Molasses dip came out crusty, need advice

[36Pickup]

Hi
Recently I mixed a small batch of cattle-feed molasses with 3 parts of water and dunked some small parts. I left them in there for a month or so and they came out great, looked like new parts and could see the part number.

With that success I mixed up a larger batch and put in a rubbermaid tub with a lid. I used a wire wheel to get most of the surface rust off and put the parts in the tub. After returning from Bonneville (two weeks in the tub) I checked the parts out. They came out with a very dense rusty-brown coating that came off in sheets when using the hose. Even then some of the muck was still on the parts like barnacles on a boat bottom.

Even the previously perfect parts came out with rough bumps and a brown coating.

The Muncie shifter rods came out black with bumps all over them as did the mechanism.

Any wise counsel or advice to correct my problem? The first success was so good that I don't want to give up on Molasses yet.
Thanks


In the bottom of the tub there was big sheets of the brown much too. I've mixed another part of water in and dunked them again.

[Lawson Cox]

Molasses is for eat'n with hot biscuits, not de-rustin' parts. LOL

[Barry Wolk]

Actually, it works quite well. It's called chelation.

You might want to add some heat. That speeds the process greatly.

[Russ/40]

The working ingredient in the feed molasses is sulfuric acid. Give it up and use white vinegar. Cheaper, works as good, and smells a he** of a lot better.

[Lawrie]

DO NOT put in any parts that are hardened IE gears shafts etc as the molassis will bugger them up.Lawrie

[Grandpas38]

Sponsored Links (Register now to hide all advertisements)

Have you considered using electrolosis? It is a simple set up. Just make sure you do it outside it does produce a hydrogen gas that you dont want lingering in any enclosed area. Also do not use stainless for your electrodes. Leave in the solution which is non toxic for 24 hours. Parts come out black rinse and dry them hit them with a wire wheel. I cleaned this half of the running board in ten minutes with a drill and wire wheel It removes paint also. I just completed a set of wire spoked wheels some painted and some heavily rusted. It worked great. Here is a link there are others out there as well

http://antique-engines.com/electrol.asp

[fordcragar]

The first time that I used vinegar, after several days, I pulled the parts out and they were all crusty too. So I put them back in for a few more days and pulled them out, they were still crusty. Annoyed about how poorly the vinegar worked, I grabbed the water hose to wash them off and the crust blew off in sheets and the parts looked awesome.

Now when I soak parts in vinegar, they are usually in there for about three days, blasted with a hose and washed with soap and water to kill the rust.

[danliveshere]

In my molasses bath i used only 20% molasses,rest water. 1 week is all it takes for bare metal parts to be clean and rust free. Of course this does not take paint off. Best part of the molasses bath is it gets in between metals and neutralises rust that a sand blaster cannot touch. I then wash parts off and coat with rust converter and the parts stay rust free for ages untill you can paint them properly.

[cadillacoffin]

ive always heard that the molasses should be mixed at 5-1 which would be less corrisive. but time and heat really help this process.

[X38]

I've always used 5:1.

[36Pickup]

UPDATE......I added a gallon of water (not sure what ratio it is now, but closer to 5 water to 1 molasses) and put some of the parts back in. I've also rinsed them off every day for the last3 days and it appears that the mix is working better now.

There is no crusty stuff hanging on the the parts, although there are still some "barnacles" left, they are disappearing along with the rust. I'm feeling much better about the molasses dip now. There are several spots that are so clean of rust that it looks like fresh metal.

I'll post another update in a week.
Thanks for all the comments.

[26 lakes]

You can use a 9 to 1 solution and it still does great. You may have the solution too concentrated. It is acetic acid the same as vinegar.

[FL&WVMIKE]

Don't forget, you can use vinegar in your radiator and engine block. Just fill it and let it stay for several days, or weeks, running it in the meantime.
If you take off the radiator, you can use a power washer to really clean out the block.
MIKE

[barryfromvictoria]

whats rust cvonverter

[BillM]

whats rust cvonverter

Ospho is one, also made by Jasco (Prep and Priime) and others. Phosphoric acid which does a phosphate conversion coating on steel. Works well under PPG DP epoxy primer but may not be compatible with other epoxies; do a test first if you are not sure. I like it because it keeps bare metal from rusting until I get around to painting it.