Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 3 of 3

Thread: Replastering - Strange "Rust Like" Spots on Gunite But No Rebar Anywhere Around

  1. Back To Top    #1

    Join Date
    Apr 2016
    Location
    San Jose, CA
    Posts
    2

    Replastering - Strange "Rust Like" Spots on Gunite But No Rebar Anywhere Around

    Hello, new member here. I have what may be a problem in my pool and I could use some help in understanding it. I bought a house 5 years ago with an IG gunite pool and I have done my best to maintain it and keep the water chemistry in balance. With the plaster starting to get rough and a few small spots of plaster starting to flake I decide to get the pool replastered. When the plaster was removed I discovered some "rust like" blotches on the surface of the gunite. I chipped away a small section of the gunite but could not find any rebar. When I could find some rebar it was nearly a foot away from the spot and buried in gunite with no sign of rust. There are several of these spots on the surface of the gunite in my pool. If these are rust stains I do not know what cause them. Any ideas? I have attached a picture of one example, before I started chipping away at it.

    Thanks
    Attached Images Attached Images
    My Pool; 15 x 34' IG Gunite Modified Kidney, 18K, Hayward Cartridge Filter Hayward, Pentair Controls and IntelliFlow Pump. San Jose, CA.

  2. Back To Top    #2
    Mod Squad YippeeSkippy's Avatar
    Join Date
    Jan 2012
    Location
    'burbs of Augusta, Georgia
    Posts
    6,470

    Re: Replastering - Strange "Rust Like" Spots on Gunite But No Rebar Anywhere Around

    Any chance of metal shavings having fallen in the pool in the past?

    Just for grins and giggles, ask your local pool store to test for metals.

    It sure looks like rust to me. Try holding some crushed Vit C tablets to the stain and see if that alters it some? Conversely if it doesn't, try a chlorine puck.
    My Amazon Smile for November12K Fiberglass IG, Infinity 4000 automatic cover, SWCG, Hayward Sand Filter, Hayward 1.5 Pump, Doheny Discovery Robot, Savi Melody LED pool lights, outdoor speakers and other assorted doo-dads. Sundance Altamar Hot Tub.
    Our pool build--> Our Pool Solved Our Sloping Yard Skippy's Cheap Pool Cooler -->Skippy's New Fountain

  3. Back To Top    #3

    Join Date
    Apr 2016
    Location
    San Jose, CA
    Posts
    2

    Re: Replastering - Strange "Rust Like" Spots on Gunite But No Rebar Anywhere Around

    I tested the spots for metal and it turned out that they are rust. I am assuming when the previous owners last had it replastered the crew somehow left metal debris on the gunite surface and then applied the plaster over it.
    Thanks YippeeSkippy for your help.
    My Pool; 15 x 34' IG Gunite Modified Kidney, 18K, Hayward Cartridge Filter Hayward, Pentair Controls and IntelliFlow Pump. San Jose, CA.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •