to Cover with TOP FLITE- MonoKote 4/30/97
is an alternative to paint or varnish for sealing the Dacron. It
provides a super smooth high gloss finish that is available in 46
colors plus clear. It adds strength to the fabric because it is
PUNCTURE and SCRATCH RESISTANT with high tensile strength of 25,000
psi. Now don't get carried away by that figure, it is only 1 1/2
mils thick. They don't say what plastic it is but my guess it is
probably MYLAR. It is a surfacing skin with its own adhesive that
is activated with heat (an electric iron). It sticks to the Dacron
surface but does not flow into the weave of the cloth and therefore
lets the Dacron retain the bare fabric, individual fiber stretching,
tear resistance. That high tensile strength is obviously a lot greater
than any kind of painted surface.
WHEN TO USE
MonoKote: while these boats are not designed for White Water they
have successfully done it with minor damage. So for White Water
or places with Dead Falls and snags are worth considering this technique.
The great high gloss color selections of material lends to wet,
wild look "paint", with no limit on graphics. The result
looks like an expensive Imron paint job. It is a lightweight film
that only adds one-fifth ounce per sq. ft. Because it is odorless
and has no dangerous fumes it fits right in with the philosophy
of building a boat in the apartment.
Now let's get
down to business, it all may sound a bit fussy but it is quite forgiving.
I don't claim to be an expert Monokote installer. I mumbled through
the procedure, inventing some techniques and made some stupid mistakes.
The bottom line was the completed boat; it really looks sharp. An
expert model airplane builder would probably laugh at my so called
"professional" instructions. Anyway I'll explain how I
did the job.
around with test panels I made an interesting discovery. I was not
overly pleased with the peel test quality of the Monokote to Dacron.
It was stuck down and the overlaps were terrific; but if you got
an edge up it was not too difficult to peel the stuff off. Now I've
told you in the instructions, while building the boat, to varnish
the woodwork prior to installing the Dacron. So now it should be
no problem that I'm going to tell you to scrub the Dacron with clear
water and a Scotch Bright pad and let it dry. This would be kind
of sloppy in the living room so take it outdoors. This smooths down
the texture of the weave and I guess provides more flat surface
for the Dacron to stick to. How much to scrub? Do it thoroughly
over every square inch pressing firmly with 5 or 6 back and forth
strokes. If you make up a test frame, suggest 8'x8 with 3/4"
sq. wood and cover with scrap Dacron. Scrub half, let it dry and
study the surface, you will see a different texture and the weave
seems to flatten.
The real secret
to this material is its ability to seal to itself with an almost
invisible seam. Because of the limited ability to heat shrink it
must be applied in "plank" fashion. This is not a difficult
problem but it does take more time than doing the Dacron. I would
say that we have been spoiled, because the Dacron is so easy to
do. Overlaps should be a min. of 1/4" and not much more than
about 3/4". The only problem with excessive overlap is, it
can cause you to trap air bubbles. On the overlaps work the iron
progressively towards the open edge to expel any entrapped air.
Of course, there is no problem with entrapping air on the Dacron
itself because of its porous nature. And that is why the Dacron
must be left un-sealed.
supplied in two sizes: 6 ft. & 25 ft. rolls x 26" width.
To "plank" a boat you have to first cut out a "plank".
Before you are ready to purchase the material you should measure
how much and what size to get. It will work out best to start at
the keel and work up. This places the final overlap on the bottom
edge where it shows the least. I suggest that you experiment with
some stiff brown wrapping paper and make a template of the rough
shape to see what you are dealing with. You need to determine how
wide to make a "plank" so that it will completely cover
the width of one bay between two stringers. You are going to discover
that some of these "planks" have quite a curve to them.
You can simplify the process and minimize waste quite a bit by not
using full length "planks". An overlapping (1/4")
butt joint will hardly show.
stores sell a small plastic gadget called "SNIPPY", it
holds a double edge razor blade and it works very well to trim this
stuff with a nice smooth edge. I set up a cutting table and clamped
down a straight board as a guide. Now I'm treading on thin ice when
I suggest using a panel door borrowed from my wife's sewing room
as a smooth cutting table.
Now here this!
Like a lot of plastic materials, MonoKote is notch sensitive. What
I mean is that it is tough and hard to tear unless you create a
cut; then it will rip like tissue paper. So the trick is to cut
the stuff with nice smooth edges. Use a razor knife or at least
make really clean scissor cuts . . . no jagged edges. Bear in mind
that the MonoKote is a replacement for paint or varnish, which also
tears easilly; so don’t be alarmed about this weakness. The
Dacron has a rip stop quality.
I didn't make
any attempt to fit the "planks" with the appropriate curvature,
I simply used rectangular shaped pieces of the material. The uneven
overlaps did not show that much. A nicer job with less waste material
would be to trim each piece to match the curve of the stringer.
the process in my head, I might suggest that with some extra helping
hands to hold the ends while you worked (you need two helpers),
you could partially stick the material in place and then trim it
right to the curve. This will eliminate a lot of waste because the
cut off curve from the last "plank" will just about fit
the required shape of the next piece. That SNIPPY tool would be
easy to use, following around the curve of the stringer.
