Mechanical removal
Where to buyWhat it is. The method in FAA-H-8083-31B for fuel tank sealant: remove old sealant with a nonmetallic scraper, and use aluminium wool for the last traces.
What it is for. Reworking a fuel tank leak, or removing sealant before a new fillet.
How it is used. Scrape, finish with aluminium wool, clean with the recommended solvent, apply new sealant as the maker says, observe cure time and leak checks before refilling (Handbook ch. 14).
Life and cure. Cure time and leak checks per the maker.
Safety. Fuel tank entry has its own procedures in the Handbook and the AMM. Read the SDS.
Specification. The AMM and SRM.
Equivalents. Not with steel tools on aluminium.
Chemical sealant removers and softeners (SkyRestore family)
What it is. Liquid (306 series) and gel (307 series) removers that soften cured sealant. The maker's sheet says they work on polysulfide, polythioether, silicone and RTV sealants. A 407 gel is sold as an NMP replacement; a distributor notes NMP has been restricted under REACH since May 2020.
What it is for. Softening cured sealant on fuel systems and other areas before it is scraped away.
How it is used. The gel clings to vertical and overhead work. Per the maker's sheet and the AMM: contact time, residue wipe and compatibility with the surface finish.
Life and cure. Per the maker.
Safety. The 306/307 and 407 formulas differ. Read the SDS of the exact product.
Specification. From the AMM or the sealant maker's removal instructions.
Equivalents. Not by brand name. Check the AMM list of approved materials.
What to do afterwards
Clean the area with the solvent the manual names, check the surface for attack, and re-treat bare metal with a conversion coat and primer before re-sealing (finish guide). Do not block drains with sealant or inhibitors (AC 43.13-1B par. 6-50h).
Questions people actually ask
Can I use MEK to soften sealant?
The AC says solvents dissolve sealants among other matter (par. 5-63b), but the right remover is the one the AMM names; MEK attacks many finishes.
Will remover harm paint?
It may. Test as the maker's sheet says.
Do I scrape with a screwdriver?
The Handbook says a nonmetallic scraper.
Limits — when NOT to use this
What the sources support, and no further.
- One remover family from distributor listings; we did not read the maker's data sheets.
- No contact times are given.
- Tank entry procedures are outside this page.
Where to buy
Distributors coming soon.
Sources
- FAA-H-8083-31B, Airframe Handbook, Volume 2 — Chapter 14, fuel tank leak repair: remove old sealant with a nonmetallic scraper, clean with the recommended solvent, apply new sealant, observe cure time.
- Socomore, SkyRestore Cured Sealant Remover, Technical Data Sheet (distributor copy) — Liquid 306 and gel 307 removers for polysulfide, polythioether, silicone and RTV sealants.
- Socomore SkyRestore New Formulation (news) — The NMP-free 406 and 407 replacements and the EU regulation of NMP since May 2020.
- 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).