The Ford Barn

bart78 · 03-23-2015, 04:34 PM

Citric acid works well at removing rust. I have a engine that was rebuilt and then left to sit in a shop. It was never painted. So the block and pan and stuff are rusty. Will the citric acid hurt the babbitt? I want to get it all cleaned up. And get it up and running.

Joe K · 03-23-2015, 05:23 PM

This question very much in parallel with our discussion of gas tank rust removal.

I would be concerned with an acid eating away at babbit. Babbit is, after all, a mechanical matrix of tin/antimony/copper (see http://www.fordgarage.com/pages/babbittgrades.htm) Copper is quite "corrode-able."

I found this while looking for information on molasses/rust reaction.

http://elantrikbits.com/lotus-elan-b...ngine-de-rust/

Pretty remarkable or what?

Joe K

bart78 · 03-23-2015, 05:32 PM

I've seen that dr x rust remover online. There are some YouTube videos on it. Looks pretty good.

bart78 · 03-23-2015, 05:42 PM

I did not know if it being milder. If it would be ok on them.

hardtimes · 03-23-2015, 05:47 PM

Quote:

Originally Posted by bart78

I did not know if it being milder. If it would be ok on them.

Hey bart,
Good to do the research that you are doing , to satisfy yourself. IMO, citric acid , left in place for any length if time, will affect soft metal...like Babbitt.
After all, if it can do anything to mitigate rusty iron, that should give a clue,eh

bart78 · 03-23-2015, 05:52 PM

Sponsored Links (Register now to hide all advertisements)

I've though about the molasses. But don't really want to wait that long.

MikeK · 03-23-2015, 06:05 PM

Citric acid will react directly with the tin in the babbitt alloy matrix, forming soluble stannous citrate. (Yes, it will eat the babbitt).

Of greater concern is what happens to the rusty block. The first reaction goes like this:
C6H8O7 + Fe2O3——> 2 FeO + 6 CO + 2 H2O + 2 H2
Citric acid + red rust yields gray iron oxide, carbon monoxide, water and hydrogen.

Notice you will be producing copious quantities of carbon monoxide! Of equal concern is the reactions that follow. Upon removal of the 'rust' and flaking of the gray iron oxide you will have bare iron exposed that WILL react, forming soluble ferrous citrate. (It will eat into the bare metal)

Next, with both the babbitt and iron touching, the citric acid solution will become a battery. The electro potential difference between the tin and the iron will cause the tin to react and go into solution. (bye bye babbitt)

Summing it all, after the citric acid solution has first eaten so deeply into the babbitt alloy matrix that the tin is no longer chemically available the excess citric acid will begin working on the iron and will not stop until one of the two reactants is consumed.

Citric acid may work on lightly, evenly rusted tools if you watch closely and stop, but I would not use it on ANY part made of dissimilar metals/alloys that are bonded together, nor any part with light/heavy rust variations or pits.

bart78 · 03-23-2015, 06:22 PM

Would it be better to just do the outside of the block with easy off? The inside is real clean.

Big hammer · 03-23-2015, 07:03 PM

Evaporust is not suppose to attack other metals just rust check their web site :-)

Tom Wesenberg · 03-23-2015, 10:55 PM

Molasses isn't to be used on babbit, so I don't think I'd use Evaporust either.

Mike V. Florida · 03-23-2015, 11:39 PM

If the block is bad enough to need derusting, does one really want to reuse the babbit?

bart78 · 03-24-2015, 06:32 AM

The inside is perfect. The outside is rusty because it sat unpaired for 30 years. There have been plenty of engines that have had rusty outsides run just fine.

Joe K · 03-24-2015, 07:39 AM

When I was a young buck (wasn't that yesterday?) I cleaned and carefully painted my Model A engine before rebuilding. The book said "ford engine green" so I went downstairs and got some Rustoleum in green color and gave it a coat.

The engine went off to the rebuilder and after a while I got it all together - and it ran the truck for a couple of years.

Fast forward to a subsequent life situation where I had the time and the space to restore the truck, I discovered the error of my ways and decided to "do it right" and repaint the engine - and do that right too.

EVERYTHING came apart. I mean everything. And checked.

To remove the paint I carefully masked off the babbitt and running surfaces (cam shaft, cylinder bores, machined gasket surfaces) and brought the block into work where they had a glass bead machine.

Yes, I was concerned about glass beads floating around in my engine.

After blasting and re-painting, I then used my newly purchased parts washer to wash the block out - and did it again with fresh solvent. Lots of little test tube brushes and pipe-cleaners to clean out all the oil ports and threaded bolt holes.

Reassembled, the engine is fine and the conversion to correct color pleases me.

