Painting a sailing boat - weather

[Willbe84]

Hello,

I plan to paint my boat when it is 16 Celcius with 78% Humidity.

"For an effective paint job to adhere, you need to paint the boat when the temperature ranges between 18.3 and 26.7 degrees Celsius. The humidity should be less than 65 per cent."

Has anyone ever set up a canopy over their boat and left a gas heater on to help the paint dry and reduce humidity?

Or can anyone suggest better ways around this?

Thanks
Ian

 

[Tranona]

Think I would use a coating that is more tolerant of ambient conditions. The temperature and humidity range you are quoting suggests it is for application in a controlled indoor environment. Rare for painting boats.

 

[ianfr]

I have painted 2 boats with Sandtex EXTRA flex gloss, which can be applied at 5 degrees celcius. Half the price of yacht paint, harder wearing, easier to apply. The first boat still looks great after 4 years.

Regards

Ian

 

[Rossynant]

As Tranona said.
Most paints should work down to 10'C temperature, or sometimes varnishes and resin 15. So maybe get another. But this may just be their insurance, as no guarantee it works, but probably will. Risk is yours...

Humidity is not as important in the air, as generally. With humid air you risk the gloss, less problem with paint adherence usually (but follow instructions, there is no rule). With wet substrate - now that may be problem, depending on paint, but. It's good idea to put some canopy to protect from rain, after some time the surface will be dried a bit - and the paint will be protected from rain till it cures. With polyurethanes a dew is problem - will lose gloss. But will adhere, sand and put another coat.
I have no experience with wet condition much, though. Proper way is to protect the paint. Then somehow people paint at equator, there is 100% humidity...

Should clarify maybe: resins and solvent soluble paints (polyurethane on solvent) should go on dry surface (no water on surface, some wetnes deep under can be lived with); if the water gets on them later on as dew or rain - the gloss and surface will be affected, but they will adhere and cure. When there is wet surface and no way to dry it, water based polyurethanes and acrylics may work acceptably.

 

[PhillM]

We have painted inside and outside for the past three years. You don't need it to be that warm to do a great job. You can prepare, prime and undercoat above 5c and topcoat above 10c.

I wait for more like 15c for exterior varnish with awrm sunshine.

Interior bilge paint etc will go off in 5c as well as will antifoul so all in all there are plenty of days you can get work done and then you just need to pick a few nice days to finish the job.

This year we do have a cover over for other works. We have left both ends open otherwise you get too much condensation. We will take it off before painting outside.

There was a wooden boat enclosed in a scaffold with shrink wrap cover in our yard last year. While that gave protection for major works they actually had to wait later than us because of the condensation.

 

[Avocet]

+ 1 for Phil's post. I've experimented with a "tent" round Avocet, using that clear, reinforced plastic sheeting that scaffolders use. Didn't work. As the temperature went up, the humidity went up too. (Though Avocet is stood on soil at present, not concrete or tarmac).