fiberglassing ribs

davlacey

i want to fiberglass a few ribs into the side of the boat im restoring for strenght. its flimsy like out of a mold im thinking 3 x 2 treated timber fiberglassed in like the pic or would i need more ribs

fergal.b

I think you should make ribs like this with plywood gussets on each side this will stiffen up the boat and protect against side impact it will also give you a base for the floor. Also if you can't get hardwood use 1" marine ply and seal with epoxy as treated timber is still a soft wood and not very strong, I know it's not the cheapest way to go but it will be better in the long run.

davlacey

thats what i was thinking it would solve the floor issue as well. i dunno how this boat was made originaly made. think this boat is made with frames like yours

fergal.b

davlacey wrote: »

thats what i was thinking it would solve the floor issue as well. i dunno how this boat was made originaly made. think this boat is made with frames like yours

There are also very thick gunnels "the timbers along the top edge" on that boat making it very strong. Did you find a makers name anywhere on your boat.

davlacey

im going to try do my gunnels the same ill make a steam box with a wallpaper stripper.no cant find any makers names i was told it was a potting boat up the north so could be from anywhere

njburke

For strong gunnels, do a search for a 'Tolman Alaskan Skiff'.
Its a very strong but light dory, originally designed by Renn Tolman, a school teacher turned boat builder turned boat building author.
His designs are very popular with offshore fisherman in the US and further afield. His designs use very little framing yet yield a very strong boat, his solution to bending ply to form a bow is quite clever, as 18mm ply can't be bent into the required form, his solution was to bend two 9mm sheets into form and laminate in place.

NJ

fergal.b

njburke wrote: »

For strong gunnels, do a search for a 'Tolman Alaskan Skiff'.
Its a very strong but light dory, originally designed by Renn Tolman, a school teacher turned boat builder turned boat building author.
His designs are very popular with offshore fisherman in the US and further afield. His designs use very little framing yet yield a very strong boat, his solution to bending ply to form a bow is quite clever, as 18mm ply can't be bent into the required form, his solution was to bend two 9mm sheets into form and laminate in place.

NJ

I think another famous boatbuilder also mentioned this method :D:D http://www.boards.ie/vbulletin/showthread.php?p=77165285 :D:D

njburke

ah great minds....

Renns method gives a very clean interior.

Look Ma, no frames


This is what I mean about his method of bending to form the bow and get the compound curve developed.


Fergal, do you know if this technique is unique to Tolmans?

BTW, Whats that method they used to use with steamed and pressed hardwood strips, it a was a cross ply /diagonal planking method. I saw a video of how they mass produced plywood hulls for dinghies in the fifies. I've also seen fruitbowls made from the same method.
NJ



NJ

fergal.b

Its the same way I built my hull in two laminations and Glen-L boats have been built like that since the 1950's a lot of there boats are also built with diagonal planking it makes for a very strong hull and can conform to the change in shape in different directions. http://www.glen-l.com/methods/plywood/mthdpw-dbl2.html

davlacey

cheers i think ill have a go at the steam bending. ive already gave it a test run and i can get the shape i need easily with half hour of steaming