cleaning up the slant six head

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ntsqd said:
I knew that long term exposure to Muriatic (Pool) acid would do that. I haven't seen vinegar do that in any of my cleanings using it. Frankly I didn't think that it was a strong enough acid TO do that. Though I rarely leave something soaking more than overnight. I've always de-greased with purple cleaner, so I had not idea if the vinegar would or wouldn't work on grease.

The head gasket surface is probably OK once it's been cut. I'd be most worried about the drool tube holes leaking if their size has been altered and that the rocker shaft saddles are no longer in the right place for proper rocker geometry.
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No drool tubes on this engine, it is a late hydraulic motor. Im at this point de-greasing another head with oven cleaner, Im gonna put the new head back in the vinegar and let it sit overnight ( maybe ) but that may wait until next weekend when I have more time.

May also try something else.

Ive soaked parts in Vinegar before and never had anything like this happen...only to the machined surfaces? Why?

Im gonna try and find out.
 
72Dodge said:
Why take a chance? /6 heads are free. Find another one and pay a few bucks to have it hot tanked.
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They are not free around here that I have found but I already did find another.

Just cost me a couple of hours of my time and gas to get out to the truck and pull it.

I may just go ahead and try the mollases deal...I dont want to pay someone 50 bucks to hot tank the thing, I have parts that need cleaning like this fairly often and I am going to find a way to be able to do it myself.
 
OK, fair enough. If you can figure out a way to do it safely and adequately for significantly cheaper and without too much time cost, all the better.
 
I once left a tubular steel part in Muriactic way, way too long. The acid ate the weld seams in the tubing the most. Then it ate machined surfaces the next most. Based on this single event I have a shaky hypothesis that the acid attacks the metal with the highest internal stress the most. High internal stress = high metal removal; low internal stress = low metal removal.
Vinegar isn't as strong (or as dangerous) of an acid as Muriatic Acid is, so it's effects for equal soak time will be less.
 
I have read more than once now ( enough to believe ) that muriactic acid is not the way to go when cleaning parts because evidently it leaves behind a scale of some sort than can never be truly de-activated, that it will cause more damage because of this in the long run.

Ive got one of my Super Six intakes in the vinegar now, I will remove after work tomm evening and see where Im at with it.

The surface that bolts to head was already badly pitted and requires machining so was not concerned with that, in retrospect I wish that I had coated the surface that carbs bolts onto with a grease so as to protect but again I have no intentions of letting it sit there long.
 
If the intake is aluminum I'd yank it sooner than that. If iron then carry on.
 
Intake is cast iron, I dont think I would venture soaking aluminum in Vinegar at this point, I may be mistaken but I believe I have read that it will eat it up pretty quickly.

I tried removing the pot metal vacuum nipple from intake before I set it in there, it broke off down below the surface of the intake, I am hoping that the vinegar will just eat what left so I do not have to mess with trying to get it out.

Have you had any experience with soaking aluminum parts in the Vinegar solution?
 
I may have done it, can't recall though. Mostly with vinegar I'm trying to remove rust or plating on hardware so that I can weld on them w/o contamination.

A friend has used vinegar to clean the contacts in the glass tube type of car fuse-blocks. I've no idea what his soak time is, but can ask if its thought that it might be an indicator for aluminum.
 
This what you're describing doesn't add up. Vinegar is a very (drinkably) weak solution of acetic acid. It isn't a good choice for cleaning engine parts, but only because it's not strong enough to do much of anything for you but waste your time, not because it "softens cast iron", which…um…it pretty much doesn't. Especially not selectively on only the machined surface; vinegar's just not quite smart enough to tell which are the machined surfaces. I won't quite say "I haven't seen it happen, therefore it didn't happen", because that's rude and unhelpful, but I will say I think you aren't seeing what you think you're seeing. I've seen an awful lot of hard-cooked gasket material that looks for all the world like it's part of the metal until it's softened enough to scrape off, whereupon it looks like you're scraping metal off. I could be wrong, of course, but use a proper transverse scraper (not a screwdriver) and a spray can of gasket remover, and I suspect with half an hour's work you'll be looking at a completely un-"softened", flat machined 100% metal surface right where it's supposed to be. I'm also curious what the other machined surfaces (valve cover gasket rail, for example) look like.
 
