Hi,
I am about to have a new mast step fabricated for my Pearson Vanguard, per the
specs on the owners website. The website calls for a step to be fabricated in
steel, but my question is: will this not react corrosively with my mast? Even
if painted or powdercoated, I am sure that eventually steel would contact
alluminum. Any advice on the best sollution here will be greatly appreciated.
Thanks,
Hal

Cautions: I haven't seen the website and don't know the Vanguard.

1) You can certainly isolate the stick from a steel mast step with suitable
plastics, but why bother?

2) Unless this is DIY and you don't weld aluminum, the extra cost of having
a pro fab it out of aluminum will be small. Aluminum is more expensive and
the welding rig is a little more expensive, but cutting the pieces is much
easier.

3) Preferably use one of the marine aluminum alloys in the 50xx or 54xx
series (for example, 5052). 6061 is very much easier to get and will
probably do just fine. I'd be happy with 6061 unless it was going to be wet
with bilge water often.

4) Paint or anodizing is not required -- aluminum hulls are often left
unpainted above the W/L.

--
Jim Woodward
www.mvFintry.com



"HallotParson" wrote in message
...
Hi,
I am about to have a new mast step fabricated for my Pearson Vanguard, per
the
specs on the owners website. The website calls for a step to be
fabricated in
steel, but my question is: will this not react corrosively with my mast?
Even
if painted or powdercoated, I am sure that eventually steel would contact
alluminum. Any advice on the best sollution here will be greatly
appreciated.
Thanks,
Hal

HallotParson wrote:

Hi,
I am about to have a new mast step fabricated for my Pearson Vanguard, per the
specs on the owners website. The website calls for a step to be fabricated in
steel, but my question is: will this not react corrosively with my mast? Even
if painted or powdercoated, I am sure that eventually steel would contact
alluminum. Any advice on the best sollution here will be greatly appreciated.

The problem of steel reacting galvanically with the mast is a small and easily
corrected problem: just put a small piece of hi density plastic between the mast
butt and the step.

A bigger problem is putting a big hunk of steel in the bilge. It will rust away
quickly and leave you with a dirty bilge in the meantime.

I would either follow Jim W's suggestion and get the frame made in aluminum, or
else take another tack entirely and mold it out of fiberglass. A triaxial
knit/epoxy grid would be plenty strong and impervious to galvanic corrosion & rust
too. It would also bond to the hull & stringers better, improving the strength &
rigidity of the boat. Best of all, you can do it yourself with good fiberglassing
skills (which if you don't have, you would benefit by learning) and no special
equipment. And it will last at least as long as the rest of the boat, which is not
true of aluminum and definitely not true of steel.

Fresh Breezes- Doug King

I think we've missed something here, Doug. The drawing at
http://www.pearsonvanguard.homestead...les/index2.htm
isn't very clear, but I think the mast is stepped on deck. The door to the
head appears to be on center directly below the mast, so the step carries
the load to posts at the fore and aft head bulkheads.

Also, the drawing of the suggested step at
http://www.pearsonvanguard.homestead...les/index2.htm
doesn't specify a material, but it calls out 5/16" plate. That's pretty
beefy in steel, so I suspect aluminum was in mind.

I agree that for a step out of sight in the bilge, that modern glass and
epoxy would be at least as good as, maybe better than aluminum, and,
something that a reasonably competent DIY person could do.

For one that's in sight on deck, however, aluminum is likely to be prettier
unless the builder does a lot of work on finishing, hard to do inside a
complicated piece.

Another possibility would be to use commercial fiberglass shapes -- either
channel or angles -- plenty of strength, easy to fab in the home shop, and
would look very professional when painted. (go to www.mcmaster.com and
search on fiberglass channel or angle -- McMaster is not a low cost or
specialist vendor, but they have some of everything you can imagine).



--
Jim Woodward
www.mvFintry.com

..
"DSK" wrote in message
...
HallotParson wrote:

Hi,
I am about to have a new mast step fabricated for my Pearson Vanguard,
per the
specs on the owners website. The website calls for a step to be
fabricated in
steel, but my question is: will this not react corrosively with my
mast? Even
if painted or powdercoated, I am sure that eventually steel would
contact
alluminum. Any advice on the best sollution here will be greatly
appreciated.

The problem of steel reacting galvanically with the mast is a small and
easily
corrected problem: just put a small piece of hi density plastic between
the mast
butt and the step.

A bigger problem is putting a big hunk of steel in the bilge. It will rust
away
quickly and leave you with a dirty bilge in the meantime.

I would either follow Jim W's suggestion and get the frame made in
aluminum, or
else take another tack entirely and mold it out of fiberglass. A triaxial
knit/epoxy grid would be plenty strong and impervious to galvanic
corrosion & rust
too. It would also bond to the hull & stringers better, improving the
strength &
rigidity of the boat. Best of all, you can do it yourself with good
fiberglassing
skills (which if you don't have, you would benefit by learning) and no
special
equipment. And it will last at least as long as the rest of the boat,
which is not
true of aluminum and definitely not true of steel.

Fresh Breezes- Doug King

Jim Woodward wrote:

I think we've missed something here, Doug. The drawing at
http://www.pearsonvanguard.homestead...les/index2.htm
isn't very clear, but I think the mast is stepped on deck.

I get a broken link. Can't see a thing. IIRC almost all the Phil Rhodes designs
had keel stepped masts, but my memory ain't what I used to think it was.



The door to the
head appears to be on center directly below the mast, so the step carries
the load to posts at the fore and aft head bulkheads.

Aye caramba... could that be the way it's 'sposed to be? Not even a cross beam
under the cabin top skin? It's hard for me to believe Rhodes designed it this
way!



Also, the drawing of the suggested step at
http://www.pearsonvanguard.homestead...les/index2.htm
doesn't specify a material, but it calls out 5/16" plate. That's pretty
beefy in steel, so I suspect aluminum was in mind.

I agree that for a step out of sight in the bilge, that modern glass and
epoxy would be at least as good as, maybe better than aluminum, and,
something that a reasonably competent DIY person could do.

For one that's in sight on deck, however, aluminum is likely to be prettier
unless the builder does a lot of work on finishing, hard to do inside a
complicated piece.

Or use peel ply. Still have to do some sanding & finishing, but not as much as
with steel. Here's where aluminum has a big advantage... no finishing, and it's
sure to be a bit lighter than the FG piece. If it's going to be outside in the
weather, I'd doubly rather have a chunk of fiberglass, plus you can put nice
rounded corners on it.



Another possibility would be to use commercial fiberglass shapes -- either
channel or angles -- plenty of strength, easy to fab in the home shop, and
would look very professional when painted. (go to www.mcmaster.com and
search on fiberglass channel or angle -- McMaster is not a low cost or
specialist vendor, but they have some of everything you can imagine).

Good idea.

I can tell you firsthand that molding small custom fiberglass structural pieces
doesn't take a lot of skill or money, but it does take some time. Looks like
McMasters could save a goodly numbert of hours.

Fresh Breezes- Doug King

Thanks for the info - you are right, I assumed steel, since that is what the
original was made of, covered with a fiberglass structure, but aluminum would
be a much better solution. I should have specified that it was on deck and not
the keel.
Thanks again
Hal