Sprint Colors.
Posted: Tue Feb 22, 2005 7:24 pm
From: "nebogipfel2004" <***@***.***>
Sent: Tuesday, February 22, 2005 11:53 AM
Subject: [LotusElan.net] Re: Sprint Colors.
Lotus didn't put in-mold "painting" into series production until the
Esprit S1. Then they experienced so many problems with it that they
reverted to conventional post-mold painting. If you ever see an Esprit S1
with it's original paint unmolested, and the pinstripes appear to be inlaid
into the paint rather than applied on top of the paint, that car was built
using in-mold painting. For that, the car would be quite rare.
In an earlier post, someone wrote something about Lotus injecting the
"paint" into the Elan mold. Lotus has never injected color into a mold on
a production basis, either as paint or pre-colored resin.
The VARI molding system (Vacuum Assisted Resin Injection) was introduced
with the 907 powered cars and was never used for production Elans or
Europas. With VARI, matched male-female molds are used instead of the
open molds used previously for cars like the Elite Mk 14, Elan and Europa.
The mold was laid up with dry fiberglass matte & pre-forms, and closed. A
vacuum was drawn on the mold, and then polyester resin was injected...
filling the mold and saturating the matte from a central point. Multiple
points on larger molds. The molds were then held heated to accelerate the
cure process. The result was a part with a finished surface on both sides.
When Lotus did attempt production in-mold painting of the Esprit, paint was
not injected into the molds. The mold was spray painted using conventional
methods prior to lay-up. The challenge Lotus had to over-come was finding
a catalyzed paint that would "cure" quickly (rather than "dry") to avoid
extending the molding cycle time unacceptably, and then be chemically
resistant to the aggressive solvents normally associated with polyester
resin. Epoxy resins would have been more paint-friendly, but Lotus never
made that leap. The matte lay-up and resin injection did not take place
until after the paint was cured.
Lotus did have a track record of using pre-colored gel-coat on production
parts. I don't recall the Elan Sprint specifically, but the roof panels
of Elan +2's were silver metallic, and that was gel-coat. No matter what
body color was ordered, the roof was silver metallic gel-coat and the body
was painted below the greenhouse.
"IF" Elan Sprints were colored in-mold, it was colored gel-coat, not
paint. I say that with some conviction not because I know what Lotus did,
but because there were no automotive paints in production use at the time
that would stand up to subsequent lamination with wet polyester resin. The
resin would eat the paint in the mold. Any Lotus body panels of the
Elan-Europa era that "may have been" in-mold colored were most likely
colored gel-coat.
John asked, "... if they used gel colour why not on all the Elans with
solid colours?"
Again, I don't "know" what Lotus did or why. However marketplace
standards for automotive finish were higher than gel-coat would deliver.
Even in the 60's - 70's, Lotus would have to paint the majority of the body
surface achieve a market-acceptable finish... "at least" on the surfaces
that readily meet the eye. However, it would be reasonable to use
gel-coat below the beltline where the finish isn't as closely scrutinized
and where it's often assaulted with road grime and grit. There it would be
more aesthetically acceptable, and it would be much more chip and scratch
resistant than paint.
With the Sprint, Lotus wanted to do a two-tone color scheme, and that was
normally more expensive to execute. Also, during that period Lotus was in
a perpetual death-fight with cost. So, a painted upper body over a Cirrus
White gel-coat lower body would make great sense as a typical stroke of
Chapman genius.
Lotus' fiberglass technology of the day was gel-coated polyester lay-up.
Ya gotta use gel-coat anyway, and pre-colored gel-coat was well developed
and common in the marine industry. Coincidentally, Chapman's other
interest was boats (Moonraker Marine was another Chapman company).
Applying white gel-coat to all bodies regardless of paint color simplified
production. It used an already necessary step to provide the color for the
lower half of the body (to marine standards), and simultaneously allowed
body painting to be "reduced" to just the upper half. A cost savings in
both materials and labor. A two-tone paint scheme that costs less than a
normal one-color paint job, but can be marketed as a step-up from standard.
Not a bad scheme.
I didn't come up with that flight of fantasy all by myself. I don't recall
sources, I can't quote contemporaries, I can't say with authority that is
exactly what happened. However, I was a rabid Lotus fan through that
period and I fed on every scrap of information I could get. The scenario I
"painted" above is founded upon, and consistent with the stories I recall
reading at the time.
