If you add dock power to the mix, your baby starts devouring anodes like it's chicken noodles. Aluminum also needs a lot of Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test Materials Boat Aluminum Building Test Test Materials Building Boat Aluminum attention paint wise. All fittings and the bottom needs to be painted more often than fiberglass. It's important to keep up with corrosion; once saltwater comes between your fittings, there's no stopping it.

But the Aluminum Boat Building Materials Test Boat Building Test Aluminum Materials horror material some people claim aluminum to be is just not true. There are experienced sailors out there with tens of thousands of miles on there aluminum hull, that still use the original paint.

They only repaint the bottom every couple of years. What is the best material for a boat? The best material for a boat depends on the water and sailing conditions, but generally aluminum is the ultimate boat building material.

It has a very good strength-to-weight ratio, which is important for a boat. It does, however, require proper maintenance. Especially in saltwater, it needs quite some maintenance, due to electrolysis. In fact, some smaller welded aluminum boats may need few if Aluminum Boat Building Materials Test Test Materials Aluminum Boat Building any frames at all, especially where bulkheads may serve double duty. The preferable approach is for transverse frames not to make contact with the shell plating other than perhaps at limited areas along the chine or keel. In Aluminum Boat Building Materials Test effect, such frames are "floating" within the hull, and are used to support and reduce the span of longitudinals which are the primary members stiffening the hull plating.

About the only case where a transverse bulkhead needs to Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test make continuous plating contact is if it is intended to be watertight. Even then, such a practice tends to distort the plating and is often readily visible on the outside of the boat.

In short, general practice is Aluminum Boat Building Materials Test Boat Test Materials Building Aluminum to NOT weld plating to transverse frames or bulkheads even if such members touch or come near the plating. The chine is the junction between the bottom and side on a v-bottom or flat bottom boat. On high-speed planing boats, this corner should be as crisp are possible, especially in the aft half of the hull.

The reason is that water should break free from the hull to reduce frictional drag at speed, and not climb Materials Aluminum Boat Building Test Aluminum Boat Building Materials Test up the topsides. As shown before, Fig. Backing members such as in 'C' and 'D' help tie frame members together when setting up and help define the chine line to assure a smooth, fair curve.

Otherwise, a Test Building Aluminum Boat Materials backing member is largely optional. If a special extrusion as discussed before is available, these are acceptable. The example in 'E' includes a built-in spray deflector, and can be bent along its length as required to conform to Aluminum Boat Building Materials Test Aluminum Building Test Boat Materials Aluminum Boat Building Materials Test an ever-changing angle between the side and bottom that commonly occurs. Side and bottom plating fit into the slots which are then welded continuously. Whether such welding is done both sides depends on plating thickness and a builder'Test Aluminum Building Materials Boat Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test s desires.

From an appearance standpoint, a continuous inside weld looks best. However, such extrusions are often proprietary items or otherwise prohibitive in cost, and a problem to buy and ship in small quantities. Completing the ends of Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test such extrusions where they join to transom and stem areas is also not always easy for the builder making a single boat.

An alternative that provides much the same effect is the tee-bar in 'C'; this is easy Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test to bend and is usually readily available. However, if the protruding flange is too pronounced, there may be a tendency to hang up on rocks in certain boats such as whitewater boats, or snag debris and catch pilings Building Boat Aluminum Test Materials Aluminum Boat Building Materials Test in other types of boats depending on their use.

A lower cost alternative is a simple round bar in 'D'; this adds abrasion protection to an often vulnerable Aluminum Boats With Steering Wheel Test corner. But if too large a diameter, won't provide Aluminum Boat Building Materials Test Test Boat Building Materials Aluminum the crisp edge needed for higher-speed planing boats you could add a flat bar deflector edge-wise against the bar slightly above the corner that might help, however.

Otherwise, round bar bends around frames easily and gives a well-defined boundary to work to when fitting side and bottom plates. A simple corner joint with side and bottom butting together as in 'A' is technically feasible, but is more difficult to fit and make fair. A temporary chine backing member may help in this regard.

