Rust repair/Fun with Napa Products!

["David A. Leonard" <dleonar1@xxxxxxxxxxxx>]

The Mission:

Banish the heavy rust from the leading edge of my  88 735i hood..rusted
through from the inner seam..bubbles and uglyness too long ignored!

Bill of materials:

Napa Polyurethane 2 part structural adhesive!  (this stuff rules)

Napa / Martin Senior " Stone Guard Spray, P/N 4004 ( Black ) Clear is 4003
(This stuff rocks)

Random orbit sander

Cheese grater surform file

Big Boxes of various sandpapers.

Hitachi 4" disc grinder and wire brush

Fine line tape(plastic masking tape)

Self etching primer  (that etch thing is important..Mitch   said..and he
knows whats up!  So I got it.( He has a very hot wife too!)

Some various sheetmetal strips, and some aviation tin snips.

Chopped strand fiberglass polyester body filler ..(We call this stuff ''
Tiger Hair")

Some plastic spreaders.

Grind the s**t out of the leading edge of the hood..oh f**k I hope it works
like I plan cause I just ground out about 2" x 1' of hood on one side, and
4" x 2" on the other side..were talking RAW here..sharp, like missing
leading edge....looks terminal!

It is very important to get all the rust you can off..you want to see shiny
metal or the rust she come back(this is impossible with seams).

Grind the back of remaining leading edge, cut long strips of sheetmetal left
over from Suburban project ( POS needs a SECOND new heater core..changed
that thing once..  two years ago.. Projects don't seem to end round here)

Cut Sheetmetal filler strips to fit..boy this is a LONG filler!

Wipe sheetmetal repair strips  with laquer thinner, sand, prime, paint,
grind off paint on surface to be glued..

Spread Urethane on sheetmetal, back of leading edge, get contour/curve just
right,  glue, clamp, heat gun (cold here in Maine in February).  This stuff
kicks in about 1/2 hour with heat..make sure to silicone the back of your C
clamp back-up wood blocks or you will have a Bimmer with hardwood blocks
hanging out of it!

Fill with Tiger, heat gun,   cheese grate, fill sand,Heat gun (I'm NOT a
patient person!!) grate, fill sand..grate f**k me... its been all day..wife
is pissed..all yesterday too...  fill sand,   go get RO sander from
basement..what an Idot ..shouda done this two hours ago! Build up leading
edge, use long surform file to re-establish contour/shape, using existing
body as a guide..(It ain't rocket science)  If you catch the filler at
exactly the right stage, it grates off well right before final set-up..can
save a lot of sanding this way.

Sand,  use a little spot putty, sand it all back off mostly.


Mask off front 2-3 " of hood with fine line tape..very carefully straight
even,  mask bottom half of Roundel,  scuff sand with 220 grit, few coats of
primer (heat gun to dry) then three coats of black textured stone guard.
 Sand off runs in first coat..stuff is runny when its 30 degrees)

Make sure to paint /undercoat the back of the repair too, and seal against
water as much as you can.

AWESOME repair..straight, no need to have the hood repainted, though it came
out well enough that
having the hood sprayed at a shop would have been worth it if I cared..I
opted for Blacked out leading edge protector/bra/ kind of look.

You can do good bodywork rust repair at home..the Urethane Panel glues are a
new wrinkle..welding warps, heats, and creates a bigger project..I've used
more than enough pop rivets in my life, and if you take rust repairs to the
body shop most of the time they will just grind and fill..looks great for a
while, but expensive and not as nice as a DIY job, and the rust will return
much sooner, as its not their car.

Anyway, after 25 years or so of doing "Hoser Body work"  The stuff seems to
be coming out awfully well.  (Can you say "Bondo Buggy")

Dave Leonard
The rust is vanquished, for a while, and it feels SOOO good!

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