paint

[jaime66]

Looking to paint our boat at the moment its a light grey but going to change it to black, so looking to use craft master paint so do we rub paint work down then undercoat then topcoat ?? cheers for all input !

[LadyG]

I wonder, is this going to include the roof? It will be very distinctive, but not "cool".

It's going to be very hot, inside and out, I guess you know what you want, but I think black will be difficult to cover if you change your mind.

Any paint job will depend on the current state of the paint and rust etc. It is a major job to prepare, likely involves sanding. Sanding to bare metal usually means u a bit of rust treatment, primer , maybe two coats, then sanding, maybe two undercoats locally, then light sanding, to get a smooth finish.

You may need to remove some fittings to make a decent job, any rust left undisturbed will soon re-appear.

Best case scenario would be medium sanding to remove gloss, de-grease, one undercoat, one topcoat, this is very optimistic.

[Rickent]

You will be roasting in a black boat,

The difference in temperature in sunlight between a light coloured boat and a dark one is massive.

[blackrose]

Firstly I'm never roasting in my black boat. It's no hotter than my neighbour's boats. However, I have a lighter coloured roof and it's a widebeam so there's a greater proportion of roof area to cabin side area. Whether that makes a difference I'm not sure.

 

On the painting itself, if the existing paintwork is sound there's no need to take it all back to steel unless you really want to. Just sand it back with say a 240 grit paper and wash off the dust. If you haven't gone through to bare metal anywhere and there are no areas of rust then you could paint over with your topcoat of choice, but it might be better to use an undercoat. I used a couple of coats of Hemple primer-undercoat over the entire cabin sides. It's a good choice of undercoat. If you have gone through the paint and you're only patch priming/undercoating the bare areas them you'll have to sand those patches smooth before applying topcoats.

 

Remember to sand with a fine paper between coats, especially if you leave any coat for more than 3 days and want to apply a new coat. 

 

I suggest you watch John Barnard's series of videos on YouTube. This is the first of 7. Professional painters go back to bare metal otherwise they might be guaranteeing someone else's old paint!

 

 

Edited July 11, 2020 by blackrose

[jaime66]

Going to keep roof light grey ,just sides of boat going black ...

 

[blackrose]

Try it and do please let us know if the black sides make the boat hotter inside. You can always change it back to a lighter colour but then you'll definitely need a light undercoat.

[Jen-in-Wellies]

Is the existing grey paint a multi layer proper paint job, or is it just primer? You see a lot of sail away boats in rusting grey primer about.

Jen

[Rickent]

4 hours ago, blackrose said:

Firstly I'm never roasting in my black boat. It's no hotter than my neighbour's boats. However, I have a lighter coloured roof and it's a widebeam so there's a greater proportion of roof area to cabin side area. Whether that makes a difference I'm not sure.

 

On the painting itself, if the existing paintwork is sound there's no need to take it all back to steel unless you really want to. Just sand it back with say a 240 grit paper and wash off the dust. If you haven't gone through to bare metal anywhere and there are no areas of rust then you could paint over with your topcoat of choice, but it might be better to use an undercoat. I used a couple of coats of Hemple primer-undercoat over the entire cabin sides. It's a good choice of undercoat. If you have gone through the paint and you're only patch priming/undercoating the bare areas them you'll have to sand those patches smooth before applying topcoats.

 

Remember to sand with a fine paper between coats, especially if you leave any coat for more than 3 days and want to apply a new coat. 

 

I suggest you watch John Barnard's series of videos on YouTube. This is the first of 7. Professional painters go back to bare metal otherwise they might be guaranteeing someone else's old paint!

 

 

A light coloured roof will help massively,  as will good insulation. 

[blackrose]

5 hours ago, Rickent said:

A light coloured roof will help massively,  as will good insulation. 

Well the OP is going to keep their roof light grey. Looks like jaime66 is copying my paint scheme! I've just repainted it and still have to put grey coachlines on.

 

My insulation isn't that great. It's a Liverpool boat after all. I'll be interested to hear if the OP's black paint job noticeably affects the temperature inside the boat or if it's all a bit of a myth. Whenever this topic comes up it always seems to be the people who don't own black boats who seem to know the most about how hot they get inside!

Edited July 11, 2020 by blackrose

[Rickent]

1 hour ago, blackrose said:

Well the OP is going to keep their roof light grey. Looks like jaime66 is copying my paint scheme! I've just repainted it and still have to put grey coachlines on.

 

My insulation isn't that great. It's a Liverpool boat after all. I'll be interested to hear if the OP's black paint job noticeably affects the temperature inside the boat or if it's all a bit of a myth. Whenever this topic comes up it always seems to be the people who don't own black boats who seem to know the most about how hot they get inside!

My boat was dark blue,  top and sides, have now painted all but a slight bit on the roof in white primer, when it is in full sun the blue bits are hot,  but the rest of the roof that is white is cool to touch,  the inside is cooler too.

 

[cuthound]

7 minutes ago, Rickent said:

My boat was dark blue,  top and sides, have now painted all but a slight bit on the roof in white primer, when it is in full sun the blue bits are hot,  but the rest of the roof that is white is cool to touch,  the inside is cooler too.

 

 

My experience too, with having a boat with blue sides and roof, thrn a boat with cream sides and green roof and now one with blue sides and a cream roof.

 

The roof colour has a big impact on internal temperatures.

[matty40s]

52 minutes ago, Rickent said:

My boat was dark blue,  top and sides, have now painted all but a slight bit on the roof in white primer, when it is in full sun the blue bits are hot,  but the rest of the roof that is white is cool to touch,  the inside is cooler too.

 

That's because the July average temperature is about 10 degrees less this year.?

[Rickent]

9 hours ago, matty40s said:

That's because the July average temperature is about 10 degrees less this year.?

It wasn't a couple of weeks ago, it was roasting.???

[WotEver]

23 hours ago, blackrose said:

I'll be interested to hear if the OP's black paint job noticeably affects the temperature inside the boat or if it's all a bit of a myth

Mythbusters actually covered this but I can’t find it. They concluded that it’s definitely not a myth and that black cars get much hotter than white ones. There are loads of videos on YouTube showing the same thing. Here’s one at random: