Duratec Primers over epoxy fiberglass.

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#1

Hi guys,

I am doing custom boat work the last few years with epoxy, over plywood and divinycell foam. Though its starting to bug my hands, as lately they itch if I get any resin on them. So, I’m looking to lessen the contact with the epoxy products.

Have you guys had success with Duratec primers over epoxy? I have a gallon of Duratec polyester base primer, and a gallon of their blue vinylester fairing primer to test.

I’ll be spraying it over Adtechs Proseal tomorrow (it fills the weave of the cloth in one application) on the cabin wall of a yacht I’m building. I contacted Adtech, and they said that 3-4 days cure of the epoxy product should be adequate for topcoating with styrene based products.

I have gelcoated over epoxy, but this will be my first foray into using polyester products directly over it.

I have been using Awlgrips product line for the last few years, in combination with West Systems epoxy. They are excellent products, and work well. But… it takes 1 day to cure between sanding and fairing application cycles. The epoxy fairing compounds shrink, which means either overfilling every low and sanding off the excess or two days minimum per low spot.

I have a gallon of Mekp-9, will this work or should I hold off until the Mekp-925 shows up?

Thanks for your thoughts and comments.

Zach

#2

Alright, so the day after I asked this question, I did a test batch of the VE primer.

It cured perfectly over some old work. (Awlgrip Awlfair, and some west systems epoxy that is a few months old.)

It didn’t cure completely over 4 day old Adtech Proseal. It stuck, but you can scrape off the leftovers with a thumb nail leaving a film.

I called up Adtech, and they said that a week old cured epoxy would more than likely work. I haven’t tried again to see.

Duratechs VE fairing primer has got to be one of the softest easiest sanding primers I’ve ever used.

With the DDM-9 catalyst it didn’t harden up super fast. I bought a gallon of MEKP-925H to play with to see if it goes any faster. (A CCP gelcoat book, said that MEKP-925 goes faster than Luperox DDm-9. I’ll have to do some testing, as searching around online everywhere else seemed to indicate it was the opposite.)

Zach

#3

I’ve had good luck spraying Duratec over epoxy. The one thing that the Duratec guys suggested to me that seems logical is cleaning the amine blush off the epoxy before applying the Duratec. I did this with some scotch bright and water, just scrubbed it like washing a car.

I can’t recall how much time the epoxy base had to cure. Maybe just a few days.

The Duratec VE high gloss top coat is my favorite. Some wet sanding and polishing yields ridiculous finish.

#4

I’ll give the VE gloss top coat a try.

I bought a gallon of polyester base primer, surfacing primer, and the VE Fairing compound… and some high gloss additive.

The surfacing primer did pretty decent, I shot 15 mils on the plug and wet sanded the orange peel out with 800 and buffed with aquabuff 2000. Which got it to shine, aside from dropping my buffing pad in a pile of sawdust. (Shiny, but a bit hazy with a few pine induced swirls…

Its one of the few products that I’ve seen that will go from 80 to 800. I’ve seen 40 grit to 220 with awlgrips ultrabuild, but 80 to 800 is a new one for me…

The mold that came off of it looks a bit better.

Cheers,

Zach

#5

Most guys just use the Duratec surfacing primer and polish it all the way out. The last plug that that I did I sprayed surfacing primer and then block to 180 grit then sprayed the VE high gloss top coat. The benefit of doing this is being able to skip some sanding grits, if sprayed right you can go right into 800-1000 then all the way up.

They have a thinner specifically for their products so you can get the right viscosity for fine finish.