"Things “THEY” Don’t Tell You About First, When They Really Should"
We’ve all seen it in the movies, where the hero has to disarm the bomb
and his sidekick is reading the directions;
" ... cut the YELLOW wire and pull the lever. ... ".
"O.K., what’s next?".
"... be sure and ground the GREEN wire FIRST !".
DOUBLE TAKE and etc., etc., etc.
In the REAL WORLD they would make copies of the instructions. Read them
thoroughly, several times. Highlight specific points and make notes. HOWEVER
---
WHO TO BELIEVE -
Take NOBODY’s word as the absolute best and only way to
do anything! Least of all my word. I’ve tried to illustrate
that as much by my errors as by what went perfectly. READ and
get several opinions. Then think over, repeatedly, what you
are going to do. FLASHES of inspiration do happen !
aniline dyes -
Commonly available through wood workers mail order catalogs. May be
available where you live in a "high end" paint, or artists supply,
store. Usually available as a WATER SOLUBLE or ALCOHOL SOLUBLE powder. Go
with the ALCOHOL; it will dissolve in both. MAKE TESTS - MAKE TESTS - MAKE
TESTS !!
Cleaning Fluids -
A way to keep your epoxy application tools "going" is to have a
container of DENATURED ALCOHOL & VINEGAR mix handy. Keep several tools
at hand. As a tool gets sticky or too messy to comfortably work with, WHILE
THE MIX IS SOFT toss it into the container. {A cut up water or milk
jug works great & costs nothing} The solution will further
soften the un-set epoxy and keep it from gelling. At the end of the work
session you can clean the tools with no panic about timing. "FAST
ORANGE", and similar "no-water" hand cleaners work
very well, are relatively inexpensive in gallon quantities, and are HARMLESS
compared to acetone and other highly volatile chemical cleaners. DO NOT WAIT
OVERNIGHT. I say this because I’ve had long sessions or put a lot of tools
& brushes into the container, created a fairly saturated solution, and
had the epoxy "set-up" at the bottom.
Fillers -
The wider the variety of fillers you have on hand the more situations
you are prepared for. There are basically TWO general types of ‘fillets’
& fillers - STRUCTURAL and COSMETIC.
- Structural -
- The fillet that is going to replace the traditional ‘chine log’
and both hold the side to the bottom and give stiffness to the hull
shape; the fillet that holds a frame to the bottom and sides, etc.
When cured should be strong, hard, resilient, and not necessarily
easy to sand
- Cosmetic -
- The fillet on the external seam at the turn of the bilge that will
be under several layers of cloth; the transition fill at the edges
of the taped seam; the external topside transition seam, the filler
used for fairing before glassing over the hull, or rudder, or keel,
etc. This is basically to ‘take up space’ under another
covering. Similar to spackling a hole in a wall before painting or
papering, or putting on extra socks to pad your feet to make an odd
size shoe fit better. Should definitely be easy to sand or otherwise
shape.
- NOTE - these can be combined . . . as an easily sanded cosmetic fillet
over a structurally filleted and taped ‘chine seam’.
Although they are readily available in ‘blister pacs’ at any number
of marine or hardware outlets, the qualities (WEST SYSTEM products excepted)
and quantities are more for "touch-up" and spot repair than
"production" work. Also, I have never seen either WOOD FLOUR
or TALC on any store shelves. The prices are usually high as
well; partially due to the small quantity packaging.
There are any number of catalog sources for your materials - prices vary
-- shop around. [RAKA Marine
advertises in MAIB - Larry
is a good source; Thank You, David
Goodchild] Remember to look out for "minimum orders"
and "shipping & handling" charges.
- Colloidal Silica -
- THIXOTROPIC or STIFFENING agent. When used as a resin filler
sets up rock hard. When used as an additive
it gives a solidifying effect to mixtures; stiff and non- sagging.
- Wood Flour -
- EXACTLY what it says it is and my basic filler. Not
only is it a filler but a thixotropic agent as
well. When "wet out" it looks like wet or darkened wood.
RELATIVELY HARD. Often add one or two of the other fillers to modify
it’s properties.
- Q-Cell -
- A finer material than 3M Glass Bubbles or Balloons. Not many
sources. Try "MicroBeads" or "MicroBalloons".
RELATIVELY SOFT - easy sanding. Leaves a somewhat course / open
surface.
- Phenolic Microballoons -
- If you like Purple - this is the stuff for you!! A fairly fine and
relatively easy to sand thickening agent. It’s dark color, when
wet out, is a good indicator when you need a ‘flag’. You can definitely
see when a rough seam or low spot is filled. Also if you are trying
to imitate a ‘Traditional’ pitch seam - you won’t need to add
so much black pigment .
- PLASTIC Mini Fibers -
- Have found one source. They are the equivalent of a
PREMIUM (HIGH COST) brand of lightweight FAIRING
- Talc -
- White, powdery, highly dense material. Relatively soft & easy
sanding. Helps make a smoother putty. Price varies WIDELY from
source to source
- SPECIALS -
- Chopped Fibers and Milled Fibers (glass fibers) - for a really
tough but rough {chopped) or ‘liquid glass’ {milled} effect.
While these are the better known materials, don’t be afraid to
experiment - BUT do it BEFORE you use it in YOUR boat.
Glass Cloth-
From the experience of building NYMPH, and the samples from RAKA Marine,
cloth schedules can be modified. With 3/4 inch material for transoms cloth
is NOT needed for STRENGTH, only surface protection. If rough use is
expected then a strong, smooth surface would be provided by a TIGHT WEAVE.
