Winter Bottom Painting Questions

[cosmoking]

Hi all,

Well, it's winter in Seattle and I've got a haulout scheduled next week for my 41' Coronado sloop. I am planning on fairing the keel, painting the bottom, replacing some thru-hulls, and getting a survey.

I guess I was being optimistic that global warming would have an effect this winter, but here we are a week away with one of the worst winter storms in 20 years on the way, and freezing temperatures to boot.

I suppose I was thinking if I make a tarp around the boat (I'll have to anyway to meet the boatyard's BMP's while sanding the bottom) that I can keep it warm enough in there to paint during the day (somewhere between 10am and 4pm when it will be light out).

My previous bottom paint (and thus first choice in recoating this time) is Interlux BottomKote, which states minimum application temp of 50 degrees. Some of the other paints say if the temp drops below 50 degrees before drying it goes from 6 hours dry time to 36! But I don't see that with Bottomkote, they just say 50 degrees is a minimum. If I'm lucky I'll have a few days in the coming weeks with 40 or 45 degree highs. Should I use heaters of some kind in the tent? I'm a little worried if I don't vent the tent the fumes will build up and make a fireball. If I vent the tent it won't stay very warm. Just putting a propane heater under the tent is just kind of scary as it is, and probably won't keep things at an even temperature. And I believe propane heaters put out a lot of water vapor.

With all these concerns, I'd really rather cancel my haulout until spring. But I'm required to get a survey by mid January and my company is shut down for the holidays so this is the best 2 weeks I'll get to work on the boat.

Does anyone have ideas on how to make this work? Will a 35-degree day be much different than a 40 degree day? Are there certain paints that would work better than others to apply in the cold?

What do pros use for the heating and tenting setup for winter bottom painting? gas heaters or electric? Vents at the top of the tent, or at front and back with fans? I've heard of folks painting one yard at a time, hairdrying that patch till tacky, then moving on. But that just sounds tedious.

Is a cartridge-style respirator sufficient in the tent or do I need the full forced air respirator?

As you can see I'm in for a couple fun holiday weeks. To think I originally hoped to step & paint the mast and paint the deck. That will never happen this time around!

Thanks for any insight!

Cosmo

[sailingdog]

First, I wouldn't use a combustion based heater around painting... many of the fumes given off by modern paints are flammable... Heat lamps are probably a better way to go, and doing just one section at a time. Fire is a very serious risk with what you're planning on doing... and many boatyards would frown upon or prevent you from doing it.

Personally, I think you'd be much better off waiting to paint until the spring.

A cartridge style respirator should do the trick, with a good organic vapor filter in it. I recommend using the 3M 6000 series full-face respirators as they're far more comfortable and easier to use than goggles and a half-mask.

As for what most pros I know do... they bring the boat into a building and heat the building.

IIRC, global warming doesn't mean that winters are less cold, usually they're more cold because global warming exaggerates the extremes in climate variation, leading to really nasty winters and boiling hot summers.

[Bene505]

Not sure what to tell, you. This is what I would do, but I haven't tried any of this, since I can wait for spring to paint...

How about setting up a tarp enclosure and using clear plastic for the south facing side? Let the solar energy in. Also use 2 layers of tarps on the top and 3 sides, and 2 layers of plastic on the south side. Get some bubble wrap and scatter peices of it between the 2 tarps. (Even 1 inch squares cut from sponges, when glued onto the bottom tarp every few feet will work wonders. Put glue on sponge squares and throw them up onto the tarp. Wait until glue dries before adding 2nd tarp.) Now you've just created a somewhat insulated, solar heated enclosure. It should be good for raising the temperature a few degrees to help get you the 50 degrees mark.

If there are outlets you can use, set up a bunch of electric heaters, but watch out for rain and puddles. Be ready to unplug it all at the first sign of rain or when leaving the site.

Between a solar-heated, crudely insulated enclosure and some electric heaters, you ought to get a decent increase above outside temperature. Save the tarps for the next time you want to cover the boat.

We had a wedding reception at our house with a big huge tent. Small heaters did make a difference in the inside temperature. So it can be done.

Not sure if sanded paint particles are flammable, but some things in particulate form are explosive, so you might want to be very cautous overall about using flame-based heaters. Others on this site would know more about that. Also, not sure what to tell you about venting.

Good luck, and whatever you do, post pictures!

[paulk]

Talk to the techies at Interlux about the temperature. (Interlux.com?) They KNOW, and won't mind telling you it won't work if it won't, because they'd rather see you get mad at some other manufacturer who lied to you, than mad at them. Waiting for warmer may be the best option, unless they tell you otherwise, or it does get warm enough.