Welcome to the FOG [big grin]
Yes, some hoses can be connected together. I understood it as the D36 hoses can connect the 36mm fitting into the rear of the 50mm fitting of "some" hoses with the proper 50mm fittings. I have a new style hose myself that does not allow that which is a bummer (I bought Festool 500684, yet it says it connects). I'd recommend taking your hose with you into a store and find a 5 meter long D36 hose that attaches into the 50mm end of your current D27 hose. My most used hose is the D36 when performing remodels, as it offers more air flow for cleanups and debris. With a 5meter+ hose is very nice to have the dust collector "around the corner" not running in the same room for even more peace and quiet. Originally I wanted a 7meter hose but now I feel like the 5meter is more manageable.
Another option is to remove the 50mm connector on the D27 hose, wrap some tape around the part remaining and insert it into a D36 fitting. This will probably fall out on a ladder so more tape around the outside should keep them together, or 4 zip ties will also secure it. That is what I currently do when wanting a looong D27 hose. If I could find a different 50mm end that fits the D36 end I would buy one in a heartbeat. Anyone know what end to purchase for an old skool D27 hose?
Festool also offers a 7meter long 27mm hose and even has one with a cover and cord included. For a painter it might be a good option.
"The initial piece and end piece of two suction hoses can be connected by inserting one into the other, therefore transforming two hoses into a single long one " Also lets you loop a single hose so it doesn't spread dust everywhere.
