For those who have built or rebuilt tube and fabric ULs, where the hard points are (cable attach points, wing, engine, tail attach etc) there are often smaller diameter tubes inserted as doublers. How have you seen these shimmed as they don’t fit tightly and therefore don’t pass load to the parent tube. Mike Sandlin for example specifies wrapping the sleeves with “vinyl tape”. I’ve seen some others say they use glass fiber and epoxy although I don’t have details and I’m having a hard time envisioning getting it deep down a tube without leaving epoxy all over the ID. I’ve thought you could put o rings or some other edge dams and drill two pilots thru just the parent tube then fill the cavity with epoxy using a syringe via the pilot hole with the other hole as a vent. The vinyl tape solution seems squishy and imprecise. Also all of these solutions make deburring both tubes after drilling a bit dicey: how do you get the sleeve out and back in to align the holes? If you had a really tight shim you might not need to deburr between the tube and sleeve maybe (one up assembly). I’ve sleeved some of my tubes using aluminum duct tape as a shim, works ok but not super precise and not cheap either. What are your thoughts, o ultralight aviators and crafters?