Thread: Anyone used molasses to derust??

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No wonder I get an upset stomach from Coke ! I remember hearing years ago you could use it to clean rust off of bumpers, too.

I agree with the damage to machined surfaces not being caused by the molasses, but by the rust that was there already pitting the metal, and then once the rust was gone the pitting was evident.

I borrowed a product from my Son Don one time, called Evaporust, that he bought at Northern Tool. He used it and didn't like it, but I soaked some cowl lights in it that were really rusty and after an overnight soak they literally came out like brand new. It made the metal look like the day it was made and it left the painted parts intact. I think we might fill the cooling passages with that product and leave it overnight or so and see how that does. When Don used it I think he did a quick soak, so the secret seems to be overnight or more.

Today I called some feed stores in the area and found out what you need to buy is "liquid molasses". Two local stores sell it, but one wants to sell it in no less than 100 gallon quantities........they want $ 1.25 a gallon. The other store will sell it in quantities of 5 gallons or more, and get $ 1.49 a gallon (your container in both cases). I think what I will do is go pickup 20 gallons and one of those plastic livestock feeder tubs. Then I will soak the 350 Chevy engine block I have sitting around and see how it does on that one. If it doesn't damage that one I think it will give Dan the confidence to drop his Olds into the same mixture.

Never thought I would know so much about molasses !

Don

Originally Posted by Itoldyouso

No wonder I get an upset stomach from Coke ! I remember hearing years ago you could use it to clean rust off of bumpers, too.

I agree with the damage to machined surfaces not being caused by the molasses, but by the rust that was there already pitting the metal, and then once the rust was gone the pitting was evident.

I borrowed a product from my Son Don one time, called Evaporust, that he bought at Northern Tool. He used it and didn't like it, but I soaked some cowl lights in it that were really rusty and after an overnight soak they literally came out like brand new. It made the metal look like the day it was made and it left the painted parts intact. I think we might fill the cooling passages with that product and leave it overnight or so and see how that does. When Don used it I think he did a quick soak, so the secret seems to be overnight or more.

Today I called some feed stores in the area and found out what you need to buy is "liquid molasses". Two local stores sell it, but one wants to sell it in no less than 100 gallon quantities........they want $ 1.25 a gallon. The other store will sell it in quantities of 5 gallons or more, and get $ 1.49 a gallon (your container in both cases). I think what I will do is go pickup 20 gallons and one of those plastic livestock feeder tubs. Then I will soak the 350 Chevy engine block I have sitting around and see how it does on that one. If it doesn't damage that one I think it will give Dan the confidence to drop his Olds into the same mixture.

Never thought I would know so much about molasses !

Don

I also recently used some ZEP Rust Remover and was very happy with the results. I bought it at home depot about 10 dollars a gallon. I used it on HEAVILY rusted shocks for the mini bike I have. Left the parts soaking for 10 hours and they came out free of any rust. Bare metal and the chrome that was not rusted was the only thing on the metal. They came out CLEAN. I believe the stuff is biodegradable also.

I actually looked at that Zep stuff tonight when I was in Home Depot, but I bought a 54 gallon tub while I was there and @ $ 10 a gallon I figured it would be too expensive to fill it up with that one. So tomorrow I am going to drive to the feed store and pick up about 20 gallons of molasses and fill the tub up with it and water. I think I have convinced Dan that it won't eat his block away, and if there is any pitting it was there from the rusting itself.

I'll post some pictures of before, during, and after the block comes out of the mixture. That tub worked out to be the perfect size for the 455 block to drop down into.

Don

This is sure going to be one sweet engine when he's done!

Originally Posted by stovens

This is sure going to be one sweet engine when he's done!

Man, I sure and thinking pancakes.


I will be waiting for pics. I sure am interested in the results with molasses.

Looking forward to the results as well.
I've been thinking of trying this for awhile now.

Today I went to Home Depot and bought three 5 gallon paint buckets and lids and headed to the feed store. We don't have any around here that carry liquid molasses so I had to go clear out to LaBelle, about an hours drive. They sell it as llivestock feed and have about a 15,000 gallon tank of the stuff. It was not as I envisioned, I somehow thought it would have berrys or lumps in it, but it is just THICK syrup, alot like 140 wt gear lube, but it smells very sweet........overpoweringly sweet. While we were filling the buckets we had to keep shooing the bees and flys away.

On the way home I passed the machine shop I was at first considering using so I stopped in to have a talk with the owner. I told him the problem we were having with oil blowby and burning and that we had a new block that we were going to derust and then maybe bring in to have machined. He asked why we were going to try to derust it ourselves and I told him because it seems the vats the machine shops use these days simply remove grease, but leave the rust. He took me inside and showed me some blocks that were as clean as the day they were made and said "these were as bad as that stack of rusty ones over there, my equipment DOES get them clean."

So we sat down and I started asking him questions, like how do you bore the engines. He said they bore them .003 short of the final hone then hone them to size. I asked him if he needed the pistons there to bore each hole and he said "I can't do it any other way !" I asked about line boring and he said he would check the straightness first with his equipment, but in most cases it isn't needed. He said he would deck the block and polish the crank in addition to cam bearings and freeze plugs.

Overall, I am pretty impressed with what I heard, and he did do a nice job of machining the pulleys for my Ford and machining Dans Buick brake drums to fit his Lincoln backing plates. He also had quite a few half done motors sitting there that looked good and were being assembled in a clean room. So, it looks like I have a huge tub and 15 gallons of molasses that I won't be needing right away. But I think I will either soak the 350 block or the flathead block I have in it just to see how it does.

What do you guys think about the boring/honing and other stuff he mentioned? Is that the right way to do it?

Don

Oh, and all this talk about molasses did give me a craving for pancakes, so I headed to McDonalds for their big breakfast this morning.

I found this discussion on another forum. It explains the chemical process and has some good ideas about containers to use in the process.

derusting with molasses - Canadian Rodder Hot Rod Community Forum