust in the first place. Frustrating!

[bonneyman]

Baking soda is a weak base, but typical vinegar is like 5% acetic acid. That's also pretty weak.

Someone told me once about spraying aerosol brake cleaner down a gun barrel after shooting corrosive (i.e acidic) ammo. He said that doing that at the range would prevent rusting for at least a day until you could "really" clean it. I've never tried it, but, maybe you have some of that aerosol in your shop?

Cant imagine brake cleaner preventing rust on clean shiny metal but I do have plenty of that around here.

Ive had issues with the vinegar attacking a cast head.....badly. I do not consider straight vinegar as a weak acid any longer.

Yeah, I've never used brake cleaner that way, but mentioned it because most guys have it in their shop. Maybe it prevents rust by displacing water?
One could also use household ammonia to neutralize an acid. NH3OH is basic, and a liquid would be easier to apply and get into all the crevices, but, the smell might be an issue

[rusty]

Kerosene will not stop flash rusting, it has a huge affinity for water , and absorbs it right out of the air. It will not dry the surface, you need to dry it with something that will either make the water evaporate (90% alcohol) or something that will displace the water. Note that Wd 40 is water based also, tho it isn't as bad as kero.

Oil should be something light, like sewing machine oil, so it will wick into places you can't reach, and so it won't attract dirt and stick it to the thing you just cleaned.

Brake cleaner has a bit of free chlorine in it, and will passivate steel somewhat, but it also can do weird things to the surface...(It converts some of the rust (ferric ocide) into ferric chloride, which is softer, and washes off, but the steel it still open grained underneath, so it's only a temporary thing)

>I have water outlets, fuel runners ect that cant be just wiped down because there is no access
Compressed air .....

Baking powder comes in a little can marked "Baking powder", it is for making cakes rise, it fizzes when you add water , not what you want;P

[1930]

Thanks for the tips/advice guys. Pulled out the intake manifold tonight and all in all I am not satisfied.

Yes the Vinegar did remove the majority of the rust but it does nothing to remove carbon deposits which is a big factor in automotive parts. Intake/exhaust runners, combustion chambers, EGR ports ect that have even the smallest amount of carbon were un-touched with a lengthy dip in the vinegar solution.

Paint was not removed as well which would have been a bonus but was not expected. Grease and oil in even the smallest amount was un-touched.

I was looking for a solution to soak parts in that would remove any foreign material from the cast parts without damaging them, looks like Im going to have to keep looking. From what I have read molasses wont do any better of a job, it will remove the rust but evidently it will leave everything else still behind.

[keykeeper]

I've used carburetor spray cleaner for cleaning grimy cast parts in blacksmith forge crank blowers and drill presses. Worked well for me to get into places brushes and such couldn't reach.

[Aunt Phil]

Used to be able to get "crude Carbolic Acid" which was pretty good at removing carbon and damn near anything else, including skin and flesh.  Can't get it any more cause some government employee decided it was dangerous to stupid people.

Carbon that has adhered to iron or about any metal is about the hardest thing to remove with any gentle process. 
If your parts are 100% iron with NO Aluminum try some spray oven cleaner to see if it loosens the carbon.
If it does, a long soak in sodium hydroxide solution or a shorter soak in heated sodium hydroxide solution will get the job done.
Of course you will then have gallons of HazMat to dispose of.