Rudder Skin, seal and prime question

[Neal Trombley]

I am starting my rudder and have deburred/dimpled the skins and stiffeners
I want to use 3m 5200 on the stiffeners but also plan on priming the inside skin with my 2 part epoxy...
should I just clean the skin and 5200 the stiffener and cleco and wait to dry then prime the rest of the skin?

or prime, 5200 cleco and wait or rivet wet.

as always thank you

I plan on the tank sealant from Vans for the Leading edge don't see where folks have used 5200 here even though the tensile strength is much better than pro seal

any other suggestions or comments always encouraged

[tgmillso]

I wet riveted my fuselage structure and used sikaflex pro as it has a really long working/skin time. This is critical for wet riveting as you always find you need more time than you planned on, because you had to drill a rivet out etc. When I wet rivet these types of structures I like to do so before the sealant has set, as the rivets will squeeze out far more sealant than the clecoes will, thus saving weight.
The 3m product you speak of is a fast cure adhesive, so I would be a little concerned about working time. Regarding the tensile strength, this is not really an issue, because the rivets are holding things together, what you are looking for is gap filling to stop capillary action. What you really care about when Fay sealing is surface adhesion, flexibility, gap filling ability, chemical resistance, paint ability (avoid silicones), ease of use and of course working time. Keep your tube of Sika pro in the freezer and it will last the entire project.
Good luck.
Tom.

[Neal Trombley]

Thanks Tom
5200 has a slow cure as well and eaiser to find locally

I like sika as well

[n82rb]

I would prime everything, then assemble in what ever method you choose.