Feather fill G2 over epoxy faring compound?

[Mhall222]

I am working on a plug for a small skiff and doing a lot of fairing work with thickened epoxy. I have been using the epoxy as it gives me far more working time and overall just easier to work with than bondo or other polyester body fillers. I had bought Feather fill G2 to spray on the plug once I get it close with the fairing compound but I got to thinking I may run into issue with bonding between the large areas of epoxy with spraying a polyester over it. Of course the epoxy is sanded but would I run into any issues with delamination between the feather fill and epoxy? I also have duratec which I has planned as the final primer coat which I was going to water sand and buff for the final plug finish before making the mold. I guess my question is pretty much will the polyester feather fill primer cure correctly and adhere to well prepped (sanded) epoxy? If I had not already about 2 gallons of duratec and the feather fill I would use K2 epoxy primer but figured the high build of the feather fill would be nice to have on this particular project.

Thanks
Mike

[rjdubiel]

how long as the epoxy been cured. Do you have a way to heat it up (even out in the sun if needed). But the epoxy that is completely cured and then sanded and faired should be just fine to put poly over it.

[Mhall222]

I am using fast hardener for the epoxy which the specs says fully cured in 4-6 hours. I went ahead and gave the company a call who I bought the epoxy from and they suggested not spraying polyester primers over the epoxy. They also said that the duratec would go over it no problem at all and it is actually a great bond between well prepped epoxy and duratec surface primer. I guess I will just skiff the Feather fill and go straight to Duratec as it too has a pretty high build ability.

[XstreamVking]

Follow the co's advice. Epoxys are fickle about adhesion with poly and it being fresh I would be cautious.

[Stoker boy]

Years ago I had a polyester boat I patched with epoxy it didn’t stick well at all. I’ve been told it will stick and I’ve been told it won’t stick well so I try to never combine the two I stay with one or the other. I generally use epoxy if I’m doing visible carbon fiber in a mold because I have more working time. If I’m doing a small part I will use polyester because the working times not really an issue.

[Mark Poole ModVP]

Duratec is great stuff! If you use a really good high end spray gun the Duratec will level out nicely and you will have a lot less sanding to do. But even if you get some texture with the Duratec it sands out quickly.

[Mark Poole ModVP]

Just curious, that appears to be an older design that you are resurrecting?

[powerabout]

Even if you get the poly to stick to the epoxy it might take 6 months then it may well start to go wrong.
Ben there tried that.

[Mhall222]

I am going to just use Duratec for all the priming on this project and put the featherfill on the shelf for something else down the road.