2k recoat technique / times?

[julianf]

Say i have a part that's been primed, and a 2k colour coat put on (no clear coat), as i understand it, in an ideal world, the colour coats should be built up within the recoat window.

But what happens outside that recoat window?

Do i have to re-prime to get adhesion, or is abrading the top coat acceptable?

(im talking parts that have just been on shelves - dusty, but thats all)

Thank you.

 

[norsa]

You will lose intercoat adhesion with your clear. Key up and shoot a couple of your base coat then shoot the clear. The biggest issue is, especially in this weather, 2k base coat I'd polyester and that will suck in moisture if you're not careful.
Nick

 

[norsa]

I am taking it by colour coat you are meaning COB not direct gloss of course. Terminology again.
Nick

 

[julianf]

I am taking it by colour coat you are meaning COB not direct gloss of course. Terminology again.
Nick

Yeah, i dont know the correct words -

This stuff -

Lechsys 29140 2K Polyurethane

Im applying epoxy primer, and then the above, and that's all. No clear coat over the top. Gloss finish from the 29140.

Thank you.

 

[norsa]

I don't know that product but if its a direct gloss 2k, just key it and shoot it.

 

[julianf]

I don't know that product but if its a direct gloss 2k, just key it and shoot it.

Follow on, very quick question -

To what extent / grade would you key it?
Are we talking brown "skotch" pads, or greater or lesser?

Thank you again.

 

[norsa]

If its flat, I would go grey. Red is for primer. That's the only ones I use. If its orange peel 6-800 dry.

 

[Burdekin]

What finish are you wanting? You could wet on wet over the epoxy and live with a bit of orange peel or flat back down the epoxy to 600 and overcoat for a smoother finish.

Spray some panel wipe over the epoxy to give it a shine, if you are happy with that level of flatness just wet on wet the topcoat. Give the epoxy a few hours to flash off and then topcoat. If the epoxy has cured and you're happy with the level of finish Scotch it, clean and topcoat.

If you want it super flat you should let the epoxy fully cure so it doesn't shrink before flatting and overcoating. Probably 3 to 7 days.

Never used that topcoat but a decent high solids topcoat will cover exceptionally easy so only needs 2 or three light to medium coats and should lay flat and come out lovely.