SlotCarsFAQ
(Frequently
Asked Questions)
all
about slot racing bodies
Question
: How to
fill pinholes and bubbles in resin molded slot racing bodies?
Not having them in
the first place is the best way ... Absent that it kind of depends
on where they are and to what extent. If it is a pinhole or void,
or very thin area (big bubble that "skinned") I've had
good luck filling these in with some modeling putty. If it is
a larger area it is good to back the area with some thin styrene
sheet superglued into place as a base for the putty. As always
with putty--thin coats is good, big lumpy blobs (like I do) are
bad. If the "bubbles" are the kinda cottage cheese variety
where it looks like an all-over blemish in an area (or the whole
part), my best luck has been to lightly sand the area(s) affected
and carefully spray on primer to build up a bit then sand back
to level. Care must be exercised here to avoid burying detail
in primer (see thin coats/thick blobs above, keeping in mind which
side of the fence I preach vs which I usually follow). [Scottrik]
Question
: What is the best primer to prepare resin slot car bodies for painting ?
I've had very good
luck with both Duplicolor "Sandable" Primer (I prefer
white unless I'm painting over pre-existing tampo printing, etc, then gray)
which is available in large aerosol cans at many auto parts stores. My current favorite is Tamiya's white spray primer as it is VERY
fine and usually needs no sanding before hitting with color. Works
very well, but is a bit expensive... [Scottrik]
Question
: What techniques can you use to make resin body molds without sticking to the
original body ?
To save a body from the clutches of the resin stick
destruction, back pour the body with a Hydrocal or fine plaster
of paris after using a cooking spray such as Pam to help separate
the body much easier from the plaster. It does not stick as hard
as it will with the resin. Then work the resulting plaster cast
over if you want changes or to add details. Then use an RTV type
rubber to cast a thick mold in a box type holder. When cured you
can then pour your resin in the mold for a slosh cast of the body
in resin. Do it thinly the first time and get it to keep flowing
till it starts to thicken up then make sure you have no real heavy
or deep spots where you don't want them. If the result is not
quite thick enough in some places do another slosh pour, being
careful to not leave too much in other areas by keeping the mixture
moving until it sets up. This will take some practice. And the original body should clean
up with some soap and water, no worse for the wear if you were careful.
The plaster mold should be coated with the recommended
release agent for the brand of rubber you are using. Because the
mold rubber is flexible it will release from the mold much easier
than the vacuum formed body will from
the resin casting. You want to make the mold of rubber thick enough
so that the mold will not distort when the resin is poured into
it and you move it around while sloshing the resin. Or pouring
a solid resin mold if you want to, as I do to make a vacuum mold
up of solid resin. Getting the vacuum formed body off the plaster mold should
be easier. But much
depends on how much wrap around the original body has. If it has
tumble home on all four sides, it can be difficult to get it off without some damage.
What I have done before is take the body
and mold under a light bulb and gently warm up the vacuum formed body till
I can gently pry it off one end first then work my way around
the body leaving the deepest end for
last to slide it off to the rear of the mold. Takes some work
and patience but have saved a number of pretty tight wrapped bodies
off the molds. Then there are some that are just to far wrapped
around to save. [Larry S.]
Links
follow for those who like to model real cars and obscure ones
at that ! [Dan]