Plaster Corruption?

memebop · Postby **memebop** » Thu 03 Dec, 2009 21:40

I have an older pool which developed a bleeding rust spot on the bottom.

I emptied the pool and sanded and grinded down into the area. I coated it with fiberglass and plastered the spot. Filled the pool and within weeks it bled again. I'm guessing the rebar in the pool bottom is corrupted.

It hasn't expanded much but looks bad.

Can this be fixed by a pro??? How difficult is it?

I'm thinking big kitty litter box if things don't work out.

Bob in Forestville, Calif.

alangmyerson · Postby **alangmyerson** » Fri 04 Dec, 2009 01:11

Once the rebar begins to rust, it expands and is difficult to contain. The section of rebar should be cut out and the hole should be filled with anchoring cement.

Guest · Postby **Guest** » Fri 04 Dec, 2009 02:38

It hasn't expanded much but looks bad.

Once the rebar begins to rust, it expands and is difficult to contain.

Sometimes a high-strength structural repair mortar can keep the bleeding and expansion under control, otherwise alan's suggestion is a certain solution.

Postby **czechmate** » Fri 04 Dec, 2009 09:42

There is pretty much no question that source of rebar rust has to be at least exposed to examine the options.
It may be just a tie wire that was left vertical and got to close to the surface with the plaster loss in years.
In the case of worse scenario, with cutting out of piece of rebar, you may consider exposing larger area to the depth needed to apply coat of Bond Kote and selected piece of mosaic to cover the affected area.
It will help you to minimize the spot where different color of new plaster will be too obvious.

There is very nice selection of mosaics available and you will have a new and better conversation piece than plain repair spot on the bottom. Further, there is much lesser chance that remnants of rust in plaster will go through this covering.

Honestly, this is what I would do if I did not want to re-plaster the whole pool.

Gavin Wills · Postby **Gavin Wills** » Sat 05 Dec, 2009 03:27

Hey there memebop, There is only one way to do a permanent repair to a rusting bar.You have to cut it out, back far enough in both directions until you find it @ min 2" cover and nice and clean, then epoxy coat each end with epirez 633 or similar, no bondcoat / bondcrete junk it ends up like it was when you opened the can white goo these products are not for permanent emersion and will fail. While you have the epirez mixed paint it on the section you cut out an you can fill it with 2+1 Sand and cement,but leave it down about 1/4" from the top.
Next,with the diamond saw you cut out the steel reo with,cut approx. 1/4" into the surface the shape of a fish,
with a small jackhammer gently remove the pool surface 1/4" then glue in some nice coloured glass mosaics.
STOP! I think it would be better to cut out your fish before you epirez the steel reo that way if you take out to
much of the surface with the little jackhammer you can coat the whole area with the epirez and rebuild it up to the right hight to make the tiles flush with the surrounding area. You get the epirez from engineers supply shops,it might be called another name in your country but it will still be an epoxy mortar binder for joining new concrete to old concrete. The join is a 95mpa join, more than 2x stronger than the surrounding concrete it will
never crack at the join if the concrete is going to crack it has to do it some where else.you wont be topping up your fish with concrete. this was a short story of how good your repair will end up.Dont forget you put the sand/cement mix on while the epoxy is wet. Regards Gavin Wills from Australia 36 years experience in Pool
construction / renovations + last 10 years only the big 50m olympic Jobs

Ausie · Postby **Ausie** » Sat 05 Dec, 2009 09:10

Diamond saw is used for a tile, mate.
Not for a rebar. :roll:

This guy is in California!!

Guest · Postby **Guest** » Sat 05 Dec, 2009 11:17

Thanks for the input Gavin

Diamond saw blades for circular saws and angle grinders can be used to cut rebar. The diamond blades for tile and masonry are different.

I googled epirez and it appears to be a brand of specialised mortars and epoxies. I didn't read up on the specifics yet.

Ray

Guest · Postby **Guest** » Sat 05 Dec, 2009 14:38

Pool User wrote:Thanks for the input Gavin

Diamond saw blades for circular saws and angle grinders can be used to cut rebar. The diamond blades for tile and masonry are different.

I googled epirez and it appears to be a brand of specialised mortars and epoxies. I didn't read up on the specifics yet.

