Message text written by "BP - Dwell time 5 minutes."
>oride or calcium hardened drips; exposing
the rusted rebar on both corners. M y plan is to expose as much of the
rebar
as possible ; grind it and paint it(rustoleum) and then patch to match the
orginal....then clean the entire portico...what can you recomend  for me
..I
have samples..but basically its a buff limestone; that is slightly warm in
color and very fine grained. I start next week ..<

Hi Mike
I think you mistakenly posted to the list instead of direct e-mail.
The prep is the critical step, of course. ICRI guideline 03730 calls for
removal of concrete all the way around any delaminated rebar, or even
bonded bar if more than 1/3 of the diameter is exposed. You have to get far
enough behind the bar, even if it means removing good concrete,to be able
to wrap your hand around it (min. 1/2" clearance. If the bar is severely
scaled, and has lost significant cross-section to corrosion, a new section
should be spliced in.

I'm not a big advocate of epoxy coating partial lengths of exposed rebar in
repair,though epoxy is great for new rebar. There has been some contention
that having part of the bar uncoated and part coated sets up a little
battery that corrodes the steel faster.as different sections of the steel
are in very different chemical surroundings. I suggest a latex-modified
silica fume/cement coating (ours is SYSTEM 49 CPBA) which simply restores
an alkaline passivation layer and sets up the steel for good patch
adhesion. Then go ahead and use one of our limestone patches for aesthetic
reprofiling. Our standard buff Indiana limestone color is #102-HB, but
limestone weathers very differently in different places, so we have at
least 2 or 3 dozen other shades, about 8 or 9 in stock. 

Recommended: FedEx us a sample, but it's your call.

Mike Edison