[C38] Stanchions
Anders Finn
anders at finn.ws
Tue Feb 1 02:05:21 EST 2011
Steve,
If you go to the website, and click the image (not obvious I know)
you'll get a brochure. It says 6063-T5, my dad's abbreviating where he
should not be when talking about shear strength rather than tensile
strength.
Spec for 6063-T5 is:
Al: 97.5% (max)
Cr: 0.1% (max)
Cu: 0.1% (max)
Fe: 0.35% (max)
Mg: 0.45-0.9%
Mn: 0.1% (max)
Si: 0.2-0.6%
Ti: 0.1% (max)
Zn: 0.1% (max)
other: 0.05% (max each)
other: 0.15% (max total)
Anders
On 01/31/2011 10:28 PM, S Orton wrote:
> Did the tech at Taco Marine tell you what material the rail extrusion
> is? I always assumed it was a 6000 series which is not a very strong,
> but is weldable, free machining and has good corrosion resistance.
> 6061 can have up to .7 % of iron in its alloy. I've been retired from
> the aircraft design for 13 years and to me T5/T6 is not a material,
> but a temper (strength) condition of the material. Please re-educate
> an ole dog.
> Cheers, Steve O
> ------------------------------------------------------------------------
> Date: Mon, 31 Jan 2011 23:17:44 -0500
> From: charles at finn.ws
> To: listserve at catalina38.org
> Subject: Re: [C38] Stanchions
>
> T5 is a lower cost material than T6. Not as hard or strong, but still
> some of the strongest aluminum made. It is a bit more ductile.
> So, is it strong enough to support those torsional forces?
> Inquiring minds want to know!
>
> And Thanks!
> Chuck Finn
> Mighty Quinn #114
> Great Lakes
>
> On 1/31/2011 8:15 PM, Anders Finn wrote:
>
> Ask and you shall recieve
>
> http://tacomarine.com/item--1-9-16-x-1-1-2-Aluminum-Sailboat-Toe-Rail--A62-0009.html
>
> According to the tech's at Taco Marine, this is our toe rail spec.
>
> Anders
>
> On 01/30/2011 12:56 AM, Steve Smolinske wrote:
>
> I have worm holes on the aft section of the stbd rail far away
> from the gates. Good luck fishing that line I did that once
> took me most of a morning
>
> Steve Smolinske
>
> Sent from my iPhone
>
> On Jan 29, 2011, at 7:55 PM, "Patrick Harpole"
> <1derful at comcast.net <mailto:1derful at comcast.net>> wrote:
>
> *Speaking of stanchions and "worm holes" I got the
> pleasure of worming a wire through pulpit (aka stanchion)
> because the bow navigation light wiring failed.*
>
> ----- Original Message -----
> *From:* Max Soto <mailto:maxsoto at gmail.com>
> *To:* Catalina 38 Listserve
> <mailto:listserve at catalina38.org>
> *Sent:* Saturday, January 29, 2011 5:31 PM
> *Subject:* Re: [C38] Stanchions
>
> The weirdest thing is that the worm holes on the rails
> are not located near a single fastener. Thy are
> located on the sides of the rails... Most of them on a
> single side.....
> Max
>
> Sent from my iPod
>
> On Jan 29, 2011, at 6:09 PM, S Orton
> <ssorton at hotmail.com <mailto:ssorton at hotmail.com>> wrote:
>
> I should of continued with the "worm hole"
> discussion, adding I don't consider it a
> structural problem unless a hole develops
> at several adjacent fasteners thereby destroying
> the clamping force between the hull and deck. If
> it is a hole here and there, fill it with 5200 and
> forget it.
> Cheers, Steve O
>
> ------------------------------------------------------------------------
> Date: Sat, 29 Jan 2011 13:26:43 -0500
> From: steve.ribble at gmail.com
> <mailto:steve.ribble at gmail.com>
> To: listserve at catalina38.org
> <mailto:listserve at catalina38.org>
> Subject: Re: [C38] Stanchions
>
> Don't know who made the toerail, but the same
> cross section is used by several different boat
> builders of the era so it must be an established
> extruder...I had the same thing on a 1980 Mirage.
>
> On Sat, Jan 29, 2011 at 1:11 PM, Chuck Finn
> <charles at finn.ws <mailto:charles at finn.ws>> wrote:
>
> Steve,
> I called Garhauer yesterday about stanchions
> and the toerail. Mike told me they never made
> the toerail as that is not something they are
> set up for. He was interested in my idea of a
> toerail stanchion, but would make no comment
> until he had seen what our toerail looks
> like. He offered to work with me on this
> after I got him some specs/pictures of our
> rail. Does anyone have a cross-sectional view
> and/or measurements?
