Midas Cars Forum - www.midascarsforum.com

Hi Atchi,

Looking at the castings it looks great, but you have reminded me, we need to find the aluminum pickling/cleaning solution, maybe someone on this board knows how to clean aluminum. I saw in a Mini magazine somebody restoring an SU carb. They dipped it into a bath of some solution, left it for a little time, then it came out of the bath sparkling clean. You could have put it on the top of a Christmas tree!

Alan

Coca cola works well on pennies and rotting teeth so may work with ally

You really need caustic to clean aluminium, so you could try oven cleaner

Geoff Butcher wrote:You really need caustic to clean aluminum, so you could try oven cleaner

Thanks Geoff,

I've got some caustic soda in stock somewhere, I'll give that a try.

Regards Alan

Hi Alan,

I hope you haven't tried that caustic soda yet. Before you do take a look at this:



You really do not want to mix caustic soda and aluminium, unless you are performing a science experiment.

Aluminium being a soft metal does not really like any strong chemicals. Lemon juice or watered down vinegar - two tablespoons vinegar to a pint of water - are strong enough to remove the aluminium oxide, but if you want the ally to shine you need to reach for the autoglym.
I usually clean ally bits like the clutch bell housings and the Metro engine mount in an old dishwasher using normal dishwasher tablets. I bought an old one for £10 a few years back and it is worth it to avoid upsetting my better half. I've not tried a gearbox casing yet, but one would just about fit inside. If the parts are really grimy I brush Gunk on first, but otherwise I just stick them in for a normal cycle. They come up a treat!

Regards,
Alistair

When I was working, we always used a caustic solution at 65 deg C as a pretreatment for aluminium before electroplating. It fizzes nicely and you don't want to breathe the fumes, but the amount of metal removed is negligible (1 minute in the bath)

Hi Geoff,

I can believe that you used a caustic soda solution to prepare aluminium for electroplating. A similar process is also used to prepare aluminium before anodizing. The point is these are both well established processes with regard to solution strength, temperature and timing.

I just wanted to warn Alan and anyone else reading the thread that this is not a good idea to dunk aluminium parts into buckets of caustic soda if you don't know what you're doing. The dangers range from dissolving your part to blowing yourself up with the hydrogen gas emitted and I thought that the video would illustrate this point.

It can also be pointed out that the dishwasher tablets, like all detergents, produce a weak caustic solution. So that is probably why the aluminium parts come out so nice and clean.

Regards,
Alistair

Yes, you'd need to be a bit cautious about dumping it in a bucket! I've just carried out an experiment with oven cleaner, but disappointingly it seems too feeble to have much effect. Also with caustic you really need to follow it with a nitric acid de-smut, depending on the alloy, and I doubt if even Alan has any of that in his garage!

Thank you all for your replies,

I think Alistair wins with the dishwasher solution, just because for me it's the laziest solution. I will just have to wait until the wife is out!!!

Although I do have some aluminum engine blocks to do, so I may have to resort to a chemical. I've learned that a good way of painting blocks and heads, is to powder coat them. I'm told that the powder coating will stand the generated heat from the engine. Brake caliper can also be powder coated.

By the way I've had great success with neat malt vinegar on steel components.

Alan

Hi,

So after a trip to Glasgow, I picked up wheels from my mate.
I also bought rear disc roters, calipers, driveshafts and CV joints from MX-5 specialist.
I have chosen VW mk1 Golf wheels for my project. With this wheel, I can measure track width.



It is 1600mm from one edge the other.
I'm hoping to make my subframe narrower by 300mm or so.


I need to find out what is the measurement between 2 wheel arches as I will be increasing it.
I will be making rear wheel arches like bubble wheel arches for escort or something like that but not too wide.

Cheers
Atchi