Sponson repair on scale--need advice.

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Brandon White

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Before I go cutting, I would like some advice on what would be the best way to cut and fix this sponson. It's my first time doing and big repair. Any help it appreciated.
 

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My thoughts would be to not cut the existing sponson inside if you can avoid it. You already have the spar and canard mounted to it so that would save some work. If the deck and bottom aren't damaged where they are attached to the sponson inside, I would leave some of that as well. That would give you an area to attach a doubler to the inside that the replacement piece can be fitted and glued to. After that is done, I'd lay a thin layer of glass(two if you prefer) along the joint to give the repair more strength, fair it out with whatever you like and paint.
I'm sure others will have a different approach to how to repair that sponson. Personally, I prefer wood boats as, for me anyway, they are easier to repair
 
That does change not cutting into the sponson inside, but only enough to replace the damaged area. I would stop at the front of the spar to preclude having to reattach it. Other than that, the rest of my previous post would still apply. Something I hadn't thought about until now is you may want to add a few ribs or stringers, along with the internal doublers I mentioned in my previous post, to stiffen the area being replaced so that it doesn't flex and break the joints
 
I would open a hole in the bottom and glass the damage from the inside. I would not use the new piece. Put the pieces in place as well as possible and tack them with CA. Tape over any gaps. Sand the inside with 36 grit and a dremel to get to tight spots. Glass inside with laminating epoxy. resheet the running surface.
 
Need more info. Is the bottom still intact? I agree with Mark Anderson that leaving msot of whats is there is the better choice. Hell I re glass the crumpled nose piece of a tunnel sponson. Put tape over the top deck. Then glass up the inside. Then filled and glass the outside. Added very little weight and was better than the chopper glass work from orginal.
 
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Brandon,

I think you got this.. if it was me.. I would be sure to not cut to close to the center tub.. see if you can keep at least an inch of sponson from the beginning of the center section forward..

I would place some tape around the broken sponson. Use one edge of the tape as your cut line.. (don't worry about getting the cut prefect).

Using a cutting disk cut away the sponson. Remove any front wings that are in the way.

You are going to want to do the same thing to the new sponson tip.. put tape on it .. if you are careful you can use most of the old sponson to align the new tape.. maybe ad 1/8 to the length.. (if you are 1/4in either long or short in the end nobody is going to know)

Sand the two parts to get the best fit you can.. (this part matters to getting it straight!).. take your time.

To mount the new tip.

I would build up 3 layers of cloth and epoxy (on the boat half) with about 3/4in sticking out the front of the opening. Try to make it neat. When its cured you will have a attachment lip to epoxy the new tip on (you will likely have to sand on that some and thats OK).. you are going to have to be as neat as you can here. when that is cured. Mix up a batch of epoxy and Q cells or any other binding filler (dont use Micro Balloons!).. and glue the new part on. Take you time..

HAVE FUN.. most important deal.. dont sweat it.. you got it!

Grim
 

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