I have a couple of gallons of various Aerogloss dope colors of various ages.  Does anyone know of an available thinner which will work with Aerogloss?

I think the Aerogloss dope formulation changed one or more times during those years so thinner that works for one batch may be a disaster with another. At one time one could not apply Aerogloss over butyrate dope, later iterations went on just fine. It may require a lot of testing to get an answer. If the dope is post late 80's, your task should be easier. My first encounter with Aerogloss was about 1947. Found out right away it was "different"!
Don

Aerogloss is MEK based so that may work.

Sparky,That just may work.I covered my homebuilt and several others with Stits Polyfiber products.They were MEK based.

Stits Polyfiber products are vinyl based (MEK is one of the solvents in their products), have no relationship to dope products, and are incompatible with dope of any sort.  Poly-Fiber materials cannot be mixed with nor applied either over or as a basecoat under any dope products.  MEK is used as a solvent in many covering/painting systems, is relatively fast evaporating but is much slower evaporating than acetone, and has more health hazard considerations than acetone.

For all that, MEK may well work as a thinner for Aerogloss.  

A few years ago Poly-Fiber offered a selection of dopes which were a good product, but discontinued their line of dopes after they bought Randolph products.

GEE Bill,Thanx for pointing out all that other info...........I think I meant to say thinned........MEK is the ONLY product used to thin Polyfiber and not void the STC.

Under the Poly-Fiber STC the only thing that is thinned with MEK is the fabric adhesive Poly-Tak.  The Poly-Brush (used for the first coats on the bare fabric & for application of the dacron tapes), the Poly-Spray (the silver material used to block UV light), and Poly-Tone (the pigmented finish coats) are thinned with either R65-75 or RR8500 Poly-Fiber thinner, and BR8600 retarder can be added depending upon temperature & humidity.