SSD,
Review his pictures again. I just did. I see old gasket material and I see what very clearly looks to me like machined iron cyl head surfaces that are being easily gouged with a screw-driver. Clearly something attacked that iron.
Have you ever soaked iron or steel in vinegar? Just because you can consume it doesn't make it benign to other materials. It removes Cadmium or Zinc plating with aplomb. Those aren't the same as iron, but until scientifically proven otherwise I'm content with the explanation of events.
 
Yes, I have put cast iron in vinegar for prolonged periods, without any "softening". There's a sound scientific explanation for why that is.

Yes, vinegar is a strong enough acid to attack zinc and cadmium—that's not in question here, but if it were, there's a scientific explanation for why that is, too.

Yes, I'm looking at the same pictures you are—where we differ is in what we think we see.

Me, I'll be content with the explanation of events once it has fewer gaps and soft spots than the alleged ones in the head's machined surface. I don't put much weight on shaky hypotheses, but others' opinions may vary. I think I'll just go back into lurk mode and watch how many dollars, days, and cylinder heads are consumed in the hunt for a way out of paying a reasonable hot-tank charge.

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slantsixdan said:
This what you're describing doesn't add up. Vinegar is a very (drinkably) weak solution of acetic acid. It isn't a good choice for cleaning engine parts, but only because it's not strong enough to do much of anything for you but waste your time, not because it "softens cast iron", which…um…it pretty much doesn't. Especially not selectively on only the machined surface; vinegar's just not quite smart enough to tell which are the machined surfaces. I won't quite say "I haven't seen it happen, therefore it didn't happen", because that's rude and unhelpful, but I will say I think you aren't seeing what you think you're seeing. I've seen an awful lot of hard-cooked gasket material that looks for all the world like it's part of the metal until it's softened enough to scrape off, whereupon it looks like you're scraping metal off. I could be wrong, of course, but use a proper transverse scraper (not a screwdriver) and a spray can of gasket remover, and I suspect with half an hour's work you'll be looking at a completely un-"softened", flat machined 100% metal surface right where it's supposed to be. I'm also curious what the other machined surfaces (valve cover gasket rail, for example) look like.
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Its raining out there pretty hard right now and I am pretty sure anyway no matter what pictures I take there is still going to be doubt in someones mind. Anyone that lives locally is more than welcome to come out and see the head first hand, I know of 3 FABO/slant.org members that live very near me.

Ive really enjoyed reading your posts and thank-you for all your time over the years. In this case though you have no first hand experience with vinegar/soaking parts, that is evident in your post. Try it sometime you might be pleasantly surprised or almost shamefully downtrodden as I was in this instance.

I wish that I had read your post before checking on my manifold which is in the vinegar as I type.

I raised the lid only to find an IDENTICAL imprint of the manifold down at the bottom of the bucket just floating on top of the sauce. It was all brown ( rust ) but had you seen it maybe it would have maybe helped you to become a believer in the power of Vinegar.

Anyway I looked the part over carefully and other than all the scaly rust and **** coming loose inside of the runners the part appeared to be in the same condition as when I had dropped it in last night.

Ill let it sit another day.

Again thank-you for your dedication to the slant vehicles over the years, guys like you have helped alot of guys like me and you prob. do not get to hear the appreciation often enough.
 
I know this proves nothing but Dan had me questioning what I thought I saw so I risked the possibility of melting and went out in the rain with a sharp razorblade, picked a spot on the head that was clearly cast iron ( machined surface of valve cover ledge ) and dug down deep with the blade.

Picked up the splinters and shards of cast iron with a magnet.

I know that someone will think that this is gasket material impreganted with just enough metal that it would stick too a magnet but there is nothing more I can or am willing to do to prove my case.

Just be careful everyone and have fun!

Id still sure like to hear a scientific explanation for this if anyone can come up with anything. Gotta be an answer.
 

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slantsixdan said:
Yes, I have put cast iron in vinegar for prolonged periods, without any "softening". There's a sound scientific explanation for why that is.

