Cast Iron Bath Tub has rust and hole around drain

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stevesahni

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We have a cast iron tub in a bath room of a condominium located in a high rise building. The tub has rust around the drain and it seems some rust has resulted in a hole since water is leaking in the condo downstairs. Any suggestions how to fix the problem. Repalcing the tub is very expensive. The tub has been there for over 15 years. Do not know the condition of the drains underneath.

Thanks.

Steve
 
Welcome SteveSahni:
Typically a cast iron tub will show some rust but will not rust through. There may be enough rust to interfeir with the gasket on the drain causing the leak.
Of course, you will need access to the bottom of the tub. Take the drain loose, clean the bottom and inside of the tub with a wire brush, replace the gasket on the bottom and use some plumber's putty on the inside. You may need to replace any slip-joint gaskets at the same time.
Glenn
 
Dear Glenn,

Thanks for your input. Any chance we can do this from the top of the tub. If not we will have to cut the sheet rock underneath (lot of hassle) and then get underneath the drain. The top is easily accessible. Have attached a photo of the drain the way it looks now. Hope this helps.

Steve



Welcome SteveSahni:
Typically a cast iron tub will show some rust but will not rust through. There may be enough rust to interfeir with the gasket on the drain causing the leak.
Of course, you will need access to the bottom of the tub. Take the drain loose, clean the bottom and inside of the tub with a wire brush, replace the gasket on the bottom and use some plumber's putty on the inside. You may need to replace any slip-joint gaskets at the same time.
Glenn

drain1 328.jpg
 
that tub in the picture is not a cast iron tub. from the looks of it .its a steel tub. and that rust does not look good at all. take the waste and overflow off of the tub. and clean up that rust. take another picture and post it.
that tub might have to come out sorry......
 
If this tub has perferated through in the area where the rust is you might have a real problem. There isn't any way to easily repair such a hole.
One possibillity would be to remove the drain trim (the silver part that you can see) which will be a challenge in itself since the center bars are gone. This procedure involves a cold chisel and hammer alone! Then you must remove the bottom section of the drain from the tub which involves opening up the area beneath the tub for access. The next step is grinding away the rust on both sides of the drain and filling with automotive fiber reinforced fiberglass and smoothing out the surfaces on bith sides of drain opening to allow for the fitting of the rubber gasket and trim to the drain line. THEN priming and painting the tub with the proper finishes which takes a specialized service. THEN reconnecting all of the drain components back up and fixing the drywall surfaces. Hmmmmmmm. I think a new tub would be easier and less expensive in the long run. If you do find this tub is cast iron and are wanting to remove it for replacement, believe it or not you break them up with a sledge hammer and take em out in pieces. By covering them with plastic carpet protector first you can keep the flying glass shards down to almost zero. Good luck!
 
I had a similar problem in my steel tub. The tub itself around the drain was rusted all the way through. I took out the drain, broke off most of the really bad rust, and got some moldable steel putty. (Not sure of the name, but it came like a fat crayon, bought it at Ace hardware). It says you can use this stuff to repair engine parts! I formed this underneath the tub, pressing it tight against the existing opening and shaping it. After a few hours, it was solid as steel, and I just painted over it with some of that porcelain touchup paint and it looks good as new. I put back in a new drain with fresh rubber gasket and it works great. It's been a little over a year and still holding up, but I know there's still rust under there, as I can see a little bit of rust stain coming through the porcelain paint, but for now it's still strong. Had I known how good this steel putty was, I'd have done a better job removing the rust beforehand.
 
the rust is on the outside of the bathtub and pieces of the outside of the bathtub are falling off. any advise.
 
The name of it is called Fast Steel and you can get at Home Depot for under $3.00....I had this problem in a rental property recently, and did not want to spend the money in replacing the bathtub bc then i would have to replace the surround because i was paying for so much already....anyway, I used this stuff, and this worked superbly...thanks Tyler for the information...your description helped me find it and helped save me tons of money.
 
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Would Fast Steel or a similar steel putty work on a cast iron drain as well? My cast iron drain is showing signs of wear but has not yet rusted through - the porcelain is worn off. What would be the best way to seal the cast iron and prevent rust?
 
My tub looks the same way. I tried to clean the rust off with CLR, but the rust is deeper. How much do you think it would cost to have someone repair it for me?
Thanks for your help.
Shari
 
Yes, that is a steel tub in the pic. This repair is not recommended for a do-it-yourselfer. But, a good bathtub repair tech can repair that (but he has to be really good). We were refinishers/repairers for 25 years, and we fixed many tubs with that same problem, and the repairs lasted for many more years. You have to find someone who specializes in small tub repairs. Most refinishers do not specialize in this type of repair, and cannot do this repair properly.
 