Later,
Tim Engel
Lotus Owners Oftha North
Sent: Tuesday, February 22, 2005 11:53 AM
Subject: [LotusElan.net] Re: Sprint Colors.
Lotus didn't put in-mold "painting" into series production until the
Esprit S1. Then they experienced so many problems with it that they
reverted to conventional post-mold painting. If you ever see an Esprit S1
with it's original paint unmolested, and the pinstripes appear to be inlaid
into the paint rather than applied on top of the paint, that car was built
using in-mold painting. For that, the car would be quite rare.
In an earlier post, someone wrote something about Lotus injecting the
"paint" into the Elan mold. Lotus has never injected color into a mold on
a production basis, either as paint or pre-colored resin.
The VARI molding system (Vacuum Assisted Resin Injection) was introduced
with the 907 powered cars and was never used for production Elans or
Europas. With VARI, matched male-female molds are used instead of the
open molds used previously for cars like the Elite Mk 14, Elan and Europa.
The mold was laid up with dry fiberglass matte & pre-forms, and closed. A
vacuum was drawn on the mold, and then polyester resin was injected...
filling the mold and saturating the matte from a central point. Multiple
points on larger molds. The molds were then held heated to accelerate the
cure process. The result was a part with a finished surface on both sides.
When Lotus did attempt production in-mold painting of the Esprit, paint was
not injected into the molds. The mold was spray painted using conventional
methods prior to lay-up. The challenge Lotus had to over-come was finding
a catalyzed paint that would "cure" quickly (rather than "dry") to avoid
extending the molding cycle time unacceptably, and then be chemically
resistant to the aggressive solvents normally associated with polyester
resin. Epoxy resins would have been more paint-friendly, but Lotus never
made that leap. The matte lay-up and resin injection did not take place
until after the paint was cured.
Lotus did have a track record of using pre-colored gel-coat on production
parts. I don't recall the Elan Sprint specifically, but the roof panels
of Elan +2's were silver metallic, and that was gel-coat. No matter what
body color was ordered, the roof was silver metallic gel-coat and the body
was painted below the greenhouse.
"IF" Elan Sprints were colored in-mold, it was colored gel-coat, not
paint. I say that with some conviction not because I know what Lotus did,
but because there were no automotive paints in production use at the time
that would stand up to subsequent lamination with wet polyester resin. The
resin would eat the paint in the mold. Any Lotus body panels of the
Elan-Europa era that "may have been" in-mold colored were most likely
colored gel-coat.
John asked, "... if they used gel colour why not on all the Elans with
solid colours?"
Again, I don't "know" what Lotus did or why. However marketplace
standards for automotive finish were higher than gel-coat would deliver.
Even in the 60's - 70's, Lotus would have to paint the majority of the body
surface achieve a market-acceptable finish... "at least" on the surfaces
that readily meet the eye. However, it would be reasonable to use
gel-coat below the beltline where the finish isn't as closely scrutinized
and where it's often assaulted with road grime and grit. There it would be
more aesthetically acceptable, and it would be much more chip and scratch
resistant than paint.
With the Sprint, Lotus wanted to do a two-tone color scheme, and that was
normally more expensive to execute. Also, during that period Lotus was in
a perpetual death-fight with cost. So, a painted upper body over a Cirrus
White gel-coat lower body would make great sense as a typical stroke of
Chapman genius.
Lotus' fiberglass technology of the day was gel-coated polyester lay-up.
Ya gotta use gel-coat anyway, and pre-colored gel-coat was well developed
and common in the marine industry. Coincidentally, Chapman's other
interest was boats (Moonraker Marine was another Chapman company).
Applying white gel-coat to all bodies regardless of paint color simplified
production. It used an already necessary step to provide the color for the
lower half of the body (to marine standards), and simultaneously allowed
body painting to be "reduced" to just the upper half. A cost savings in
both materials and labor. A two-tone paint scheme that costs less than a
normal one-color paint job, but can be marketed as a step-up from standard.
Not a bad scheme.
I didn't come up with that flight of fantasy all by myself. I don't recall
sources, I can't quote contemporaries, I can't say with authority that is
exactly what happened. However, I was a rabid Lotus fan through that
period and I fed on every scrap of information I could get. The scenario I
"painted" above is founded upon, and consistent with the stories I recall
reading at the time.
Later,
Tim Engel
Lotus Owners Oftha North