>
> If I were to guess, I would say our toerails
> were made of T6 aluminum as it extrudes and
> anodizes well and is one of the hardest and
> strongest types. I have cut this stuff on a
> lathe and it does not remotely behave like
> ordinary aluminum! You need ear protection.
> I agree with Steve O. that low bidder could be
> our problem here, which of course would vary
> by batches and years. All aluminum I am aware
> of can contain some small levels of iron, but
> I recall Grumman successfully figured out how
> to reduce this back when they were the
> aircraft frame folks. By the way, don't try
> to weld on this stuff as it requires TIG and a
> lot of practice! One more thing, aluminum can
> corrode when exposed. The neat thing about
> this stuff is it almost immediately begins to
> form an impermeable skin as part of the
> corrosion process that essentially stops
> further corrosion and it is able to do this
> across a wide PH range. Now you know pretty
> much all I know about this stuff!
>
> Regards,
>
> Chuck Finn
> Mighty Quinn #114
> Great Lakes
>
> On 1/29/2011 12:19 PM, S Orton wrote:
>
> Phil, I don't think a backing plate is
> worth the effort- the underside
> clearance/access is very tough. Use
> oversize washers if possible. If the
> holes are rotted out, fill with epoxie and
> redrill. My toe rail also has worm holes,
> near the gates. I assumed the reason was
> low bidder on the extrusions with much
> more impurities included. The aircraft
> specs would preclude what we a seeing.
> Has anybody contacted Garhauer about this
> problem? I can understand corrosion at
> the SS fasteners, but these worm holes
> appear unrelated.
> Cheers, Steve O
>
> ------------------------------------------------------------------------
> Date: Sat, 29 Jan 2011 10:09:44 -0500
> From: steve.ribble at gmail.com
> <mailto:steve.ribble at gmail.com>
> To: listserve at catalina38.org
> <mailto:listserve at catalina38.org>
> Subject: Re: [C38] Stanchions
>
> Great thought about the backing plate,
> Phil. I've always considered stanchions
> and lifelines to be expendable in the
> event of emergencies...that they were
> basically to break your fall, not
> necessarily there to support the weight of
> the world. That said, obviously I/we
> don't want to replace these things every
> month or two so they need to be stout
> enough. It seems like one of the first
> things to go, when looking at the entire
> stanchion "system" is the through-bolt
> hole (as Phil indicated) and that a
> backing plate would disperse the
> loads/forces among the 4 bolts/holes
> rather than the two that experience
> expansion when torque is applied the the
> stanchion. Long story short, assuming
> we're all not going to run out and replace
> our stanchions for another design, that
> Garhauer already has the the backing plate
> (the base prior to welding to the
> stanchion tube) so it should be an easy
> and relatively inexpensive process to
> upgrade the holding power of our existing
> equipment.
>
> On Fri, Jan 28, 2011 at 8:07 PM, Phil Gay
> <eyriepg at comcast.net
> <mailto:eyriepg at comcast.net>> wrote:
>
> I thought I would explain what I think
> I know about metals from my aircraft
> engineering background. I agree that
> the toe rail on our C38s is an
> aluminum alloy. Pure aluminum does
> create its own oxide coating which
> retards corrosion. But, when it is
> alloyed to increase its hardness and
> strength, it loses the ability to
> protect itself unless it has a pure
> aluminum cladding on the surface.
> Typically these alloys have an anodic
> coating (the dark surface on our toe
> rails) or a chemical conversion
> coating which created this protective
> oxide on the exterior surface.
>
> Near the bow of my C38 the toe rail
> has started to pit. I don’t think it
> has progressed much lately with all
> the rain water that we get here in the
> NW. I doubt that it has weakened the
> extrusion much at all. I agree with
> the statements about the loads on the
> stanchions. Later model Catalinas
> have the stanchions that fit into
> sockets molded into the toe rail as
> well as being bolted through base
> plates to the deck. BTW I am pretty
> sure that the deck area where the toe
> rails are attached on our C38s is
> solid un-cored fiberglass. A lot of
> the looseness of the bases is caused
> by the rocking of the bolts, and
> subsequent elongation of the holes,
> because they don’t have backing plates
> to hold them vertical. I think that
> there are ways to securely attach our
> stanchions to the toe rail if they are
> also bolted inboard to the deck. I
> have also thought about having the
> existing stanchions modified so that
> they angle outboard to allow more room
> to pass around the shrouds.
