More will follow as we go!
Wednesday, January 17, 2018
Custom Wheel Sneak-Peek!
Just a couple of little little teaser shots during mock-up of the custom wheels we had made for the Boss Schott Wheels make absolute jewelry for custom aluminum wheels. The machining tolerances on these wheels are almost unbelievable (check the fit on the billet center caps for a hint)!
More will follow as we go!
More will follow as we go!
Thursday, January 11, 2018
Rear Bumper Fabrication Project – Part 1
While
this blog showed little activity throughout most of 2017, the fact is, there
actually was a bit of progress being made on a somewhat ambitious endeavor I
decided to undertake. The following update spans several months of time in the project and MANY hours, but is condensed for easier reading. As of this writing, we are working consistently on the project in hopes of moving the project forward with much more energy. But first, a
little background:
A
few years back, I was on the hunt for a ready-made composite “tucked” rear
bumper and in the market; there were a few commercial outfits that offered
them. So, I set to doing my “homework”
and communicating with a number of builders who had experience ahead of mine, I
was able to quickly eliminate two of the offerings for either fit issues or
quality issues (or both). That left a
single source that talked a very good game and frequents most of the larger
Mustang forums on the net (mostly to maintain a passive-aggressive
advertisement campaign that is clearly frowned upon by most forum admins, but
that’s another story). Anyway, with some
trepidation, I ordered a tucked fiberglass bumper from the outfit and was
assured I would love it and that “countless” customers have installed them
without a single problem.
The
day came when my new bumper arrived and I headed straight out to fit it to the
car and admire the end result. Ya………never
happening. While the gel coat surface
was pretty decent, the bumper fit like absolute CRAP. So, trying to be the “good feedback”
customer, I documented every issue with pictures and verbal description, along
with measurements where needed and sent it over to the supplier.
Naturally,
on review of my notes, the response was the usual “nobody else ever had a
problem with it until now” and “there must be something wrong with your car” routine.
Given that data and Ford body assembly
manuals and specifications don’t lie, I returned the garbage bumper for a
refund and set off to thinking about alternatives. At the end of it, the options that were out
there really didn’t have the right “look” I was after anyway, so I guess there
was little lost in the end but time.
Selecting
the Fabrication Method
First
on my mind was to just knuckle-up and chop and section a factory steel bumper
and get on with it. But, if you have
ever done a chopped, sectioned and tucked steel bumper for a Mustang, you will
understand my hesitancy in choosing that route if other viable alternatives
exist.
After
a number of “happy-hour” conversations with friends and colleagues in the “biz”,
I was encouraged to build a bumper from scratch. But instead of steel, go to the trouble of
making a tooling-quality mold and fabricate the bumper from vacuum-bagged,
resin infused epoxy/carbon fiber (or epoxy/fiberglass) laminate.
My first
thought was; “Sure! Let’s pick the one
way to build a rear bumper that likely involved more work that working one up in steel!” What a great idea! As it turns out…….it was the perfect idea. Will it be faster? Nope.
Will it be less expensive?
Nope. Do we have all of the tools
to produce the mold? Nope (but
close). Will it work to make a bumper
exactly the way we want? OH YES. Will it allow us to make extra parts, exactly
like the original, over and over again?
You betcha! Are we just a wee bit
crazy? Beyond the shadow of a
doubt! So………..guess what we’re gunna
do????
Building
the Plug
On
a complex shape like a rear bumper, the first order of business is to make a
full scale model of the exact shape you want in a medium that can be easily shaped. This model is often referred to as the “plug”
or “buck” and in its finished form, will be a beautiful “A”-class surfaced
model of the exact shape that the composite rear bumper will be. From this plug, the tooling mold will be pulled
and all finished parts will be molded in it.
This is a rather gross oversimplification, but you get the idea.
After
countless hours walking my brain through the entire process I would use to
create my unique, tucked rear bumper, I decided to construct the plug using a
simple steel support structure with 2-part pourable, closed-cell urethane foam
poured around it to perfectly match the plug form to the body. This would allow the foam plug to perfectly
index to the body every time so even the smallest details could be maintained
and were repeatable each time the bumper model would need to be taken off the
car for work.
