June 14, 1902. j 
478 
How to Build a Launch from a 
Set of Plans. 
BY C. G. DAVIS. 
Before we do any more let us finish up the planking. 
This is done in the following stages: Opening and caulk- 
ing the seams, paying the seams, plugging the nail holes, 
planing off the plank, sandpapering it, giving it a prime 
coat of paint, filling the seams with putty, and painting 
the final two coats of paint. 
You may not need to open some of the seams; some 
seams the amateurs make need closing instead, but we 
will suppose you have made a good job of it. There will 
even then be places where, the seam is wider than in 
others; to equalize this opening, some builders make a 
wooden wedge of oak cut with a shoulder so it can only 
go a certain depth, and run that along by hand, using a 
hammer when it becomes too tight, and so make the seam 
open at least the thickness of the wooden blade. 
Others merely go along the seam with the iron known 
as the making iron, Fig. 32, used by caulkers, while 
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Fia-52 
others combine the two by marking a wheel with its 
edge wedge-shaped, like the blade of the making iron, 
putting this wheel in a handle and rolling it along in the 
seam. Fig. 33. The three methods all accomplish in more 
Fig, -55. 
orlesslengthof time the same object — they wedge the two 
edges of the plank apart with a V-shaped seam into which 
the cotton can be rolled or hammered with a caulking 
roller or caulking iron, which differs from the making 
iron in the fact that it is blunt edged and drives the cot- 
ton in Avithout cutting it. Fig. 34. It takes lots of ham- 
11 
Fig-54. 
niering to pound a strip of cotton into each seam, but pa- 
tience will succeed. The roller. Fig. 35, on small boats 
Fig* 35. 
is far the quicker method, but care has to be exercised or 
else the roller will start off and cut a score into the 
plank instead of keeping into the seams. 
If the seams are anywhere near regular, two or three 
strings of cotton wicking twisted together will fill the 
seam nicely. If irregular, it is better to take regular 
caulking cotton, which only differs from cotton batting 
in the way it is put up, being in strings about the size of 
your thumb, instead of in sheets, and of slightly inferior 
quality. 
The caulking iron may cling to the cotton, if so an 
occasional dip of the iron into a rag soaked with grease 
will prevent it. 
When every seam is caulked across the ends of planks 
and all, take some lead-color paint mixed quite thin and a 
seaming brush (Fig. 36), that is one with one set of 
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5 ETA M I NGi BRUSH 
bristles set in a row, and run the paint well into the seam 
and on the edge of the cotton. This will not only hold 
the cotton in, but give the putty something to cling to. 
Plugging, 
To plug the nail holes in the planking requires about 
1,500 }i'm. white-pine plugs, and for the oak top strake 
about 150 >sin. oak plugs. You only need a dozen or so 
mahogany plugs for the transom. 
Don't try and whittle round sticks and stick them in, 
sawing them off; they will not stay in and look badly, as 
the end grain finishes up blacker than the rest and looks 
unsightly. Buy the plugs, they cost but little, and then 
dip them in white-lead paint with a little varnish in to 
make it sticky, or in glue. The latter is better,' for the oak 
anyway, as it don't show a white ring in the dark oak as 
lead might. Any one can plug, you would think, yet there 
is quite a little to it to learn to put the grain of the 
plug the same as the plank it goes into, so all will shrink 
and swell alike, and don't hammer them in and bruise the 
wood down, for when the oil of the paint touches them 
they will expand back, and then your plug will stick out 
beyond the plank. Tap them in lightly. 
Planing Off and Finishing. 
To properly plane off the hull so as to take down any 
ridges that may be caused by one plank being thicker than 
another, and make a smooth, rounded surface free from 
Hat spots, requires quite a knack. You may be able to 
do it first time if you are careful and patient, but it is 
quite hard work to the uninitiated. You can feel most 
of the inequalities by running your hand over the plank, or 
see them by eye. A thin batten bent across the plank 
will often show up unevennesses the eye and hand could 
not detect. Before you sandpaper get a bucket of hot 
water and a sponge and thoroughly wet all the outside 
of the planking. This will make the wood and plugs swell 
out all they are going to. 
Then sandpaper across the grain. I was going to say 
as long as you like. Few do it long enough, but elbow 
grease is what tells; this alone will make a launch hull 
look smooth and nice. Paint never can hide an uneven 
surface. The sunlight will expose it with shadows. To- 
ward the last, sandpaper lengthwise, to take out any 
scratches that might otherwise show. Scrape all oak 
with a cabinet scraper to a perfectly smooth surface. 
Puttying and Painting. 
Simple as the process of putting on the half-round 
mouldings is, there is quite a knack in it. Not so much 
in the middle as at the ends, where it should be tapered 
off gradually, both in depth and in thickness. It looks 
clumsy and cheap to snub off the ends full sized. Bung 
the fastenings in this the same as you did the top strake. 
Varnish the underside of the oak mouldings before you 
nail it on to help hold it on and to prevent the rain 
water from running down and carrying a black stain 
across your white paint. Oak exposed to water gives out 
a black stain, and for this reason you should keep all oak 
well varnished. 
Putty all the seams and any small nail holes that may 
show, and then paint the hull two coats of white paint 
above water and two coats of red lead, if for fresh water, 
of some anti-fouling bottom paint if for salt water, use. 
Green. makes a very pretty finish and lasts well. The 
oak should have three coats of varnish, the first well 
rubbed in and the last a spar varnish. 
Deck Frame. 