>
> Phil Gay
> C38 049 Que Linda
> Everett WA
>
>
> *From:*listserve-bounces at catalina38.org <mailto:listserve-bounces at catalina38.org>
> [mailto:listserve-bounces at catalina38.org
> <mailto:listserve-bounces at catalina38.org>]
> *On Behalf Of *Anders Finn
> *Sent:* Friday, January 28, 2011 4:25 PM
>
> *To:* listserve at catalina38.org
> <mailto:listserve at catalina38.org>
> *Subject:* Re: [C38] Stanchions
>
>
>
> Really? I thought that toe rail was
> aluminum. Should be pretty resistant
> to salt corrosion. I think what my old
> man is trying to say is that the toe
> rail is at least as strong, if not
> stronger than the plywood under the
> deck to which the stanchions are
> currently screwed into. It would be
> interesting to know the dimensions of
> the toe rail if anyone has them (I
> think my dad is going up to measure in
> a few weeks) and I can figure out what
> kind of moment could be applied safely
> to the toe rail if one could find a
> way to apply the load evenly.
>
> Anders
>
> On 01/28/2011 04:06 PM, Don Strong wrote:
> The toe rail really is not that
> tough. As well, in salty boats as old
> as mine (1980), the toe rail has some
> indication of chemical decomposition
> along the bottom side. I treat my toe
> rail with care. Like the rest of this
> wonderful 30 year old device, I hope
> it lasts longer than I last.
> Don
>
> On 1/28/11 2:15 PM, Anders Finn wrote:
> Think about pivot point. If there is
> indeed only two bolts, the only thing
> keeping it from pivoting is
> compression between the plate and the
> toe rail. The bolts are there simply
> to provide a leverage point. That's
> what concerns me.
>
> Anders
>
> On 01/28/2011 02:13 PM, Chuck Finn wrote:
> This type of fitting is used by: C&C,
> Hunter, PDQ, Bayfield, and Freedom
> yachts. I think the footprint is the
> entire toerail, which is significantly
> stronger than our pad fastened to a
> plywood deck.... If I was to worry
> about strength, it would be the shear
> force exerted on the bolts if the
> toerail stanchion base is not a good
> fit with our toerail... I would weld
> the stanchion to the base rather than
> rely on the throughbolt. I can also
> comment on the strength of at least
> the C&C toerail as I have raced these
> boats and that means bounced a time or
> two off the lines and stanchions!
> Have crewed Hunters as well, but don't
> remember the stanchion design.
>
> I think my next step will be to
> contact Garhauer as they are reputed
> to have first made our toerail. I
> also could easily fabricate my own
> bases that would incorporate Ander's
> ideas.
>
> But, will it look pretty?
>
> Chuck Finn
> Mighty Quinn #114
> Great Lakes
>
>
> On 1/28/2011 4:16 PM, Anders Finn wrote:
> Yeah, I just got a chance to look at
> this. I think Steve is right here
> about a large drop in torsional
> resistance. However, that being said,
> those stanchions forward of the
> cockpit are not really THAT strong. I
> would like to see at least a three
> bolt design with a larger outer plate
> to provide some surface to disperse
> the torque to the hull.
>
> Anders
>
> PS. They say they're used on Freedom
> 32's however, from pictures, I can't
> see anything resembling a toe rail
> that would support load on them.
>
>
> On 01/28/2011 12:42 PM, S Orton wrote:
> Chuck, If I understand the concept
> correctly, it is a very poor
> structural design. There is no foot
> print to react the outward cantilever
> force on the stantion- you need a four
> bolt pattern to react this force in
> all directions and I only saw two
> fasteners parallel to the toe rail.
> Cheers, Steve O
>
> ------------------------------------------------------------------------
> Date: Fri, 28 Jan 2011 08:27:31 -0500
> From: charles at finn.ws
> <mailto:charles at finn.ws>
> To: listserve at catalina38.org
> <mailto:listserve at catalina38.org>
> Subject: Re: [C38] Stanchions
>
> Max,
> Here is the rigrite url:
> http://www.rigrite.com/Hardware/Stanchions_&_Bases/Stanchion_Bases_SS.html#SS%20Stanchion%20Bases%20that%20Attach%20to%20Toerail
> <http://www.rigrite.com/Hardware/Stanchions_&_Bases/Stanchion_Bases_SS.html#SS%20Stanchion%20Bases%20that%20Attach%20to%20Toerail>
>
> As you can see, this would put the
> stanchion on the outside edge of our
> toerail and would eliminate the base.
> This would result in a lot of room on
> the deck. I am thinking of using two
> of the bases for the gate and then
> moving forward. My issue about this
> would look is that I will have to
> connect to the stern rails and bow
> pulpit, which would remain as they are.
> I would also have to fill all the
> holes in the deck from where the
> plates were and re-route the holding
> tank vent, but that would be worth it
> for the extra room on deck and the
> elimination of possible leaks.
>
> What to our C38 folks think?
