Is there someone who knows which sealant for TB 20 tanks inspection covers are usable?
Thomas
I don’t have a maintenance manual for TB 20, but as a general rule, tanks are sealed with a two-component polysulfide sealant. The choice is fairly wide, and when choosing the right one, pay attention to three parameters:
- Viscosity: liquid for application with a brush (called class A), a non-flowing thick paste for application with an extrusion gun, spatula or gloved hand (class B), or a somewhat thinner flowing paste (class C). For the inspection covers, any of these would do, so it’s a matter of personal preference.
- Curing speed: the number after the letter A/B/C denotes the application time in hours after mixing, usually between 1/4 and 4 hours. Full curing takes 15-20 times longer. Note that these times are listed for the normal ambient temperature. It can harden much faster when it’s hot and much slower when it’s cold.
- Adhesion: high or low. If the inspection cover is to be periodically removed, a low-adhesion sealant can save you some trouble removing it, though it isn’t really critical.
The one I see used most often is B2 high adhesion, which works in the vast majority of cases.
This stuff, informally known as “PRC” and previously known as PR1422 or PR1440.
Thanks for the information Peter and Ultranomad, very helpful. I have found PR 1770 class B ( two part kit),
but it is expensive. Is there anything else on the market only for the inspection covers?
Thomas
Now I found aircraft spruce USA 11,90 USD and aircraft spruce eu 16,85 €
Aerolife Polyprotech Fuel Tank Sealant – Single Component
Thomas
Thomas wrote:
but it is expensive. Is there anything else on the market only for the inspection covers?
Is this an integral tank where the glue is eventually submerged in fuel? If yes I would not take chances. Fuel leaks are a major pain and in my experience two component products are simply stonger than one component products
A source in Germany:
https://www.globalaviation24.com/Lubricant-Chemical/Adhesive-Sealant/PPG-Sealant-AMS-S-8802-Semkit-150ml.html
If ordering from abroad pay attention to the shipping. It could be dangerous goods making international shipping very expensive.
One-pack anything is rarely any good. Sealant or paint…