Chainplate Relocation Revisited.
In the January 2000 issue of Flashes there are 4 articles regarding chainplate relocation in older
boats. The one that I wrote is on page 15 this is a sequel to that.
Recently the port bolted chainplates of my Lippincott #11771 failed, this was due to a buffeting
which the hull experienced from motorboat generated waves while tied to a dock. The deck to
hull joint from forward of the upper chainplate to 10’ aft was separated and I believe led to the
chainplate bolted connection failure.
With that I decided to repair the damage by removing the old bolted in place chainplates and
epoxy bonding replacements similar to Herm Nickels description in the 2000 Flashes. Read the
Nickels piece for a further description of wrapping the chainplates with woven roving.
It has been suggested that individual boat builders may have varied how they fastened the
chainplates to the hull. So before cutting into the inner glass liner and removing any of the foam
core, one should determine if their plates are bolted as were mine. Start by removing the rub
rails, if you see several flat headed screws this is a pretty good indication. I would then go
inside the hull and remove the single glass/resin layer which is covering the inside of the plates
just under the deck and above the top of the foam core. (The bolted in plate will be exposed.)
First the inner glass fabric of the hull must be removed followed by the 1” foam core. This was
done with a Fein oscillating tool using a wood/metal flush cut blade, other types are available
but this was what I had on hand. Be careful not to cut into the outer hull laminate. Then wire
brush off any remaining foam core. I did this until the foam core white changed to yellow an
indication that resin was being removed, a change in smell was also noted. As the photos show
this cut out was about 8”x 15”. I made the woven roving wrap around the chainplates longer
than Nickels suggested because I wanted to be sure about the bonding of the wrapped plate to
the hull and to spread out the load. I did not use mat as Nickels suggested because epoxy does
not bond to mat, possibly because a proper resin to glass bonding agent is not applied to mat
during its manufacture.
As a test on dry land I tightened the lowers to 300 pounds for several days and saw no
decrease in tension level during that time period. We have also hoist launched the boat without
pullout of the plates and no lasting decrease in lower shroud tension. The lower chainplate
during hoist launching sees a vertical load of the lower shroud (250 lbs.) plus 1/4th of the boat
weight, (200 pounds) for a total of 450 pounds, this assuming a boat weight of 800 pounds. We
saw no decrease in lower shroud tension during a hoist with a Loos tension gauge
“Mas” brand Epoxy was used because it does not blush a waxy amine film onto the surface
during curing or polyester resin could be used to save money. Full cure of epoxy is 3-5 days.
This modification is not easy and is messy, but it can be done. And now that I have done it I will
no longer be concerned about the possibly of dropping the boat during hoist launchings.
New chainplates were purchased from Nickels, see their website. It just occurred to me that I
could have saved 48$ by cutting the old chainplates into Tees and glassing them into place.
Bolted in place chainplates removed
from Lippincott #11771
Port side inner fiberglass liner and
foam core removed and woven
roving epoxy bonded to hull.
Roving sized to fit the cut out area.
Or up to the deck if you prefer, it
couldn’t hurt.
Chainplate tees wrapped with woven
roving prior to bonding to the hull. Only
pre-epoxy the “Tee” part of the
chainplate. Not more as I have done.
This pre-epoxying was done to be
certain that the roving fitted tightly
against the Tee.
The overall size of the plate wrap was
8”wide and length to fill the cut out area
with the chainplate in the installed
position.
Forward chainplate epoxy bonded to hull with 3”
wide fiberglass tape layered over woven roving.
It may not look like total wet out has been
achieved but it was. Tape was used because it
has a woven selvage and does not unravel so
will be neater.
Please remember that Article I, section 46 rules that the attachment point of the upper shroud
must not exceed 23” from the front of the centerboard pin. This point can easily be determined
from your measurement certificate. Dimensions W+X-23” will give you that point along the
centerline of your deck from the bow. A perpendicular across the deck will give you the max
forward of the upper shroud attachment points. An idea might be for a class measurer to assist
determining this and noting on your certificate that the chainplates have been relocated.
Questions, comments, improvement suggestions wsloger@att.net or tele 843 216 1939