Land Rover Chassis Repair - Rust and Welding
Treating rusted Chassis |
Clean as mentioned above, but then take an old screw
driver or ice pick type tool and poke at it, especially in the
corners, poke very hard and literally try to stab a hole through the
surface, some places you will (If it is
rusted badly) then work at those
holes and make them as big as possible with your poker.
You can also take a ball pein hammer and hit the
chassis all over, you should hear a good pong pong sound each time, when
you hear a dull thud you will have either found an internal support, very
internally rusted spot or a spot where there is a lot of mud or gunge
inside. Concentrate on this spot until you have established the cause of
the thud. If there is sand/mud/gunge inside, drill a large hole, 14mm or
so directly beneath the problem area, if there is already a drain hole it
is probably blocked.
Once everything is cleaned up, you can carefully
asses the damage. You may consider cutting the holes out or cutting out
entire sections and replacing them with new good sections. Anything larger
than a finger hole or a mass of little holes must be cut out and replaced.
If they are flat sections, cut back until you cut
into good steel, obtain new pieces of plain mild steel, treat them as
explained on this page and weld them in place.
rusty bits include some major piece of
chassis like a spring hanger or bumper horn or even a whole cross member,
then you must make a few careful profiles on stiff cardboard or sheet
steel and take careful measurements, including diagonal measurements to
ensure that you fit your new replacement section in the exact same place
as the original. It may be a good idea to drill a reasonably large hole in
the item such that you can get a small paint brush in to
paint it once it
is all welded back together.
Take note that there are always a few
the steel that disappear when cutting a section out with a grinding disk
or gas torch.
Treating a Rusty Chassis
on a Land Rover
Use a wire brush, either hand operated or on an
electric drill, on the surface and try to remove as much rusty material as
possible, donít be worried if you create a hole, attack the surface with
Anything that is vaguely rotten will come off,
sometimes if the rust is severe, you may need to use an angle grinder with
a grinding disk. Grind the surface lightly. Brown dusty powder is rust and
must come off, only when you start making sparks and the surface is shiny
can you move on to another area.
Once all rust has been removed you can patch up the
holes as needed (See next section)
You must then clean the surface with water and let
it dry properly.
If the surface is vaguely rusty or still
brownish/blackish in colour you must paint it with a Polycell product
called RUSSIST. An alternative is straight phosphoric acid but it is less
effective than RUSSIST.
Russist contains phosphoric acid which reacts with
the rust (iron oxide) and forms iron sulphate which is dark blue/black in
colour and is resistant to further rust. It is for this reason that you
must only apply this product to RUSTY metal as it does not bond on clean
You should apply the russist as instructed on the
container, then apply your favourite paint as the russist acts as a primer
for most paints. Russist can be sprayed on and you can apply spray paint
If you used straight phosphoric acid (With gloves !)
you must thoroughly wash the item after the it has stood for a good few
hours, then let it dry and apply paint.
Welding Chassis on a Land Rover
There are two types of welding commonly used on
- Oxy/Acetelene (Gas) welding where the surface is
heated with a flame and steel filler rod is hand fed into the hot
- Arc / MIG Welding where the surface is heated
with an electric current
Gas welding is very controllable and is used for
careful work with thinner metals
Arc welding is more common in the DIY market but it does not give as neat
a weld as a MIG welder.
It is upto the welder to decide which welder to use.
When welding larger flat sections it is important to
tack weld the plate on first, this is done to prevent the plate from
warping from the heat, here an electric welder is the best to use as the
GAS welder tends to heat the area too much.
Once the tacks are made (Each corner and half way
between corners) you can weld it in completely.
Take EXTREME care when welding on a vehicle,
check what is behind the welded area, check proximity of fuel lines, rags,
electric cables in the vehicle and on the floor etc etc. When you are
happily welding away, there could be a small fire burning somewhere which
you don't smell or see and when the weld is complete you have a major
emergency on your hands.
Further care must be taken when using an electric
welder on a vehicle, common practice is to remove the battery terminal and
alternator connection as some systems have bad earths, it is perfectly
safe to connect the earth clamp DIRECTLY to the welded article so that the
welding current travels directly to the weld, any other connection may
route itself via your electrical system and damage sensitive items.