Molasses rust removing on a wheel

[Howard Wright]

Hi All

On my Brookfields Special thread I mentioned that I was trying out molasses as a method of rust removal.  Jamie asked to be kept up to date so I thought a new thread may be a good idea.

I've posted some pics below.

The wheels were quite rusty when I got them so I did spend some time wire brushing and removing as much of the rust scale as I could.

The molasses was bought from a farm supplier and is used to feed horses (5 litres cost £8)  I also bought a huge rubber bucket over 20" in diameter.  I mixed the molasses 9 to 1 with water, dunked two wheels in and covered them with boards to stop vermin getting in.  They were under cover and outside.

Firstly molasses smells especially once it starts to ferment and it develops a yucky mouldy crust so this method is not for the feint hearted!

I pulled a wheel out today, just two weeks since it went in, and I was quite pleasantly surprised.  After a good hose down and another wire brush the wheel looks pretty much rust free.  The molasses won't take off paint though. I dried the wheel with a hot air gun but within a 1/2 hour or so surface rust had already begun to develop so I gave the wheel a coat of primer (I had to brush paint as SWMBO won't let me use power tools on a Sunday so no compressor for spraying)  

Hope this is of interest to others contemplating molasses rust removal?

Cheers

Howard

[JonE]

Howard - what is the process - does it make acid during the fermentation?

[andrew34ruby]

Your finished primed finish looks rather rough, and it's not easy to wet flat a wheel to get a smooth finish. So my question has to be -- why not blast? Mine were abrasive blasted and after 2 coats of epoxy primer and 2 or 3 coats of 2 pack gloss the finish is good with no sanding.

My photo is of the blasted bare steel, though it looks like grey primer.

   

[Howard Wright]

Hi Jon and Andrew

Jon  I think molasses contains a chemical (chelating agents) that dissolve metal oxides.  Apparently it is recommended to take loads after a nuclear bomb as it removes the nasty radioactive stuff.  Well that's what I read!

Andrew   Because I'm a cheapskate and can't (didn't want) to spend that much money. I did have my chassis, axles, hubs etc sand blasted and it worked well but at a cost.  On heavily rusted parts you still get a rough finish.  The rough finish in the photo is when the wheel had just been removed from the molasses.  After a wash and wire brush its much smoother (zoom up on the full wheel picture).

I've also read that some of the sand particles could get in the spoke holes and cause wear but I'm not sure this is really a problem.  I did price up sand blast and powder coat for the wheels but that was £70+ a wheel.


Cheers

Howard

[Duncan Grimmond]

Crikey, I've just had four(4) wheels blasted and powder coated for £76.00. Admittedly they had new rims and spokes which made for less work.
I hope your wheels run true. Looking at the state of the spokes and rims I'd guess the nipples would be seized making it impossible to true them up?

[Howard Wright]

Hi Duncan

I don't think it would be a good idea to try touching these spokes and the rims aren't silky smooth so that's the reason I'm not shelling out on blasting.

To be fair the wheels are serviceable as long as they run true and a preliminary spin on the axle suggests they're OK.

Cheers

Howard

PS Let me know who did your wheels as they sound very reasonable and possibly worth a trip north!

[Bob Culver]

Many sources are sceptical about blasting panels but maybe the thick hard steel of Sevens is better. 
Is there a tendency to stretch and loosen the spokes?
With a relatively inexpensive home treatment and final finish, if after a bit of running the spokes  work free in the rust and become slack not a lot is lost.
Are replacement spokes dual gauge as the originals or same thickness throughout (which looks clumsy)? In my experience the original spokes are very robust, even when rust pitted. Are new nipples with the exact original cycle thread available? Does anyone make a dinkum die or die nut (not just close NF!)

[Ian Williams]

I have used Molasses quite a lot in the past, it is effective but slow, another month or two and Howard's wheel would have come up clean. I found it is good to remove as much rust as possible manually to speed the process, the down side is that as the Molasses ferments it smells rather unpleasant!

[JonE]

I was really surprised that even on really grungy spokes, a little heat from a kitchen flambe gas torch freed them relatively easily.

[Tony Press]

What about the chance of water getting into the hollow rim when submerged ?