140 to 160 degrees checked with a candy therm. and powder dye worke best
for me. Lift out with tongs every 15-30 seconds and check color. If you
have no way to check the water temp, test on some of the scraps after you
cut the canopy out.
 

I've had variable success using this technique. It worked fine on a
Spirit 2M canopy, but didnt work at all on the next clear plastic
canopy(can't recall the model) I tried. I assumed that the difference
could be attributed to a different type of plastic. No proof, and I'm
still wondering. Rit dye works great, when it works at all.
 
 

Tried it on a SIg WWII canopy. Rit liquid, hot water, 24 hours!! Didn't touch
it. Same for the canopy of my Pica Duellest
 

Also try adding a teaspoon of salt per gallon of hot water, the salt helps
adhesion. Steven R Bolin