perfection

[Iliade]

A fairly silly question to which I have a nasty idea I know the answer: My boat was previously painted 'baby' blue. I flatted this off and overcoated with dark blue Hempels' normal one pack paint. This didn't adhere at all well, coming off in sheets.
I guess therefore that the original paint must have been a two-pack. Assuming this to be Perfection or similar, can I just sand off the Hempels and repaint with dark blue Perfection, or must I also undercoat or worse, prime and undercoat?

 

[pvb]

I guess therefore that the original paint must have been a two-pack. Assuming this to be Perfection or similar, can I just sand off the Hempels and repaint with dark blue Perfection, or must I also undercoat or worse, prime and undercoat?

For best results, you'll certainly need to apply 1 or 2 coats of Perfection Undercoat before the gloss. And you'll need to be careful about overcoating time limits.

 

[30boat]

You can overcoat a two pack paint with anything so the paint that you've applied must have come off because of poor preparation.Before you repaint with Perfection you must remove all traces of one pack paint.Make sure the baby blue paint is also a two pack or else remove it all.

 

[rob2]

As already said, a one-pack paint should go over a two-pack OK, so it sounds as though the surface is contaminated. Worst case scenario is that the paint was polished with a silicon and that is notoriously difficult to remove completely. I've known car sprayers to strip back to bare metal to combat this!

Rob.

 

[Pye_End]

For best results, you'll certainly need to apply 1 or 2 coats of Perfection Undercoat before the gloss.

This is consistent with my experience of using Blakes over a 2 part. For a very small patch where there was no undercoat the new top coat flaked soon after.

 

[30boat]

This is consistent with my experience of using Blakes over a 2 part. For a very small patch where there was no undercoat the new top coat flaked soon after.

I painted my boat with Perfection three years ago with no undercoat.The paint is still firmly attached.It's all in the preparation.

 

[pvb]

I painted my boat with Perfection three years ago with no undercoat.The paint is still firmly attached.It's all in the preparation.

To what extent were you changing the colour? That's where undercoat helps.

 

[Paddingtonbear]

I think that the silicon polish comment is about the truth unfortunately for you.

 

[Pye_End]

I painted my boat with Perfection three years ago with no undercoat.The paint is still firmly attached.It's all in the preparation.

Quite possibly. It was a 'hard to get at' patch so struggled to sand and clean like the rest.

 

[30boat]

To what extent were you changing the colour? That's where undercoat helps.

I was painting white on white gelcoat. Had I been changing colour I would have applied undercoat.

 

[William_H]

Two pack paint is a bit like a gel coat. very inert very good gloss. Your lack of adhesion may have been as said polish residue (silicon) but also because of the gloss of the 2 pack. If you were to hit it with wet and dry sand paper this would remove the silicon and rough up the 2 pack making a better mechanical bond. As said anything goes over 2 pack but 2 pack when being applied has powerful solvents which will soften the underlying old one pack paint causing huge problems. good luck olewill