Darkroom sink drain leaking - what to use?

[DREW WILEY]

Terminology actual varies even in different parts of this country, awty, as well as specific product selection; so do plumbing codes and their degree of enforcement. My own darkroom sink is made of heat-welded polypropylene. None of the above stick to that. How would you handle that kind of drain hookup?

 

[TheFlyingCamera]

There is silicone, and there is silicone. With much of it, of the hardware store variety, "S" stands for s .. t. But if anyone thinks silicone can't fail, they don't begin to understand the topic. One problem with silicone is that it doesn't get along with certain substrates over time, so will fail in that repect unless correct surface preparation is done first. Another problem is that it leaves a residue which must be thoroughly scoured off if you want to use something else later. Where silicone does tend to last in a plumbing aspect is when it acts merely like a gasket, permanently squeezed inside a fitting. Argue if you must; but I sold over a million dollars of tube sealant per year for all kinds of applications, including marine, industrial, and military. Many of them were pro products not found in home centers.

Don't buy anything called "siliconized acrylic". In caulking tube style, it's fairly easy to find GE Bathroom grade 100% silicone. Check the expiration date; it matters. Let it fully cure before use. There are also siliconized plumber's putties more durable than the common variety. Go to a true plumbing supply house and see what they have.

Now as per plumbing epoxy putties. That's the nuclear solution. Unless these crack through embrittlement and joint movement, their problem is that they're hell to remove it you have to do that. I personally keep on hand a variety of darkroom maintenance sealants; but some of them are specialized and not commonly encountered.

I'm using it as an ersatz gasket. If I need to remove it and it gets beyond stubborn, the parts of the drain pipe I applied it to are cheap vinyl/pvc pipes so it's not going to be an emotional or financial burden to replace them.

 

[DREW WILEY]

Well, at the time I put my sink room all together, there was a true industrial plastic pipe supplier right across the street from the business where I worked. They had everything it seems - all the way from medical micro-pipette tubing to solvent-resistant drainage pipe up to eight feet in diameter. If one of the refineries needed a $4000 pure teflon ball valve, they had it in stock. So my personal needs were pretty easy to solve there; and being business neighbors, it didn't cost me much either. I sent industrial customers there, for what they offered; and they sent customers to us for what we stocked, back when we had out own industrial sales division. Most of the classic "heavy industry" involving large volumes of "hot"solvents has since moved closer to the refineries further up the Bay, while big Biotech and Pharmaceutical plants have moved in, bringing their own effluent and environmental nasties, but at least less flammable ones.