For light to "normal" use a light regular weave should do (2.75
oz.). Probably hold true for ½ inch ply as well.
A bottom would be well protected, with less resin required, with a tight
weave. The side panels with a light weave. Bilge panels are a toss-up.
Limber Holes -
These are openings in frames to allow water to collect at low points for
easy bailing, or cleaning. In "hard chined" designs, which
"Tack-N-Tape" or "Stitch-N-Glue" usually are, they are
typically at the "knuckle" of the chine. In these designs it is
also usual to set the frames and place the "skin" around them with
internal epoxy/filler/tape fillets. Plans may either skip detailed
discussions on timing, or talk about them when discussing the frames {remember
the hero and the bomb ?}. In the case of "Nymph" the shape
of the holes is also to allow placement of the fillets & tape on the
longitudinal seams. The frame shapes are on the plans and it is implied to
cut them (the limber holes) when the frames are cut out. HOWEVER, because
they ARE at the point of the chine they remove the support of the change of
angle between panels. NOT a STRUCTURAL problem, just a headache hanging and
aligning the panels. In later books/designs this was corrected by
instructions to mark and cut out most of the hole, but leave a
"tab" intact. This piece would be cut with a keyhole saw, and the
hole cleared after assembly.
Another, not as elegant but easier, method is to not mark
the opening and install the frame whole. After assembly cut a circular
opening with a HOLE SAW chucked in a drill. YOU choose the size; either
fillet only in this area or simply use a few narrower pieces
of tape.
Putty Knives-
AGAIN - CHEAP is GOOD. Shop around. Epoxy does stick
to metal !! They are going to get covered with
the stuff. The set resin can be sanded off and metal does resist the sand
paper. The plastic ones are also very inexpensive and flexible. The plastic
can be cut to shape but do wear away when sanded clean.
You can also get some 1/8 inch ply and make your own shapes. [I
used a 1/8 inch hardboard template so I can keep making identical ones]
If they are coated & sealed with epoxy they are then impervious to
chemicals. {see "Cleaning Fluids"}
"Sheetrock" or "Drywall" Screws -
Not just for walls anymore. Their reputation for snapping off is most likely
due to the material of the usual interior grade construction screw.
With the usual CONSTRUCTION DUTY electric driver set at a high
clutch setting {efficient for, "We’re burning daylight; you guy’s
are paid by the hour", construction jobs}, you can twist the turret off
a tank !! I have a $30.oo Ryobi electric (not cordless) with 6 clutch
settings; some heavy duty, 12 volt battery powered units have 12.
By using long ones at places like the transoms and frames, they can be
"backed-out" half way to allow the joint to be "spread".
After the epoxy adhesive / filleting material is inserted, they are then
re-tightened to clamp the joint. Waxing (NOT soap) screws
always them easier to drive and in this case will prevent ANY CHANCE of them
getting stuck in the epoxy.
Styrofoam Cups -
"They" say not to use them to mix epoxy. Like everything else it’s
a case of knowing your materials. CARELESSNESS is the lowest
common denominator. IF you let a quantity (the "typical" 300
grams), of mixed epoxy "go off", the exothermic reaction
will MELT the cup. You WILL have a potentially dangerous mess on your hands.
HOWEVER, if you PAY ATTENTION to what your doing, make up smaller batches,
and get to know the characteristics of YOUR "mix", the insulating
properties of Styrofoam cups can help during COLD WEATHER
operations. Plus, if the cups are USED you will be re-cycling as well.
Other Mixing Containers-
DON’T USE WAXED containers; plain paper are O.K. Metal food cans are good,
all around useful and universally re-cycled .. EVEN AFTER you’re done with
them.
"Power Disk Sander", etc. -
For any number of reasons you want to sand as little as possible. However,
when working with resins there are times you’ve got to SAND.
When epoxy/wood flour structural fillets set up they are rock hard.
[Dave Carnell recommends
using agricultural limestone as a filler material ... he was a chemist (?)
and has been building boats for years. I still say - WHY !!? That’s making
hi-tech ROCKS !!]
I’m a firm believer in fine tools. Sometimes the "fine tool"
is too much tool. The shipwrights of yore had NOTHING BUT hand tools and
time. Today it’s LASER guided cutters. If you are making
your living building boats, you’re probably NOT reading THIS. IF you’re
thinking of building a dream, a small one - not a circumnavigator, then this
could help you get started.
BUY TOOLS APPROPRIATE for the job. Also THINK and READ --
CONSTANTLY. Just because a tool is typically used for operation X
in industry Y does not mean it can’t be used for something
else.
Professional builders like Devlin use Milwaukee and De Walt
tools. A 4½ inch angle grinder can cost more than $200.oo. Mine is from
Sears - $39.oo on sale. Not only is epoxy tough, it makes abrasive dust. It
is going to eventually "eat" the insides of air cooled tools.
Devlin’s probably sooner than yours, but he can amortize. Put the METAL
CUTTING DISK AWAY and get a KLINGSPOR
SANDING CATALOG sanding disk or two; the "flat" style in
course and medium grit. WEAR A MASK and GOGGLES.
This tool & disk makes faster work of the task {sometimes VERY
FAST - PRACTICE a LIGHT touch}. It is also a nice setup for scarfing
& beveling. It’s handy size, small shape/heavy weight for in
situ work. {Oh, S___! I forgot to bevel that frame. etc.,
etc.}