>
> Chuck Finn
> Mighty Quinn #114
> Great Lakes
>
>
> On 1/27/2011 11:21 AM, Max Soto wrote:
> Chuck, Did you send a link for the
> rigrite stanchions?
> Regards,
>
> Max
>
> 2011/1/26 Chuck Finn <charles at finn.ws
> <mailto:charles at finn.ws>>
> One way I know it is sailing season is
> the scrape on my shin obtained as I
> climb from the cabin to the cockpit.
> The other wound is the bruises on the
> side of both legs as I bang into the
> stanchions. I love the look of our
> boats, but the design idea that the
> stanchions should follow the inward
> bend of the tumblehome really does not
> work for me. There just is not enough
> deck for a guy my size. I am still
> considering bending and re-welding the
> current stanchions into a vertical
> position, but perhaps even a better
> solution would be to remove the
> current stanchions altogether and
> going with a toe rail stanchion like
> you see on C&C yachts. Rigrite.com
> <http://rigrite.com/> has these.
> Attaching stanchions directly to our
> toerail seems to be a viable option as
> the rail is really heavy duty.
> Additionally, you can buy the bases
> and use the current tubing assuming it
> is not the light weight stuff Tom has
> commented on. This would give us a
> lot more deck space for size 11 feet.
> Just thinking aloud at this point, but
> I really am tired of the bruising!
>
> Chuck Finn
> Mighty Quinn #114
> Great Lakes
>
>
> On 1/25/2011 3:25 PM, Max Soto wrote:
> Good to know that they share the same
> foot print... If the removable
> stanchion's base also fits, I'll go
> for that one next time..... A little
> heavier, but if they bend, it will be
> so much easier to replace.......
> Thanks, Max
>
> 2011/1/25 Steven Ribble
> <steve.ribble at gmail.com
> <mailto:steve.ribble at gmail.com>>
> Max, yes...same foot print. Garhauer
> has a square-ish base that I think are
> for removable stanchions and a one
> that's trapezoidal for the solid/fixed
> type, which is what mine are (also
> characterized by the "flat top"). I
> can't speak to the quality comment
> that Tom refers to, I just know mine
> have been on the boat for 30 years and
> only needed to be replaced because the
> over-wintering force exerted by the
> shrinkwrap caused them to bend. I
> thought I saw reinforced/gate style
> stanchions on their website, but don't
> know about the footprint.
>
> On Tue, Jan 25, 2011 at 12:13 PM, Tom
> T. <tdtron at earthlink.net
> <mailto:tdtron at earthlink.net>> wrote:
>
> After hurricane Dennis (the Menace)
> skirted Tampa Bay a few years ago with
> a near miss, we got tangled up with a
> piling with the surge and had our
> starboard lifelines damaged along with
> the stanchions on that side.
>
> I replaced the stanchions near the
> rail at the aft end of the cabin
> with Catalina Direct stanchions. I
> replaced both sides so they would
> match. My boat had standard
> stanchions and those stanchions should
> have been the reinforced gate entry
> types which are heavier and more
> expensive.
>
> I didn't shop Garhauer and I probably
> should have but the original
> stanchions were JUNK so anything was
> an upgrade! The metal in the
> replacement stanchions was much
> heavier gage and with the reinforced
> foot design of the gate type stanchion
> there was no comparison between
> quality or strength of the two types.
>
> The reason I bring this up is some of
> our members may have stanchions like
> the ones I replaced which may be a
> disaster waiting to happen. If the
> stanchions at the front of the gate
> are like the thin, weak ones like I
> had they could fail. The thin tube
> original stanchions may be OK for
> middle of the lifeline mounts but
> where the gates terminate they are
> inadequate
>
> Tom Troncalli
>
> ----- Original Message -----
> *From:*Max Soto
> <mailto:maxsoto at gmail.com>
> *To: *Catalina 38 Listserve
> <mailto:listserve at catalina38.org>
> *Sent:*1/25/2011 12:00:20 PM
> *Subject:*Re: [C38] Stanchions
>
> Steve, do they have the same
> footprint???
> Regards, max
>
> Sent from my iPod
>
>
> On Jan 25, 2011, at 9:30 AM,
> Steven Ribble
> <steve.ribble at gmail.com
> <mailto:steve.ribble at gmail.com>>
> wrote:
>
> Our stanchions are
> Garhauer...I replaced a couple
> last season...about $50 each.
>
> On Mon, Jan 24, 2011 at 7:06
> PM, Max Soto
> <maxsoto at gmail.com
> <mailto:maxsoto at gmail.com>> wrote:
> Hey Steve,
>
> I'm not surprised if they were
> made by Garhauer......
>
> Regards,
>
> Max
>
>
>
>
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