Association Forum - Bottom Paint

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

Catalina 25 Specific Forum

Bottom Paint

New Topic

Topic Locked

Printer Friendly

Author

Topic

JanS48
Navigator

Member Avatar

USA
141 Posts

Initially Posted - 04/03/2015 : 20:39:06

Greetings All - another newbie question.
C25 FK STD Rig
This is my first year owning my C25, the bottom is in need of painting, I'm planning on scraping away anything loose and lightly sanding the rest. How much paint am I going to need? The current paint is an Interlux blue ablative. On those bare spots is two coats sufficient? Is is Ok to roll on the lions share? Should it be thick or thin going on? How soon after painting should it be put in the water for the season?

Thanks in Advance
Jan

82 C25 SR FK
Sailing out of Newport Harbor.

Steve Milby
Past Commodore

Members Avatar

USA
5851 Posts

Response Posted - 04/04/2015 : 08:15:57

If there are bare spots, I suggest you apply two fairly thin coats this year. As I recall, one gallon should do the job with a little left over. I apply it with a short haired roller, and I use a cheap brush for places that I can't reach with a roller. Antifouling paint will cause cardboard-type roller covers to disintegrate. Usually a roller cover that has either a plastic core or a phenolic core will be ok. You can usually buy them at most hardware stores. Read the label on the paint can, but you can usually launch a boat 24 hours after the last coat. Mask the waterline stripe with tape.

If you store the boat on the hard during the winter months, then one coat will probably be enough each year, unless you see some thin or bare spots.

By the way, since you have some bare spots, a little light sanding might be in order, but usually you won't need to sand ablative paint each year. I usually only wash mine before applying a fresh coat of paint, unless I find a particularly rough spot.

If you sand it, I suggest you wet sand it. It's messy, but the water will prevent the dust from becoming airborne and getting into your hair and eyes and lungs and skin pores. In any case, only the lightest sanding will be enough, and only where it is rough.

Steve Milby J/24 "Captiva Wind"
previously C&C 35, Cal 25, C25 TR/FK, C22
Past Commodore

Edited by - Steve Milby on 04/04/2015 08:23:37

islander
Master Marine Consultant

Members Avatar

USA
3994 Posts

Response Posted - 04/04/2015 : 08:35:16

What Steve said is good advice, 1 gal gave me 2 coats. Use a 3/8 nap roller and 80 grit sandpaper. This can be hazardous, Don't breath the dust! Use a good respirator.

Scott-"IMPULSE"87'C25/SR/WK/Din.#5688
Sailing out of Glen Cove,L.I Sound

Voyager
Master Marine Consultant

Members Avatar

USA
5234 Posts

Response Posted - 04/04/2015 : 21:21:47

Scott do you thin the paint with paint thinner? Whenever I apply ablative I get a single thick coat and have a about a pint leftover for the padmarks and keel block. I noted that the boat bottom paint thinner is not regular-old paint-store generic thinner for $7.00 a gallon but its $25.00 "special marine" paint thinner. (Special formulation thinner)!!!!!!

Bruce Ross
Passage ~ SR-FK ~ C25 #5032

Port Captain � Milford, CT

islander
Master Marine Consultant

Members Avatar

USA
3994 Posts

Response Posted - 04/05/2015 : 06:59:55

Bruce, Last time I painted the bottom it was a warm day. I would guess that if it is cooler the paint will be thicker and you might need an extra quart to get two coats. It was warm enough that I started at the front working my way back on one side then up to the front on the other side. By the time I got back to the front the paint on the first side had dried enough to just continue on around the boat again with the second coat. Also depends on how you paint. If you constantly overlap or lay it on thick the coverage would be less. Also you have a fin keel vs my wing. Possibly more area to cover? No, I don't thin it.

Scott-"IMPULSE"87'C25/SR/WK/Din.#5688
Sailing out of Glen Cove,L.I Sound

Steve Milby
Past Commodore

Members Avatar

USA
5851 Posts

Response Posted - 04/05/2015 : 07:16:47

As I recall, there are a couple of types of thinner for most antifouling paints. One type is for use if you spray it on, and I think it evaporates much more quickly. The other type is for use if you roll or brush it, and it evaporates more slowly. I suggest you call the customer service phone number on the can, and ask the experts for the product number of the type of thinner that you need, and then order that specific product online. I bought a can at WM, and it must have been the type for spraying, and it evaporated faster than I could roll the paint on. If you have to spend that much for it, you might as well get the type that you need.