When the outside of the hull is complete you are ready 
to frame the deck. This is always built with an arch 
or rounded top which boat builders call the ''crown" of 
the deck to drain the water off. Our launch has a crown 
of 2in. in 4ft. Cut out a pattern or template of about 
: A'm. pine, from which you can mark out your beams. To 
lay out this template (Fig. 37), draw a half circle in the 
middle of it and divide it into eight equal parts. Divide 
the 4ft. template into eight equal parts also and set off 
the heights on the template corresponding to the heights 
on the division on the circle. By drawing a curve through 
these spots you have the sweep or crown to cut your 
beams by. Cut out five beams 4ft. long and J^in. wide by 
ij^in. deep, and two heavier ones %'m. wide by 3m. deep, 
one for each end of the cockpit. 
Cut a notch in the clamp on each side, so the beams 
will fit down flush with the top of the side planking and 
nail them with one galvanized iron nail through the beam 
and into the clamp. 
Cut the circles to make the rounded cockpit out of i^in. 
yellow pine and spike them fast to the clamp and beams, 
as shown in plan, leaving them stand up high enough to 
make the round correspond to the rest of the deck. 
When you have fitted an arched piece to the transom 
to match the crown of the beams, and have planed the 
clamp beams and all down even, put on the covering 
boards. 
It is an excellent plan to build the forward deck so it 
can be removed to permit getting at the tank or taking it 
out any time for repairs. All that is necessary to do 
this is to nail a ledge piece fore and aft on each clamp 
under the deck that will extend out about %in. beyond 
the covering board. Then the beams can be notched into 
this and yet be short enough to lift out clear of the 
covering board. Put the edge of the deck all down with 
screws instead of nails, as the rest of the deck is built, so 
by taking them out the deck may be removed at any 
tirfle. 
Wherever you want a cleat, put a reinforcing block of 
oak under the deck to screw them to, as the soft wood of 
the decks would not hold much strain. Nail right through 
the sides of the deck beams into these blocks, which are 
to be fitted snugly between them. 
Decking. 
For decking mahogany, costing about 17 cents pet- 
square foot, is by far the best finish. Oak will cost about 
6 cents, and pine 5 cents. Get whichever you decide to 
use cut into strips 2in. wide by y^m. thick, and lay the 
decking in straight lines fore and aft, beginning with 
the middle piece and working off toward each side. 
Wedge each piece up very tight and be sure and have 
what is called a caulking seam on top, the same as in the 
planking of the hull. Run a shaving off the top edge of 
each piece, with your plane, so the seam will have a de- 
cided opening at the top to take putty. Be sure the edge 
of the grain is on top, for if you lay the flat of the grain 
uppermost, it will raise up in splinters. Make neat joints 
in fitting the many pieces and bore a hole for a plug to 
cover the head of each nail. Put two nails into' each 
piece of deck at every frame. 
Flooring. 
The laying of the floor is so simple it does not need 
much description. Cut the beam on which the floor is 
laid so they land on top of each (or every other frame 
would be close enough), and nail them fast. Leave sec- 
tions of the floor loose so you can get at the bottom 
of the boat. 
Make your seats of wide white pine cleated together on 
the under side with cross pieces about every iSiir. and put 
the supports to the floor under these cleats. 
Coaming. 
Nothing hurts a lunch's appearance more than a coam- 
ing made up of a series of angles. A neat, round coaming 
will often retrieve an otherwise poor looking hull. It is 
this the eye sees most, and hence it pays to make this part 
as sightly as possible. It is difficult work for an amateur 
I'll admit, but half the battle is won if you only begin 
right 
Sweep a circle on the floor the size you want your 
coaming, and- at intervals of 6in. around the circle, 
lengthening to a foot, at each end nail a series of uprights 
braced so you can bend the coamings around them. If 
you tried to bend around these, each upright would bear 
hard and tend to break the wood; so first, as a padding, 
bend three or four J^in. flat strips, some you can easily 
bend cold, around the form, and then bend the coaming 
around on these after first giving- it a good steaming in 
the steam box. 
As the two ends are different, you will have to alter 
your mould to fit each. When you take them off the 
mould, you will not have much difficulty in fitt'ng them 
into position on the launch. The straight pieces on each 
side will not have to be steamed. Where they join either 
make a square butt or else halve them and reinforce the 
joint with a butt block, which also does duty as-a place to 
put the rowlock sockets into. 
You find the shape of the coaming by the same method 
as you did the planking, by taking a "spiling." Why it is 
called spiling I never could find out, unless it means you 
spoil or spile one piece to determine the shape of another. 
Take a very thin piece of wood about 3-161'n. thick and 
6in. wide. Bend this in as a temporary coaming, and tack 
it just enough to hold it while you mark or "scribe," as 
they call it, the line of the top of the deck. When you 
straighten this piece out you will find it has a decided 
hump or mound in the center. This is caused by the 
crown of the deck. . 1 
Set off with a pair of compasses this curve on the piece 
of J^in. oak you are going to make the coaming out of, 
and cut it out to. shape, 6in. in width. When you fit 
this in and nail it "fast, leave it standing up 4m. above the 
deck. Countersink and plug all the holes. Where the 
joints come screw them fast into the butt blocks. (Fig. 
38.) Then putty the seam around the outside and bend a 
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Fig -55. 
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LAP BUTT 
quarter round Hin. oak moulding in the corner formed 
by the coaming and deck. It will take 30ft. of this mould- 
ing. Any mill will sell you half-round moulding, so pur- 
chase 15ft. of i l /d\n. and have it resawed into quarter 
round. If you can't buy it, take j£in\ square strip of oak 
and plane it off by hand. 
[to be continued.] 