After
protecting the entire tail of the car with masking tape and waxed foil tape for
easy release of the foam, a temporary box was fastened to the back of the car
to contain the 2-part expanding foam we would use to produce the core of our
bumper plug. With an expansion ratio of roughly
30:1, we would need less than ½ gallon of foam base stock to complete the plug
core.
The
steel support structure was bolted into place through the factory bumper
bracket holes and the urethane foam components were mixed and poured into the
temporary box and allowed to expand to match the body contours and cure
overnight. The next day, the box as cut
away from the rigidly cured foam “blob” now stuck to the back of the car. The mounting bolts were removed and the plug
core was gently pulled away from the body, revealing a perfectly molded inner
surface that registered very securely into the features of the rear bodywork.
Next,
the plug core was bolted back on and the rough trimming of the shape began with
very simply hand saws, an electric knife and Surform tools. After about an hour, the bulk of the foam
core was carved away and the very slightest vestiges of a new bumper shape were
starting to emerge. At this point, there
would no longer be a need for the crude tools of rough shaping and all other
work would involve very delicate sanding, measuring, sanding, measuring,
sanding, and………measuring.
After the foam has expanded and cured, the temporary box is removed and the rough foam buck is rough trimmed to get rid of the extra material. |
There
really is no secret to establishing the final shape of the bumper. In its simplest description, it’s pretty much
the “artist’s eye” that guides the form.
I have had the image of what I wanted in a rear bumper clarified in my
mind’s eye for several years, so I would often close my eyes and envision what
I wanted and then open ‘em up and remove bits of foam that didn’t look like my
mental image.
With simple sanding boards and Surform tools, the basic bumper shape is roughed-in. The shape is roughly 1/2" to 3/4" larger than the final shape will be. |
After rough shaping, the first stages of intermediate shaping can begin. This takes the shape to with 1/8" or less of the final bumper profile. |
Since
the shape is essentially a mirror image from left to right, I made a series of
almost 20 templates to document the final shape of the plug and allow me to
replicate the shape from left to right as closely as possible. The process to arrive at the final shape took
roughly 80 hours of hand work before I was happy with the shape and fit of the
base plug. And once I had that shape
completed and all of the templates made and massaged to fit perfectly, I
removed the plug, placed spacers between the body mount and plug and
reinstalled the plug again. Naturally,
this placed the entire plug surface proud of the body by the thickness of the
spacers, so I had to once again shape the entire plug back to the desired
shape. However, since the templates were
now fully complete, the process of “drawing down” the final plug shape was only
about 8 hours.
Final shaping begins with lighter grit sandpaper boards and blocks and once a shape is defined, a template is made to ensure the shape is maintained and can be repeated later on. |
The final foam bumper plug shape is established and checked many times with the templates to make absolutely sure the shape is correct. |
“Skinning”
the Plug
With
the plug now in the exact shape I want, it needs to be protected from damage so
the final bodywork and finishing can take place. The foam plug surface is now very delicate
and is easily damaged by even the slightest impact. So, to protect the plug, a thin covering of
an epoxy/fiberglass laminate must be applied to the plug to allow the shape to
be preserved and protected and to provide a solid base on which body fillers,
primers and paints can be applied to finish the plug. The process of applying the protective laminate
surface to the plug is called “skinning”.
This very light, 2-oz fiberglass veil cloth is used in the process of skinning the plug. This material is very shear and when wet-out with epoxy resin, it virtually disappears into the laminate skin. |
A layer of regular masking tape is placed around the perimeter of the bumper to help with releasing after the epoxy laminate has cured. |
Quite
simply, skinning the plug involves wetting the surface of the foam plug with a
special epoxy laminating resin and embedding (laminating) a few thin layers of
very light fiberglass cloth into the resin surface. Special tools are used to roll out any air
bubbles that may be trapped in the resin and cloth and the matrix is left to
cure for several days to ensure complete hardening of the resin and
stabilization of the plug.
