Dow-Corning FAQ: 111 Valve Lubricant, Electronics Silicones, and Coatings

I'm the office administrator for a 90-person manufacturing company. I manage all maintenance, PPE, and chemical ordering—roughly $250,000 a year across 12 vendors. I report to operations and finance, which means I get to hear about it when something doesn't perform.

When I took over purchasing in 2020, I learned the hard way that 'silicone' means a lot of things. This is the FAQ I wish someone had handed me. It was accurate as of early 2025; product lines change, so verify current names, data sheets, and approvals before you place a PO.

What is Dow Corning 111 Valve Lubricant and Sealant?

Dow Corning 111 is a non-curing silicone grease. I know—the name says 'sealant,' but it doesn't skin over or cure like a tube of bathroom silicone. It's made to lubricate and seal valves, O-rings, and rubber or plastic seals. It forms a viscous, water-resistant barrier that stays where you put it.

If you have pneumatic systems, manual valves, or process equipment with elastomer seals, 111 is one of those things you keep on the shelf. If your facility needs food-contact documentation, check the current technical datasheet for an NSF H1 or similar listing; don't rely on an old listing.

I went back and forth between the small tube and the one-pound jar for about a day. The jar is cheaper per ounce, but the tube is cleaner for a small crew. Depending on your team, the better buy is the one they'll actually use before it gets lost in the cabinet.

What are Dow Corning electronics products actually used for?

'Dow Corning electronics' in a distributor catalog usually means silicone materials for printed circuit boards, sensors, and power modules: conformal coatings, encapsulants, thermal interface materials, and adhesives. A thin conformal coating can protect a board from humidity and vibration. A potting compound can protect a sensor from shock and moisture.

Since I'm a buyer, not an engineer, I've learned to ask three questions. What is the material's viscosity? How long is the pot life? And what is the shelf life once the container is opened? Those three numbers decide whether the production team can actually use it. I've seen a $180 cartridge of conformal coating sit past its shelf life because nobody wrote a date on it. Wasteful. Now I put a received-on date on everything before it hits the shelf.

What should I know about basement coatings before buying a Dow-brand silicone coating?

This category is full of marketing. Most 'basement coatings' are moisture-barrier paints, but a true silicone masonry coating is different. It is usually vapor-permeable, so water vapor can escape while the surface still blocks liquid water. That can be useful below grade because it reduces the blistering you get with non-breathable paint.

If you have an old concrete basement, fix the obvious water problem first: gutters, downspouts, grading, sometimes footing drainage. A coating applied over a wet wall is a gamble. I'm not saying coatings don't work—they are part of a system. But if a salesman tells you one coat will cure a flooded basement, get a second opinion.

Which porcelain tile adhesive is best for outdoor use?

First, match 'outdoor' to the right standard. Look for a cement-based thin-set mortar rated for exterior use, ideally one that meets ANSI A118.4 for modified thin-set or A118.15 for the stronger polymer-modified type. Porcelain is dense and low-porosity, so you also need back-buttering to get good contact on the back of the tile.

Where does Dow Corning fit? Dow doesn't make the trowel-on thin-set mortar, so don't go looking in the silicone aisle for that. Where DOWSIL products enter the job is in the movement joints: a flexible, weather-resistant silicone joint sealant, often meeting ASTM C920. A perfect adhesive with rigid joints can still fail because the concrete slab expands and contracts.

How do you place sealants on teeth?

Carefully—by a dental professional, and only with a dental product. If you're Googling this because you bought a tube of 'silicone sealant' and wondered if it works on teeth, stop. Engineered silicone for valves, electronics, or basements is not for inside your mouth.

Dental sealants are resin-based or glass ionomer materials designed to bond to enamel. The procedure is: clean the tooth, isolate it, etch with a mild phosphoric acid gel, rinse and dry, apply the sealant, then cure or let it set. That summary comes from the dental/ADA world, not from my purchasing experience. If you are a patient, ask your dentist about sealants. If you are a dental professional, you already have the right product codes.

Can I use Dow Corning 111 as a regular silicone sealant?

No. This is the mistake I hear from almost every non-engineer (including me, once). Dow Corning 111 is a non-curing grease-type lubricant and sealant. Regular silicone sealant cures into a rubbery solid. 111 does not. If you use it to caulk a window or fill a wall crack, it will stay soft, catch dust, and probably fail.

What if the listing says 'sealant' in the name? Read the technical datasheet for cure type, temperature range, and recommended substrates. The word 'sealant' is used for maintenance greases and construction caulks; they are not the same. A maintenance tech was not happy when he realized the 'silicone sealant' I ordered for a panel gap was actually grease. That's on me.

Why does the brand say DOWSIL or Molykote instead of Dow Corning?

Dow Corning became part of Dow a while back—the formal change happened after 2016. A lot of products were renamed to DOWSIL for silicone materials and Molykote for lubricants. But old store listings and label photos still say Dow Corning, so people keep searching 'dow-corning.' That will probably continue for another decade.

What was best practice in 2020 may not apply in 2025. If you're an admin buyer like me, use the product family, exact code, and current data sheet instead of relying on the brand name alone. The fundamentals haven't changed: verify the data sheet, check shelf life, and keep a clear label on what you open.

Why does shelf life matter so much for silicone materials?

Because modern silicone products are formulated systems. A sealant or conformal coating contains crosslinkers, catalysts, fillers, and adhesion promoters. Those ingredients age, especially after the container is opened. If you use expired material, it may look fine in the cartridge but fail to cure, or cure poorly and fail.

In 2022, I found a cartridge of 'Dow Corning' sealant with no date. We used it to caulk a maintenance room. It never skinned over. I had to send a guy back out to scrape it off and redo the job. The material cost wasn't the problem—the labor was. Now I date everything when it arrives, and I tell the team to use the oldest stock first. That's basic inventory discipline, but it saves real money.