Steve Milby J/24 "Captiva Wind"
previously C&C 35, Cal 25, C25 TR/FK, C22
Past Commodore

Stinkpotter
Master Marine Consultant

Members Avatar

Djibouti
9015 Posts

Response Posted - 04/05/2015 : 08:37:13

I thin my paint with water--cheap (free), manageable, and essentially odor-free. (The paint is water-based Pettit Hydrocoat SR, which is also easier on cheap rollers--even foam--due to the lack of oil-based solvent.) I generally thin just about any bottom paint a little--it seems to promote a smoother surface from the roller, and ensures that a gallon will allow touch-ups of trouble-spots followed by a full coat. If I'm storing a partial can for next year, I leave a thin layer of water on top of the paint.

A common strategy with ablative paint is to put on one coat of a color that starkly contrasts with what you want, and then paint over it with the color of your choice. That first coat serves (for years to come) as a "signal coat" showing areas where the paint is thinning--such as on the foreward edges of the keel and rudder. Some years you only need to touch up the thin spots and refresh the color along your waterline. Depending on your sailing and power-washing, you might only need to add a full coat every other year. Letting it get too thick can promote peeling.

Often the reason bottom paint loosens from fiberglass is residual "mold release wax", applied to the mold before the hull is laid up. If the wax was never thoroughly removed with something like acetone before the first coat of paint (and too often it isn't), the paint will loosen forever, and the wax tends to stay forever. After sanding bare spots lightly, wipe down with acetone using gloves rated for solvents.

Dave Bristle
Association "Port Captain" for Mystic/Stonington CT
PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired),
Now on Eastern 27 $+!nkp*+ Sarge

Edited by - Stinkpotter on 04/05/2015 08:38:22

bigelowp
Master Marine Consultant

Members Avatar

USA
1736 Posts

Response Posted - 04/11/2015 : 14:47:32

All depends on the paint . . . . . one gallon (ablative) will do @1.25 coats un-thinned on my fin keel -- but that is with West PCF(?) Gold when I (the frugal one) does the job. The yard pained last year not using the West system and used 1.5 gallons (more or less) for one coat. My guess is that if we are in tougher environments and or on a mooring/slip we will be less likely to thin the paint and will, therefore, use more. A trailer sailor has more leeway to cut with thinner and get more use out of anything they put on the bottom. Ditto for those who clean their bottoms mid season. Anyway, my rule of thumb is one gallon per coat per season.

Peter Bigelow
C-25 TR/FK #2092 Limerick
Rowayton, Ct
Port Captain: Rowayton/Norwalk/Darien CT

GaryB
Master Marine Consultant

Members Avatar

USA
4275 Posts

Response Posted - 04/11/2015 : 18:34:39

I'm going on 7-1/2 years on my bottom job and about 3 years since I had the bottom pressure washed. And the boats been in the water the whole time. Not sure why you guys aren't getting more life out of your paint.

Association Member

GaryB
Andiamo
'89 SR/WK #5862
Kemah,TX

Edited by - GaryB on 04/11/2015 18:35:51

Stinkpotter
Master Marine Consultant

Members Avatar

Djibouti
9015 Posts

Response Posted - 04/11/2015 : 20:58:18

quote:
Originally posted by GaryB

I'm going on 7-1/2 years on my bottom job and about 3 years since I had the bottom pressure washed. And the boats been in the water the whole time. Not sure why you guys aren't getting more life out of your paint.

Agreed, to a point... If the paint is ablative, it's mostly an issue of how much time the boat is in motion through the water. If the paint is hard, it has to be re-done after winter storage on the hard. Hard paint can be effective for several years if kept in the water. Ablative paint is not significantly affected by winter storage on the hard, and should last at least a couple of seasons on a lightly-used sailboat in salt water. It can be added as needed, and the contrasting "signal coat" approach is a good strategy.

By the way, one thing I've concluded about the water-based Pettit Hydrocoat SR I now use is that being water-based, it doesn't seem to loosen the underlying paint the way that I've seen oil-based paints do. Correspondingly, Pettit says it can be applied over "anything"--I think I now know why.