Silicone sealants in the sources
Where to buy| Product | Cure | Specification stated | Service range |
|---|---|---|---|
| DOWSIL 732 (Dow) | Acetic cure RTV, one part | MIL-A-46106 Type I (distributor) | About -60 to 180 C, peaks to 205 C (distributors) |
| RTV3145 type (Dow) | One-part RTV | MIL-A-46146 (distributor) | 50 to 200 C (distributor) |
Distributor listings, not Dow data sheets.
What silicone sealant is
Silicone RTV (room temperature vulcanizing) sealants cure by reacting with moisture in the air, are one-part, and stay flexible at high temperature. They are used on non-fuel areas: heat, weather and electrical sealing. MIL-A-46146 covers one-part RTV silicone compounds that are not fuel resistant (EverySpec); MIL-A-46106 covers one-component RTV silicone adhesive-sealants. A fuel tank takes a polysulfide or polythioether, not silicone.
DOWSIL 732 multi-purpose sealant
What it is. A one-part silicone RTV sealant, acetic cure (distributor description).
What it is for. General weather and temperature sealing outside fuel areas, where the SRM allows.
How it is used. Per the maker's sheet. Acetic-cure silicones give off acetic acid while curing; read the SDS and the manual before using near bare metal or electrics.
Life and cure. Skin-over, tack-free and cure times are on Dow's sheet, which we did not read.
Safety. SDS.
Specification. MIL-A-46106 Type I Group 1 (distributor listing).
Equivalents. The SRM names the silicone, including whether it must be non-corrosive.
Silicone and the AC
AC 43.13-1B ch. 11 recommends a non-corrosive sealant (it names MIL-S-8802) where dissimilar metals need sealing in salt-spray surroundings; silicone is not named there. Silicone residue can also hurt bonding and paint adhesion, which is why removal and cleaning matter (sealant removal).
Questions people actually ask
Can I seal a fuel tank with silicone?
No. MIL-A-46146 silicones are described as not fuel resistant, and fuel tanks use fuel-resistant sealants.
Why does silicone stop paint sticking?
General shop experience: residue is hard to clean. The manual's cleaning rule decides; we give no data.
Limits — when NOT to use this
What the sources support, and no further.
- Distributor listings only. No Dow data sheet was read.
- Specification text not read. We use their scope lines.
Where to buy
Distributors coming soon.
Sources
- DOWSIL 732 Multi-Purpose Silicone Sealant (distributor listing) — Service range about -60 to 180 C, MIL-A-46106 Type I. Distributor listing, not the Dow data sheet.
- MIL-A-46106, one-component RTV silicone adhesive-sealants (index entry) — Scope line of the specification.
- MIL-A-46146A, adhesive-sealants, silicone, RTV, non-corrosive (EverySpec) — Specification for one-part room-temperature-vulcanizing silicone compounds that are not fuel resistant.
- FAA AC 43.13-1B CHG 1, Chapter 6 (corrosion control, safety precautions, finishes) — Pars. 6-90 (safety precautions), 6-134 to 6-136 (finish, conversion coat, 48 hour rule, fasteners), section 4 (corrosion preventive maintenance, MIL-C-16173 Grade 4); par. 5-63 (cleaner types).
- Socomore, SkyRestore Cured Sealant Remover, Technical Data Sheet (distributor copy) — Liquid 306 and gel 307 removers for polysulfide, polythioether, silicone and RTV sealants.