[motownbob]

I have a 1997 crestliner sportfish. Stictly a fresh water boat, kept on a trailer. Lately i have noticed some very tiny blister like bumps on some of the painted surfaces of the aluminum, especially noticeable around the drains in the transom[splashwell]. Does anyone have any idea on what is causing this? What to do to stop this from getting worse? Thanks, Bob

[Solittle]

I'm going to guess that you have an electric start motor with battery. If so you may have a small current leak somewhere. No big deal - just disconnect the battery when not using.

[allanwh]

I have a 20 foot aluminium hull with a 130 hp honda and I am having the same experience.. Paint Blistering around rod holders and where stainless screws penetrate the hull. I will disconnect the batteries as suggested but I have also been told that a sacrificial anode on the hull will help. Can anyone add to this..Thankyou

[akriverrat]

yeh. get rid of the paint. it traps water beneath it and rots the aluminum. paint may be pretty but with most aluminum boats it ends up being a liability.

[Luna Sea]

Disconnecting the battery wont help if the battery's not in a box. I learned that one calm drizzly weekend sitting in salt water. Yup, right where the deck meets the back of the boat I got those dreaded pin holes. Current travels through the moisture or something to that effect. Drilled a couple of holes in the hull and added a bolt on zinc. If you do this, lock the studs/bolts in place with nuts and washers, then add the zinc otherwise when the zinc goes you'll start leaking.

[1sinbad2]

I am considering a 2000 crestliner Sportfish 1750 and the paint on the aluminum plate around the perimeter of the bow is blistering. Should I just remove the paint and polish the aluminum or install some sort of sacrifical anode. I'm a newby--but is a "zinc" a sacrifical anode? I am not a corrosion engineer. How or where should the sacrifical anode be placed.

[Bond-o]

I just went thru this a couple of years ago, with my 74 Starcraft 221 Islander.......Before I painted my hull, I noticed that anywhere there Wasn't any paint left, I had tons of Pin-Holes...... The Original paint was getting pretty thin over most of the hull....Anyway, I sanded, zinc primed, sandable primed, sanded,+ sanded,+ Shot it with a 2-part Urethane paint..... I then added 3 coats of brushed/rolled Rustoleum, Below the water line........ Being a trailer boat, I now just touch up the bottom a couple times a year, with just a disposable brush....After all this work I found some more pits in some scratches......I found that by Bonding the boat, the Hull should be bonded to the engine, just like the outdrives are bonded to the engine...... This gets everything on a level playing field, so to speak.....Then, You have to Ground All of your Electrical Circuits Directly to the Batteries.......And the Pitting Stopped.....AAnnndddd, The Added Bonus of a Properly Bonded Aluminum Hull(Cabin prefered)........Is the Safety Factor of the Faraday Cage Effect,In case of Lightning Strikes...........

[Lark40]

I'm reading these posts in amazement.My Crestliner outboard runabout is 45 YEARS OLD! Electric start since new and has no corrosion or leaks whatsoever.And, it runs in semi-salt water (Chesapeake Bay).Add all the zincs that people are recommending, you have some sort of electrolysis problem.Bondo - we also have the same (other) boat. I have no corrosion, but the rivet problem is well known. I'm printing out all your good advice.

[1sinbad2]

Bondo--how do you bond the boat to the hull? Can the paint be removed and the aluminium be left unpainted?

[Bond-o]

how do you bond the boat to the hull?

???? Boat to Hull,??? 1 in the same isn't it????Go do a Google Search.... It's Really a Very Indepth thing..... BASICLY , Grounding(bonding) Everything Together.....

Can the paint be removed and the aluminium be left unpainted?

I have No Idea....I prefer Painted Boats.... Bare Aluminum will Oxidize in a matter of Hours,+ turn Grey......