Rust removal... But Land Rovers don't rust, do they? Well, the bodywork doesn't, but there's still a steel ladder chassis under there. Whilst the following chemistry won't help with de-rusting the chassis, if you have some smaller steel items the procedure given below may be of some use.
Having remembered some of my University Chemistry lectures (yuk), and with a bit of research on the web, the following may be of interest:
- Take a large plastic bucket.
- Add a gallon of water.
- Add a tablespoon of washing soda (Na2CO3). (I initially tried baking soda - NaHCO3 - but washing soda works better. You don't need much, it's just to improve conductivity)
- Insert a piece of scrap metal.
- Attach the POSITIVE lead from a battery charger (or battery) to the scrap.
- Attach the NEGATIVE lead to the rusty piece of metal you wish to clean.
- Submerge the rusty bit of metal.
- Switch on charger.
- Leave overnight.
The results are quite amazing: Before:
Although the process does leave a gunky result in the bucket...
This is the result (metal washed off with clean water and a plastic scrubbing brush) and then dried with a cloth:
(Don't do this in the kitchen sink or you'll be in trouble with the boss!!!)
Now if only I could find a plastic bucket big enough to fit the chassis...
When I'd de-rusted all the small metal bits I could find, the cathode (scrap metal with the positive battery lead) looked like a piece of swiss cheese, with lots of holes right through it!
By increasing the current strength (amperage), or by increasing the surface area of the sacrificial cathode you can increase the speed of the reaction. But as far as the chassis goes, I'm afraid the best method of rust removal is by using a wire brush on an angle grinder (See Tools section). As mentioned in the Disclaimer, wear goggles. AND hearing protection. AND a face mask. AND gloves. AND overalls (doing this whilst wearing shorts results in lots of loose brush wires embedding themselves in your thighs). Not that wearing overalls stops this, but at least they don't go in quite as deeply.
Since I already had a Karcher power washer , I did purchase a sand-blasting attachment to use with it. Did it work? Well, yes, after a fashion. The trouble was, in order to remove a patch of rust the size of my hand, I went through half a bucketful of sand. Not to mention how many litres of water.
For the nooks and crannies where the angle grinder struggled to reach, I used a wire cup brush on a drill (See Tools section), and it was only some time later that I discovered a thing called a
<cue suitably dramatic music>
The only other tip I can give for removing rust from a chassis, is to take it section by section.
Unless you have access to a professional sandblasting shop.
But if you want my advice, just buy a galvanised chassis and have done with it.
That requires much less work.