16 Apr 2008
We've started cladding.
No surprises here, we're using five-bar aluminium tread plate again,
same as with Wothahellizat 1. Apart from the fact that we like the
look, it's very practical, being very difficult to damage and impervious
to scratches from trees etc. Not that it's really impervious, it's
aluminium and not that hard, but the pattern hides any scratches
you do get.
Most of the first sheet in place.
This sheet will have three panels, the top (not yet glued on) and
bottom ones are fixed to the frame, while the middle panel is glued
to the shutter.
Mon 21 Apr
Still cladding. The plan called for 11 days to
do the entire job but as always the plan is wrong (the fact that
we're still here 6 months after the original finish date bears witness
to this). Still, after five days, we have maybe 40% of the truck
clothed so we won't be that far off.
In area we've done about half of
the truck, but in time I reckon we're only about 30-40% done.
In doing this cladding
I'm encountering the same issues I did seven years ago while building
Wothahellizat 1, to wit...
Last time I made most of the cuts with a circular saw fitted with
a tungsten blade. Typically I would make the cut just outside the
line then plane it back with an electric plane.
This worked well but required the setting up of
a fence to guide the saw, creates a cut that is wider than I would
like, and it's almost impossible to plunge the blade into the material
to start a cut in the centre of the sheet.
This time I'm using a 4" grinder with a very
thin (1mm) cutoff wheel (a steel one, the wheels designed for aluminium
are hopeless). By itself this works OK but if you regularly rub
the wheel with wax it cuts through the sheet like...oh I dunno,
something that cuts through something else really easily.
The resultant cut just needs a little deburring
with a file and I'm done.
At a casual glance one would be forgiven for thinking that the patterns
on a sheet have a pitch that's a submultiple of the sheet size.
They look like that are 60x60mm which would make sense because the
sheets are 1200x2400 so this would give an integral number of patterns
on a sheet, and allow you to simply stick sheets side by side and
have the pattern align.
The pitch is 59.54x63.73mm, which means that,
almost certainly, any two sheets placed side by side will not
have aligning patterns.
Now maybe this won't matter to you in your application,
but to me misaligned patterns on a truck body looks like sloppy
This means that for every sheet on a side, apart
from the first one, you have to measure the pattern, compare that
measurement with its neighbour, and cut off as much material as
required so that when they are placed together the patterns align
when you look along the body.
Nicely aligned patterns on the tread
Note that this means that you could lose as much
as 63mm from each sheet, so you should not design the body to require
the full 2400mm if you want to align the patterns horizontally.
Note also that, in theory, the same problem applies
vertically. There are two reasons however that this is not really
an issue, firstly the runs are short, we're only talking about say
2 metres in height as opposed to a length of maybe 8-10 metres.
Secondly, you only see the vertical alignment when lying on the
ground looking up at the body, not a position normally taken.
These two sheets are aligned pretty
well horizontally (the red line) but not vertically as indicated
by the fact that the centre "five-bar" pattern has six
bars. This can be fixed by trimming the width of all sheets, but
that causes problems with the placement of support beams in the
frame at standard 1200 centres as you would not know the width of
a sheet until you trimmed it.
The sheets have what I call a "grain" and if they are
not all placed the same way up they can look vastly different at
If you look under most of the bars in the above
photo you will see a light mark that mimics the bar. I call this
the "shadow", and I make sure that this mark is below
the bars on every sheet.
On Wothahellizat 1 there was a single panel that
was fixed on "upside down", ie. with the shadow above
the bars, and in some lights it looked like a totally different
material. It bugged me for years so I'll not make that mistake again.
Last time we used 3M VHB (Very High Bond) double sided tape to fasten
It worked well but on Wothahellizat 2 we're using
Sikaflex. There are a few reasons for this.
Firstly, when I was dismantling the old body I
had a hell of a time removing the panels that were fixed with VHB
but at least it was possible with hand tools. However the single
panel that was glued on with Sikaflex (for reasons that escape me
now) was impossible to remove manually. I had to rip it off with
a fork lift.
Next there's the surface preparation. Unlike the
standard double-sided (or "mirror") tape that's fairly
thick and a little spongy, VHB is only 1mm thick and has no give
at all. Therefore the surface has to be almost perfectly true or
there will be gaps between the frame and the sheet.
This is difficult to achieve.
Sikaflex on the other hand can be globbed on in
just about any thickness, so I don't have to grind every weld perfectly
flat and I can adjust the thickness to ensure that adjoining sheets
VHB sticks instantly, you only get one chance
to position the sheet. If you place the sheet and immediately realise
it's not quite right you can remove it but you ruin the tape because
half will stay on the frame and the other half will come away with
the sheet. If you don't notice an error until after a few minutes
during which time you've pressed the sheet home and maybe helped
it along with a rubber mallet, bad luck, you'll ruin the sheet if
you try to remove it.
