cement laundry sink leaks at drain

[Nate Nagel]

Hi again,

after this weekend's floor stripping extravaganza, I have an ugly but eat-off-it clean cement floor in my laundry room, which makes me happy. As a result of this, I think I've determined where the musty smell was coming from - it's not the washing machine as SWMBO suspected (I think she just wants an excuse to buy a new one, not that I'd need one if she really wanted it) but from the drain of the deep sink. Due to the slope of the slab, it was all running under the tiles to the corner under the washing machine, thus incriminating the innocent appliance.

Upon investigation it appears that this cement deep sink, which is absolutely huge, heavy, and otherwise in good condition, has a leak around the drain assembly, which appears to be a piece of steel cast into the sink, and the water is apparently running down the outside of the drain assembly and dripping off the P-trap.

My plan, which is the best I could improvise on short notice, is to chuck up a knotted wire wheel in my 4" grinder, knock off most of the rust, prep with phosphoric acid, and smear some roofing tar around the offending area, possibly including some scraps of screen for reinforcement. Good plan? Bad plan?

I really don't want to replace this sink as it's enormous and quite handy, and like most other ancient, huge, useful things probably impossible to find a direct replacement.

I'd appreciate opinions and any experience as the faucet is leaking as well, and rather than buy a new faucet for this sink (it clamps on the edge of the sink and attaches to the water lines with unions from above, quite unlike the faucets you'd use with a new sink) if the sink is hopeless I may as well bite it and buy a new, modern sink and faucet to match all at once.

thanks,

nate

[Speedy Jim]

The faucet is a common hardware store item: Central Brass # 465

Clean the drain as you plan (use protective gear and eyewear!), but I'm thinking epoxy applied with a small, stiff brush.

An alternate might be silicone sealant.

Dry the area thoroughly first with a hair dryer or even a (small) propane torch.

Jim

[Nate Nagel]

Actually mine looks more like this one:

but the actual spout comes out the underside of the faucet not the top (no big deal.) Your suggestion would require replumbing (extending the pipes) but would probably provide for a more stable installation... anyway my point was not that I'm having a hard time finding a replacement faucet but that it would be pointless to rebuild or replace my existing faucet (I'm leaning toward "replace" simply because the clamp screws appear to be rusted solid, and drilling/tapping all those holes looks like a PITA) if I'm going to end up replacing the deep sink shortly anyways.

Hmm, maybe POR-15?

That was my original thought, but then I thought Permatex No. 2 would probably work better, which eventually led me to the roofing tar idea.

Check. Propane torch at the ready, I'd already thought of that.

nate

[hallerb]

e quoted text -

a new fiberglass tub is low cost, and nice.

break up the old tub in location, i buried the remants in my yard.

I found the drain pipe rusted thru, withn no easy fix.

it broke off in my hand

[Nate Nagel]

quoted text -

I am not entirely nuts about replacing this sink with a new 'glass one... it's bigger than anything I've seen at my local Big Box; it's heavy (read stable,) and also the plumbing coming down from above is preferable in my opinion (allows plumbing to drain completely if required as the spigot is the low spot.)

I just got a brainwave - how 'bout if I have the same problem as you, I simply take a plastic kitchen sink strainer, bust out the center of it, and attach it to the underside of the sink (after grinding the old steel piece flush to the underside of the sink and smoothing the area) with construction adhesive or similar? The only downside to this is that a standard sink strainer is about 4-1/2" and the steel piece is about 6" wide so I'd have to improvise a plate of something in between.

nate

[beecrofter]

You can probably run new fittings through the concrete and use hydraulic cement to imbed them in the original concrete. A bit of a chore to do but worth the effort. Around here "Rockite" was a brand that worked for such tasks.

[Nate Nagel]

forgot to mention, it's a double sink but the drains are connected within the concrete to a single tailpiece. I'd have to core drill both sides to do as you suggest, and I'm not sure that I have enough room to bring two p-traps together and hook up to the exiting drain stack (tees out of the stack above the slab) but thanks for the idea, it is something to think about if all else fails.

nate

[Joe]

Get it clean, dry and warm and patch it with Bondo. Remember to work fast. And the stuff really is waterproof, ya know.

Joe

[Jmox34x]

Can’t get the pipe to tighten back onto this, bought a new one metal and plastic

[Marilyn Manson]

The image from the top appears to show that the drain doesn't sit tight on the sink. Is that the case? Is the whole drain and threaded portion loose?

If so, can it be removed and replaced with all new parts? I can't tell the condition of the sink itself. Would a new drain, with properly applied plumber's putter, even seal properly?

*If* the only problem you are having is threading on the new drain pipe under the sink, a Fernco connector might help with that. Fernco makes a number of different shapes and sizes and they work great for drains since there isn't a lot of pressure.

FWIW, years ago I replaced my beat up concrete sink with a fiberglass unit and never looked back. They come in Polypropylene also but I think that fiberglass would be more rugged.

[trader_4]

Agree, either a new drain assembly or a new sink. Given the state of what we can see, the latter sounds like the better idea.

[Marilyn Manson]

I had the "advantage" of a concrete sink that had a small crack across the bottom that was beginning to seep. I could barely call it a leak, but it sure wasn't going to get any better, so the replacement decision was a no brainer.

Fun fact: If you tip an already weakened concrete sink so that it falls forward onto a concrete slab, it turns into pieces that are a lot easier to carry. ;-)