filler over epoxy

[trackster]

Can Evercoat Z-Grip filler be used over DP40LF epoxy primer if used in the "window" for the primer as per PPG ?    I know it is designed to go over bare metal.  I have the Z-Grip but it is 2 years old.   Is it still viable with new hardener?  I'm trying not to have to purchase new filler for just the small amount I need at this time.   Thanks to all.

[kb426]

I read the spec sheet: http://www.evercoat.com/images/ePIM/original/TDS_100282_Z_GRIP_FILLER_1_2015_EN.pdf
It doesn't mention anything about epoxy but most companies don't. PPG was the instigator of the epoxy for underlayment so I don't have any real concrete info for you. I've done bondo both ways and not had trouble but I haven't used that particular product. The standard evercoat works on almost anything as long as it's sanded properly. Sorry I'm not more help.

[idrivejunk]

I've always sanded the epoxy, and I think thats your best bet. It would always be nice to skip sanding but thats a situation I haven't tried and that I don't believe is recommended. Scuff it at the very least.

The filler is probably OK if it stirs up and flows OK still, and if it wasn't already a couple years old when you bought it. The manufacturer might say that all filler should be used within a hundred days of manufacture.

Try a dab with fresh hardener first, but I bet you're OK.

[enjenjo]

Do a test  with the filler. Most filler uses BOP paste as a catalyst. It reacts with Cobalt Oxide in the filler to make it harden. First stir the filler, and make sure there are no lumps in it. If not, mix up a gob of the filler with the correct amount of catalyst, stir it in and let it set up. It should be hard, and have lost the rubberiness in a couple hours. If not, you can try some fresh BOP. If it still does not set up, you can add a few drops of MEK liquid catalyst to the BOP and try again. If it doesn't harden at that point, you might want to get some new filler. BOP, and MEK, react with different parts of the resin  formula.

[trackster]

Bought new hardener and mixed up a sample after a good stir on the filler.   Looks like it is good to go.  Thanks for the input.