Yes—the primary reason sealer is reduced is to make it spray slicker. I don’t care about that because it’s going to be sanded anyway.Lizer,
Just curious- are you saying you don't use a true reduced seal coat? Just spray the epoxy 1:1 and wet sand to 600 and call it a seal coat? I have a few small parts I'm painting and eliminating the reduced seal coat would be helpful as I'm just putting base right over the epoxy.
What’s the max safe window (time) between the 400 and sealer knowing you need 3 days cure to sand.imo if your going to sand it then its not a sealer coat. its another round of primer. to me, sealer is a thin coat of epoxy or urethane sealer just prior to, maybe 30 min, base or color going down. if your blocking @ 180 grit then a full 1:1 coat like lizer said will be needed then sand that with 400 to get the 180 scratches out. after the 400 then then a quick reduced "sealer" coat just before your color is recommended. i believe this is what dave was referring to as an adhesion coat.
Thanks @Jim C So just trying to understand. If I have been sanding an epoxy primed surface lets say for a month down to 300-400. And I am happy and ready for base….i think he said by the time he gets it sanded its not going to be fresh at that point. it will be well cured. in that situation then a fresh coat needs to go down. this way the epoxy wont be so chemical resistant that the base wont bite into it and lock on. the longer that epoxy sits the worse the adhesion will be. i have never had an issue with single stage or urethane primer adhering to sanded epoxy but basecoat.....all the time. you really cant let epoxy sit say five days, sand and spray base. the adhesion will be terrible. best adhesion will always be a reduced sealer coat 15-30 min before base.
yes thats what your looking for.Thanks @Jim C So just trying to understand. If I have been sanding an epoxy primed surface lets say for a month down to 300-400. And I am happy and ready for base….
At this phase a fresh seal coat of epoxy reduced sealer just prior (30 mins for example) to base is acceptable. ?.
Thanks @Jim C I do plan to shoot base/clear. So what it sounds like I need to do is going to stop sanding at 180. Shoot more epoxy primer to re-start the window. Sand to 400-500 (solid no pearl or metallic) within a few days and the seal and base clear right away. Makes sense to me. I’ll just have to dedicate the time and plan it so I can work within the all the windows while balancing the weather…..might need the big guys help on that part.yes thats what your looking for.
epoxy can go over out of window sanded epoxy to refresh or restart your recoat window.
for your other question, i would not take epoxy that is say 14 days old, sand it with 600 and apply 2k primer over it. 600 is a bit too fine. typically if you took primer to 600 you would not be putting more primer over it. if you sanded that epoxy with say 180, then put 2k primer over it then that would be acceptable but i still think 14 days is too long. what i am saying is that 2k primer and single stage has better adhesion that basecoat does so poor adhesion on out of window epoxy will be less evident. in a nutshell, the longer epoxy cures then more chemical resistant it gets. the sooner you get something on it the better. its as simple as that. the 7 day window imo is too long. its ok for 2k primer and ss but not base. typically get a base on epoxy in no more than 36-48 hours and as said before, 30-60 min over a sealer coat of it is best.
Lizer thats great! That would save me a few days of waiting for it to dry enough to dry sand it. I am effectually slow at this not being a pro and that makes all these windows a lot of pressure. Wonder if it’s just me that feels that way.You can spot wet sand epoxy within a few hrs of spraying it. You could safely wet sand all of it the following day.