Trimming
the Plug
Once
the epoxy laminate “skin” has fully hardened, the plug is pulled from the body
and any excess flash is trimmed off the plug back to the original shape. Now, the bumper plug is much more stable and
solid and it can be handled with confidence that no damage will occur and the
shape will be maintained even when the bumper plug is not bolted to the body.
Prepping
the Plug for Finishing
With
the plug now fully skinned, the heavy masking was removed from the body and the
plug was test fit to the body to begin to establish the scope of the finish
work required. In the “skinned” state,
the plug is still pretty rough on the surface and will require very fine detail
work to get all of the gaps perfected and the surfaces filled and finished to the
perfect, class ”A” surface necessary to pull a mold from. The bottom line is simple: To get a perfect part, we need a perfect mold
surface. And to get a perfect mold surface,
we need a perfect plug! Needless to say
there is a TON of work left on this plug to get where we need to go, but at
this point, the shape is exactly what I want and it achieves the exact look I
want in a tucked rear bumper. When
mocked up on the car with tail light bezels in place, the look is very clean
and changes the look of the 70 Mustang tail substantially without looking odd,
angular or “industrial.”
Now,
the process will slow down once again as we begin to refine the plug edges to
achieve the desired gaps all the way around the surface and to begin final
shaping of the license plate aperture.
Then we will move on to preparing the surfaces for final finishing on
our way to mold making. LOTS of work to
go, but in the end, I think it will all be worth it!
Tuesday, January 9, 2018
2017 In Review – New Rear Bumper Project
"Where the heck have you been?"
Honestly, 2017 was an unimaginable blur in life that welded together some of the happiest, stressful, frustrating and saddest times all into a year that, in the end, I was happy to see off with my beloved family around me. In the end, there was A LOT that happened in 2017 that took precedence over car building, but believe it or not, progress was made on a particularly complex element of the Boss project as you will see in a later post. However, as a quick catch-up, 2017 went something like this:
- I Got Engaged!
- Wind Storm
Early
Spring brought a substantial wind storm to the area that managed to do
significant damage to my house roof (shop was good!!). End result was a load of expensive repairs
required. More later.
- Coupe Tuning
- Bathroom Remodel (Finished in October)
- Crushed Shed (First casualty of wind storm)
- New Roof & Gutters (Second casualty of wind storm)
The
second casualty of the windstorm, we had to have the entire roof replaced on
the house, and while we were at it, replaced the house gutters and added them
to the shop! Bottom line = $$$$$$
- Introducing: The Dodge Demon SRT
After almost 2 years of my secret day-job life, I was proud to have been able to enjoy the launch of my latest “baby”. After extremely confidential work, our FCA SRT Engine Group was able to enjoy the launch of our Dodge SRT Demon! Currently the quickest production car in the world and the highest output V8 in history, the lists of “firsts” in this car are indeed impressive. But perhaps most entertaining and rewarding is watching this production car heft the front tires clear of the track surface on production tires! Yes ladies and gents, THIS is what I do in my “day job”.
- New Tractor
- Niagara Falls with Family
- Daughter’s Wedding
- Mom’s New Knee
After
years of suffering with painful, failing knee joints, my Mom finally decided to
have her worst knee replaced in mid-September.
With outstanding preparation on her part and equally excellent surgical
prowess from her surgeon, Mom’s knee replacement was textbook-perfect and her
recovery truly impressive. In just a
month from her surgery, she was done with rehab and discharged from physical
therapy. And here, at just three months
after surgery, Mom is already planning the replacement of her other knee! Lack of pain is evidently a remarkable
motivator!
- Mom & Dad’s 50th
- Well Tank & Main Gas Line
- Lost My Grandmother
- New Grandchild on the Way
As
it seems to have always been in our family, blessings come in the most
unexpected ways and times. On the heels
of losing our beloved “Omi”, our son informed us that he and his betrothed were
expecting a child, our fourth grandchild.
So where loss had dominated the mind and heart, a new life will arrive
and be celebrated in the summer of 2018!
- Shop Tool Re Org
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