Yes, vinegar is a strong enough acid to attack zinc and cadmium—that's not in question here, but if it were, there's a scientific explanation for why that is, too.

Yes, I'm looking at the same pictures you are—where we differ is in what we think we see.

Me, I'll be content with the explanation of events once it has fewer gaps and soft spots than the alleged ones in the head's machined surface. I don't put much weight on shaky hypotheses, but others' opinions may vary. I think I'll just go back into lurk mode and watch how many dollars, days, and cylinder heads are consumed in the hunt for a way out of paying a reasonable hot-tank charge.

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I'd love to have a scientific explanation for this occurrence, what we know thus far is an iron casting soaked in vinegar for a lengthy, but unknown exact amount of time exhibits a loss of cohesive metal properties to some considerable depth. What factors are missing? Acetic acid concentration, cast iron constitution/"alloy", and? I'm not saying that the conclusions are correct, only that absent anything concrete that's more scientifically plausible, that I'm satisfied with what we have. Not comfortable, but satisfied.

I'm doubting that we can get a spectral analysis of the iron to determine what elements are in it, but conceivably a high value of any of the reactive metals (Cad, zinc, tin, etc.) may be the actual cause due the the vinegar attacking and removing it from the iron alloy thereby destroying the casting's integrity. As most know, any iron is not all iron, there literally millions of versions of iron and they all have unique sets of characteristics depending on the alloying elements.
 
I guess Im not the only one, Im sure there are others but have to leave for work now and no time to search

Maybe I need to take a better look at the un-machined surfaces, I had scraped them in similar fashion and thought that there was no degradation of the metal. I did not spend alot of time or effort though on the un-machined surfaces since they were not areas that needed my further attention.

http://www.triumphexp.com/phorum/read.php?8,869849
 
slantsixdan said:
Yes, I have put cast iron in vinegar for prolonged periods, without any "softening". There's a sound scientific explanation for why that is.

Yes, vinegar is a strong enough acid to attack zinc and cadmium—that's not in question here, but if it were, there's a scientific explanation for why that is, too.

Yes, I'm looking at the same pictures you are—where we differ is in what we think we see.

Me, I'll be content with the explanation of events once it has fewer gaps and soft spots than the alleged ones in the head's machined surface. I don't put much weight on shaky hypotheses, but others' opinions may vary. I think I'll just go back into lurk mode and watch how many dollars, days, and cylinder heads are consumed in the hunt for a way out of paying a reasonable hot-tank charge.

popcorn.gif
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I knew a bloke who soaked his 1928 Chev 4 cast iron exhaust manifold in Molasses....it was for a fair while, and when he took it out, it crumbed in his hands.
 
Not quite as defined or pronounced as it was yesterday but I though the picture would still be of interest. The part itself is down 6 inches under the sludge.

Im going to let it sit for one more day and pull it out. Not going to risk losing the intake.

The Vinegar does not touch the paint but the areas where there is no paint now to be seen were heavily corroded with rust. Very clean now, runners look good as well.
 

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Here's an intake I cleaned up......by beadblasting.....:)
It's a single barrel intake that I modified back in the 80's.
 

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just wondering: soak is purple cleaner, dawn solution, etc, spray down with $2 can of engine degressor, and $1.50 at the car wash????
i make bits and spurs and have used 50% soluton of muratic acid, works well to clean the heavy metal, but i left a buckle made of 1/8 in mild steel a little too long! became 1/16 in thick! LOL perhaps a difference how the acid works on mild vs "hard" cold rolled like bits and spurs are and then again how it works on cast iron. the vinegar: i have no experience with it except for making home made salsa!!! LOL
another notion: soak in gas (not diesel) for cleaner. maybe someone on here is a chemist with vinegar background! really, i'm always interested in finding cheaper better way to clean nasty parts!!!
if some off us guys didn't joke around a little we might get "soft"!
 
Instead of the 50% Muriatic (Hydrochloric) acid solution, try vinegar straight on a sacrificial part. It's a little slower, but I think that you'll like the overall results better.
I've quit using Muriatic entirely after trying vinegar. Safer, easier on the environment, easier to dispose of, and doesn't have caustic fumes to worry about breathing and rusting what ever they land on (BT,DT too many times).
 
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