Re: RIVETS PULLING OUT!

Bruce D Anderson (saltyb@integrityol.com)
Mon, 27 Sep 1999 22:03:01 -0700


- - - - - - - - - - - - - - - - - - - - - - - - - - -
West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
- - - - - - - - - - - - - - - - - - - - - - - - - - -
At 10:38 PM 9/27/99 EDT, JBlumhorst@aol.com wrote:
>- - - - - - - - - - - - - - - - - - - - - - - - - - -
> West Wight Potter Website at URL
> http://www.lesbois.com/wwpotter/
>- - - - - - - - - - - - - - - - - - - - - - - - - - -
>In a message dated 9/27/99 4:47:51 PM Pacific Daylight Time,
hapilife@efn.org
>writes:
>
>> - - - - - - - - - - - - - - - - - - - - - - - - - - -
>> West Wight Potter Website at URL
>> http://www.lesbois.com/wwpotter/
>> - - - - - - - - - - - - - - - - - - - - - - - - - - -
>> The rivets holding the eyes on my mast where the shrouds attach are
>> pulling out!!!! How do I fix this? It's an HMS 1988 p-15.
>>
>> I just chipped my gelcoat too and decided that after 5 months in the water
>> straight it was time for me to clean up and check everything...good thing
>> I noticed the rivets...wouldn't have been fun getting dismasted !
>> Ken Silverman, p-15 "vegan Lorax"
>>
>
>Ken,
>
>The problem with attaching the shrouds with rivets is that they are under
>tensile strain (as well as shear strain), meaning that they're being pulled
>out along the axis of the rivet. Rivets don't hold well that way.
>
>There were a few years when Joe Edward was making the boats that the shrouds
>were attached with pop rivets. The original HMS company used thru bolts and
>tangs and all the P15 's and P19s from International Marine have them too.
>
>The best way to attach shrouds is:(1) Attach strouds to tangs with double
>forks. A fork is a gadget that has a fork on each end with a clevis pin
>between the forks. You attach the tang to one end of the fork and the shroud
>to the other (2) attach the tangs to the mast with a thru-bolt (with washers
>and nylon locknuts)
>
>You don't absolultely need to use forks to attach the shrouds to the tangs.
>You can swage the shrouds directly onto the tangs, with a stainless steel
>thimble set inside the loop. But the forks make it easier to take them on
or
>off or to replace.
>
>You can see pictures of tangs at the Dwyer Mast website www.dwyermast.com.
>Just go to masts, select one, and look at the accessories at the bottom of
>the page. Tangs are flat stainless steel plates about 1" x 3"; they have
>holes in both ends; they are bent about 20 degrees so that when one end is
>attached to the mast, the other end points down at the chainplates in your
>hull.
>
>Even better than just a thru bolt is a thru-bolt with an aluminum
compression
>tube around it. Example: say I use a 1/4" bolt for attaching the tangs to
>the mast. I get a short piece of aluminum tube with a 1/4" inner diameter
>and a 3/8" outer diameter. I drill a 3/8" hole in both sides of the mast,
>slip in the tube, and then trim the tube so it's flush with the mast on both
>sides. Then I assembe the tangs on the mast, putting the bolt thru the
>sleeve. This way, I can tighten the bolts with no fear of putting a crink
in
>the mast, and I don't have galvanic corrosion occurring between the mast and
>the stainless steel bolt.
>
>The tangs on a thru bolt with a compression tube are good method for
attachng
>shrouds because (1) it won't pull out, (2) the tangs can swivel as the mast
>flexes so there's no point loading of forces, and (3) the tube will last
5-10
>years before it gets corroded and it's better to replace the tube than to
>have a big hole from galvanic corrosion in your mast.
>
>That's how I refitted the tangs and shrouds on my P19. (And, BTW, when I
>removed the existing thru-bolt that didn't have a sleeve, there was
noticable
>enlargement of the original hole from galvanic corrosion) That's also how I
>attached the bail for the boom vang, with a compression post.
>
>But, for my boat, I'm a little compulsive about these matters, and since
>tangs and forks are the time-tested way to do it, that's how I do things.
>
>If you have any questions, email me back. My boat is out being totally
>re-wired (found a GREAT guy to do it!) , so I can't get a picture of a
>compression tube, or forks or tangs until Wednesday or Thursday.
>
>Best,
>Judy
>1985 P19 #266 "Redwing"
>SF Bay, CA
>
>
>Judy, I was out in my wwp19 2 wks ago off Pt. Robinson in Puget Sound and
got myself demasted. I had a new mast and did my own swedging at West
Marine the day before. Blowing about 15-20 , a glorious day- I was really
bombing and there she went-2 swages let go-came undone andmast went over,
both sails under water. It's tough getting it back on board alone. Had
to flag down a passing boat. Carry a good pry bar onboard - a good idea.
Anyone have some wisdom on swedging

Bruce Anderson Galilee Wind