So clearly the first thing I need to do is figure out what my tub is made of and how badly it's damaged. The rust stain looks similar to the picture, the house was built in 1979, and I suspect they used whatever materials were cheap and standard at the time. Would that be steel? How can you tell? I don't think the damage in my tub is quite as bad as that pictured, but how do I get a good diagnosis?
 
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To determine if a tub is steel, start with a magnet. If it sticks it is steel or cast iron. Then stand in the middle on one foot. Does it flex? If so, it is steel. You can also often see the bottom of the tub through an access door on the other side of the wall from the shower controls. Being of 1979 vintage it is almost certainly steel.
 
magnets! of course! So, first I confirm that it's steel, then I take out the drain cover and scrub the rust. Eventually, I should see clean steel. So, how do I determine what needs to be done next? If there are no holes all the way through, can I just resurface? Or do I need to fill in whatever has rusted away?

thanks for your quick response to the first diagnosis question
 
I know you didn’t want to replace the tub because of the expense. Have you checked www.craigslist.com or www.freecycle.com for used tubs. Even a repair will still not last as long as a tub that doesn’t have this problem to start with. The repair may be more practical in your situation but this might be another option.
 
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I have the same problem with one of my tubs in a rental. In fact, the picture is nearly identical to mine right down to the lack of a cross bar in the plug. I was thinking of using the Miracle Method but after a visit by their technician, I don't feel confident. Has anyone used this method?
Thanks.
 
if your gut's warning you off, trust it. My parents got their sink "refinished" with some sort of coating, and they can't set the soap bottle on the sink edge anymore. It's too fragile
 
I have decided not to try the professional refinishing method for now. The local hardware store recommended a rust converter.
 
I read this thread from beginning to end and i think people needs to know few things about professional refinishing.

Bathtub refinishing is not for everybody...
if you have few thousands of dollars available and few days available, you definitely should choose to replace the damaged tub (no questions about that). there's nothing like new tub & tiles & plumbing.

Bathtub refinishing solution exists to help people that has a damaged tub but don't have the money or the time to demolish and replace the tub & tiles.
Bathtub refinishing (when it's done right) is a great solution to extend the life of your fixtures.

Bathtub reglazing finish is not bullet proof!!!​

Professional coating for tubs is basically a polymer that was designed to strongly adhere to the surface (after a proper prep) and it is high gloss and has certain impact resistancy. the finish is designed for impact of human body and light solid (shampoo bottles soaps etc.)
BTW, heavy shampoo bottle dropped on a tub from high can chip a real porcelain tub !!!!! so there's no reason that the refinishing finish would be different.
Reglazing should be applied ONLY by HVLP spray system. that's the only way to get smooth finish. beware of refinishes that offers brush or roller application. it might be strong enough but it doesn't look good.

In order to keep the finish integrity , refinished bathtub should be maintained like a standard acrylic tub.No abrasives , no acids , and no scrubbing pads can be used - only mild cleaners and a sponge.

NOTE: most people dont know that , but if you clean an acrylic tub with abrasive pad or abrasive cleaner you void your warranty.
so its the same with bathtub refinishing.

its very easy to maintain , and if you used a company that preps the tub right and use a good quality coating, you can have your tub in good condition for the next 5-10 years.


in case of such a rust on the drain:
the easy and expensive solution is to replace everything of course.
But you can get it repaired by a refinishing pro that should do the following:
1. clean the surface and degrease it
2. grind the rust completely with rotary tools
3. etch the surface using hydrofluoric acid
4. sand and clean again.
5. fill and even the surface with water resistant filler.
6. re-glaze the tub with professional coating.

Bathtub refinishing is a great solution to give face lift for a bathroom, while minimizing the costs. the results are amazing when it's done by a professional.
I personally have hundreds of happy customers with almost no complains.

I'll be happy to answer any questions about bathtub refinishing.
I'm not from the states, but my coating supplier is American and it's almost the same kind of market here in Canada.

i hope it was helpful.
 
All-

I have the same problem. There is a rust around the drain controller on the top. It has rust and I think when I filled my bathtub it leaked to downstairs aparment. Only time I fill the tub it leaked. I have put a tape around it and it is temporarily fixed. I do not know what to do. I do not have money to replace the tub and I was thinking if reglazing would fix my problem. All people I call for estimate and ask if it would fix my problem; noone gives me answer. they say yes but it seems like they jsut want the job and are saying yes. I want to know if Reglazing would fix my problem. I am new to this and even answers above- I am not able to comprehend. Any recommendation in Norther nj area. Please please help. It is 15 yr or more old tub.
 

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