So I love to get skinny. and we can all agree there are way to many factors to take into account when building a boat from scratch. but this is my estimate for boat size vs. hull thickness. Now for guys who like to get into the least amount of water possible there is no replacement of displacement. basically extra wide and light weight, but if you want it to last very long it better be tough. if you run in rocks, logs, or a river setting where you might find yourself on a dumped piece of steel you better hope you've got a thick enough hull to stand up to the torcher.
For this theory/ draft estimate I will be comparing 3 hulls and 3 different hull thicknesses. all boats will have 32" deep sides and 72" floor with a 102"beam. keep in mind the density of fresh water requires 62.4sq/ft^3. so for every cubic ft of displacement it will float 62.4lbs.
displacements @ 8" deep.
1672-48.8 ft^3
1872-58.6 ft^3
2072-65.6 ft^3
given these displacement estimates multiply by 62.4lbs
1672-3045#
1872-3657#
2072-4094#
this means that every hull will displace that amount of weight @ 8" deep.
now lets explore hull weights. we all know most boats are .100 but a few make a .125 hull and evry once in a great while you will find a .190 witch one is best?
for these examples I estimated sqft of hull skin then multiplied by what each thickness of material weights. to keep it simple I divided total sqft and converted to how many 4x8' sheets each requires.
all weights are for 5052 aluminum sheet .100-45.7lb --- .125-57lb --- .190-84lb
16'= 5.36 sheets ---- ---- .100/ 245lbs ---- .125/ 306lbs ---- .190/ 451lbs
18'=6.01sheets ---- ---- .100/ 275 ---- .125/ 343 ---- .190/ 505
20'=6.67sheets ---- ---- .100/ 305 ---- .125/ 381 ---- .190/ 561
now that's just the skin, no frame work. So I come up with a flat rate to estimate interiors.
.100skin add 500lbs for frame work and interior of a 20' boat. for 18' on each thickness I will subtract 50# and for 16' subtract 100#
boat length- 16' 18' 20'
.100 245/645 275/725 305/805
.125 306/606 343/693 381/781
.190 451/651 505/755 561/861
^^^that is skin weight / full hull weight with interior.^^^
I come up with that rate of interior framing with the thought that the thinner the material the more frame work required. I may have went a little heavy, you decide.
so what is the best hull? would love to hear your opinion even if you don't like the last section about interior weight and think it might be off.
For this theory/ draft estimate I will be comparing 3 hulls and 3 different hull thicknesses. all boats will have 32" deep sides and 72" floor with a 102"beam. keep in mind the density of fresh water requires 62.4sq/ft^3. so for every cubic ft of displacement it will float 62.4lbs.
displacements @ 8" deep.
1672-48.8 ft^3
1872-58.6 ft^3
2072-65.6 ft^3
given these displacement estimates multiply by 62.4lbs
1672-3045#
1872-3657#
2072-4094#
this means that every hull will displace that amount of weight @ 8" deep.
now lets explore hull weights. we all know most boats are .100 but a few make a .125 hull and evry once in a great while you will find a .190 witch one is best?
for these examples I estimated sqft of hull skin then multiplied by what each thickness of material weights. to keep it simple I divided total sqft and converted to how many 4x8' sheets each requires.
all weights are for 5052 aluminum sheet .100-45.7lb --- .125-57lb --- .190-84lb
16'= 5.36 sheets ---- ---- .100/ 245lbs ---- .125/ 306lbs ---- .190/ 451lbs
18'=6.01sheets ---- ---- .100/ 275 ---- .125/ 343 ---- .190/ 505
20'=6.67sheets ---- ---- .100/ 305 ---- .125/ 381 ---- .190/ 561
now that's just the skin, no frame work. So I come up with a flat rate to estimate interiors.
.100skin add 500lbs for frame work and interior of a 20' boat. for 18' on each thickness I will subtract 50# and for 16' subtract 100#
boat length- 16' 18' 20'
.100 245/645 275/725 305/805
.125 306/606 343/693 381/781
.190 451/651 505/755 561/861
^^^that is skin weight / full hull weight with interior.^^^
I come up with that rate of interior framing with the thought that the thinner the material the more frame work required. I may have went a little heavy, you decide.
so what is the best hull? would love to hear your opinion even if you don't like the last section about interior weight and think it might be off.
