Painting over darker areas

[blackrose]

16 minutes ago, jacko264 said:

Yes but we sand down the panels with 120 sanding discs first then the bus is washed and degreaser  is used  before primer  etc 

by the was its how  it's been done for the 30years I've worked there and a long time before I started there ??

Graham

 

Well if you're using an abrasive as course as a 120 grit paper on a powertool you might not have a lot of the original paint left. That's a very different situation than the paint on boat we're talking about. ?

Edited July 3, 2020 by blackrose

[jacko264]

Well looking at the photos  of the panels   It looks like he is painting the full side  so to me it's a full paint job not a touch up 

but I so pose it's up to every one to do what they think is right  ? 

Graham

[dmr]

2 hours ago, WotEver said:

It does, so it probably would.  Tekaloid is lovely stuff to use, but I doubt it would play well with enamel.

Have you used it and does it paint nicely or is it too fast drying to keep a wet edge?

 

I think (not sure) that the lovely Bondaprimer is Xylene. That dries dead quick (minutes) and enamel paints over it with no problems at all, BUT if you put BondaPrimer on top of enamel it all goes very wrong unless the enamel is 100% dry which means several days of sunshine, 24 hours is not enough.

 

..................Dave

[WotEver]

2 hours ago, dmr said:

Have you used it and does it paint nicely or is it too fast drying to keep a wet edge?

Yes I have and yes it does dry fast. I’ve only used it on small things (Windows, table frames) and I’m not sure I’d want to brush paint a boat with it. As you say, you’d have to work very fast to keep a wet edge. 

5 hours ago, blackrose said:

it's probably best that someone using an International marine top coat sticks to the recommended International undercoat.

Indeed. I was simply correcting your misapprehension that coloured undercoats were not available for marine paints. 

[Richard10002]

On 03/07/2020 at 16:56, WotEver said:

You can't beat Craftmaster...

https://craftmaster.myshopify.com/collections/paints-high-build-undercoat/products/dark-red

It certainly does.

https://craftmaster.myshopify.com/collections/paints-high-build-undercoat

I painted my grab rails in red a few years ago. Craftmaster Dark Red undercoat, then an Alpha Red topcoat. Looked fabulous, and still does if I polish it.

 

On the roof I used Pre Cote White as undercoat, and Craftmaster Raddle Light Grey as topcoat... looks good, but not as good as the red, as I struggled to keep a wet edge in the heat.

 

[markaitch]

ok guys, it's me with the paint issue.

Used white international pre-kote with 50% fire red (top-coat) mixed. Gave it 2 coats of this pink undercoat...... now I'm on 5th fire red topcoat, might be the last! it's taken 5 coats! So originally I painted 2 coats fire red that didn't cover the blue. I probably should have just carried on with a few more coats of red and not started again with undercoat?..... what a chuffin mission this has turned into lol

[Tracy D'arth]

Used to have white vans with a red flash.

Used Ault and Wiborg red paint straight onto the makers white, with their own thinners. It was polyurethane and had to be one coat as the wait time for a second was many days or it pulled. Brilliant cover.

Of course they don't make this paint anymore!

All the good stuff paint wise seems to have gone off the market.

TD' 

[Higgs]

 

It is usual to find that reds will need more coats to produce their full colour. The other usual requirement is that the colour the red is going over is even, with no patchiness of the underlying colour. The colour over which the red is painted will influence the red colour, until full build up of the red is achieved; the number of coats needed will differ between paints. 

 

Primers are needed on bare steel or any bare surface, to provide a bond between the bare surface and the following coats of paint. The undercoat provides sealant of the primer against moisture and provides a surface suitable for the topcoat to adhere to. Sanding back will open up the paint and an undercoat would be advisable to reseal the surface and provide an even colour, prior to over-coating. 

 

The undercoat's primary job at the beginning of a full paint job is to seal the primer; the primer tends to be porous. The primer's job is not to seal the steel, it is to provide a suitable surface of bonding between the steel and the next coat of paint, which is usually an undercoat. 

 

 

 

Edited July 18, 2020 by Higgs