I think Allen's talents are wasted on something as mundane as Healeys -
they should send him on the first manned Mars mission, just in case
something breaks and they need somebody to fix it with a hair brush, two
forks and cement made from an ingenious mixture of crumbled Pop Tarts
and powdered milk ...
:)
-Graham
-----Original Message-----
From: Allen C Miller, Jr. [mailto:acmiller@mhcable.com]
Sent: Thursday, April 08, 2004 8:01 AM
To: healeys@autox.team.net
Subject: A better mudpie
I am hopeful there are few of you out there who share a penchant to
stand out as different. If so, read on.
When the heat shield kit for the 100-M arrived from Moss, both my
restorer and I felt it fell way shy of the mark. The boards were about
1/2 the thickness of the originals, were glass smooth and grayish vs
buff in color due to the masonry refractory used today. One of the
longer pieces had cracked in transport, so we had decided to return them
for credit and start out making our own -- that is, until, I walked past
the boxwood near our front door.
You see, the original shields have a very nice 'burlap' texture pressed
into the exposed side. I believe from talking with furnace men that
refractory shielding is a slurry of asbestos and masonry (gypsum?)
binder which does not model very well. To keep the air entrained for
insulative value, yet achieve a relative smooth surface, it was
necessary to press-mold shielding with a board backed with several
sheets of absorbent, porous cloth. On the BN-2 Healey shields we took
off the M, clearly original, the shields were pressed between
cloth-backed boards,probably paint-sealed canvas on the smooth side, and
absorbent burlap on the other to press out the water with minimal
pressure.
What does this have to do with our boxwood? Well, you see, I didn't have
time to send the shields back to Moss and cast about for an acceptable
substitute (we're miles from the nearest Home Depot where they sell
Hardy Backer, and the glass blowing studio which sells board for its
blowing furnaces is 75 miles away), so I decided to work with what we
had. Since one of the Moss boards needed repair anyway, and all of them
were too thin, I decided to repair the one and build the thickness of
all by screeting a 1/8" of buff colored masonry cement on each side,
press in plastic bug screen and smooth over. This worked well, but the
texture was a little off.
So how you get a burlap texture. Walking past the boxwood, the answer
was obvious. Afterall, I'm a New Englander and nothing gets thrown away.
And even with the Artic Snap we had in March, it was still time to take
the burlap off the boxwood. A little moldy, but nice texture. I cut up
enough in strips, ran them through the wash, and mirabile dictu, perfect
heat shield texture. On all but the one that goes under the floor board,
I pressed the burlap into another coat of furnace cement, then sponged
off the excess to expose the weave. Lightly sanding, I sponged on two
more coats, watered down a bit, until the surface was identical -- I
mean identical -- to the achievements in absestos of post-war English
industrial ingenuity.
Water resistence was confirmed when my wife pointed out several white
globs on the sink and counter where the Tranformation occurred. It took
a blunted knife and several minutes to chisel out the furnace cement,
despite copious applications of hot water -- more than all the steam
your Healey Steamer will generate in a 100 Texas summers.
Proudly displaying the grotesquely deformed shields to my restorer, I
received a silver, but the gold commendation eluded my efforts on the
issue of color. A little too yellow, he opined. This was quickly
remedied with high heat paint of the appropriate buff off-white color,
almost identical to the unsmudged portions of friable asbestos intact on
the original shields.
Concerns for rot in the encapsulated burlap on the underfloor prompted a
variation. I applied a coating of cement, then pressed in a damped piece
of the burlap, removing it after a few minutes, leaving the design
pressed in. Light sanding removed the peaks.
This has led to a new obsession: developing the most arcane means of
heatshielding the rest of the compartment. I wanted to keep our
carpeting looking old and mean, with no fat underlayment like you
sometimes see. The idea of shielding the underside of the tunnel and
firewall pieces on the outside is under development. I have laid woven
fiberglass cloth on the concave (outer) side of the tunnel, modeling the
cloth and cutting to fit the curves, the pieces held on the outside by
tape. I've bought another furnace cement, this one with the promising
notations "DANGER - CONTAINS FREE SILICA". The texture is much like
asbestos jacketing on old boilers and pipes. You are supposed to lay
this stuff up with dampened rags to help model the surface without
compressing the air entrainment. Sounds really good. I'm half done, and
the result is a shell like a plaster cast which is rigid, and readily
removes with the fiberglass backing intact from the tunnel. When done, I
think I am going to use the more plastic beige cement, and line the
exposed (under) side with tarpaper stuck to the cement for a truly
waterproof shield, readily removable, and provided good clearance from
the tranny. If this succeeds, I will repeat with the moveable firewall
piece. My restorer has supplied a template for the firewall section
above the steering tube on the inside, and we are considering a similar
3/8" insulation piece to fit on the compartment inside, this time
tarpaper facing inward consistent with the original appearance.
So there it is, simply worded in as little space as possible.
Allen Miller
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