Welcome to our monthly Newsletter. This month you will find :
1 KIT BOAT NEWS
2 STEEL BOATBUILDING
3 BUILDING TIMES
4 CARTOON SECTION
5 WOOD EPOXY
6 QUESTIONS ANSWERED
1 KIT BOAT NEWS
Things are moving along smoothly here at Bruce Roberts International. The
Kit section continues to grow although these do take some time to develop
and are not available for all models but we will be expanding the range as time
progresses. To view the first of the optional extras that will be made available
please check out ../kits/al900.htm
2 STEEL BOAT BUILDING
All things progress smoothly also with owner built boats around the country.
The owner/builder of the NY 46 launched recently in Brisbane, Australia has
reported that upon launching she floated approximately 1 1/2" above her
designed waterline. With the mast and rigging yet to be added she should
ride near perfectly. This is a good result after 4 years of part time labour
which leads me to another point. One of the most asked questions we have
here is builders wishing to know if they can increase the thickness of plate
specified in the plans and often it is quite difficult attempting to
convince first time builders that the plate size specified on the drawings
is more than sufficient for the job. By adding just 1mm to the thickness of
hull plating an additional three quarters of a ton will be added to the
overall weight of the average 35 to 40 footer which results in more cost,
less performance and different handling characteristics from those
originally calculated. So please try to stay with the scantling sizes stated
in the plan. Often 3mm plate is specified where thinner plate could been
used but it is our experience that plate less than 3mm is too difficult for
anyone but the most experienced welders to use with out any distortion
occurring. Some thought has gone into the material specifications for your
selected vessel. Please try and stick with them.
3 BUILDING TIMES
Surfing through the boat sites we discovered this from an anonymous author
on a chat site in reply to a question re boatbuilding times. We consider
this to be true advice and have reprinted it below.
Assuming this boat is a single or even multi-chine design, getting-out the
frames is time consuming. For any ammeter figure around a full day for each
frame. Erection of the stem and frames depends on the building method and
takes an additional few days to get everything plumb to the world. The
actual templateing and hull plating (tack welded) will require several hours
per plate. Just make sure that you can handle the weight of the size plate
you are using (don't make the sections too big-dangerous to handle. Finish
welding is very time consuming. Figure 15 minutes per foot of weld
(skip-welds about 3 inches long, then backstep). Outside welds go rather
quickly as then you may extend the bead length greatly. I know of many
amateurs who have built 32-35 ft multi-chine boats (hull & deck only) in
three and four months. This is a minimum of 7-8 hours per day.
The best we have heard is two weeks for a CW25 from receiving the plans to
having the hull fully welded and ready for inverting. This was from two
experienced welders. A call from another builder just this week revealed
that he had started building his Spray 45 mid December and now had the
entire hull plated (tack welded) and was proceeding with the full welding.
He had taken holidays due over Christmas and had got his project off to a
flying start.
4 CARTOON SECTION
5 WOOD EPOXY SPRAY
Travelling down the East Coast of Australia we checked on the progress of a
wood epoxy Centennial Spray 36. Building wood Epoxy outdoors is difficult
but Wayne Morris is doing a stirling job. Starting last year he is now at
the stage of attaching the strip planks. Unfortunately we were not able to
get many pictures. The one's we could get are shown HERE
6 QUESTIONS ANSWERED.
Picked from the many questions received over the past month.
Q : What height shed do I need for a Pilot house version with deep keel.
for R 345)
A : From the top of the pilot house roof to the bottom of the keel is 12'
6".
You can measure this off sheet 1 which is to scale. I would
suggest minimum of 15 ft. I have seen boats built in low sheds by building
the hull then when turning it over set the keel down into a hole that has
been dug to receive it in the middle of the shed. This also makes it much
easier to get into and out of the boat all during fitout. An example of this
is on the website where after building the hull of his steel R434 in a
nearby farmers shed the builder dug a hole next to his house so that he
could put a lean to off the side of his house without going up. Click on Gallery
and then click on the R434 section.
Q : I am looking at two engines which are at a good price but are rated at
380 hp
I know the wave runner 38 is specified up to 600hp in total so these engines
would put me some 160hp over . I would be grateful for your advice on this
matter.
A : Regards the WR38 ... if you have the planing hull then the larger
engines are OK ... if you have the semi displacement hull then anything over
2 x 250 is wasted.
Well that's all for another month. Keep up all the good work out there.
Remember we are here to help if we can if by chance you need us.
Happy Boatbuilding,
Phil