Sikaflex on the other hand takes several minutes
to go off, plenty of time to adjust the sheet's placement.
Firstly, which Sikaflex to use? I asked several people, including
some in the truck body building game, and they all said 227.
Then I looked on the Sika website, They state
quite clearly that 252 is the recommended product for panels on
truck bodies. I rang Sika here in Australia and got the same answer
so that's what I'm using.
They also state that the area to be glued should
be cleaned with their 205 cleaner and primed with 210 primer.
Now maybe they just want to sell more products,
but I think it makes sense to follow the party line, so that's what
I apply the glue very liberally and try to ensure
that just a little squeezes out from around the edge of the sheet.
I then resist the urge to wipe the excess or clean up in any way,
do this and you will spend the next half hour with black sticky
crap everywhere, several rags stuck to your fingers, and a worse
mess than you started with. Let it dry, it's easy to cut off with
Clamping. Sikaflex provides quite a good bond
immediately, even a large sheet will stay in place and will not
fall off the frame once it has touched the glue. So I find that
minimal clamping is required, certainly you should not clamp too
tightly as this will expunge the glue from the clamped area.
The sheet will however slide downwards and this
has to be addressed, but not by clamping. With a large sheet I feel
that the force required to hold it up by clamping alone is too great.
Also you need to be able to rest the sheet in position several times
while cutting and trimming it to shape. Therefore I feel that some
simple support is required and I've made a few widgets that I can
clamp to the body in various ways to provide "platforms"
to rest the sheet on. These stay in place until I feel that the
glue has set enough to support the sheet.
When I was sourcing the tread plate I was offered a much cheaper
product that, on the surface, seemed like a bargain. This plate
came from an emerging industrial nation who shall remain nameless...OK
I'll give you a hint, this nation will be hosting the Olympic games
in a few months, but that's all I'll say. It was about half the
price but I wanted to have a look at it first.
A quick visit to the engineering firm I was buying
from confirmed that I didn't want the cheap plate. The ribs (or
"bars" as they are called) were hardly raised from the
surface of the plate at all, this means that the plate would not
be as strong as the better quality version. Also the pattern was
irregular and looked like it would be difficult to match between
sheets. I asked about this and was told that they do sometimes use
it and in fact find it impossible to match the patterns, so they
only use it for small jobs where sheets are separate and don't have
Tue 22 Apr
Mark & Gail arrive for a visit today. Roger & Kerryn,
two other motorhoming friends, were also expected to arrive but
their bus broke down at Mark & Gail's place so they're grounded
for a while. They hire a car however and drop in anyway, we light
a fire and enjoy the evening catching up.
Wed 23 Apr
We were hoping to get two sheets a day stuck on but it's been more
like one a day. This is partly because I want the sheets to be as
accurately placed as possible, with edges and patterns aligned,
and this takes time; and partly because we have to add the insulation
to most sheets before they are placed.
We do this because in most cases we cannot get
to the back of the sheets, so the insulation has to be added first.
Sometimes I can scribe the sheet from behind which makes it easy
to know the shape of the insulation. But often I cannot get to the
back at all, so I have to measure the bracing and transfer the measurements
so I can cut the foam. This can take longer than the cutting of
the sheet itself.
Two of the sheets ready for gluing.
Thu 24 Apr
While Mark is here to help
I thought we'd get into some demolition of the old body remains, just
remove the timber so I can cut up the steel at a later date.
Or that was the intention.
Once on a roll though we can't stop and before
long we have the old lounge room roof completely stripped.
The lounge room roof has been stripped,
the floor sits behind.
Fri 25 Apr
We do some more cladding this morning then Mark says he'll go over
and chip away at the demolition. Chris is keen to get it done so
we down tools and join in.
Within an hour or so there's no lounge room, just
a pile of scrap.
The lounge room in pieces, just one
large bit left to cut up.
Chris starts burning the timber.
While I cart the last remaining piece
over to the workshop and chop it up.
The final pile of metal, Mark says
I should put it on eBay as a kit motorhome in flatpack form.
Meanwhile the timber has all but
vanished, there's nothing but a pile of ashes left.
Chris attends the pile hoping to
make it even smaller.
Wed 30 Apr
We've got the last of the large cladding panels on so tonight we
fire up the heater. The house is still full of holes, and we have
towels blocking off most of the bedroom shutters which have yet
to be clad, but the heater does a reasonable job of raising the
Apart from being warmer when we go to bed though
it's of little use because we're still sitting outside.
Thu 1 May
It's exactly one year since we started building, and while we're
not finished we're getting close. We are however marking the day
by moving into the truck, that's right, as of today we're officially
living in our new motorhome.
Chris doesn't trust me to get the TV working in
time for her favourite show so we still sit under the tarp for most
of the evening.
