On Fri, 2 Oct 2009 05:41:37 GMT, wrote:


I'm looking for some info on aluminum boats. I currently have a 21 ft
Seaswirl Striper (fiberglass). It's a good boat...but I want something
that is more appropriate to the weather here in Oregon so I'm looking
for
something with an enclosed cabin. And since I'm getting to old and heavy
to be climbing along the outside of a cabin, the walk through windshield
sounds like a good idea. Apparently that limits me to aluminum boats,
although I've no real preference either way. The two models I like so
far
are the Hewescraft Ocean Pro and the Weldcraft Ocean King (links below).
If anyone knows of a fiberglass model with similar configurations to
those,
please let me know.

http://www.hewescraft.com/2007/oceanpro/index.html

http://www.weldcraftmarine.com/model...cean_king.html

SInce it looks like I'm going aluminum, I'm hoping to get the benefit of
others experience.

One of the significant differences is that the Weldcraft boats have a
"marine grade plywood" floor while I believe the Hewescraft boats have
an
aluminum floor. Although the Weldcraft boats certainly look nice in the
pictures, my first impression on the plywood was that they were cutting
some corners to make it cheaper. Or am I wrong there? A wooden floor
would certainly be easier to remove than a welded floor should any under
floor maintenance be required. So I'm hoping to hear what people who
have
actually owned an aluminum boat think about the pros and cons of each.

Another probably stupid question is regarding the corrosion issue. I've
heard the story of the copper penny eating through the hull. While I'm
not
planning on experimenting with a $60,000 boat...it does make me wonder
how
expensive that sort of thing would be to repair.

Also, I've heard that corrosion is less of an issue for boats that are
trailered. I'm figuring on every other weekend in the water, with about
a
70/30 split between salt and fresh water...plus maybe two weeks a year
moored in salt water during the summer salmon season. I've heard that I
should use magnesium in fresh water and a less noble aluminum in salt
water. So...for a boat that goes back and forth...do I need to swap them
out, use both, or just use one or the other?

Ray in Oregon

Ray,

If you are 70% in salt and 30% in fresh use Aluminum. Your primary
concern must be protecting your boat in the most corrosive water
type... salt. And.. who want to change their anodes each time? Mag
anodes work great but for fresh water only. If you use them in salt
you will actually see them working like an anti-acid puck. So avoid
Magnesium if you touch salt or even brackish water. Your anodes will
not waste away very quickly if you trailer your boat. It takes
approx. 24 hours for the the cell to stablize anyway. I have 20 years
experience in the pleasurecraft corrosion field.

Reply:

Copper in an aluminum boat will set up a battery in salt water. It will
corrode through. The only hole in my boat in 18 years was in the anchor
locker where a piece of copper wire lodge in a plugged limber hole. Cost
me
$100 to have the hole TIG welded by a real expert at TIG. I have an
aluminum spool gun and do weld aluminum. but sometimes it pays tio hire an

artist.

Yeah...that's kind of my concern. A stray piece of wire or what not getting
dropped somewhere. That's why I'm so curious about the wood floor. A wood
floor would be a safe place to set something metal...but it would also
provide cracks and crevices for smaller stuff to hide in.

So, in the case of the wire in the anchor locker, the hole there was the
only damage? While I'm sure it's not fun, just having a small hole welded
doesn't sound so bad. I've heard people talk about the entire hull getting
thin. But I think I'm confusing the potential problems and causes. So, to
recap...there are two basic concerns:

One is corrosion caused by contact between dissimilar metals, which can
occur in or out of the water? And prevention requires special coatings or
other protective separation between the metals. I've heard people say that
it's ok to use stainless steel screws. Or does that still require some sort
of treatment? I'm thinking mounting stuff like rod holders and such. If I
use stainless steel screws, is it as simple as drill and screw?

And the other concern is electrolysis. It is more common in salt water, but
will also happen in fresh water. If not controlled, it will cause a
thinning of the hull wherever the hull is in contact with the water. It's
controlled by the proper anodes, and a trailered boat will allow the anodes
to last longer because the of the reduced water time. Would water
accumulation inside the boat, such as rain water, cause the same reaction
even if it's on the trailer?

Thanks again to everyone.

The drain plug, if the bow is high, should drain rainwater. Just don't
leave the plug in when the boat is sitting on the trailer!
--
John H

All decisions, even those of liberals, are the result of binary thinking.