Hi guys,
I might be telling my granny how to suck eggs but, if you are running out of hardener before the filler tin is empty you are using too much hardener.
As a guide you use a small pea size amount of hardener to a large golf ball of filler(2 to 3% max). If you put large amounts of hardener as it sounds like you are doing, you will have problems at a later date with your paint work.
This is because as you are no doubt aware the hardener is an organic peroxide (methly ethyl ketone peroxide), any hardener left after the cure will bleach through, red paint will go pink and white will yellow, black grey etc.
Thinning down polyester filler with anthing other than ployester resin will cause solvent popping (little blisters and holes) in the later applied paint work.
If you use and mix the filler every time you use it, the hard stuf at the bottom of the tin does not happen and you should still have hardener at the end, throw it away as this has a shelf life the same as the filler. By the way if you get the smallest amount of hardener in the tin of filler it will send the lot of. Hope this helps frome a body filler boffin.
