Pull a plug mould off a aluminium hull

Hey everyone I have a plate aluminium tinny which is a awesome little boat but I was trying with the idea to pull a mould off the hull and rebuild it in a fibreglass version with more freeboard and hull flare anyone ever pulled a fibreglass mould off a aluminium hull?

 

You need to consider that it probably has dimples at the rivets which may make it hard or impossible to pull the mold off. Also, if there are lifting strakes or gunnels, the same. Fairing an aluminum boat may not be any easier or faster than building a proper plug. Particularly since you are changing the sides, which would include a lot of modification work.

 

Sure, it’s doable, but the mold will be ugly!
You could fair the alu hull, but that would be labor intensive, and probably render the plug useless.
Just build a plywood/epoxy boat from careful measurements?

 

If the only issue with your tinny is the lack of freeboard, would it be feasible to rivet or stitch weld an additional 'sheer strake' (for want of a better name) to the existing gunwhale to increase the freeboard?
You could add more sheer (and hence flare) if you increase the depth of the extra sheer strake at the bow, in relation to amidships.

Edit - do you have any photos that you can post on here of your tinny please?

 

I did consider that but I was also thinking more of building out of fibreglass for a smoother ride the other thing I was thinking if I layed up o er the aluminium with my chopstrand and bi axial cloth and then release the 2 and modify/add the flare and freeboard to what im after

 

It is the hard way of doing it. Also, what makes you think fiberglass will give you a better ride?

 

I've been on ali and built fibreglass boats for long enough to know it is a much smoother ride

 

How about some bow and stern shots to clarify the configuration of the fin looking appendage ?

 

How much more freeboard do you want to have?
I presume more at the bow than at the stern?
Will the extra freeboard at the bow be higher than the bow rail that is shown in the photos?

 

I would say there abouts or 100mm-150mm higher to add some flare to the bow

 

Dimensions?
The freeboard looks generous already, except for the drastic dip in the transom.

 

To add flare you need to first remove the gunnel and create some kind of structure to keep the shape of the boat. You will have to cut off the steps on the stern too. I think it is a lot more work than building a plug.

 

You want to make modifications to a boat to build a boat to build a boat? Correct?
Where are the savings over building a boat once?

 

Im going to guess that the boat is less than 16’ long, and already has pretty tall freeboard, so I’d be cautious about additional freeboard’s possible impact on stability.
Radon and Anderson in California make boats with “tongue depressor” bows, which is a simplified version of the Carolina flare, knocks down spray like a champ. Maybe something along those lines could keep the interior dryer without adding a lot of weight and height?
I’m still not sure what I’m looking at under the stern in the first set of pics?
Aussie builders are certainly fond of large reverse chines, this one is no exception.
I would think that the space under the swim steps could have easily been hull surface to extend the waterline.