In this case the bottom is fitted first and cut with care along the chine line a temporary backing member may aid in fitting. Then topsides are installed, letting the Aluminum Boat Building Materials Test edge overhang the junction a distance as required to form the spray deflector flat. While a good design, this configuration also takes care to assure fair lines. As mentioned, on the modern aluminum hull, most plating is reinforced by longitudinals.

While a good set of plans will specify what to use for these members, this does not necessarily rule out another alternative if what is specified is not available. The cheapest and most easily obtained is Building Aluminum Boat Materials Test the simple flat bar 'A'.

These are available in many sizes, often in the form of extrusions with radiused edges that facilitate welding, or you can cut your own from plate. Other stiffeners are often extruded shapes that Aluminum Boat Building Materials Test Aluminum Building Test Materials Boat can get costly and may not be as readily available in Model Boat Building Materials Youtuber the sizes needed.

Angles as in 'B' are usually easy to get and have good strength to weight, but the asymmetrical shape may make bending in two planes difficult. Tee's 'C' present a symmetrical shape that forms more easily. Inverted channels 'D' are also an effective stiffener, but rectangular tubes 'F' , and "I's" 'E' are largely overkill since that portion of the member Aluminum Boat Building Materials Test against the hull adds weight with little or no gain in strength, but at a higher cost.

On the other hand, the special hull stiffening channel configuration sometimes available as in 'G' makes an effective stiffener. A less effective member strength-wise is the split pipe or tube as in 'H' which is sometimes also stocked as a ready-made stiffener.

When installing longitudinals, bending can present problems depending on curvature and member type. One approach some builders take to reduce bending effort is to gore members along their flanges as in Fig. This idea is sound, but the execution takes care to assure fair curves. Good practice also calls for radiusing the corners at Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test the gores slightly to minimize hard spots against the plating.

Avoid over-welding, and completely around the ends of each cut. This allows a strong fillet weld on both sides of the junction the inside weld can be intermittent. A Boat Building Test Aluminum Materials simple corner junction here as in Fig. In fact, some builders extend the bottom plating considerably past the transom on faster planing hulls to form integral non-adjustable trim tabs. These can later be bent down slightly if Building Materials Aluminum Test Boat Aluminum Boat Building Materials Test required for best performance and then bracketed to the transom once an optimum position has been found.

Transom thickness technically need be no more than that of the side or bottom plating. Additional thickness may be required - Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test at least in the area of the cut-out - either through the use of doublers or thick inserts.

A thicker insert is preferable at a cutout to avoid the need to seal joints between doublers by welding. Where Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test thin plating meets thicker plating, bevel the thicker edge at a slope equal to at least three times the thickness of the thinner plate see Fig. The insert should have rounded corners rather than being a hard square Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test or rectangular shape. There is an on-going debate as to whether welded aluminum boats should be made as light as possible via light plating and framing but with more of it , or with heavier plating using minimal but Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test also somewhat huskier framing members.

A boat built with light plating and framing is lighter in weight for more-economical operation, has a higher speed for a given power, is more-easily trailered, has greater payload, and because it has Materials Boat Aluminum Building Test Materials Aluminum Boat Test Building Aluminum Boat Building Materials Test less material, will cost less.

Advocates of heavier plating and framing counter that thicker plating is stiffer which better resists flexing, twist, and fatigue, won't dent as easily, and will deter longer any effects of corrosion. Then Aluminum Boat Building Materials TestAluminum Boat Building Materials Test ong> too, they claim thicker plating is less prone to distortion by welding heat and it's easier to make stronger joints since it's more likely that both sides of joints can be welded without problems or Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test defects.

In addition, thicker members are often easier to handle and work since they resist distortion and are not so "floppy". Who's right? As a designer I feel there's validity in both camps, but with some Test Building Aluminum Boat Materials Aluminum Boat Building Materials Test Boat Aluminum Materials Test Building qualifiers. First, there is a natural tendency among builders in any material to over-build and second-guess the designer, even when a boat uses the heavier plating approach initially.

The typical idea is that if so much is good, Building Test Materials Boat Aluminum Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test then a little more must be better. The result is that such boats weigh more than the designer predicted. And who gets the blame when the boat doesn't perform up to predictions? You guessed it - NOT the builder. In other words, I'd favor the latter change but might question a plating increase. Much depends on the boat and its expected service. For pleasure boats, I tend to favor lighter scantlings, but for more Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test rigorous duty, heavier construction may be justified.

