Hopefully someone who knows a bit more will respond, but I've had good luck (not with hypalon, but with other fabrics) by thinning out the first coat of adhesive to a very thin mixture so it penetrates the fabric fibers.
You should be able to do this with most hypalon glues using toluene or MEK. It'll take a while for the extra solvent to flash off (meaning the cure time for the coat to get to the non-tacky state will be substantially longer; something like a light bulb placed nearby should help keep moisture from forming on it, and speed the cure time.)
Note that this is guesswork, but is well founded in other areas.
Luck;
jky
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