CURVE! On the next boat that I did (the Westport Dinghy) I got a
little more optimistic about the shrinking ability of the stuff
and tried spanning two "planks" with one width of the
MonoKote. The trick seemed to be to stretch the material as tight
as possible along the middle stringer before sticking it down. Lay
it in place; then peel out the poly keeper from underneath. Pull
like hell on the four corners and adjust it sideways to even up
the wrinkles on the outside of both "planks". Heat shrink
the sides of the "plank" so that it lays down flat but
not really stuck to the Dacron along the stringers. You will want
to get under this edge in the next step.
Here it gets
a little fussy, I slipped a plastic guard (a piece of .005 mil Mylar,
about a foot long x 1" wide) under the edge of the MonoKote
so that I could not cut the Dacron . Now I carefully cut off the
excess with a razor knife and a metal ruler straight edge... A series
of short straight lines made a nice looking job. Now iron it down
tight to the stringer area.
with larger widths of MonoKote I got into heavy duty compound curvature
in the bow area. I tried using a heat gun for the shrinking and
had mixed results. It does work quite well but it is tricky because
of the distinct possibility of burning a hole...I did burn two small
holes while working on some really stubborn wrinkles. Not a total
disaster, the patches hardly show. The trick is to watch with an
Eagle eye and keep the gun moving!
tell you to set the iron at 275 deg. temp. It is not a bad idea
to experiment with the iron on that sample test frame that I told
you to make. My iron melted the Dacron on the wool/cotton setting
so I went back to the the dot between rayon and silk. That measured
between 320/340 deg. a little higher than the 275 deg. seemed to
stick it tighter to the fabric. MonoKote sells sealing irons and
they have neat little cotton booties to use as a softer surface
to avoid marring the skin. I tried simply ironing on a cotton handkerchief
and that worked fine. The worst mistake that I made was on the first
piece that I ironed in place. It didn't seem to be stuck on all
that well, it was then that I discovered that I had forgotten to
remove the protective poly material that is used to cover the adhesive.
I guess this only goes to show you how forgiving this stuff is,
I peeled it off, removed the poly skin and ironed it on again for
a successful job.
Along the edge
of each piece that goes on requires a bit of fussing because it
becomes a compound shape due to the angle going around a curve.
The iron will shrink up that much so that it lays flat. The only
problem is to work progressively towards the edge so that you don't
trap air bubbles. If you do trap a bubble it is almost impossible
to squash it flat, I had some success with a needle point carefully
piercing the outer layer to let the air out while ironing down.
attention along the Gunwales to avoid re-heating and loosening the
HeatnBond tape that holds the Dacron in place. Just run the iron
along the Gunwale 1/2 width at a time.
The ends of
the boat should have an overlap onto the front face of the stem.
This may be a little bit too much compound curve and require some
tabs to be cut. Stagger the tab cuts from one side to the other
so that you maintain water tight integrity.
You can create
all kinds of graphic designs by adhering different color MonoKote
over the surface. Here is where you must be careful to not trap
air bubbles if you use wide pieces. TOP FLITE also makes a special
trim grade of the material that is adhesive backed, just peel and
stick. This is supplied in 5" x 36" sheets (23 colors).
I can't say
that this is the only material that will work for this purpose;
however I did test a few competitive products with poor results.
MonoKote is sold in most good model supplies stores. You can also
mail order it from:
P.O. Box 9078
Champaign, IL 61826-9078
800-637- 4989 for orders
800-637-6050 for assistance
TOP FLIGHT MonoKote
is distributed by:
GREAT PLANES Model distributing co.
P.O. Box 9021
Champaign, IL 61826-9021
(Look for a
color chart in RCM Radio Control Modeler Magazine)
hate it when this happens! July 23, 1997
here is to store your boat under cover when not in use.
The first boat
that I applied MonoKote on was done in late 1994 and it still looks
great. I did the suggested procedure of keeping the boat under cover
to protect it against UV degradation when not in active use.
The can of worms
was opened last December 7th when I made a test panel of black MonoKote
on Dacron and placed it outdoors for an exposure test. Late June
I discovered some lifted areas and ironed them back down. It was
attributed to the very high heat that was building up due to the
panel being laid on a flat surface and trapping the heat.
Two weeks later
upon a more complete inspection it was discovered that the MonoKote
had become brittle and will fracture when stretched. . . like pressing
a finger onto the surface.
Go back to the
first boat, the stuff is doing fine just give it a break and keep
it under cover when not in use.
A friendly awning
maker suggests applying a product called 303 PROTECTANT that contains
UV screening and is available in marine supply stores.
I applied a
very thin coat by spraying it on in patches and then rubbing it
out with a rag to a uniform coat that dulls the high gloss a little
and ends up kind of iridescent and streaky looking ... Especially
bad on black—not too noticible on other colors.
this for the 303, it is mighty hard to wipe off. Wipe and rub on
the black MonoKote and the iridescent effect persists. This tells
me that it will probably last quite well.
Do NOT Cover a man-carrying aircraft with MonoKote!
It only sticks
fairly well to the Dacron. This is no real problem on a boat, but
can you imagine a bubble of this stuff lifting off the fabric from
negative pressure, like on the aft surface of one wing panel! The
situation would be worsened by the high tensile strength of the
material. I call this problem the Steve Whitman effect...don’t
get caught by it.
Very truly yours,