If your rocker panels (outer
sills for those in the UK) are of the see-through variety they need to be replaced. The
cost of the new panel is negligible. So many bus owners (like myself) have ordered these
panels some time ago and all that remains to be done is to weld them in place ..... That's
where the trouble starts. I had never undertaken such a job. I had no welding
experience whatsoever. Pressed by time (annual inspection coming up very soon) and an urge
to do this myself (disappointed by work done by others) I bit the bullet and went ahead.
The result was so encouraging that I wanted to share my experiences so others can perform
the same procedure. As I said I had no welding experience and I still had to acquire many
of the necessary tools. All in all it
took me about 10 hours to do the entire job. That seems a lot. However most of the time
was needed to do the prep work. The welding itself took only about an hour. Since this was
my first attempt I took my time realising that I wanted to do it right rather than having
to do it over. The end result was well worth the effort. The car passed its official
inspection without any problem. I was even commended for a very professional welding job!
Cut out the old rocker panel.
That's easier said than done. The end result of your work will depend largely on how well
you did this part of the job. To make life easy for you I will explain this procedure in
great detail. I have even gone so far as to prepare a couple of drawings so you will
understand how these parts fit together. Note that I did this work on a '77 bay window
||NOTE: The drawings are not to scale!
Start by cutting away the sloped part of the original rocker.
The best tool for this purpose is a grinder with a cutting disc. Such a tool will set you
back about $50. Note that the rocker is spot welded to the rest of the car at locations A and B. After cutting away the
sloped part you will have the upper and lower parts of the rocker with the spot
welds still attached to the rest of the car.
In order to provide a solid base for the new welds
you need to grind away all of the remaining rocker at location A.
Be careful not to cut into the outrigger. We need it to remain in place but with a good
shiny surface. The success of your welding depends on how clean the surfaces are.
Note: Later I found out
that cutting out spot-welds is more easily done using a special spot-weld drill bit. Ask
your FLAPS for this tool.
The upper part of the old rocker needs to be cut away
too but not entirely. It depends on your new rocker. If the new rocker has a U shaped
rubber seal channel that clicks into the old one you can leave that part of the old rocker
in place. If it does not fit (like mine) you will have to remove the channel for the seal
as well. I left the uppermost horizontal strip in place (the black part in fig 3). The old seal channel has a small ridge that keeps the
seal in place. I left that part of the old rocker as I wanted to keep this ridge which was
not present in the new one.
After all the cutting and grinding is done you have
to examine the state of the outrigger (or inner sill). In my case it was in reasonable
condition. However if you can poke a screwdriver through the outrigger at any spot you
choose you need to replace this part as well. I presume that's a more complicated
procedure. I have not yet done that so I have no clear-cut recipe for you. What I did do
is to remove all of the rust that I could get at. Next I sprayed
chemical rust converter into the outrigger. Let it work into the rust for several hours
then clean it using water and soap. Next I sprayed rust inhibiting paint
through all of the holes that lead into the insides of the outrigger. I guess that will
preserve it for a number of years. It's the best I could do. Cars are built to be
biodegradable anyway but in our climate it does not take very long . You can not stop this
process, only slow it down.
Does it fit ?
Try the new rocker on for size. Now is the
time to see if you did your cutting right. The new rocker should fit without leaving
gaping holes. I was careful not to cut away too much material so in this stage I had to
grind a little more on the left and right sides to make sure the new rocker fitted snugly
in to place.
Prepare the new rocker
Depending on the source of the new rocker you may
have to perform minor surgery on the metal. In my case I had to remove two small pieces of
metal from the seal channel. After removing all stickers etc from the rocker we can
prepare it for welding as described in fig 2. Most likely your new rocker will have
been primered at the factory. We do not want paint on all of the spots that are going to
be welded. So use your wire brush or sandpaper to clean all places where you intend to
|You need to drill a series of small (4 mm)
holes along the lower part of the new rocker. We will use these holes to simulate spot-welds (they are called 'plug-welds') using our MIG
welder. Along the upper lip we need to make small triangular cutouts. Do not drill holes
here because you will probably not be able to get at them with your welder. The nozzle is
to wide to fit into the seal channel. However you can just get at the these cutouts and
weld against the remainder of the old rocker (location B in
Do the welding!
|After you have finished welding it's time to clean things up.
Grind away any excess metal, however be careful and do not cut into your new rocker panel!
Note: this photograph was taken during a practise run.
below shows the result of a few seconds grinding. This particular weld looks quite good.
When it is finished this weld will be completely invisible.
Bare metal should be wirebrushed. You may need to use some
bondo to fill in pits in the welds. Remember that these welds are vulnerable to new
rusting. I put a layer of rust inhibiting primer over the whole rocker and finished it
with the famous Taiga Grün. I did not even spray the paint on. Just used a good
quality brush. That's good enough for me at this time. The last thing I did was to spray
"ML" protection into the insides of the rocker. This stuff comes in a spray can
with a special thin hose and nozzle. Use the holes in the outrigger to insert the nozzle
and give it a good spray. This will prevent additional rust building inside the new rocker
and help seal the new seam.
|This is how the end results looks, a rock solid rocker panel. No
longer that browny bubbly half rotted look but firm, shiny and freshly painted. This will
last you for a good number of years. And it will make you an even more proud owner of your
bus. Note: I still need to replace the sliding door seal.
Tools and materials required for this job
In order to carry out the work described here you
need the following tools in addition to the standard set of screwdrivers, pliers, hammers
new rocker panel
I bought mine at the local FLAPS for only $7 (tax included).
grinder with a cutting disc
I had never used a grinder before. Be sure to wear safety goggles and gloves. From
experience I know that's important!
I had never used a welder before. I did not even know what type of welding was
required. After some research I found that a MIG welder is needed. I used one of the
cheapest models available. It's an "Easy MIG 120" gasless unit. It uses 0.9 mm
flux core wire. I found it to perform very adequately for this job. It's price? Around
Having a spraygun helps but you can do without. I used it to spray rust
converter and primer into the hollow outrigger.
Using the hose and nozzle I sprayed this stuff into the rocker and
outrigger after all the work was done.
Comments or questions:
Please e-mail me !