Stainless Bow Roller/Sprit & Fibreglass Mould of Bow Section

[Jokani]

I purchased a boat with a damaged bow roller, but repairing it was not high up the priority list.

Now I have a new gen anchor, and the roller would need some extensive alteration to allow it to fit.

A new one would also allow me to have an attachment point for a chute, which would be a big bonus.

I am thinking of a design similar to this but approx. a 1/3 shorter::



I'm confident in drawing the design for the fabricator, with the exception of the 3 points where it attaches to the bow.

To ensure I get it right, in particular the angles, I am thinking of taking a fibreglass mould of the bow, but that would take quite a bit of time and effort.

Any thoughts on a quicker easier way?

Or any tips on the easiest way to create a mould?

 

[andsarkit]

Make a mock up in 15mm copper plumbing pipe. If you don't have a proper bending device you can use a cheap bending spring and bend it around your knee. You can use some compression joints to join it all together which will allow you to make adjustments and then lock it in the correct position.

 

[bristoljim]

I purchased a boat with a damaged bow roller, but repairing it was not high up the priority list.

Now I have a new gen anchor, and the roller would need some extensive alteration to allow it to fit.

A new one would also allow me to have an attachment point for a chute, which would be a big bonus.

I am thinking of a design similar to this but approx. a 1/3 shorter::

View attachment 137179

I'm confident in drawing the design for the fabricator, with the exception of the 3 points where it attaches to the bow.

To ensure I get it right, in particular the angles, I am thinking of taking a fibreglass mould of the bow, but that would take quite a bit of time and effort.

Any thoughts on a quicker easier way?

Or any tips on the easiest way to create a mould?

I went through this exercise - 24ft boat so a bit easier. Female glass mould ,then filled it with gyprock adhesive which I happened to have, but any plaster should do , this gives you a male plug for the fabricator to fit the stainless to.
Jim

 

[Neeves]

Simply cut what you want from plywood or mdf, the fact the plywood is flat is not relevant as long as you get all the angles right. you may need to make it twice. Once to get the angles right, which might need small pieces glued onto what you start with and when you are finished cut it neatly as one piece. First off - make it from a decent bit of stiff cardboard.

If you really want to make a mould - simply cover the bow with packing tape, make up some filled resin, sufficient it will not sag. Plaster the bow with the filled resin and leave to set off. It will release from the packing tape cleanly.. You now have to grind back the 'outside' of what you made (angle grinder) to closerr to what you want. But you can now coat the inside of your moulding with packing tape and make an exact copy of your mould. Use the mould, once you grind it back, to indicate to the metal fabricator what you want.

Most fabricators will be able to make what you want, from that photo, simply by making a visit to your yacht - they do this sort of thing everyday - its their lifeblood.

Jonathan