Learning stuff all the time.

[bigk]

Just learnt not to put magnesium in the molasses tank. Put a good Suzuki clutch cover attached to some cases in a week ago, pulled half a clutch cover out! Alloy cases fine, rust gone on the steel which is the desired effect, magnesium dissolved. Oops.
K

[frank jnr]

Hey K, should I be worried??? Was that my RM case's....Hahaha

[mx250]

Just learnt not to put magnesium in the molasses tank. Put a good Suzuki clutch cover attached to some cases in a week ago, pulled half a clutch cover out! Alloy cases fine, rust gone on the steel which is the desired effect, magnesium dissolved. Oops.
K

So, it worked well on alloy. Is it a good way to clean up crank cases, to get the grease, cake on dirt and grim off?

[hodaka]

Hey MX250 , in my experience the best way to get grimey crankcases looking like new again is to have them hydroblasted or aquablasted , different name but same job depending on who does them ?
I have had dozens done over the years and wouldn't do it any other way as they come out looking like brand new . 

[bigk]

Works unbelievably on rust and you have to see it to believe it. Alloy seems to be hit & miss though and as I've just dicovered, magnesium is a no no. I've had a set of wheels with painted rims in for a couple of months now, pull them out every now & again, pressure wash them, put them back. The then rusty spokes & nipples now look like new, the alloy bearing surfaces are also bright & shiny, but the best part is the paint is gone from the rims and they are good enough for a quick hand polish. Love the molasses tank, just don't get any on yourself else you'll smell like a big stick of licorice for a while. Not your cases Frank Jnr.
Cheers,
K

[brebel]

I found that 'CLR' reacts to magnesium aswell

[huskibul]

  Hi big K, you've got me in sounds unreal , how long would it take in the tank to clean-up spoke/nipples? would it work just painting it on spokes,by cleaning and recoating etc? would it affect anodised rims? cheers huski

[firko]

A mate's into hot rods and he's building a track style roadster using left over crap from other projects (my favourite way of doing stuff!). He had these really horrible rusty old Kelsey Hayes wire wheels from a '35 Ford that had 70 years of numerous paint jobs and rust. He left them for a month in a molasses tank and I was there when he pulled them out and couldn't believe how new and clean they looked, back to the bare metal. He's currently got a Model A cowl in the solution so I'll see if he's taken any photos of the process. If so I'll pop 'em up here.

[maicomc490t]

For my money molasses baths are the best bang for you buck with steel but the alloy bit is new to me. My brother in law has played around with vintage cars / hot rods for years and he has a HUGE molasses tub that can easily take guards (fenders?) doors etc and the results are staggering. Essentially non toxic and safe to swim in too but you do kinda smell funny.

The mag was probably taken out by the slightly acidic process caused by the fermentation that produces the end result. When I have used it it leaves a sort of green tinged skin on the steel and doesn't rust for years after even when left unprotected - a bit like parkerising - that black oxide finish on machine tools etc?

It doesn't like cast iron very much either, but for steel it's great. The secret is patience as it must stay in the brew for at least a few days and normally a couple of weeks depending on how bad the rust is. You can't paint it or spray it on but like previous posters have said it is quite amazing and can be used as a pre blasting process to drastically reduce the time the blasting will take which should save you money as time = dollars!

As far as the reference to hydra-blasting and aqua-blasting - it's the same as vapour -blasting that I do - they are all the same animal but a negative word on that process too. If the guy doing the blasting or the owner of the goods being blasted doesn't take precautions to plug oil galleries and threads etc and thoroughly pressure clean mechanical parts after the process serious damage to an engine can result due to glass bead left behind. That's why I'm so good at it, lol, I care about the work I do so make sure who ever does it is aware of the risks.

Dave Mac 

[bigk]

The longer you can leave it the better, but at least a week. I use a 9:1 ratio of molasses to water. It costs about $50 to set a green wheelie bin tank full. You will be amazed. Keep it a fair distance from the house, the smell can be strong at times.
Cheers,
K

[gage]

Bigk, when you say 9 to 1 - is that nine litres of water to one litre of molasses or is it the other way around.

Regards, Ron

[SAABCOMBI]

I made up a bath, and the parts went black, then l cleaned it off with wirer wheel on my grinder, it worked ok, but l may be doing something wrong, l left the parts in the bath for about 3 to 4 weeks.

[bigk]

Yep, 9 parts water to 1 part molasses.
Cheers,
K

[VMX247]

Just learnt not to put magnesium in the molasses tank. Put a good Suzuki clutch cover attached to some cases in a week ago, pulled half a clutch cover out! Alloy cases fine, rust gone on the steel which is the desired effect, magnesium dissolved. Oops.
K

what about a shorter period of time ,say 24-48 hours ?
cheers