Punk Technology "Primer"

Life Cars & Motorcycles
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Most peoples vehicles will be way too shiny for this trick, but it might be useful to someone.

A while ago I reported the use of crumpled aluminium foil as an abrasive pad, self forming and especially useful for cleaning awkward shapes, like, for example, corroded spokes. The abrasive action can be enhanced by incorporating grit, grinding paste or toothpaste into the crumples, though this would often be overkill.

One drawback is that the foil can get quite uncomfortably hot to the fingertips (I assume this is just due to friction. One is, incidentally, making thermite, but I don’t think its likely to be ignited). Edit:I suspect some of the heat might be generated by rapid oxidation of the freshly exposed aluminium surfaces.

Used wet with vegetable oil the pad stays comfortable, and rust, old paint/primer, and aluminium flakes form a protective paste which can look rather like a metallic primer.

Ordinary veg oil takes a long time to set, and will probably never be a suitable base for a proper paint job, though good enough for my present banger-bodging purposes.

Boiled linseed oil, commonly used as a wood finish, (if you can get it here, or a local equivalent - tung oil?) would set quicker. One could probably also use laquer or paint, but that’s getting to be too much trouble.

2

Now with exciting pictures. See paint dry!

Should have done a before and after, but if you don’t know what a rusty car looks like, you probably don’t need to.

Large rust-patch on the tailgate

Deep pitting next to the window seal

Its been on about a month in some fairly heavy rain, with no bleed-through yet. Probably will eventually, but then so does proper paint.

Its ok on vertical surfaces but on flat surfaces like the roof the oil attracts a lot of grit. I might try an alternative, quick drying binder, like PVA

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Its particularly effective on the crappy OEM steel brake pipes when they get a bit (not a lot) rusty.

(Of course in Taiwan its a judgement call as to whether these are bad enough to need replaced. In the UK the MOT tester would probably fail them at the first fleck of corrosion and I’d replace with copper. They don’t tend to last 20+ years in Scotland.)

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Lubricate with Coke (or other phosphoric acid-containing soda) for more effective rust conversion.

You Will need to rinse the sticky sugar residue off later though.

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[quote=“urodacus”]Lubricate with Coke (or other phosphoric acid-containing soda) for more effective rust conversion.

You Will need to rinse the sticky sugar residue off later though.[/quote]

Coke is a lubricant? :astonished: You mean…er…socially? Perhaps with rum in it?

I’ve tried the phosphoric acid rust-removal trick and I think it does work, but I doubt its worth the trouble in this context.

I doubt there’s any rust conversion going on here, unless there’s a low-level thermite reaction. I think this is just an abrasive which also makes “paint” in situ, (delete the auto-ation) but its quite cost-effective in both effort and money.

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A scouring pad of aluminium is just an abrasive. A good one, with self-generated abrasive powder too. Adding phosphoric acid to the mix DOES turn rust back into iron.

My use of the word lubricate is wrong: use the word Wet instead.

Alu foil dipped in Coke is my weapon of choice for restoring rusty parts, especially pitted rusty spots on chrome (also use number zero zero steel wool for that job).

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[quote=“urodacus”]A scouring pad of aluminium is just an abrasive. A good one, with self-generated abrasive powder too. Adding phosphoric acid to the mix DOES turn rust back into iron.
[/quote]

Well, yeh, but IF I have to clean the coke residue off afterwards, then I lose the protective oil/rust/aluminium paste effect, which I think is the main benefit (they still havn’t bled through).

I’m not sure there’s usually a huge need to “turn rust back into iron”. Its not going to be structural iron, after all. Perhaps its going to be less permeable/more protective than unconverted rust though. Might set up a test sometime.

Edit: I’d guess if one intended to follow-up with a protective and cosmetic treatment separately, for example, wax on chrome, or touch-up paint, or even a primer/undercoat/topcoat “system”, then phosphoric cola would be a better preparation, and that’s probably what most people would want to do, at least in visible areas.

I’m not likely to bother with that, so a simple one-step process is better for me, and my use of the word “primer” in the title is misleading.

If I cared about cosmetics, I probably would have bought a different car.

Having said that I think many people who want to apply a cosmetic fix to rust spots don’t get around to it because its a hassle, so a simpler “temporary” fix, even if unsightly, might still be useful to them as a holding action.

Last time I tried phosphoric cola was a long-shot attempt to clean up pitted motorcycle forks and fill the pits with superglue. Did seem to clean the pits (aided with toothbrush) but the superglue didn’t go on evenly or stick well enough.

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I should mention that on some of the rust patches (I think maybe the pitting one shown above, but I’m not sure now) I used a short section of aluminium tubing (bit of old TV aerial) packed with tightly-rolled aluminium beer can, in a power-drill chuck, as an initial clean-up tool, followed by the oil-foil.

I think it would also be possible to use the end of the can as a cup-disk, but I didn’t have the right sized bolt for the chuck.

Eye protection and gloves indicated. Sharp bits of metal, worst case the whole thing, could fly off.

One could also try an aluminium roofing nail in a drill or Dremel. I’m thinking the chuck would grip the nail at the pointy end and the head form a little grinding disk. I can’t try that here because I don’t know where to get them, but IIRC B+Q (and probably builders merchants) had them loose in the UK.