[Rhodes22-list] Bob Mellor and the Gift - Now Stringer/Floorreplacements

[Jack Chirch]

Bob -
My guess (worth what it costs you) is that any change in hull shape will be
compensated for by deflection in the new (?)cabin sole, assuming it's
screwed to the new stringers, and they're tabbed to the hull. If the hull
flexes outward as the weight comes off the bunks, the sole develops a bit of
a concavity.  Just makes it easier to find your bowling ball (always in the
center of the cabin floor).

I don't recall the year of your boat & that may make a difference. My 81 is
currently torn apart much like yours. I've replaced all four stringers,
and--like you--found no aft cross member. I hadn't considered the likelihood
of problems from hull deformation, but since you raise the question, I'm
scratching my head over a related one:

Last fall I pulled the centerboard on Pax during the stringer replacement
adventure. It was clear that the CB pendant and its tube needed replacing,
and I thought a coat of bottom paint was in order.  Winter (and life) got in
the way, and last week when I tried to reinstall the CB, I ran into an odd
problem.  The piece that I'd identified as the CB pivot pin doesn't fit.
It's the right diameter, but it's nearly a half-inch too long.  I assumed
that I'd just confused a loose piece of scrap tubing with the real CB pivot.
Now you've got me wondering; could the cb housing have been squeezed
together that much from sitting  with the cap off for seven months on the
trailer ?   Hmmmm.  

I think I may get out the jacks & cribbing before I order a new pin.

Comments/suggestions from liberal, conservative & undeclared board members
welcome!

Jack Chirch

 

-----Original Message-----
From: rhodes22-list-bounces at rhodes22.org
[mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of bobmellor
Sent: Sunday, April 15, 2007 3:52 PM
To: rhodes22-list at rhodes22.org
Subject: Re: [Rhodes22-list] Bob Mellor and the Gift - Now
Stringer/Floorreplacements


Ed

Thanks once again for your input.... I am forever grateful for any and all
help.

I had already scoured the archives for many topics.... using the "ask"
search method and others.   I've collected a vast amount of info on many
topics, but have not found the answer for this particular question.  
(interestingly the specific search link you provide points me to a few of my
own previous posts).

I already had Casey's books and visited epoxyworks, and (I believe it was
your previous recommendation) have picked up a copy of Vaitses' book.  I am
now familiar with tabbing procedures, "hard" spots, etc... and have a little
expoy experience under my belt since doing several other repairs.

My specific question is the recommended "state" of the boat when positioning
and replacing the stringers and floor.

I realize that this assembly contributes to the structural stiffening of the
boat, and that (especially with stringers and floor etc removed) there must
be some deformation in the hull shape when in the water versus on the
trailer, versus hanging on the eyes, etc..etc...

I may be overthinking (and very well may be wrong) that on the trailer with
the bunks, the cross section of the hull might be compressed so that it is
slightly narrower than it would be on the water or hanging from the eyes. 
If that is correct, I would also think it might be better to put the
stringers/floor in without the bunk pressure, so the in the water     it
would be closer to an "unstressed" condition and on the tralier in a
compressed condition.  If done on the trailer, the stess in the water would
be more like an expansion action trying to pull it apart.  (Not sure how the
longitudinal cross section would be affected on trailer, water, or hanging)

Currently the two middle stringers and the starboard stringer are out.   It
does not appear that the middle pair of stringers were ever attached to the
forward crosspiece.  The rear ends of all four stringers are not attached to
anything.  (There was no rear cross piece as shown in some of the archives
diagrams).  The starboard stringer, having no rear atttachement, was severly
warped at the aft end backwards under the galley base.  

Again, I might be overthinking this and it may not be significant one way or
the other, I just want to do it correctly.

My  specific questions:

1. what "state" of the boat is best for this replacement - on trailer, in
water, hangiing by eyes, or on a homemade cradle of some type?  (or does it
not make a significant difference)

2.  should I add a rear crossmember to connect aft ends of stringers?

3. should the forward ends of the middle stringers be physically fastened to
the front crossmember?

I'll be emailing Stan as well directly on this as all of the answers may or
may not be known to the list.

diagram attached
http://www.nabble.com/file/7885/stringers.JPG 

Thanks all..

bob m
   


B

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