I have some cast aluminum uprights off a 93 rx7 and they have the usual oxidation on them. I cleaned all the grime I could with some castrol super purple cleaner and it got them clean but the aluminum fought back with a heaping of nasty white oxidation. What can I use to finish cleaning these upright? Im thinkin about sand blasting and then Coating them with something that will prevent the oxidation. Any suggestions? I want to keep them unpainted for crack detection.
Some wheel cleaners work OK, but beware; some so-called aluminium wheel cleaners are only for cleaning the proctective laquer or clear powder coating
and aren't actually designed to work on bare aluminium.
Dilute caustic soda will clean them spotlessly, but will leave the surface looking grey. A neutralising wash of dilute acetic acid (or ordinary
household white vinegar) is needed imediately post caustic wash.
The best method would definitely be to have them bead blasted (not sand) which will brighten them and compact the surface.
Blasting with glass beads or other mild media such crushed chrerry stones.
The other thing you could try is boiling them up in a pan with rhubarb leaves this should get rid of any oxidation.
quote:
Originally posted by britishtrident
The other thing you could try is boiling them up in a pan with rhubarb leaves this should get rid of any oxidation.
quote:
Originally posted by britishtrident
The other thing you could try is boiling them up in a pan with rhubarb leaves this should get rid of any oxidation.
The odd thing though Rorty, and I don't know why, but as you said, alkalis clean alloy, acids don't normally seem to touch it, but then
rhubarb does????????????
I used the dilute caustic method prior to making my blaster.
The leaves contain a much higher concentration of oxalic acid and nephrotoxic acid so much that they are highly poisionous.
The other acid that is used for cleaning aluminium alloys is Phosphoric acid --- aka rust remover Naval Jelly, Jennoite.
No its not rhubarb leaves are toxic. They contain high levels of oxalic acid and its nasty stuff. Effects of poisoning vomiting diarrhoea, prevents blood clotting, permanent damage to digestive tract, Oh yeh and death. It can enter the body through skin contact or by inhalation and you don’t need much as little as 5g will kill you so boiling rhubarb leaves is a bad thing
quote:
Originally posted by longwayoff
...as little as 5g will kill you so boiling rhubarb leaves is a bad thing
As a possibly safer option, I have found that most household cleaners that warn you not to use them on aluminium are good for cleaning aluminium. I
have used Flash many times to clean aluminium engine parts (after de-greasing with Gunk or similar)
Oven cleaners are good (try on a sample first)
[Edited on 26/5/05 by JonBowden]
quote:
Originally posted by JonBowden
As a possibly safer option, I have found that most household cleaners that warn you not to use them on aluminium are good for cleaning aluminium. I have used Flash many times to clean aluminium engine parts (after de-greasing with Gunk or similar)
Oven cleaners are good (try on a sample first)
[Edited on 26/5/05 by JonBowden]
Without any question the best way is aqua blasting, its glass beads carried in very high pressure water I have had lots of aluminium bits done by a
motor rewind place litereally next door to where I work, he did me loads of bits for £10. They cam up like new, I have told everyone about it !
I'll put a pic in my archive. You can see what it looked like before in the 'my fabbed manifold' pic.
[Edited on 26/5/05 by Jeffers_S13]
Believe me Rorty boiling rhubarb foliage is dangerous. Oxalic acid can enter the body through contact with the skin; it can be inhaled it can cause serious burns to the eyes if inadvertently splashed into them. Even low-grade very dilute oxalic acid is dangerous stuff. However quickly becoming one of the more common ways of doing yourself serious harm these days would appear to be using paint strippers that contain Dichloromethane or sometimes called Methylene dichloride or Nitromors “It’s a bit slow, so you get out your hot air gun or fan heater, just to speed things up and there you go phosgene gas and your dead” I have had five incidents reported to me this year alone in our region. In every case it been fatal and its involved a chap in his garage or garden shed.
have seen demos of a company that makes machine to do blasting with dry ice, seemed very effective from what i saw, thogh don't have any info on cost, as useless as a solar powered torch really
quote:
Originally posted by Jeffers_S13
Without any question the best way is aqua blasting, its glass beads carried in very high pressure water I have had lots of aluminium bits done by a motor rewind place litereally next door to where I work, he did me loads of bits for £10. They cam up like new, I have told everyone about it ! I'll put a pic in my archive. You can see what it looked like before in the 'my fabbed manifold' pic.
[Edited on 26/5/05 by Jeffers_S13]
I actually work in Warwick, the place I used is call GEM Rewinds. They just happen to have an aqua blaster which I found out through another guy I
use for my aluminium welding, in fact he installed it. As I say they are next door to where I work (Cape Engineering) its a 'call in and ask for
so and so' type job though, dont go ringing up. Just go into reception and ask for John Dwyer. Prolly wise to mention that I told you about the
place or he'll wonder who the hell you are (!) not that he knows me name or anything but Ive been there a few times now so he sort of knows
me.
You'll have to call in and see some of the other bits I had done, if you bring what you want blasted I'll get them done the next day at
lunchtime. I live not far from Coombe Abbey, let me know and I can U2U some directions etc.
James
We used to boil bike engine casings in a washing up powder solution to bring them up lovely
[Edited on 26/5/05 by locogeoff]
quote:
Originally posted by longwayoff
Believe me Rorty boiling rhubarb foliage is dangerous. Oxalic acid can enter the body through contact with the skin; it can be inhaled it can cause serious burns to the eyes if inadvertently splashed into them. Even low-grade very dilute oxalic acid is dangerous stuff. However quickly becoming one of the more common ways of doing yourself serious harm these days would appear to be using paint strippers that contain Dichloromethane or sometimes called Methylene dichloride or Nitromors “It’s a bit slow, so you get out your hot air gun or fan heater, just to speed things up and there you go phosgene gas and your dead” I have had five incidents reported to me this year alone in our region. In every case it been fatal and its involved a chap in his garage or garden shed.
As Rhubarb leaves are only 0.5% oxalic acid You would need to eat around 5+kg of rhubarb leaves to kill yourself ok a lot less than that will make you ill --- but I don't think boiling them up is going to be a unleashing a WMD
You can get blasting attachments or ordinary pressure washer -- it works quite well if messy.
Back in my days of homebrewing, I once sterilised a load of stuff in an aluminium saucepan. The pan came up immaculate afterwards thanks to the
bruclens steriliser! Chlorine based I think.
Liam
Ill just bead blast them. I have the setup to do it but im mainly concerned about what to coat them in to prevent the parts from re-oxidizing. I was gonna use a clear gloss made by por-15 that seems pretty tough. Are their any aluminum specific clear coates out there that you guys have tried?
Yes, I have some of my polished, spun aluminium wheels sealed with a clear powder coating specifically for the job. Any good powder coaters would be able to advise you.
Anodize processors use a chemical called "de-smut" which is ferric & sulfuric acid. This stuff will leave the surface spotless and very
silvery. Be careful with media blasting the surface as any surface discontinuities will be peened shut.
John