Reply to "Undercoating R&R"

> boy that job sounds like one fitted for inmates, you know, guys with
> shackles on their ankles. Its not a job for an aerospace engineer! LOL...

Heh, heh, heh.

> Since dropped floor pans are also in my future, I appreciate the heads up.

I'll start a new post with some additional info on that.

> I think I'll leave the oem undercoat intact, and just apply new undercoating
> to the new floor pans.

I'd at least check the old undercoat in a few spots to see what the metal is
like underneath.

> It would be an understatement to say your Pantera is getting more than a new
> motor this winter. wow.

Yup. The longer the engine build slips, the more I take the car apart and
the more work it gets. Unfortunately, I'll be 400 miles away from the car
for the next couple of months.

> Been there and done that. There are a couple of easier ways, if there really
> is one, to strip the coating off. I used aircraft stripper.

I've used aircraft stripper before and it works well but I didn't want to
use it on the bottom of the car due to fumes and the stuff dripping on me.
I think it would be better for the engine compartment but luckily my car
didn't have an undercoated engine compartment so all we had to do in that
area was prep and paint.

> heat gun in some area's, got it hot and also used the putty knife to
> scrape it off.

I didn't even think of that. That probably would have worked well in some
spots.

> Nice first post Dan!

Thanks. It's not exactly my first post, though I've mostly lurked here.
I've posted before but lost posting priveledges during one of the forum
upgrades so I re-subscribed from a new email address.

> It sounds like you have done an excellent job. It's interesting to hear that
> your car had little or no rust under the original undercoating. Some cars are
> like that. If that is the case, then as George says, you might as well leave
> it alone. dont fix what is not broken. I think a lot of it depends on how
> long the bodys sat arround in bare metal down at that Vignale assembly plant
> in Turin.

I've heard stories about that. I bought my car when I was on a one year
assignement in the lovely Mojave desert. The near zero humidity out there
probably didn't hurt. I checked the car over thoroughly before I bought,
including taking an ice pick to the underside of the car to make sure it
was solid. Oddly enough, there was some structural rust below the rear
driver's side lower suspension pick up points. The other side was rock
solid but the driver's side didn't have the drain holes drilled so water
pooled there causing some perforation. It could have been ground out and
repaired in place but I bought a repair panel from PPC and cut out the whole
section. I made sure the new panel had the drain holes, of course.

> Here in the land of the black sun, they salt the roads throughout the winter.

Same here but I keep the Pantera parked throughout the winter and drive my
1987 Mustang instead. I have an old Triumph TR7 coupe that I drove for a
winter here. It was a low mileage car with no rust and a spotless under-
carriage. After seeing what that did to the underside of the car, I decided
the nice cars would stay garaged during the winter.

> Electo chemical stripping, where they submerse the entire car is something I
> have no experience in. I have heard stories about people who had it done 5 or
> 10 years ago and are now finding the acid was not entirely washed out of there
> car, and is now actually causing corrosion deep inside the chassis sections.
> If anyone has any experience in this, I would be interested to hear from you.

The acid dipping method is the one that had the seeping seams and internal
corrosion problems, though they may use some sort of an acid neutralizer these
days. A local Mustang shop that does high end restorations uses a similar
method but it is alkaline-based, not acid. Lonny uses Redi-Strip in
Evansville, Indiana. The car is dipped in an alkaline rust removal tank,
rinsed and dipped in a phosphate tank, then drained. The phospate will weep
for a period of time but does dry. Lonny puts the body on a rotiserie which
shortens the draining/drying time. Redi-Strip recommends allowing the vehicle
to sit a few days, or use a heat gun around the seams to dry the surface
completely before applying primer. At any given time, Lonny may have several
vehicles stripped to bare metal in his shop and they may sit that way for 5
or 6 months before he paints them but they never show any rust. I believe
the phospate forms a barrier to rust. Here in the humid midwest, a similar
media-blasted body will quickly start to rust. The only downside I can think
of (other than the car has to be stripped to a bare tub) is that any of factory
corrosion inhibiters that were used inside the boxed body sections will be
removed by the process. I think I'd want to re-rust proof those areas with
something like the cavity wax Johnny mentioned. Lonny doesn't like any of
the traditional media blasting approaches because of the dust residue which
hides and kicks up when hit with the air from the paint gun. The dry ice
blasting shoouldn't have this problem. These days, the factory sheetmetal
body panels are E-coated. I've never used this service but there are places
that do that:

http://www.redi-coat.com/photos.html

> I too like the 3M scotchbrite discs. But my favourite tool is the Black &
> Decker powerfile.

I'll have to see if those are available here.

> I came to the conclusion that the metal preparation is more important than the
> type of "rust preventing" paint you use. However, my favourite is self etching
> primer.

In my limited experience, I've got to agree. The surface prep is the most
important part.

> I have not tried SEM Shield. Is that a primer type paint or gloss type paint?

It can be applied to bare metal or using a primer and is available in
gloss, standard and flat finishes. A hardener is also avialable. We
applied it to the bare metal and used the standard black:

http://www.sem.ws/product.php?product_id=154

> If you only want to get off the undercoating, dry ice blasting is the
> solution.

Sounds like an excellent solution. I'll have to see if anyone in the area
offers the service.

> Dan, did you ever dyno the engine with the Aussie heads? Just curious since I
> have pretty much the same motor, built as per your suggestions, going into my
> car. Thanks.

No I never did. The Aussie-headed motor was just meant to be temporary.
The original plan was to build a stroker for the Pantera and move the
Aussie motor over to the '56 F100 project truck (it's a bolt-in replacement
for the 289 the truck came with):

http://www.bacomatic.org/gallery/album05

Over the years, my plans changed as I obtained more and better parts.
First it was just going to be an offset ground 3.7" stroke crank with a
set of ported iron heads and more cam. Then I came up with the aluminum A3
high port heads and a matching intake so I considered a 408 cube stroker
with a 4" stroke. Then I came up with a 400 FMX block (rare tall deck 400
block with the SBF bellhousing pattern) and though about a 434 cubic inch
engine with the A3 heads. Then I came up with an XE Aussie NASCAR block
and a set of C302B heads so I was back to a 408 cube stroker. Finally came
the Fontana aluminum block for a 407 cube (4.1" bore by 3.85" stroke) all
aluminum stroker with the C302B heads. The Aussie headed motor is destined
for my dad's '71 Mustang convertible. I'm not sure what will go into the
truck but I've got dad's 428SCJ with a 406 tri-power induction that would
look nice there.

So many projects, so little time (and money),

Dan Jones
St. Louis, Missouri
1974 Pantera L
1956 Ford F-100 project
1966 Mustang 2+2
1977 Triumph TR7V8 project
1980 Triumph TR8 convertible
1987 Mustang GT