Best OverallGorilla
Gorilla Super Glue Gel
- Gel formula, no-run on vertical surfaces
- 45-second handling time
PEPermatex
Permatex
Permatex 81781 Black Silicone Adhesive Sealant
- RTV silicone
- Bonds silicone rubber
- Temperature resistant -65F to 400F
- Waterproof
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On this page
Is the Permatex 81781 Black Silicone Adhesive Sealant worth it?
Yes, for the right buyer. The Permatex 81781 Black Silicone Adhesive Sealant ranks #8 in our Best Adhesive for Rubber to Rubber 2026 list (best for silicone). Its biggest strength: rTV silicone is the only adhesive type that bonds silicone rubber reliably. The main caveat: does not bond EPDM, neoprene, or natural rubber as well as contact cements.
Overview
What the Permatex 81781 Black Silicone Adhesive Sealant does well
Required for silicone rubber bonding. It stands out for rTV silicone is the only adhesive type that bonds silicone rubber reliably and temperature range -65F to 400F - suitable for automotive and industrial silicone seals. One caveat, does not bond EPDM, neoprene, or natural rubber as well as contact cements.
Specs that matter
Key features
- RTV silicone
- Bonds silicone rubber
- Temperature resistant -65F to 400F
- Waterproof
The trade-offs
Pros & cons
Pros
- RTV silicone is the only adhesive type that bonds silicone rubber reliably
- Temperature range -65F to 400F - suitable for automotive and industrial silicone seals
- Permatex is the OEM standard for automotive gaskets and seals
Cons
- Does not bond EPDM, neoprene, or natural rubber as well as contact cements
- Acetic acid cure - slight vinegar odor during curing
Fit check
Should you buy the Permatex 81781 Black Silicone Adhesive Sealant?
Buy it if you're…
- Shopping for rubber to rubber 2026
Think twice if this matters to you
- Does not bond EPDM, neoprene, or natural rubber as well as contact cements
- Acetic acid cure - slight vinegar odor during curing
Where it ranks
Featured in 1 best-of list
| List | Rank |
|---|---|
| Best Adhesive for Rubber to Rubber 2026· Best For Silicone | #8 / 10 |
Cross-shop
Alternatives to the Permatex 81781 Black Silicone Adhesive Sealant
Products ranked near it in our research, each better for a slightly different buyer.
Buying advice: adhesives
- Porous materials like wood, paper and fabric bond well with water-based glues. Non-porous ones like metal, glass and most plastics need epoxy, cyanoacrylate or a polyurethane adhesive. Polyethylene and polypropylene resist almost everything, so check the label lists them.
- Thin glues need parts that meet closely. If the joint is loose or the surfaces are uneven, epoxy or polyurethane glue fills the gap and still holds.
- Fast-setting glue is convenient for small fixes but leaves no time to adjust a big assembly. For furniture and glue-ups, a longer open time is worth more than speed.
- Standard PVA softens with moisture. For outdoor projects, cutting boards or anything washed often, look for a water-resistant (Type II) or waterproof (Type I) rating, or use epoxy.
- Once opened, super glue and some epoxies thicken within months. Smaller bottles that you finish quickly often work out cheaper than a big one that goes off.
Answers
Permatex 81781 Black Silicone Adhesive Sealant: common questions
Is the Permatex 81781 Black Silicone Adhesive Sealant worth buying?
Yes, for the right buyer. The Permatex 81781 Black Silicone Adhesive Sealant ranks #8 in our Best Adhesive for Rubber to Rubber 2026 list (best for silicone). Its biggest strength: rTV silicone is the only adhesive type that bonds silicone rubber reliably. The main caveat: does not bond EPDM, neoprene, or natural rubber as well as contact cements.
Who is the Permatex 81781 Black Silicone Adhesive Sealant best for?
Based on our research it suits rubber to rubber 2026. It's ranked #8 of 10 in our Best Adhesive for Rubber to Rubber 2026 list.
What are the downsides of the Permatex 81781 Black Silicone Adhesive Sealant?
The main trade-offs owners and reviewers point to: does not bond EPDM, neoprene, or natural rubber as well as contact cements; acetic acid cure - slight vinegar odor during curing.
What are the key features of the Permatex 81781 Black Silicone Adhesive Sealant?
RTV silicone, Bonds silicone rubber, Temperature resistant -65F to 400F and Waterproof.
What are the best alternatives to the Permatex 81781 Black Silicone Adhesive Sealant?
Worth comparing: Gorilla Super Glue Gel, Shoe Goo Adhesive and Sealant and Amazing Goop Contact Adhesive Sealant. Each ranks near it in our research for a slightly different buyer.
Where can I buy the Permatex 81781 Black Silicone Adhesive Sealant?
It's sold on Amazon. Prices and stock change often, so check the current listing before you buy, our link takes you straight to it.