Bottom Paints & painting again?

[LouK]

Sailed to Baltimore to pull boat for the winter this weekend and had 4 hours to contemplate next spring's to-do list. Although I generally enjoy most things boat keeping, bottom painting clearly trails the list.

Remind me:
a.) Why do we fool around with rollers, rather than spray? I mean cars & airplanes both get sprayed, why not boats?

b.) Any bottom paints faves for the Chesapeake cruising, either hard or soft?

thanks,
LouK

[capt jgw]

Bottom paint may be too thick and heavy for spraying. Masking is a problem, with a roller you only need one line of tape on the edge. Spraying needs a couple feet masked off. Overspray might get on other boats and with bottom paints it's more toxic. I have sprayed VC 17, it's thin and light so sprayed well but the other issues were present.

[psk125]

Capt J mentioned masking being a problem with sprays, but it's not just that kind of masking. Do you have a positive pressure air system that you can use to avoid breathing fine droplets of poison? Interlux wants you to spray with such equipment for their REGULAR paint, and antifouling is by definition even worse for you. While you're at it, consider that everyone downwind of you spraying might also want you to provide them the equipment too.

[Jammer]

Originally Posted by LouK

Sailed to Baltimore to pull boat for the winter this weekend and had 4 hours to contemplate next spring's to-do list. Although I generally enjoy most things boat keeping, bottom painting clearly trails the list.

Remind me:
a.) Why do we fool around with rollers, rather than spray? I mean cars & airplanes both get sprayed, why not boats?

It's cheaper, faster, and less messy. The main benefit of spraying is that you get a more even coat.

[Apollo19.5]

Beside the correctly mentioned above, aircraft and cars predominately want even, lighter thin coats. Boat bottoms want thicker coat so as to have material thickness to progressively wear through. First two are suited to spraying, last is better suited to roller/brush.

[Rumrace]

Agree rollers are terrible and cause paint failures. That pile edge gives the water something to play at.
My old freshly painted donzi is red and white. Doesn’t have bottom paint just wax. The White bottom is 5 paper thin layers of white imron on 3 coats of an oxide primer designed for steel. It bonds with glass really well.
Good bottom paint can be sprayed no worries. Takes serious pressure dialed in and the nozzle is scrap after and maybe the needle. You must use the proper thinner for the brand. Then an extender so it doesn’t dry in the gun.
My hull is vinylester skinned so I have 3 light coats of black soft. I bet I’m a half a knot faster with my smooth bottom versus rolled lumps and hole. When Zebras attacked our club our boat had none.
Do not paint bottom paint on any metal bits below the water. Almost all contain zinc or copper. Either will turn your metal bits in to sacrificing anodes. Drive or prop paint for metal stuff.
Masking is a passion. Taping a boat 4 times with a stripe is average. You take tape off immediately. I wet sand the last coat of 3 primer the second coat of colour second and final coats of clear. 3 tapings minimum. On a stripe you don’t want an edge for the water to pick at. Same goes for where you meet bottom paint.
I love DuPont paints for all of the above. I also like Auto Air from California
If you have any epoxy patches they might appear more glossy through the paint. I use an 800 grit cloth paper designed for polishing metal. Leaves a mild red stain. It should blend the gloss issue