Whatever you have as distortion in the cases, if it is not from welding - or if you intend to do some critical machining somewhere, all the throughbolts will easily clamp the job tight enough, alu flexes a lot, so no need for lengthy planing the mating faces.
The use of silk threading plus liquid seal on aircraft engine joints may simply show the ignorance of modern tech there plus the big problem of certification costs for any mods in aviation. This practice is best ignored here , just apply a good sealant. I like the anaerobic Loctite types that also do great load transfer across the joint. That is one of the reasons I do not use silicon here, argument is, a rubberlike medium in a certain thickness will hardly produce a rigid unit. So instead I´d point to the Loctite types like 573 , 574 , rubberlike anaerobic types also there, as required. These seals don´t shrink, no thinners , have strengths from very light to medium, so think before using. You cannot remove them easily, so some scraping, sanding is necessary, or use Loctite gasket remover or tough paint stripper overnight. Threebond is quite similar I believe, documentation is better with Loctite, shelflife no factor.
Vic
The use of silk threading plus liquid seal on aircraft engine joints may simply show the ignorance of modern tech there plus the big problem of certification costs for any mods in aviation. This practice is best ignored here , just apply a good sealant. I like the anaerobic Loctite types that also do great load transfer across the joint. That is one of the reasons I do not use silicon here, argument is, a rubberlike medium in a certain thickness will hardly produce a rigid unit. So instead I´d point to the Loctite types like 573 , 574 , rubberlike anaerobic types also there, as required. These seals don´t shrink, no thinners , have strengths from very light to medium, so think before using. You cannot remove them easily, so some scraping, sanding is necessary, or use Loctite gasket remover or tough paint stripper overnight. Threebond is quite similar I believe, documentation is better with Loctite, shelflife no factor.
Vic