I tell you this to indicate that it IS possible to do this this way - but it is a LOT of work. And there is some risk on leaving some grit or doing some damage along the way.

Better though had it been done the right way in the first place. The next engine (gordon smith compressor) I took the hint.

Joe K

Tim B. · 03-24-2015, 10:00 AM

I tend to agree with Mike.

I've used a series of various sized and shaped wire brushes and extensions for various items with great results it may get you what you want. But if you want to follow your current path Alkaline cleaners may be an option for you. Some are available in sprays however most use heat and they are as caustic as an acid if you come in contact with them. For the most part Alkaline based cleaners will leave the base metal alone and remove only the rust. They do not have the problem with hydrogen embrittlement. Not sure about rabbit. Each cleaner has unique cleaning characteristics and you'd have to check Mfr specs. Here's some info.

http://heatbath.com/metal-finishing-...ine-derusters/

Tom Wesenberg · 03-24-2015, 11:58 AM

I have protected, blasted, and cleaned a couple blocks just as Joe said he did his. Yes, it's a lot of work and time consuming, but the end result was good.

BILL WILLIAMSON · 03-24-2015, 06:22 PM

I own NO RUSTY parts!! BUT, in my 5 month nightmare, I've grown RUSTY, any ADVICE?
Bill W.

MikeK · 03-24-2015, 09:02 PM

Quote:

Originally Posted by BILL WILLIAMSON

I own NO RUSTY parts!! BUT, in my 5 month nightmare, I've grown RUSTY, any ADVICE?
Bill W.

Put 1 lb of epsom salts into a tub of hot water and soak for 30 minutes.

Joe K · 03-24-2015, 09:26 PM

Crown in a dixie cup?

Internal soak. Rinse & repeat.

Joe K

Papa's CCPU · 03-24-2015, 10:02 PM

Quote:

Originally Posted by Joe K

Crown in a dixie cup?

Internal soak. Rinse & repeat.

Joe K

2x on Joe K's method......

Big hammer · 03-25-2015, 09:40 AM

Quote:

Originally Posted by BILL WILLIAMSON

I own NO RUSTY parts!! BUT, in my 5 month nightmare, I've grown RUSTY, any ADVICE?
Bill W.

Your humor isn't rusty :-)

03-23-2015, 04:34 PM	#1
bart78 Senior Member Join Date: Jul 2011 Location: Stephenville tx Posts: 1,019	Citric acid rust remover Citric acid works well at removing rust. I have a engine that was rebuilt and then left to sit in a shop. It was never painted. So the block and pan and stuff are rusty. Will the citric acid hurt the babbitt? I want to get it all cleaned up. And get it up and running.

03-23-2015, 05:23 PM	#2
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Citric acid rust remover This question very much in parallel with our discussion of gas tank rust removal. I would be concerned with an acid eating away at babbit. Babbit is, after all, a mechanical matrix of tin/antimony/copper (see http://www.fordgarage.com/pages/babbittgrades.htm) Copper is quite "corrode-able." I found this while looking for information on molasses/rust reaction. http://elantrikbits.com/lotus-elan-b...ngine-de-rust/ Pretty remarkable or what? Joe K __________________ Shudda kept the horse.

03-23-2015, 05:32 PM	#3
bart78 Senior Member Join Date: Jul 2011 Location: Stephenville tx Posts: 1,019	Re: Citric acid rust remover I've seen that dr x rust remover online. There are some YouTube videos on it. Looks pretty good.

03-23-2015, 05:42 PM	#4
bart78 Senior Member Join Date: Jul 2011 Location: Stephenville tx Posts: 1,019	Re: Citric acid rust remover I did not know if it being milder. If it would be ok on them.

03-23-2015, 05:52 PM	#6
bart78 Senior Member Join Date: Jul 2011 Location: Stephenville tx Posts: 1,019	Re: Citric acid rust remover Sponsored Links (Register now to hide all advertisements) I've though about the molasses. But don't really want to wait that long.

