Dow Corning Silicone vs Thermoplastic Polyurethane: A Buyer's FAQ on Grease, Sealants, and Rubber Handles

I'm a procurement manager at a small industrial maintenance company—about 25 people and roughly $110k a year in materials. I've been signing purchase orders for silicone, sealants, o-rings, and molded rubber handles for six years. When I first started, I assumed the lowest quote was the best quote. Two costly reorders later, I learned to compare total applied cost, not unit price.

This FAQ is for anyone trying to do the same with Dow Corning–related products. It covers DOW CORNING 795 silicone building sealant, silicone grease for packing o-rings, rubber handles, and the whole silicone vs thermoplastic polyurethane (TPU) decision.

Are 'Dow Corning' and 'DOW' the same thing?

Basically, yes. Dow Corning used to be a separate joint venture, and after Dow took full ownership the silicones products moved to the Dow brand. A lot of old stock still says 'Dow Corning', and the current products are often listed as DOWSIL. If someone tells you the formula changed because the label changed, that's a red flag—same product code, same chemistry, new sticker.

I might be misremembering the exact transition details. The practical takeaway is: don't get stuck on the name. Get the product datasheet, check the batch number, and buy from an authorized distributor.

Can I use Dow Corning silicone grease on every packing o-ring job?

I wish the answer were one word, but it's not. Silicone grease is my default for packing o-rings and assembling valves because it's neutral, chemically stable, and won't attack most elastomers. A thin film helps the o-ring seat without getting pinched, and that saves real time when you're building a box of fittings.

But 'most' is doing a lot of work. Some elastomers have specific compatibility requirements. I learned that the hard way when I skipped a compatibility check because 'we've used this grease forever.' The assembled part was rejected, and we had to redo the order. Now I read the o-ring manufacturer's compatibility chart before I order. Silicone grease is a lubricant, not a sealant—use a thin film, not a blob.

Why does my packing o-ring keep failing even after I use silicone grease?

Because grease can't fix a bad fit. In my experience, the root cause is usually a wrong cross-section, incorrect durometer, or an incompatible elastomer—not lack of lube. When I audited our 2023 maintenance log, I found that at least half of our seal replacements were avoidable. The o-ring looked pinched or split, but the real problem was a groove that was too shallow or a chemical the material couldn't handle.

So before you blame the grease, check the gland dimensions, the Shore A durometer, and the compatibility table for your fluid. A $2 o-ring can take down a $4,000 line if you guess wrong.

Is DOW CORNING 795 silicone building sealant right for every joint?

DOW CORNING 795 silicone building sealant is a one-part, neutral-cure sealant. Translation: it cures without the strong vinegar smell of standard caulk and stays flexible in moving joints. It's often used for weatherproofing around glass, metal, and masonry. If you're working on a facade joint, it belongs on your shortlist.

But if you're sealing a gap on a workbench or a corner in a storage room, it's overkill. You're paying for performance you don't need. And if you need adhesion to a specific plastic or coated surface, read Dow's technical datasheet and do a small test first. According to Dow's published literature, joint design and substrate compatibility matter as much as the sealant itself.

Is it worth paying for the Dow Corning brand name?

I'm not going to tell you to ignore brand. For critical building sealants and o-ring greases, a material with a long service history and published datasheet is worth a lot. Dow publishes test data, warranty information, and sourcing documentation. That paperwork matters when a job is specified by an engineer or when you need to prove compliance.

But for a non-critical application where a generic passes the test and saves money, I'll use the generic. My rule is: brand for critical, datasheet for everyday. The product code matters more than the sticker.

Silicone vs thermoplastic polyurethane (TPU): which is actually cheaper for a rubber handle?

This is the question that makes me open a spreadsheet. Per-pound resin cost is only the start. For a rubber handle, you also have tooling, cycle time, scrap rate, packaging, and field failure cost.

TPU generally has great tear, abrasion, and cut resistance. It's often easier to injection mold into a durable grip. Silicone handles heat and cold well, stays soft in cleaning chemicals, and gives a different grip feel. Neither is universally better.

Tooling note: multi-cavity molds change the math completely. Silicone parts often need different process control than TPU. If your molder only runs a thermoplastics press, they'll tend to steer you toward TPU. Ask for process-specific quotes, not just material options.

I had a project where we switched a tool handle from TPU to silicone because the handle sat near a heat source, and the failure rate dropped. I also had a part where silicone tore too easily—the test batch looked great, then the field says otherwise. Actually, the part also saw a lot of sunlight, and the UV resistance pushed us back to silicone in the end. Let the test decide.

Is silicone automatically more eco-friendly than TPU?

This one surprised me. I used to assume something called 'silicone' was more sustainable than 'plastic.' But eco-friendliness depends on raw materials, energy use, lifespan, and what happens at end of life. Silicone isn't compostable, and TPU has its own recycling tradeoffs.

If a supplier claims their handle or sealant is 'green', ask for the evidence. Per FTC Green Guides, environmental claims need to be substantiated. That's not a debate—it's a legal standard. A vague eco badge on a datasheet doesn't count.

For us, the greenest option is usually the one that lasts longest in the actual environment. A material that fails early is never sustainable.

What does durometer mean for silicone and TPU parts?

Durometer is a hardness reading, usually on the Shore A or Shore D scale per ASTM D2240. A 70A silicone is much softer and more flexible than a 70D TPU. You'll see this spec on o-ring kits and handle grips.

For a rubber handle, a softer durometer usually means more cushion and grip, but also more vulnerability to cutting. For a packing o-ring, a softer o-ring might seal better in low pressure, while a harder one resists extrusion in high pressure. Test, don't guess.

If a supplier quotes a 'premium' handle without giving the durometer, ask. It's one of those small details that separates a good quote from a painful one.

My order is small. Should I be treated like a real customer?

Yes—within reason. Small orders are normal because every project starts as a sample. A distributor who ignores a $250 order today probably won't see the $15,000 order next year. When I started out, the suppliers who took my small test orders seriously are the ones I still call.

That said, some manufacturers genuinely can't pack one tube on their automated line. That doesn't mean they hate you. It means you need a distributor that stocks small volumes. You'll pay more per unit, but you won't pay hidden handling fees if you ask the right questions upfront.

Ask about minimum order quantities and lead times before you send the PO. If a rep makes you feel small, move on. Today's small order is tomorrow's production run.