Need to clean an aluminium block

Exfrogger

1000+ Posts
Hi All,

I need to clean an ali engine block and peripherals inside and out. What’s the go?

My local engine shop doesn’t recommend any of his pickling baths for the job.

R 16 block, so the liner lands need to be cared for in particular.

Ex
 

Fireblade

Member
I am a recent convert to soda blasting - does an excellent job of cleaning aluminium without damaging the substrate.
 

seasink

1000+ Posts
Be extremely careful if someone suggests a hydrofluoric acid cleaner as used industrially. It works, but can do you serious harm if spilt or splashed.
 
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PeterT

1000+ Posts
Soda blast is best. Not bead/sand. Even though you may block holes with spare bolts etc., you'll struggle to get the glass out of the oil galleries and the engine will die a premature death.
 

Exfrogger

1000+ Posts
I’ve got the dish washer angle covered. I even had our old one set up in the shed until I burned it out.

Ann is used to finding some pretty weird things in the dishwasher - well on the odd occasion she unpacks it...

But she’s stranded in PNG ATM and I put into it whatever my devious little heart desires...

I’ve never been particularly enamoured with the results using standard dishwashing powders, gels.

I have a pressure washer and it’s good for the first pass. Is there a bath solution one might use?

Noted on the soda blasting.
 

schlitzaugen

1000+ Posts
Do it professionally and have it steam blasted. It will come up shining better than new with absolutely no side effects. All the tiny galleries and such will be absolutely spotless. In fact you might want to put it in the lounge on the coffee table then. Probably the most expensive option but by far the best. Have a look at Bad Obsession Motorsport on Youtube what things look like after steam blasting.
 

Kenfuego

1000+ Posts
I've always used domestic oven cleaner, to clean pistons, heads, and so forth, no particular brand comes to mind as it is a while since having to resort to a cleaner. But I would take the precaution of testing the spray to check there is no damage or discolouration , from the chemicals.

Easy to use, spray on and use a pressure wand with water to clean off. Might be a bit harder to use on the interior surfaces and judge when to hose off..
 

schlitzaugen

1000+ Posts
The even better way is dry ice blasting. The media is abrasive when applied, then evaporates to a CO2 gas leaving no residue whatsoever.
A bit niche though, so might be hard to find.

I'd be curious to compare the results side by side. Never used dry ice blasting.

A quick google suggests the only difference (in the result) is that mould is removed more readily by ice blasting. Not sure it is relevant to us here.
 

JohnW

Too many posts!
Be extremely careful if someone suggests a hydrofluoric acid cleaner as used industrially. It works, but can do you serious harm if spilt or splashed.
Worse than harm, it kills and not quickly. Truly one of the worst chemicals around. Totally agree with you - I'd run a mile. :(
 

JohnW

Too many posts!
The even better way is dry ice blasting. The media is abrasive when applied, then evaporates to a CO2 gas leaving no residue whatsoever.
A bit niche though, so might be hard to find.
Geraldton..... Could be a challenge. Sounds like a great idea. To be super pedantic, it sublimes. No liquid phase. I'd not heard of the technique but what an interesting idea! Thanks.
 

schlitzaugen

1000+ Posts
I've read about it a bit and it seems people don't really agree if the dry ice sublimates before it hits the surface or not. Not sure if it's important but there you go. It does however seem it was developed for food preparation equipment in industrial settings and the main reason is it gets rid of microcrap that can foster bacterial development.
 

schlitzaugen

1000+ Posts
Worse than harm, it kills and not quickly. Truly one of the worst chemicals around. Totally agree with you - I'd run a mile. :(

Totally.

We used hydrofluoric in the geochem lab at Uni and there was a big warning news item cut out from an old newspaper and posted to the wall about a guy in WA who spilt a tiny amount on his hand. Took a dive in a swimming pool immediately to wash it off, but still died a week later. This is truly the stuff of your nightmares. It works by entering your bloodstream apparently and killing your white/red (?) cells one by one without being consumed in the reaction, kinda like tetrafluorocarbons destroying ozone molecules in the atmosphere so a tiny amount keeps going forever.

Avoid for good, you don't need it.
 

JohnW

Too many posts!
Totally.

We used hydrofluoric in the geochem lab at Uni and there was a big warning news item cut out from an old newspaper and posted to the wall about a guy in WA who spilt a tiny amount on his hand. Took a dive in a swimming pool immediately to wash it off, but still died a week later. This is truly the stuff of your nightmares. It works by entering your bloodstream apparently and killing your white/red (?) cells one by one without being consumed in the reaction, kinda like tetrafluorocarbons destroying ozone molecules in the atmosphere so a tiny amount keeps going forever.

Avoid for good, you don't need it.
I remember the incident and knew the guy who owned that business. Awful. I wonder whether they still use it in palynology?
 

schlitzaugen

1000+ Posts
Don't know.

We used it to dissolve alumosilicates but we were testing at some point if we could go to aqua regia directly adding at the same time a little bit of boric acid, thus bypassing the hydrofluoric stage. Seemed to work to some extent, I think some types of rocks (we mainly worked on endogene) dissolved better than others.

Hydrofluoric itself has some problems because it can form stable tetrafluorates which are never going to dissolve no matter what you use. You had to get the concentration/amount just right and I guess that went for boric as well.

I wouldn't imagine palynology needs to deal with a lot of alumosilicates because spores can't survive in say anything of higher grade than regional metamorphism where you start forming feldspars, which are the dissolution nightmare. Maybe you can find spores in something like a gneiss or similar but then again, I imagine you wouldn't care if the feldspars dissolved or not since your spores wouldn't be in there.
 
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