Switching from a GNAV to a traditional kicker and boom reinforcement?

[Ed]

I have a CST oval section boom which has always had a GNAV.

I am in the process of converting it to an internal mainsheet.
Main reason being it means :
-you get 180 degrees of ratchet in light winds when you are using the mainsheet for leech tension.
- when you change rake your always have a mainsheet which centres the boom

I am considering either stiffening my 2006 vintage soft mast which struggles with a square head or replacing it, at which point i would like to go to try a traditional kicker or maybe a lever vang.

So here is the question.

Do i need to add internal reinforcement to the tube if i change the way the force is applied?
I have seen alot of 14s which a vertical carbon plate put inside to support the structure, which always struck me as a little odd.
THese 14s use a spinnaker pole as a boom though so maybe that is the reason.

The reason for considering it now, is that when i put the blocks in the boom for the internal mainsheet, then if reinforcement is required i need to offset the forward end sheave to one side to accomodate this.

I guess some reinforcement on the outside of the boom ofr the strop wouldnt go amiss, but that is easy to do later on.

Thanks,

Ed

[Phil Alderson]

I have not come across internal reinforcement like you have described. I think it would need to be done carefully to avoid having hard stress raisers at the ends of the plate.

Will the distance from the kicker take off position to the gooseneck be the same or greater than with the gnav on full?
If so then the loads will be about the same.

Are you planning to use a cloth strop for the kicker around the boom?
If the area of the cloth is about the same as the pusher part of your gnav then the loads will be about the same.

If you make sure that you don't add any holes to the boom around where the kicker take off is I think it is likely to be OK

Is there a downside to offsetting the fwd sheave?

[Ed]

On offsetting the sheave, no downside other than it doesnt look right.

I asked one of the guys who had one and apparently it is because they use spinnaker poles which are liable to crush so need the reinforcement.

I hadnt considered whether i should use webbing or something else, but i had planned to add reinforcement at the point i would be holding it.
As far as the GNAV and kicker, the contact point is very large at present, so i would have to reinforce to a similar area.
The aim would be to use it at the same location.

Thanks,

Ed