Proper way to bottom paint alloy?

v26wa · #1

Ok, beached the boat today after about 5 weeks in the water. The bottom was covered with "slime" that when its dry is impossible to get off. I had a 7 h.p. pressure washer to her & still couldnt get it all off. So next year I think I will bottom paint her. I could have fished all day, not cleaned :x ! So whats the proper way to apply the paint & any brand recommendations ? Thanks !!

http://www.youtube.com/user/BLM26CC · #2

Holy sand blasting Batman,

Wow, sounds like the best bottom paint to me, is called "Mr. Trailer" having relations with..."Missy Boat ramp".

Did Bostons toughest scum come off where the hull, where it met the beach? Maybe more beachings are in order.

:roll: :lol: :lol: :lol: :roll: Don't mind me. I just never get the reason for the in-water, months at a time, "nort o' de border".

Comedy styling of the Jettywolf.....over & out.

Thank you , thank you.....proceed., please.

#3

I have seen a few alloy boats pressure washed & even barnacles fly off. Is the nozzle on the cleaner wand up to scratch?

v26wa · #4

Peter, the stuff came off ok when wet, but when dried on it was a bear to get off. My point being that I could have spent the day fishing instead of cleaning. Thanks peter !

#5

Jay or Jim might be along soon .

When I'm in FL. and in the water for a couple weeks, when I haul out I use a sponge and freah water and in about 15 min. Im good to go down the road.

#6

I'm sure Pacific has a preferred process

The way I do it for an unpainted hull is home brew but it seems to work well:

Tape the waterline with blue masking tape and then cover that with thick duct tape (like gorilla tape). Make the blue tape wide enough so the duct tape does not contact any aluminum. The heavy tape withstands the blasting to come next

Using a pressure washer with a sand feeder I water/sand blast the bottom to a bright abraded surface, rinse with high pressure water fed with a mild acid solution.

Blow off with air, get hull dry quickly

Apply Interlux etching primer, 2 part, 1 thin coat as soon as hull is bone dry

Apply Epoxy barrier coat, 2 coats (helps electrically isolate the hull from water and provides a better foundation for the bp)

Before last epoxy coat is hard apply first coat of bottom paint, I've been using E-paint lately, pretty good results

Apply one or two more coats of the bottom paint.

Next time if you sand be sure to not sand thru the barrier coat, the job is much easier on repaints, just clean, sand lightly, mask & paint like a glass job.

v26wa · #7

Thanks Chaps. Do you need barrier coat or can you paint directly on aluminum ?

#8

IMO you need to at least apply the etching primer. The barrier coat provides additional benefits at nominal additional cost especially considering the ease of adding it to the process. However bottom paint on bare aluminum will not perform well since the alloy will oxidize and kick it off.

http://www.youtube.com/user/BLM26CC · #9

right on, I knew someone sensible would be along soon.

#10

I was always told that after sanding the hull you have to put equal amount of coats (min.2) of primer as you do bottom paint. I use the interlux aluminum primer, three coats then two or thrrr coats of Trilux with bilox at the bottom of each season. The trilux wears off and is so thin by end of the season there is never any build up to have to deal with like you get on micron on NON ALLOY boats. Maybe john from ironwood could give more details. Mty

#11

Marty, the etching primer is only needed as 1 thin (translucent ) coat, It is an acid base and it digs in and seems to stop oxidation quite well. I advocate for 2 coats of epoxy barrier over the etch primer before the bottom paint but it isn't a deal killer. Other primers (over the etch) are a plus as well.