[T2] Cleaning the van/prepping for paint - underside - a bit long winded

[Joe Average]

So I'm working on our '78 Westy. It's revealed a few details I'd like to 
share with everyone.

First - inspect your outer seat belt mounting bolts. They amount to the 
sheet metal floor of the van with a small plate about 1/8" thick spot 
welded to the bottom of the floor. To the bottom of this is a nut spot 
welded in place. My plates were in fair condition but the sheet metal 
floor above it was rotting out. Obviously in a crash when my seat belts 
might be called upon to save my hide, this might not be good. Especially 
if a guy (like me) needs to lose a few pounds.

I bounced around on the web and saw that replacement panels are 
available but I'm making mine. For darn near free. I made a replacement 
underside plates out of 1/8" or 3/16" steel with the edges rolled over 
for strength. Mine looks very much like the original. Just used a sheet 
metal break to do the bending. I think it could be done in a bench vice 
too.

Am undecided whether I'll weld the end of this underside plate to the 
rear bulkhead at the back of the fender well. The factory did not and I 
wonder if the engineers wanted the sheet metal to distort in a crash and 
absorb some of the crash forces. The spot welds don't look to be 
structural - just to hold the plate against the floor. Might have been a 
great place to put seam sealer to prevent the rust...

Looking around the web I saw people making plates to put under the floor 
when installing seat belts into antique cars out of 1/4" plate with a 
nut welded to it. The problem I saw was the sharp corners they left on 
the plates. Wonder if that would cut and weaken the floor steel during a 
crash and risk a tear-out?

Anyhow - I marked the center of the bolt hole with a magic marker cross 
beyond the welding zone. I cut out the floor around the seatbelt 
mounting point and made a patch. Will do some plug welds through the 
patch into the underside plate I made after welding a big nut to the 
bottom of that. Will seam weld the patch into place.

Tools: MIG welder, angle grinder. I'm using a mix of cheap air tools and 
an electric 4.5" grinder. My 220V MIG is a pretty good one but the 
metals in question are so thin, any welder down to the entry level 
import welder would probably work just fine if the operator a decent 
welder.

ALSO - I'm cleaning out the fender well of all the undercoating to 
inspect for rust. The ends of the rocker panels behind the front wheels 
are rotted out but the rockers themselves are fine. Not too many more 
miles and there would be complicated repairs needed which could spread 
to the bottom of the 'B' pillar and I don't want to get into that. Fix 
it right now so it doesn't need to be fixed later. Brush on rust 
converter and weld through zinc paint everywhere is the goal. Stop the rust.

The undercoating was hiding some rot around the rocker end and maybe 
contributing to it. I also noticed surface rust under the undercoating 
in the top corner behind the seatbelt bolt. No damage yet but the 
undercoating was not doing it's job. Also noticed surface rust at the 
front of the fender well below the back of the step. The undercoating 
had let go there too. Was also a blister in the undercoating forward of 
the shock absorber. All in all, my Westy is very solid though.

I HIGHLY recommend removing that undercoating mess. At least with paint 
you'll be able to see where the rot might be setting in. Or at least 
remove the old and renew the undercoating.

How to get that mess removed was fun. Am about 95% done now. This was 
not without risk based on my methods - so don't do this in the garage 
and put your home at risk. I torched the undercoating with a propane 
torch. Made it crispy, burned a little, stunk badly, and then I was able 
to wire brush it out/off in dry flakes. Scrape off the melted/hot mess 
with a wooden paint stick. A plastic putty knife melts. A metal one just 
ruins the paint which might still be a good foundation for the new paint.

Again that 4.5" electric grinder with a knotted wire wheel did most of 
the work - even on the tar I did not make crispy. Am also removing the 
seam sealer b/c I found a few places where it too had let go and surface 
rust was developing. Despite the mess and the torch - the paint under 
the undercoating never got hot enough to blister or fall apart.

Here is where a lift or rotisserie would be really, really nice. Don't 
burn down your bus, garage or house. Be careful!

In the places where the big grinder wouldn't reach - I tried my little 
2" air grinder (90-degree) with a Scotchbrite pad or a sanding disc. 
Neither was a good solution - both simply loaded up with tar.

The fix for that detail seems to be the same $25 two inch 90-degree air 
grinder coupled with a 1" knotted wire brush from the local hardware 
store. It was $10.

When that wire brush is coupled with a drill, it turns too slowly (maybe 
2000 rpm) to get much work done by my measure. Maybe other folks have 
more patience than I do! ;) However when spun at 20K RPM, it TEARS 
through anything but can still be used in such a way that the base 
factory paint is not completely removed . Fortunately I lucked out and 
bought a wire brush that was rated for 20K RPM too. Wear eye protection 
of course. The cheaper non-knotted 1" wire brush was rated at some speed 
lower than the better brush. Was half the price too.

Along the way I also tried a plastic long bristle brush supposedly for 
removing undercoating and it frankly was $10 wasted. I'd love to try 
it's 3M cousin which makes big promises. my purchase was of a no-name 
brush. Despite the 20K RPM of the little air grinders - my two 90-degree 
air grinders don't have enough torque to push against the surface being 
cleaned very hard. Partly b/c the undercoating it pretty hard now - not 
soft like it might be if it was 20 years newer.

After everything is cleaned up, a few wipes with a cloth and lacquer 
thinner makes the original factory paint look like new but it is rough 
enough to have some "tooth" so the new paint will stick. This is where 
the little Scotchbrite pads shine so to speak. Add some tooth to the 
paint anywhere and everywhere.

So what remains is new seam sealer, steel patches welded in and then 
multiple coats of paint. No undercoating will be put back on my bus. 
Will probably use something like Rustoleum brushed on. Multiple coats of 
primer and black paint. If it doesn't hold up it'll be easy to sand it 
back off and I'll try something more serious. I was considering "stone 
guard" paint as used on the exterior rocker panels of some brands of 
vehicles. It's tough stuff but again - it might disguise rust until the 
rust is quite advanced. Any thoughts anyone?

I also bought the seam sealer/caulking at lunchtime from a Mom 'N Pop 
auto paint store. It is a urethane sealer/adhesive. Was $14 per caulking 
tube.

I'm leaving out all the brands tools/supplies b/c in the past I got a 
stern finger pointed at me over this sort of thing. P-mail me for that 
info if you want.

Chris in TN
'78 VW Westy 2.7L complaining of a cool breeze in one of it's wheel wells
'65 Beetle 2.0L ever patiently awaiting some TLC
'97 VW Cabrio feeling neglected
'99 CR-V AWD EX at 252K and keeps on ticking...
Brenderup 1205S