03-23-2015, 06:05 PM	#7
MikeK Senior Member Join Date: May 2010 Location: Windy City Posts: 2,919	Re: Citric acid rust remover Citric acid will react directly with the tin in the babbitt alloy matrix, forming soluble stannous citrate. (Yes, it will eat the babbitt). Of greater concern is what happens to the rusty block. The first reaction goes like this: C6H8O7 + Fe2O3——> 2 FeO + 6 CO + 2 H2O + 2 H2 Citric acid + red rust yields gray iron oxide, carbon monoxide, water and hydrogen. Notice you will be producing copious quantities of carbon monoxide! Of equal concern is the reactions that follow. Upon removal of the 'rust' and flaking of the gray iron oxide you will have bare iron exposed that WILL react, forming soluble ferrous citrate. (It will eat into the bare metal) Next, with both the babbitt and iron touching, the citric acid solution will become a battery. The electro potential difference between the tin and the iron will cause the tin to react and go into solution. (bye bye babbitt) Summing it all, after the citric acid solution has first eaten so deeply into the babbitt alloy matrix that the tin is no longer chemically available the excess citric acid will begin working on the iron and will not stop until one of the two reactants is consumed. Citric acid may work on lightly, evenly rusted tools if you watch closely and stop, but I would not use it on ANY part made of dissimilar metals/alloys that are bonded together, nor any part with light/heavy rust variations or pits.

03-23-2015, 06:22 PM	#8
bart78 Senior Member Join Date: Jul 2011 Location: Stephenville tx Posts: 1,019	Re: Citric acid rust remover Would it be better to just do the outside of the block with easy off? The inside is real clean.

03-23-2015, 07:03 PM	#9
Big hammer Senior Member Join Date: Jun 2014 Location: Land of Lincoln Posts: 3,127	Re: Citric acid rust remover Evaporust is not suppose to attack other metals just rust check their web site :-)

03-23-2015, 10:55 PM	#10
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Citric acid rust remover Molasses isn't to be used on babbit, so I don't think I'd use Evaporust either.

03-23-2015, 11:39 PM	#11
Mike V. Florida Senior Member Join Date: May 2010 Location: South Florida Posts: 14,054	Re: Citric acid rust remover If the block is bad enough to need derusting, does one really want to reuse the babbit? __________________ What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II

03-24-2015, 06:32 AM	#12
bart78 Senior Member Join Date: Jul 2011 Location: Stephenville tx Posts: 1,019	Re: Citric acid rust remover The inside is perfect. The outside is rusty because it sat unpaired for 30 years. There have been plenty of engines that have had rusty outsides run just fine.

03-24-2015, 07:39 AM	#13
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Citric acid rust remover When I was a young buck (wasn't that yesterday?) I cleaned and carefully painted my Model A engine before rebuilding. The book said "ford engine green" so I went downstairs and got some Rustoleum in green color and gave it a coat. The engine went off to the rebuilder and after a while I got it all together - and it ran the truck for a couple of years. Fast forward to a subsequent life situation where I had the time and the space to restore the truck, I discovered the error of my ways and decided to "do it right" and repaint the engine - and do that right too. EVERYTHING came apart. I mean everything. And checked. To remove the paint I carefully masked off the babbitt and running surfaces (cam shaft, cylinder bores, machined gasket surfaces) and brought the block into work where they had a glass bead machine. Yes, I was concerned about glass beads floating around in my engine. After blasting and re-painting, I then used my newly purchased parts washer to wash the block out - and did it again with fresh solvent. Lots of little test tube brushes and pipe-cleaners to clean out all the oil ports and threaded bolt holes. Reassembled, the engine is fine and the conversion to correct color pleases me. I tell you this to indicate that it IS possible to do this this way - but it is a LOT of work. And there is some risk on leaving some grit or doing some damage along the way. Better though had it been done the right way in the first place. The next engine (gordon smith compressor) I took the hint. Joe K __________________ Shudda kept the horse.

03-24-2015, 10:00 AM	#14
Tim B. Senior Member Join Date: Oct 2011 Location: Southern Maine Posts: 162	Re: Citric acid rust remover I tend to agree with Mike. I've used a series of various sized and shaped wire brushes and extensions for various items with great results it may get you what you want. But if you want to follow your current path Alkaline cleaners may be an option for you. Some are available in sprays however most use heat and they are as caustic as an acid if you come in contact with them. For the most part Alkaline based cleaners will leave the base metal alone and remove only the rust. They do not have the problem with hydrogen embrittlement. Not sure about rabbit. Each cleaner has unique cleaning characteristics and you'd have to check Mfr specs. Here's some info. http://heatbath.com/metal-finishing-...ine-derusters/

03-24-2015, 11:58 AM	#15
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Citric acid rust remover I have protected, blasted, and cleaned a couple blocks just as Joe said he did his. Yes, it's a lot of work and time consuming, but the end result was good.

03-24-2015, 06:22 PM	#16
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: Citric acid rust remover I own NO RUSTY parts!! BUT, in my 5 month nightmare, I've grown RUSTY, any ADVICE? Bill W. __________________ "THE ASSISTANT GURU OF STUFF"

03-24-2015, 09:26 PM	#18
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Citric acid rust remover Crown in a dixie cup? Internal soak. Rinse & repeat. Joe K __________________ Shudda kept the horse.