Building a Bruce Roberts Longboat 21

[alaskarog]

Originally Posted by apex1

Welcome both... Commuter Boats and alaskarog...
Alaska, you might be happy to find, that the design will fit the strip planking method already with just minor modification, cos in principle the way to build is equal.
Stick to epoxy !!! it is the more forgiving, easier to handle resin, and has the big advantage to stick better to any material than poly (lower delam risk). And you have your experience already in the pocket.
Have some very deeep thoughts about the material!!! You are familiar with wood and Epoxy, the wooden strip is much, much cheaper than foam, the hull is not as weak as a foam cored one while you have to turn the junk (read, stays in shape with less effort). Maybe the savings on your foam bill can balance some extra $ you have to transfer to B. Roberts for modding the design.
Lay back, have a beer and weigh out point per point......................
During your construction lookout for bargain prices on Armaflex. AF Armaflex is the quality you need! Neither the wood core, nor the foam is a sufficient insulation in your Latitude! And 3 - 5 people below deck import a massive load of humidity below deck, on top of the natural developing moisture on your resin or painted surface! But believe me, it´s painful to pay that amount of money for the stuff, but worth every penny.

Kindest regards, success and good luck
Richard

Richard,

I'll look into your recommendations. After checking out the company's website I did send an email to the regional distributor of the Armaflex AF and asked him for cost/availability information here in Alaska. I really do like the idea of wood core. I'll just have to see where this idea might take me. All of the issues like attaching any interior bulkheads, stringers, engine beds, interior panels, deck hardware, etc., are already clear in my mind when I imagine doing them with wood and epoxy versus in foam and fiberglass. When you build in wood core do you generally use solid wood strips or are you using plywood that is cut into strips as required to get the necessary bends?

Regards, Roger

Originally Posted by alaskarog

Richard,

I'll look into your recommendations. After checking out the company's website I did send an email to the regional distributor of the Armaflex AF and asked him for cost/availability information here in Alaska. I really do like the idea of wood core. I'll just have to see where this idea might take me. All of the issues like attaching any interior bulkheads, stringers, engine beds, interior panels, deck hardware, etc., are already clear in my mind when I imagine doing them with wood and epoxy versus in foam and fiberglass. When you build in wood core do you generally use solid wood strips or are you using plywood that is cut into strips as required to get the necessary bends?

Regards, Roger

Hi, Roger
we use solid wood for strips, then crossplank at least one layer of 3mm or 6mm veneer on the outside, befor glass / Ep is layed up. Depending on size of the boat and hullshape naturally. Have a look at my Gallery.
I am NOT against foam in general, we did some nice boats in foam too, but went completely to Mahagony / Epoxy! We may change the species of wood once, or may use a different resin in future, but we´ll never go back to foam. Feel free to have your own thoughts about it.
Another little dirty trick (if I´m allowed): have a laser level (a cheap one does) on your wishlist before you buy the first pot of resin.
If a good Fairy has mercy, and you got it, apply and fix it on a tripod as if it is forever! Mark a line on (at least) two sidewalls of your "Boatyard", right angle if possible, or mark all walls, with a permanent marker. FINE LINE... Pump up your tripod and set another one at a higher level, you now have two "reference" lines to fix either your hull reference line (you´ll need that once a week), or your level again. Use the laser to make the centerline of your mould / frames setup. Once the centerline is fixed, move the laser beam upward to the ceiling, get a ladder and mark it there too! Every time you move you level, you´ll be happy to have some refence! Sounds silly, but there will come a day you´ll send me strawberries in winter, for that.
Have succes
Regards
Richard

[alaskarog]

