Mike and others -
Here's a partial answer, though it's not specific to LBC's.
Mike Ross wrote:
> . . . fiberglass fender flares on their Spits or GT6's . . . I've read
> about the technique, but was wondering how they hold up. Anyone know of
> a good reference book or website for this procedure? . . .
Subject:
Re: Flare adhesive
Date:
Sun, 27 Dec 1998 11:14:04 EST
From:
MrBru@aol.com
To:
"914" <914@porschelist.org>
CC:
914@porschelist.org
In a message dated 98-12-24 12:21:51 EST, you write:
<< Being a bit of a perfectionist like I suspect many Porsche people are,
I
have been waiting to put the 4 flares on my autocrosser. I have been
contacting a lot of people, learning as much as possible. Successful
efforts that last in that environment have all been straight 'finishing
fiberglass with a couple of sheets of cloth. However, I remotely aware
of
the adhesive progress and I, too, think the new items may be better. (I
used a steel to steel glue in prior company that had to be ground apart,
for
example). Couple of questions:
> 1) do you have specifics on the Evercoat? Name, model number, etc.
Hi, I checked on the Evercoat and it's called SMC/FRP Repair #872 & 873.
it is 2 part epoxy for plastic/fiberglass to steel or other substrates.
They recommend use of their adhesion promoter #206. They have other
products for plastics, and a general purpose universal structural adhesive
#101. It may be cheaper and work the same, not too sure personally.
> 2) I have been looking into a SEM product specifically for steel to
fiberglass. It requires two parts to be mixed very well and at time of
use,
so they have two tubes to fit into a 'caulking' gun with a mixing nozzle
on
the front. I found a body shop that would rent the $$ gun, but they
honestly stated that, in most cases, the renter can't clean the mix
nozzle
and ends up buying a new nozzle. Nothing is cheap, of course. Any info
experience or comment on the SEM path?
Most shops throw away the mixer nozzles, I don't know how you'd clean it.
I understand the SEM products are very good and if you have availability
no
reason not to use them.
> 3) I am concerned that the flares look to be a sheet molding compound,
versus normal fiberglass lay-up. (Sheet molding is where a large flat
sheet
is radiant heated, then dropped onto a form and vacuum pulls down to make
the contours, then trimmed to size.) All flares I have found on the West
Coast are a dull gray, smooth one side, rough on the inside, not smooth
as
the sheet lay-up in a sail boat and smoother than the chopper gun used in
speedboats. Point is: will these adhesives that are specifically
engineered for "fiberglass" stick to this stuff. In any case, is the a
cleaner primer needed? I assume wax removers from any body shop are the
right stuff. Re-sellers of the flares all are ignorant of the material
and
adhesives.
You're probably right, most fiberglass uses a silicone based mold release
compound. It is hard to remove, They make specific cleaners and
recommend
use of the adhesion promter above. A long time body shop owner I know
recommends simple rubbing alcohol in quantities to remove the silicone.
Rub
on & off with 2 rags & get clean ones often. It will have to be clean to
adhere.
An easy check is to use some spray paint, see if it fish eyes, and then
sand
it back off.
> 4) The fiberglass had the advantage of "fill". One person used the word
"pack" in referring to the process, assuming some large gaps between the
poorly fitting flares, especially as they 'flared' away from the original
sheet metal's surface. Many adhesives have tremendous film strength but
no
strength in fill. Even fiberglass resin needs cloth. Do these adhesives
have that weakness, too? Is there a way to 'extend' the adhesive with a
filler (glass beads, etc) to use as filler. Gold may be cheaper is some
cases than the glue.
Follow Ed's recommendations of carefully sanding & fitting the flare to
avoid
space. I don't know about adding a filler - probably should refer to the
manufacturer.
It does say in the manual however that a different product is recommended
afterward to shape and fill low areas.
> 5) The leading edge of all 'glass flares have been irregular (Of course,
it
cannot be MY car.) Is a very precise fit needed with these and I sand it
down later, or is it a must for a line-line (curve-to-curve)fit first?
Fit it is recommended to fit closely within 1/8in. max, The epoxy has
enough body to fill small voids.
> 6) Convention wisdom is to use screws to hold the flares until adhesive
sets, then remove and lay on another sheet of fiberglass to fill holes
and
assist the flaring. I assume same here: pull the screws and fill with
body
filler.
You're right. the epoxy has a 30 - 45 min work time so you will need to
clamp
the pieces effectively, and screws are the best method for flares.
Thanks,
Jeff Brubaker
> If you can comment or clarify any of these topics, and add other info.
it
would be appreciated.
Mike Yates
myates@stdcom.com >>
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