Rusty block

[Mike Szadaj]

I had this 440 bored out awhile back. As it sat waiting for me to get back to it, surface rust set in. I called around trying to find a place that could take off the rust without ruining the bores. No luck. Then I came upon a You Tube video of some guys using a product called DRX. They put a small block in a tub, poured the stuff in, and it came out looking great. I ended up using Evapo Rust. Since I live in Michigan, and the stuff needs to be used at 65 degrees or warmer, I did it in the mud room of my house, which is only partially heated, using an aquarium heater. Because the stuff is not cheap ($75 for 5 gallons), and I was doing a big block, I had to keep turning it to get it all done. Here are some pics. I think you will agree it does a great job. You can actually get it on your skin with no ill effects.

 

[HALIFAXHOPS]

Nice!

 

[dvw]

How long did the process take?
Doug

 

[69L48Z27]

I’m a big fan of Evaporust. The cast parts will kill it really quick.

I think you could have had the engine cooked or tumbled without effecting the bores. It would need re-honed but it looks like it needs re-honed now.

 

[OH71RRunner]

That is impressive! I've got a block in my garage in similar condition. Definitely gonna give evaporust a try after seeing this.
Thanks for sharing!

 

[Mike Szadaj]

How long did the process take?
Doug

I left it in on each side 2 days, although that might have been longer than needed.

I think you could have had the engine cooked or tumbled without effecting the bores. It would need re-honed but it looks like it needs re-honed now.

Both of those methods would require another boring. Another aspect I contemplated was that the other methods also would not have gotten into the water jackets and oil galleys.

 

[hunt2elk]

Phosphoric acid is some neat stuff. I like Metal Blast made by Rust Bullet as an alternative to Evapo Rust. Both are good products.

 

[Mike Szadaj]

Phosphoric acid is some neat stuff. I like Metal Blast made by Rust Bullet as an alternative to Evapo Rust. Both are good products.

As I was looking for a solution I heard of different acid based stuff, but safety, cleanup, and disposal all seemed to be problems. Evapo Rust is water based. It can also be reused, so you can put it back in the container for future use.

 

[Dibbons]

For my small block, I used molasses and water at a 10:1 ratio in a 55 gallon drum for a couple of weeks. Works so-so, still had to wire brush some with a drill. I will final hone the cylinder bores and lifter bores right before assembly which is sometime off in the future.

I tried dumping two cylinder heads in a 5 gallon bucket with Evaporust but the next morning all the cleaner was on the floor (when I forced the second cylinder head down into the liquid, it split open the bucket). I paid good money for 3 gallons.

 

[Mike Szadaj]

Here it is after soaking 4 sides in the solution. As you can see, it didn't reach all the way to the middle, but I can hone the lifter bores and wire brush where it didn't get to.

 

[69L48Z27]

Why does cooking or cleaning a block require boring? I’ve done three engine rebuilds now that were low mileage engines that we chose not to overbore, all within spec. Machine shop did not indicate this would be a problem. They were honed. Hope I didn’t miss something.

Evaporust can be reused but at some point it will become very dark, black, when it does it will become ineffective.

 

[Mike Szadaj]

Why does cooking or cleaning a block require boring?

I don't know. Every place I called, the first question I asked was if they could clean the rust off the block without ruining the cylinder bores, and every one said no. Some of the processes sounded like they would be very rough on the block.

 

[zyzzyx]

When every Machine shop used to "Hot Tank" a block, they would use a caustic soda solution.
Disposing of that solution has become a nightmare and very costly so almost no one does it anymore.
Easy off oven cleaner is a good substitute for the home guy that wants to clean off surface rust, but
submerging a block in a tank of warm solution cleans out all of the water jackets and oil galleys. If you had the
finished diameters of what the bores were honed to when it was originally done, and compared them to what
it is now after your cleaning with evaporust, you would be able to know if any material was removed. The rusting
of cast iron will remove material, but the surface rust you had shouldn't have removed a significant amount
of material. If you hone the bores too much, pistons start rocking, skirts start breaking, so be aware.
If a block is tumbled, you'll probably have to bore it because the surface will be upset and will need to
be honed past your piston clearances. Good Luck!

 

[Cranky]

https://www.amazon.com/Evapo-Rust-O...t&qid=1602691390&sprefix=evapo,aps,194&sr=8-3
13.58 per gallon

Wow, little dude sure talks loud (yells?) eh?

Couldn't listen to it anymore even with the volume turned way down and clicked it off around 8 1/2 minutes....

 

[Mike Szadaj]

Note to Cranky: It looks like you replied to the wrong post.

 

[Cranky]

Note to Cranky: It looks like you replied to the wrong post.

Posted a link to Amazon for Evaporust showing what it costs from them since the pricing was mentioned from other places....and made a comment to what Ed said about the vid. Basically, I felt the same way Ed did about the guy that made the vid. Thought it was loud too and imo fast paced.

 

[Mike Szadaj]

What I am saying is all of that relates to the "Tell me your experiences with Evaporust" post. If the people involved with that post don't click on the link to this post they will never see your reply.

 

[Cranky]

OK

 

[Richard Cranium]

Evaporust can be reused but at some point it will become very dark, black, when it does it will become ineffective.

Are you saying that black Evaporust doesn't matter?