Fri 2 May
We're mostly inside now, the TV is installed (albeit rather dodgily)
and the chairs are in, but we're still cooking under the tarp because
there's some gas left in the camp stove and we're too tight to waste
The fridge is outside as well, we're in that limbo
area between living inside and living outside the truck, much the
same as we were with Wothahellizat 1. When you build like we do,
ie. no house and only one set of possessions, there's always a period
when you're half in and half out, where the coffee is inside but
the milk is outside, the food is inside but not the cooker etc.
It's a real pain but I'm sure we'll get over it
and it won't be for long.
Our home of the last year, a tarpaulin
in the corner of the workshop, is being taken down.
>The fridge is still outside and the
camp stove (left of centre on the bench) will stay in service until
the gas runs out. The "kitchen" bench is now mostly covered
with paint tins.
Sat 10 May
Before we could move
in I had to at least get some of the plumbing working. As I mentioned
the other day I've decided to redo the plumbing because we were having
problems with the pump losing its prime overnight.
So I've move the pump to a spot below the floor
and therefore below the tanks, this means that it will always be
primed and removes the requirement for a non-return valve. I've
also added my second pump, the two will run in parallel.
Also I've replaced the complicated valve system
I had to allow filling/draining from the either tank. In it's place
I've added two solenoid valves that can be operated from outside
where I stand while filling.
The solenoid valves are in parallel with the pumps
as shown below (one only shown, the system is duplicated).
This allows me to selectively fill and drain from
either tank under electronic control, ie when filling I can control
the valves to determine which tank receives the water. Similarly,
when draining I can control the pumps individually to suck from
either or both tanks.
The system now looks something like the diagram
below. This is the same as the ideal schematic above but the elements
have been rearranged to physically fit in the space available.
Note that I've separated the two systems in this
drawing, in the real thing they are all mixed together due to space
Here's a photo of the finished product,
the wiring has yet to be done.
Fri 16 May
I'm slowly getting really pissed off with technology. I know this
new stuff is great and overall very reliable but it's so frustrating
when it doesn't work.
For example, I've been using my mobile phone for
connection to the internet for the past few years and in general
it's been good. But the modem function of my current phone seems
to have shat itself, leaving me with no access to the World Wide
In the past when something like this has happened
I've got all flustered and wondered how I would survive, and admittedly
that was my first reaction the other day. However each time technology
causes me aggravation I get a little closer to saying "Sod
it" and chucking the computer and everything related to it
in the bin.
This time I just couldn't be bothered fixing the
problem and left it for a couple of weeks (That's why there's been
no posting here for quite some time).
Eventually Chris broke and suggested we get a
new broadband modem, I agreed and we're now back on line. I'm happy
to be connected again but that was a near thing, next time I get
any agro it could be the end of robgray.com as we know it.
And while I'm on a rant, let's talk about VB.NET.
There that feels better.
I've been using VB6 for years and, while it could
do with some improvement, it handles the job of building smallish
If VB6 is the Vervet monkey of programming languages,
VB.NET is a 400-pound gorilla. It's so large and complicated that
I find it very difficult to get my head around, there are next to
no examples in the help files and every one I've downloaded from
the net has not even compiled let alone ran and worked.
Anyway, I've calmed down now and the diaries are
back, until the next bout of total computer-generated frustration
What I need are some hobbies that don't require
the use of computers, bird watching an astronomy are two that spring
to mind. Let me know if you have any ideas.
Sat 17 May
One of the shutters is catching on the frame
as it opens. Fortunately they are designed to be removed without
too much trouble, so I unbolt it and plane the offending sheet of
Sun 18 May
We've finally finished
the cladding, thank goodness for that. Now that the truck is weather
resistant we can move it from the workshop into the wash bay which
is less sheltered. This will free up the space we're been occupying,
and I'm sure Peter will be happy to have most of his workshop back.
The truck in its new clothes.
Tue 20 May
We've been walking on a
motley collection of assorted boards for some time and it's getting
a bit annoying so it's time to do the floor.
Last time we used straight 19mm thick ply for
the floor and lifting some of the old sheets the other day drove
home to me one of the reasons Wothahellizat 1 weighed so much.
This time I think we can do better.
We've decided to make the floor out of a home-brew
laminate, featuring a layer of 6mm ply, followed by 10mm of closed-cell
insulation, and finally some 3mm ply.
This should provide reasonable insulation while
being light and strong with a little give.
I also have to make some trapdoors to access the
water pumps and the winch.
The 20,000lb winch is mounted in
the middle of the chassis so I need an easy way to access it.
To provide some isolation between the outside
and inside the trapdoor's layers overlap those of the surrounding
The trapdoor layers overlap the floor
to increase the interior/exterior isolation.
The trapdoor in the kitchen floor
through which I can access the winch.