Practical Boat Owner — November 2017

PRACTICAL

10

Using afromosia

hardwood I cut two

60mm x 30mm wooden support

backing mounts measuring 365mm long.

These mounts would be attached

underneath the platform, bolted through

the slats, and then the ladder frame be

attached to them.

This would

strengthen the

installation, spread

loading and give

clearance under

the platform frame

for the ladder to be

extended.

13

With the wooden mounts placed

back between their marks on the top

of the platform, I used the point of a thin

steel scribe to push up through the slats

from beneath to pinpoint the position of the

holes that’ll need to be drilled.

14

Three fi xing holes for each side of the

frame can then be drilled through the

platform to the size of the nuts and bolts –

in this case M6 threads. Leave one hole

undrilled (you’ll see why later).The holes

are countersunk for the slot head bolts.

16
Once bolted in position, the other
holes can then be drilled through
from the top of the platform. So now each
wooden mount is secured by three bolts.

11

Centre marks were drawn on the end

of each mounting piece and these

were lined up with the lines running

through the fi xing points for each side of

the frame. The edges of each wooden

mount were then drawn onto the platform.

12

I next drilled

pilot holes

for the frame

fi xing points. It’s

important to

ensure accurate

drilling at this

stage with the

drill bit at 90° to

the slats to

ensure all the

fi xings and

components

will line up

during assembly

later on.

18

A pair of

these 12

gauge screws

will now hold the

wooden mounts

in position

underneath the

platform when

the nuts and

bolts are

removed. The

bolts can also be

cut to length at

this stage with a

junior hacksaw.

17

Now, however, the nuts need to be

removed to fi t the frame. But what will

stop the timber mounts from falling off?

This is where the remaining hole can be

used and a further hole drilled which is big

enough for a 50mm long retaining screw.

7

The ladder would be installed under

the platform but the fi xing points

could be marked out from the top.

The fi rst job was to centre the

frame exactly mid-way along

the platform and make sure

it sat square.

8

When the centre position was

established the next job was to

determine where the fi xing holes would fall

in relation to the wooden strips. The

forward hole would be OK, but note the

one with the pencil in it is the one that falls

too close to the edge of the slat (see

‘Test fi rst with templates’ on the

previous page).

9

When the fi xing points were marked

up, I drew a line through them to join

up the circles. I’ve drawn a centreline

through the holes which gives greater

accuracy before drilling – it’s rather too

easy for a drill to wander around a marked

circle, increasing the margin of error.

15

With one hole drilled through the

mount using one of the previously

scribed marks, the mount can then be

bolted in position through the appropriate

hole in the slat above.

60mm x 30mm wooden support

could be marked out from the top.

The fi rst job was to centre the

one with the pencil in it is the one that falls

too close to the edge of the slat (see

‘Test fi rst with templates’ on the

Step previous page).

by

step