Sealant tape for aircraft fuel tank

[MAKPolymer]

Hello,

I know that sealants are used in fuel tanks. The application process can be messy. Is there any tape available that can be used as a sealant? For example self-fusing type tape. Any advise would be helpful.
Thank you.

 

[WKTaylor]

Self fusing tape is typically fuses-to-itself.... not structure with protective finishes.

This question deserves a longer answer... I have no time. Basic/questions.

There are many ways to seal an integral fuel tank.
Metallic or composite structure?
Fay surface Installation?

Your knowledge should start with these...
SAE AIR4069 Sealing of Integral Fuel Tanks
SAE AIR5774 Composite Fuel Tanks, Fuel System Design Considerations
AFWAL-TR-87-3078 Aircraft Integral Fuel Tank Design

 

[TugboatEng]

What type of material are you looking for? I use a lot of PTFE gasket tapes and can make recommendations for those but I don't think PTFE is acceptable for what you have described so far.

 

[MAKPolymer]

Self fusing tape is typically fuses-to-itself.... not structure with protective finishes.

This question deserves a longer answer... I have no time. Basic/questions.

There are many ways to seal an integral fuel tank.
Metallic or composite structure?
Fay surface Installation?

Your knowledge should start with these...
SAE AIR4069 Sealing of Integral Fuel Tanks
SAE AIR5774 Composite Fuel Tanks, Fuel System Design Considerations
AFWAL-TR-87-3078 Aircraft Integral Fuel Tank Design

Thanks. I need to learn them first and then come back to you.
If i understand your comment correctly, a self -using tape can not seal a fuel tank properly? If so, is there any tape or strand-like sealant that can be used to avoid standard process of application of sealant?

 

[MAKPolymer]

What type of material are you looking for? I use a lot of PTFE gasket tapes and can make recommendations for those but I don't think PTFE is acceptable for what you have described so far.

Thanks. PTFE may not be acceptable. However, I have no experience and could not find any sealant in a form of tape that could be suitable. The idea is to have uniform sealing and easy working.

 

[3DDave]

What sort of fuel tank? Welding is the old-fashioned method for sealing one-piece metal tanks. If it's a wet wing in a riveted assembly then sealants are used. Of course roto-molded tanks are generally self-sealed except for an o-ring or gasket where the fuel lines or filler cap are attached.

 

[MAKPolymer]

What sort of fuel tank? Welding is the old-fashioned method for sealing one-piece metal tanks. If it's a wet wing in a riveted assembly then sealants are used. Of course roto-molded tanks are generally self-sealed except for an o-ring or gasket where the fuel lines or filler cap are attached.

Its riveted assembly.

 

[SWComposites]

if this is an aircraft fuel tank, then it should be sealed using the sealants specified by the OEM. yes they are messy. tape is not going to work.

 

[WKTaylor]

HINT...

Heavy Acft manufactures use VERY LITTLE/NO 'wet sealant' on initial structural Assy using automated Assy/fastening methods... it 'gums-up' every thing it touches. Fay sealing is the worst.

Modern assemblies are made from very corrosion durable metal alloys, have high quality finishes applied in layers for 'deep isolation' and have very tight installed fasteners [solid rivets, interference lock-bolts, etc] installed 'dry' [bonus: 'fatigue durability' and absolute sealing built-in]. Automated Assy is so rigorous/controlled... it it like boring-magic to watch in-action.

When/IF absolute sealing is required, THEN, fillet/injection-pack/fastener-over-coat [etc] sealing is applied... usually 'minimally' and mostly by mechanics... where gaps, steps and 'other factors/issues could come into-play. this would be a very long discussion and involves design judgement and other factors

Fay surface sealing is mostly used during structural repair and modification installs [many reasons]... pressurized and unpressurized structure.

/NOTE/ I seem to remember that a few companies did/do supply partially cured sealant in tape form... for aerospace... but only for removable doors, panels, floorboards, etc. These Tapes are too thick for structure assy... no squeeze-down/squeeze-out.

 

[MAKPolymer]

hello,
I have just found this tape.

General Sealants Inc® Sealant Tape Polysulfide Black 90Ft Roll GS#424​

Link: https://shop.boeing.com/aviation-supply/p/424-1-32-5-8=33?source=igodigital

Any experience with this regarding fuel tank sealant application?

 

[WKTaylor]

Thanks MAK!... I knew that...

/CAUTION/ The link you cited [@ 'Boeing shop'] referred to '...MIL-S-1130...', which drove me nuts trying to track the spec down.

I sniffed-out the correct MIL spec... it is actually MIL-S-11030 SEALING COMPOUND, SINGLE-COMPONENT, NON-CURING, POLYSULFIDE BASE
/NOTE/ The Type-III 'tape' comes in only 1-Thickness: 0.050-in. I assume that if it is 'tacked'[pressed]-in-place on stiff structure, the it might be possible to use a smooth plastic non-stick roller [polyethylene, PTFE... and maybe Delrin, 6/6Nylon[PTFE-filled] etc], to roll-it-thinner 'warm'... but will never be thin-enough for permanent structures in fay surfaces.

/NOTE2/ There is non-curing sealant for integral tank structure sealing... via groove-injection... but that is a design/practical mess... intended for structure that undergoes high stress/flexure.