Originally Posted by apex1

Hi, Roger
we use solid wood for strips, then crossplank at least one layer of 3mm or 6mm veneer on the outside, befor glass / Ep is layed up. Depending on size of the boat and hullshape naturally. Have a look at my Gallery.
I am NOT against foam in general, we did some nice boats in foam too, but went completely to Mahagony / Epoxy! We may change the species of wood once, or may use a different resin in future, but we´ll never go back to foam. Feel free to have your own thoughts about it.
Another little dirty trick (if I´m allowed): have a laser level (a cheap one does) on your wishlist before you buy the first pot of resin.
If a good Fairy has mercy, and you got it, apply and fix it on a tripod as if it is forever! Mark a line on (at least) two sidewalls of your "Boatyard", right angle if possible, or mark all walls, with a permanent marker. FINE LINE... Pump up your tripod and set another one at a higher level, you now have two "reference" lines to fix either your hull reference line (you´ll need that once a week), or your level again. Use the laser to make the centerline of your mould setup. Once the centerline is fixed, move the laser beam upward to the ceiling, get a ladder and mark it there too! Every time you move you level, you´ll be happy to have some refence! Sounds silly, but there will come a day you´ll send me strawberries in winter, for that.
Have succes
Regards
Richard

Richard,

I already have a laser level so I've got that one covered! I have a very nice 24' x 40' shop located right behind my house so I am set up nicely for a project of this size. I wish that I had built the shop with taller walls so I could build an even bigger boat. I only have 10' ceilings and a 9' door so that kind of limits my options. WHen I built my shop building I was planning primarily on using it for airplane and general woodworking projects, not a large and deeply hulled boat. I have in floor radiant heat, lots of light and AC power outlets, plenty of work benches, a bathroom, and a separate mechanical room so I don't have to listen to the noise of the large air compressor that pipes air throughout the shop. I probably should install some kind of a dust collection system to help with the dust that might be produced by a project like this. I also have an arc, tig, and a small wire feed welder, as well as a plasma cutter so I'm going to try to make as much of my own hardware as I can practically do.

Roger

Originally Posted by alaskarog

Richard,
Roger

envious................................

[Commuter Boats]

FAST FRED, said it well in the powerboat section...Airex and any foam based hull materials


" #16
Yesterday, 03:15 AM
FAST FRED
Senior Member

Join Date: Oct 2002
Rep: 263 Posts: 2,064
Location: Conn in summers , Ortona FL in winter , with big dock & room for O'nite stop .
All this talk about Fiberglass cracks and core damage has me wondering, which type of construction requires the least maintenance?

Fiberglass gets problems due to flexing. Eventually it cracks and water gets in the laminate.

The USCG requires a 400% safty factor on hull loads , interesting that at 400% there is almost NO flex.

An almost Zero maint boat can be created with Airex , by NOT reducing the skin scantlings for the foam.

In other words if a 1/2 thick solid glass layup would be fine , splitting the laminate 1/4in outside , 3/4 Airex and 1/4 inch inside would not weigh much more than solid but WILL be about 300% TO 400% STIFFER.

A boat built by hand over a plug (no female mold) will not have bonding hassels to the foam. A bit of workmanship on thru penitrations , as there installed , and you have a boat that can be ignored for decades.

Franz Mass built many ocean racers with this technique , that are still out there sailing.
Probably because a leak , stanchon base , whatever causes no problem for the Airex core .

With no rot (ply core or balsa ) , and no water migration found in other core materials , many of the Lifeboat services prefer Airex for the unlimited service life , and ease of repair.Lifeboat service is ROUGH & Tough.!

Surface finish is time consuming , but not expensive.

FF"

Thank you F F, I've built several very successful boats utilizing that philosophy.
The biggest problems that we see in fiberglass boats today are
#1 Poor quality product ( building materials)
#2 Under trained labor and inadequate supervision
#3 A lack of stiffness
alaskarog, I'd like to avoid a debate on the merits of the various construction methods but completely agree with the philosophy that Fred has stated above and I have found that three quarters of an inch of foam on the topsides and one inch of foam on the cabin tops can go a long ways toward making a vessel more livable in our environment.
Gerald