Hi,
I'm a big believer in fiberglass, the flexible marine grade, is low cost and
good stuff. I can get it for $5 a quart from the Navy MWR marina. I use
the mat with it instead of the cloth, as one layer is a lot thicker and
stronger, although on outside body panels I use the cloth. I did repairs
this way years ago, and they lasted for years. For outside
panels I dent in the affected area, grind out the loose rust, and fiberglass
it, then use a thin layer of bondo on top, as its way easier to sand and
shape. The fiberglass gets you a strong water impervious shield, and
the bondo makes it easy to get a smooth finish. I'm doing my 67 this way,
and when I'm done I plan on spraying the other side of the repaired surface
with spray undercoat where I can reach it. Spray grease is also good, like to
get the inside of the "rusty roadster rocker panels" I figure on squirting
the stuff in through the screw holes that attach the door sill trim. Here are
a few key points:
-use several layers of cloth where needed, avoid just glopping on the resin,
as it can crack. Resin with cloth is like concrete with re-bar, really
strong, but
without it, well, don't fly over R/R tracks
-follow the resin to hardener formula exactly, many folks are tempted to put
in
a little extra hardener to ensure set up. This gives you brittle
fiberglass. Too
little gives you the most horrible un-hardening mess you ever saw...don't ask
how I know this to be true. I ensure set up by keeping things warm for a
few hours by shining my 300 watt shop lamps on the area. Worked great
this last weekend in 55 degree temps. Surface was about 80 degrees.
-Use in well ventilated space, plan on throwing away the paint brushes and
mixing bowls afterwards, and when you sand the stuff wear a mask.
I just got a scanner, and when my project pictures get developed I can send
you some samples of my work if you would like, probably later this week.
My last ship was a Navy Coastal Minehunter, all hand laid fiberglass.
I saw one of these ships do a very poor dock approach, instead of denting
like a steel ship, it both smashed out a section of the concrete pier, and the
ship flexed inward and popped back out. End result was scuffed paint on
the ship and probably about 10 thousand dollars to repair the pier.
My car is not very rusty, except for the forward part of the floorboards,
but it does have about 32 years of small dents, most filled with crappy
cracked bondo, that I'm grinding out and re-fixing as described
above.
Good Luck,
Jim
67 1600
Chesapeake Va
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