However, rather than simply increase plating thickness, you might get similar results by adding a few more internal stiffening members instead. An appealing possibility on metal boats is tanks integral with the hull, which is acceptable for diesel fuel but not gasoline. Because the hull shell plating provides one or more of the tank sides, and internal tank members can double as hull stiffening members, such tanks can save Aluminum Boat Building Materials Test material and add capacity without taking up more room.

However, I favor separate tanks for boats less than about 40' for the following reasons. First, tanks might be of such a size or located in such a Test Building Aluminum Materials Boat position that welding tight seams all around the perimeter is difficult if not impractical. Second, because full welds are required, there is a greater chance of heat buildup and ultimate hull plating distortion. Finally, special consideration must be Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test given at the intersections of tank ends, hull stiffening members, and internal tank baffles when required.

Attempting to fit and weld tank ends tightly around stiffeners that pass through the tank is tedious if not impossible. Instead, hull Aluminum Boat Test Building Materials Boat Building Materials Aluminum Test stiffeners should stop at tank ends, with similar members cut and fitted inside, or with internal baffles installed in line with such stiffeners as substitutes and to maintain continuity.

Conversely separate tanks built outside the hull are physically Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test easier to manipulate during assembly and welding, easier to test and assure integrity, easier to repair or replace, and not as likely to suffer damage in a collision. Aluminum tank thickness is sometimes shown as a function of Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test Test Materials Aluminum Building Boat tank capacity such as the following:. To 50 Gals:. However, for practical purposes, most tanks should be at least.

Thicker tanks also require less stiffening, and since plating material is usually suitable, no special thinner stock need be Aluminum Boat Building Materials Test ordered as might be implied from the above list. Water and waste holding tanks should be coated on the inside to prevent corrosion from impurities and the effects of aluminum hydroxide precipitation that can turn water "milky". Also Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test provide striker plates or doublers on the bottom under sounding tubes if being used to prevent damage to the inside of the tank.

All tank tops should be canted, sloped, or cambered so condensation or moisture will drain Aluminum Boat Building Materials Test off the tops. Tanks can be made out of the same material used for the hull plating , , etc. Special computer-aided design programs coupled with numerically-controlled cutting equipment have made it possible to literally pre-cut all the components Aluminum Boat Building Materials Test Aluminum Boat Building Materials Test Building Test Boat Aluminum Materials of a metal boat to precise size and shape in kit form ready for final welding assembly.

However, for successful results, a skilled boat designer familiar with the material and fabrication techniques, along with the ability to operate Building Boat Test Materials Aluminum Aluminum Boat Building Materials Test the software to within exacting tolerances is a prerequisite. Otherwise, as they say, a miss can be as good as a mile. If one major component is not spot-on, you could waste a lot of costly metal quickly Aluminum Boat Building Materials Test Aluminum Test Materials Boat Building Aluminum Boat Building Materials Test and perhaps assemble a boat that could be so inaccurate as to suffer severely performance-wise.

But done right, the system has inherent appeal since such boats should be easier and faster to assemble. Is this technology suitable for Boat Aluminum Test Materials Building the do-it-yourselfer building just one boat? It depends. The ability to provide such a technologically-advanced product does not come cheap. The design process usually requires an entirely different building and assembly system than would be the case for Test Building Aluminum Materials Boat a "one-off" which may use simple, traditional framing, is more-costly, and often takes more time than traditional design methods even though a computer is used and necessary.

For the production builder, the higher design and development costs will Aluminum Boat Building Materials Test be amortized over a great number of boats. And the labor savings would no doubt make up the investment manifold over time. First, usually such designs are proprietary; that is, the rights are owned by a boatbuilding firm Aluminum Boat Building Materials Test who commissioned the project and is unlikely to have any interest in sharing their design or making it available as a "stock design" to anyone else.

Second, facilities for pre-cutting metal boats are currently far and few between, Aluminum Boat Building Materials Test and not all have equal capabilities and expertise when it comes to boats. Third, if a do-it-yourselfer is not near such a facility assuming a design is available , shipping costs can be prohibitive on just a single unit.