FWIW, and I agree with much below. Will assume you are dealing with balsa and
not plywood as a core. Have repaired both and will share the following, YMMV,
etc... Probably way too much info, but:
1) Damp balsa does not mean structurally unsound.... (yet)
2) I prefer to remove more rather than less. This allows you a large enough
area to work, makes it easy to clean/prep the surfaces, as well as being
certain that you are not building any voids into the finished result. You can
also use really thick glass-loaded epoxy that simply cannot be injected into a
small hole. As with drywall/sheetrock, it is sometimes easier when doing
repairs to give yourself space to work, and to prep the surfaces.
3) I like the hole saw approach, cutting through one skin only. The hole saw
also allows you the opportunity to install a structural filler piece, well
bedded in glass-filled epoxy. Rather than just troweling in the schmutz. you
can laminate a sheet of fibreglass into a high density layup of the appropriate
thickness, (even tapered, or curved) then use the same hole saw to cut out a
"puck" from that sheet and install into the hole. Bulletproof.
4) IMO Working from below is best if you have the space/access, for a number
of reasons, including the fact that any holes won't move. Working from above
can be easier, though the cosmetic redemption is harder.
5) Epoxy is available in a range of cure times. "hot in the pot" should not
be an issue if you pick the right one. Never had that happen, but I have had
it get a little warm and further shorten the cure time. (have had polyester
resin get pretty hot....)
6) To make a patch that feathers on the edges, laminate progressively smaller
pieces of cloth (alternate mat and cloth with polyester resin, I like biaxial
stitch mat with epoxy) on a sheet of waxed paper, then lift that and stick it
onto the wound like a bandaid, peeling off the waxed paper. Best is to do
this (or any sequential application of epoxy) on top of the previous epoxy
application while it is at its B stage (gelled but not cured) Not only is the
putty still it pliable, but it will not need prep to achieve a good chemical
bond. You can not simply epoxy over top of cured epoxy and expect a bond.
(google "amine blush")
7) when done, (but not cured) you can carefully lay some PE film (or waxed
paper) over top and smooth. this can help tame any stray edges and depending
on the repair, actually functions a bit like a vacuum bag, assisting in
adhesion to curves. You can also shape any putty into smooth shapes or radii
for a more professional result.
8) Read up on fillers. If you expect to fill space, you don't want the epoxy
to flow, you need colloidal silica, If you want it to be strong you need to
load with glass, you want to sand it microspheres. (don't put yourself in the
position of having to sand the structural part of a repair....)
9) make a notched trowel and use appropriate fillers for fairing/finishing.
The notches leave little ridges in the epoxy. Sand those off and stop.
OK, that's enough...
Dave
---------- Forwarded message ----------
From: <cnc-list-requ...@cnc-list.com>
Date: 30 January 2017 at 09:25
Subject: CnC-List Digest, Vol 132, Issue 70
To: cnc-list@cnc-list.com
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Today's Topics:
1. Re: Deck Coring Around Chainplates > Chainplates (Danny Haughey)
2. Re: Deck Coring Around Chainplates > Chainplates (Danny Haughey)
3. Re: Deck Coring Around Chainplates (Hoyt, Mike)
---------- Forwarded message ----------
From: Danny Haughey <djhaug...@juno.com>
To: cnc-list@cnc-list.com
Cc:
Date: Mon, 30 Jan 2017 09:08:16 -0500
Subject: Re: Stus-List Deck Coring Around Chainplates > Chainplates
Hi randy,
It seems you are definitely going in the right direction. I had a problem like
this on one of my old boats but, under the bow rail feet. I traced out the
size of the plate and oped things up a bit with a hole saw to give deeper
>>>snip
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