Can It Be Converted To Another Building Material?

See The Following Table & Notes For An Answer.

We're often asked about the possibility of changing the building method or materials for one of our designs that has already been designed for construction in another material. Much of the practicality in conversion depends on the designed displacement of the vessel, weight of the material, re-ballasting possibilities and so forth.

For instance, to consider converting one of our steel Coasters to build in plywood, would be quite plausible. There would be a noticeable savings in weight in doing the boat in plywood instead of steel, and, in this case, we'd either consider adding a little ballast or creating a revised set of lines to further refine the shape at the reduced displacement. The reduced displacement would require less power for the same speed and/or get more speed with the same power (if the hull form permitted).

To take one of our older designs that was designed for ferro-cement construction and build it now as a cold-molded boat would also result in a lighter boat. This could be an opportunity to add ballast to stiffen up the boat and enhance her performance. However, this would also mean making the rigging stronger, since the loads on the rig are directly related to the stability of the boat. We've marked the table to show this possible conversion and give an example of how to read the table.

The following table provides a general guideline in answer to this conversion question. Although not intended to be construed as a rigid conversion rule for all cases, it will help get the dialog underway. In many cases, our designs are already drawn up for several optional materials, as can be seen from the materials codes column in the price list. (Insert link to plans price list.)

The following Materials Codes refer to the versions that have been drawn so far. Check with us for other options or whether there has been a change in the one you're interested in.
    The codes are:
  • AL = Aluminum
  • AX = Airex® cored fiberglass
  • CF = C-Flex® fiberglass
  • CM = Cold-molded wood (may be done with veneers over ST)
  • CR = Carvel planked wood
  • FC = Ferro-cement³
  • GL = Solid fiberglass
  • GL/ST = Glass skin over strip-planking
  • LP = Lapstrake wood planking
  • PL = Plywood, sealed and glued with epoxy
  • SC = Steel chine
  • SR = Steel, round bilged
  • ST = Strip-planked wood
From:
To:		ALAXCFCMCRFC³GLGL/STLPPLSCSRST
ALN/AYesYesYesYesYesYesYesYesYesYesYesYes
AXYesN/AYesYesYesYesYesYesYesYesYesYesYes
CFYesYesN/AYesYesYesYesYesYesYesYesYesYes
CMYesYesYesN/AYesYesYesYesYesYesYesYesYes
CRºYesYesYesYesN/AYesYesYesYesYesYesYesYes
FC³No²No²No²No²No²N/ANo²No²No²No²YesYesNo²
GLYesYesYesYesYesYesN/AYesYesYesYesYesYes
GL/STYesYesYesYesYesYesYesN/AYesYesYesYesYes
LPYesYesYesYesYesYesYesYesN/AYesYesYesYes
PLYes¹Yes¹Yes¹Yes¹Yes¹Yes¹Yes¹Yes¹Yes¹N/AYesYes¹Yes¹
SCNoYes²Yes²Yes²Yes²Yes²Yes²Yes²Yes²Yes²N/AYesYes
SRNoYes²Yes²Yes²Yes²YesYes²Yes²Yes²Yes²Yes²N/AYes²
STYesYesYesYesYesYesYesYesYesYesYesYesN/A


Notes:
º = May have less room due to framing.
¹ = May require revised lines/hull form to take full advantage of this material. For instance, plywood and other sheet materials are most efficiently used in large pieces and require a "developed surface" hull form; i.e… one that is made up of a combination of cone and cylindrical shapes that allow the material to wrap around them without being cut into smaller pieces.
² = Would require revised lines for more displacement to carry the added weight of the material for which the design is being converted. This is usually true in the case of converting to a heavier material like steel.
³ = All ferro-cement designs specify the use of the high strength ½" 19 gauge square welded mesh. "Chicken wire" is of inadequate strength and not acceptable.
N/A = Not applicable; no conversion required.


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