Stevej, the battery is in one of those battery boxes and its out of the weather, so I have NO idea lol
Stevej, the battery is in one of those battery boxes and its out of the weather, so I have NO idea lol
I was looking at the pics through the dirty screen on my phone and I couldn't really see what it was, I can see it better now on the desk top and it looks like salt or calcium build up. No idea how to fix it.Originally Posted by 2_kilo_killer
2 kilo killer u can use a cheap Multimeter from dicksmiths u place one terminal onto the hull and the other end on a earth wire and see if u have any power running thru the hull it should read 0.00 if u have any plus reading u have power running thru the hull
i think it could be either two problems
u scrubbed it back and didnt use etch primer or its elctrollysis, i hope its the first one for your sake
my mates bought a boat it was advertised for $24,000 they offered the guy $14,000 and he accepted we checked the boat over and someone had installed a electrical box for a main power off switch and the silly bugger bolted the black earth wire directly to the hull resulting in the whole hull rotting with electrollysis but lucky i spotted it and solved the problem before it got any worse and it fixed the problem
The hull will always be connected to the battery negative through the motor.
Is that corrosion also happening in the next channel?
Is there a trailer skid in the area below it?
Marto I appreciate u looking mate. Ta
Gazza, I'll grab a multimeter from Dickys ASAP n check it. What do u mean didn't use etch primer, what is that?.Sorry I know it's a dumb question but I hate to pretend to know and nod along with people lol
Fed, it is in the channel below it also but not as bad. I'll have to check the skid in the morning n get back to you. Cheers
Bugger, vinegar didn't work blacktoboats. Thanks anyway mate.gotta try everything hey lol
etch primer is a special aluminum primer u apply before painting, it etches the metal so the paint will stick otherwise it just flakes off over time
Are you using a steel wire wheel brush on your drill?
2_k_h,
Firstly, NEVER use a wire wheel on ally, especially when it is in a salt water environment, even more so if it is in an area as shown (bottom sheet pressing that obviously 'held' a bit of salt water over some time).
In cleaning (abrading) the ally, some of the wire (minute pieces) gets worn away and collects in areas as ferrous dust, but also imbeds the ally surface. Add a perfect electrolyte (concentrated salt water) and you have the perfect environment for accelerated galvanic action (without any stray current involved).
Much better to use a scotch barrel buff in the drill, talk to a tool shop etc. can also get them with scotch/sand paper etc.
Did you remove the floor to take these pics? (I can see 'low flour gussets in the second pic). If so, where does the floor edge meet the bottom sheet? About the same area as the crusty deposits? Floor boards wrapped in carpet?
Out of interest? Did the hot water melt the crusty deposit at all?
Forget vinegar, total waste of time, it's just not strong enough.
1. Remove all crap from tinny and pressure clean all internals, concentrating on affected area. Inspect for pitting etc.
2. From Bunnings buy some HCL, hydrochloric acid (pool section, or near concrete coatings area), and get appropriate PPE if you don't have it. 1L should do, but not sure it comes in this small qty.
3. Cut small strips of rags, say 60mm wide, and lay in pressings along a 'test piece' of the affected pressing(s). Get boat bottom level if possible.
4. 'Carefully' mix acid and water in the ratio 1:20 acid to water. I.e. 50ml acid to 1000ml water. Must add acid to water, not the other way round.
5. Carefully apply to affected area to wet sufficiently. Lift rag strips and inspect after 3-5 mins. Acid mix will clean the affected area, but can be aggressive to ally too if left too long. If no reaction try another 5 mins etc, but don't leave too long. May be better to go a stronger mix than leave too long.
6. Flush area very well with water (hose), then apply same to all affected areas once you have it sussed.
Cheers
Brendon
PS. Inspect pitting very closely!
Sent from my iPhone using Tapatalk
yeah, I did mention to just try it first before moving onto something stronger. Diluted pool acid should work, I agree.
Cw yes I was. Ummm yr post and the next post tells me I shouldn't have ....shit. Cheers mate
Gofishn, jeez. Thanks for that....I did the vinegar thing on the footpath with a chunk of salt?, nothing. Then found some hydrochloride acid in the garage, repeated this on the footpath and NOTHING, with straight acid
...yes I removed the floor...."low flour gussets"..what does that mean ?(sorry).... Yep it's a half floor like the hornets have and its a carpeted floor with marine carpet. I don't think the floor ACTUALLY meets the hull. It's screwed on further inside..
hotwater did nothing
wow the rest, umm given that straight acid didn't dissolve the chunk on the footpath, does that negate points 1-6?
thanks heaps. It's very frustrating
Hi 2 -k-k , I wouldnt be using a ferous wire wheel or hydrochloric acid on a alloy tinnie at all . If you want to clean it up with acid I'd suggest u use an inhibited phosphoric / hydrofluric acid - such as mag wheel cleaner at about 10 to 20% solution .apply it with a synthetic scourer . If you use hot water it will work quicker , make sure you rinse it off and out of the hull very thoroughly after about 2mins and dont get it on yourself.ie rubber gloves and safety glasses.Id then follow this with a wash with a mild solution of an alkaline cleaner ie 1% truck wash - this will neutralise the acid residue - coating the affected area in white oil will also slow the corrossion issue.
Regards
Beastmaster
Keep Ya Tip UP
Beast
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