Ray

Apparently you never used them.
Diamond saw will not cut through rebar, at 6000rpm it won't even cut your finger.
Not even premium hacksaw blade will.
Rebar is a hardened steel. It is commonly cut with metal abrasion disk or side grinder disk.
Good diamond blade cost around 80 dollars, metal cutting disk about 12.00.
But believe what you googled up. It is a free country. :wink:

Postby **czechmate** » Mon 07 Dec, 2009 07:07

It is funny, how the subjective opinion can get in the way.
Sure, diamond blade will cut steel also, but for a single rebar cutout who will ruin a 100 bucks blade?
All is needed to chip enough concrete around the bar to cut it with a thin wheel metal cutting blade for a side grinder. It is quick, efficient and cheap. Blade is about 4 bucks.
Harbor Freight store if in the area, has the best price.

Gavin Wills · Postby **Gavin Wills** » Tue 08 Dec, 2009 18:28

Sorry asie, you don't known do you,Lesson # 1 you think when I diamond core drill to put new bigger 100mm
FWR lines through the walls of olympic pools I miss the steel NO! do you think when i core drill to put any fittings in any concrete you can miss the steel NO! starterblocks backstroke and false start markers, do you know how many holes you core drill renovating a 40 year old olympic 10 laner NO! well Last month when I drilled 26x 50mm x 150 deep core holes every one of them cut through the 12mm reo.So diamond saw blades do cut steel very well.And yes they are used to cut tiles,but our tile blades are continuous rim blades not segmented that we use to cut out reo. You you have any other problems let me know GW from Australia

Gavin Wills · Postby **Gavin Wills** » Tue 08 Dec, 2009 18:41

Mr Pool User the 30' long 1/2" reo we use in Australia is annealed / softened you can bend a 2' length around your knee. how else would you be able to bend it around a pool with tight curves.toughend steel bs GW from Australia.

Postby **czechmate** » Tue 08 Dec, 2009 19:17

Gavin Wills wrote:Mr Pool User the 30' long 1/2" reo we use in Australia is annealed / softened you can bend a 2' length around your knee. how else would you be able to bend it around a pool with tight curves.toughend steel bs GW from Australia.

Mr.Wills, with all the respect to your extensive experience in pool building, we do not import your Australian rebar to build our pools here, in the US.
Quite on the contrary, we use the rebar made here.
It is the same as the rebar we use in commercial buildings for floors, walls columns, highway roads etc.
Also, around here we use hand tools to bend this hardened steel. Works like a charm and you can use it with a bare knees and shorts in the hot summer!
It is called the "hickey". Comes with a rigid pipe handle, about 4 1/2feet long and is used by electricians to make a sweep bends on their rigid pipe.
Therefore it comes in different sizes to fit on different O.D. pipe.
You see, the only thing we bend around our knees is maybe a little kid once a while.
Knees are complicated things, as you well know and designed for different purpose than bending steel for living.
So Mr. Wills, you are certainly quite welcome to open to us your well of wisdom.
Just take in consideration where the particular question is coming from.
Otherwise you may be just waisting your time, or worse, putting yourself in light you might not much appreciate later.

patricks pools · Postby **patricks pools** » Wed 09 Dec, 2009 14:14

Just to clear something up here....I have cut rebar inside a gunite pool with both a diamond core drill bit and also with a diamond blade on a gas saw. It takes a while and a lot of water but it does work.

Postby **czechmate** » Wed 09 Dec, 2009 16:55

Core bits are designed for reinforced concrete. The rig provides cooling and removes slush with continuos stream of fresh water. Diamond blades as known in construction industry, are designed for concrete, stone and ceramics. Abrasive disks designed for cutting metals do not have any diamond properties in general at all.
I have used both for last 40 years. Some core bits in 6" O.D. for electrical service conduits through the building foundation.

Gavin Wills · Postby **Gavin Wills** » Sat 12 Dec, 2009 17:28

$100 4'' diamond blades, I wouldn't use one to cut reo if they cost that much either, I do remember that in 1980 I bought my first db for $25 and i thought that was a ripoff but when it just kept cutting and cutting, bargain.
Today we can buy 100mm blades for $15/$20 that can cut about the same 15/20 12mm deformed bar.Talking about cutting steel with diamond blades.Most renovations on the old big pools we cut of the tops to concrete in a wet deck gutter. we use wet 450mm quickcuts,like a chainsaw,to cut 100 lineal metres,with one blade we cut through 12mm reo every 200mm, so that is alot of reo but those blades cost $350. regards GW