Need to clean an aluminium block

schlitzaugen said:
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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Not sure, but it was commonly used in palynology. I'm not sure why. Maybe it took fine deposits off the grains so you could get a really sharp image.
 
schlitzaugen said:
I guess it was commonly used in any geochem lab. We were trying to move away given all the issues with it.
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As you would too! It's one of the truly horrible chemicals I reckon.
We've done a fine job of diverting the thread! :)
 
JohnW said:
As you would too! It's one of the truly horrible chemicals I reckon.
We've done a fine job of diverting the thread! :)
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I think that you and Schitz have high lighted what a nasty chemical this is and is to be avoided. There are obviously less dangerous methods of cleaning an alloy block.
 
Bead blast, pipe cleaners and good brushes to clean the oil galleries and pull the main gallery and then wash it and blow it dry. Use your senses to feel if you find glass as you do all this. Not hard but finicky / necessary, locktite on the main gallery plugs too.
 
COL said:
I think that you and Schitz have high lighted what a nasty chemical this is and is to be avoided. There are obviously less dangerous methods of cleaning an alloy block.
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Thanks Col. I'm hard pressed to think of a worse way of cleaning anything, truth to tell. It is truly ghastly stuff. It used to be used a lot to make those beautifully embossed lab. chemistry bottles with ground glass stoppers - we have a few.
 
Matthew said:
Bead blast, pipe cleaners and good brushes to clean the oil galleries and pull the main gallery and then wash it and blow it dry. Use your senses to feel if you find glass as you do all this. Not hard but finicky / necessary, locktite on the main gallery plugs too.
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You can buy wonderful round gallery cleaning brushes in various diameters. It's a bugger once you start loosening the years of accumulated abrasive grime.
 
Yes, I have a set of these, the block itself was spotless once finished and not much crap in it at all really. Pulled it through several tiomes but the main gallery was clean to start with..
 
schlitzaugen said:
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.
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Septone sells AliBrite (I have a bottle of it in the shed). The SDS claims it has hydroflouric acid at “0-<1%”
 
I've used a wand on my spray gun with a feed into a bucket of truck clean. After physically removing dirt grain build ups in crevices etc the wand works well.
 
most of these suggestion won't clean the only bits that matter .... inside the block in all the crevices and galleries. Surely in this day and age the local rebuilders have a way of hot tanking aluminium blocks.... they have been in common use since the 60's ( buick v8s)
 
The way I clean my aluminium stuff at home is with a high pressure washer to get most of the crap off. I take all the plugs out for that so I can get right in there. I use water for the most part, but sometimes kerosene to soften stubborn stuff before the last water blast. Sometimes I also use truck clean (green goo, they say it's biodegradable and quite good at removing grease in my experience). Blind bolt holes are the worst but I run a tap down those, then a bolt with a side groove cut with a thin disc in an angle grinder, then a bolt, until I can wind it all the way by hand to feel if there's anything left in there. It should go in very easily, with two fingers and almost no torque.

i do go over everything everywhere after that and clean by hand with whatever fits, scotch brite, steel wool, whatever. A final rinse is needed to remove all the tiny particles of debris generated thus. If I had a big enough ultrasonic bath I would give it some time in that too.

If there is any staining left after that, I would take it to a vapour/steam cleaning place (or dry ice but I haven't found a place here) but this last step would be only for cosmetic appearance.

Chemical cleaning of Aluminium is very problematic and it won't take this staining off.

Yes, chemicals to clean Aluminium have been around for a long time, but we've changed our expectations and have come up with better mechanical ways (any blasting process) to clean because they are safer/less polluting and in fact cheaper. We pay more, of course, but that's not because costs have increased. The cleaning equipment may be more expensive (no idea) but that is a one-off.
 
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