Let me put it to you this way......if you own a wooden boat that is more than five years old I can just about guarantee you have some form of wood rot. However, sometimes you have to be like a detective to find it.  My hull cosmetically looked very solid but after spending so much time around it I was able to see certain clues that made me wonder.  I drilled some inspection holes in the sponson tips (this area was always hidden) and in one of them I was concerned enough to open it up.  AND THIS IS WHAT I FOUND!  Now....mind you......I was glad I did this but at the time of discovery I was a bit 'worried' to say the least!
 
 
 
 
 
 

After a little bit of clean up and after I started calming down....I was able to get a good look at what was going on.  It appears the sponson tip had multiple repairs to it, had very poor drainage and the years just took its toll.  What was encouraging (if anything??!!) was the fact that the rotten portion was confined to only the first foot or so of the sponson.
 
 
 
 

My first attempt in anything I do with my hydroplane is to try to preserve as much as possible and replace only what is absolutely necessary. Some people may have replaced the entire sponson after seeing this.....I just had to see if I could make a structural repair without doing just that. They key in this step is to keep removing (chisel & wire brush) the rotted wood until you get to solid wood - and then go a little more. This picture shows just as I was getting into the 'good wood'. Be sure to stagger those joints - makes for an easy way to fit the replacement pieces back in and provides for a strong section.
 
 
 

The first patch of marine plywood goes in.
 
 
 
 
 
 
 
 

The new pieces consist of marine plywood, Sitka spruce, silicon bronze wood screws and epoxy.  Most of the pieces could be fit in identical to what was there before.
 
 
 

All of the frame pieces in place and one perfectly placed drainage hole to guarantee the water that gets in can get right back out!
 
 
 
 
 
 
 

The finished sponson bottom with two sheets of marine plywood and the molding added back into place.  It sure does look much better then it did when I first opened it up.  I believe the fix will be 'better' than when it was new!
 
 
 
 
 
 

The next step is to cut out and fit the aluminum to the bottom.  I used 5052-H32 temper because of its toughness, its ability to take the shape of the sponson and it can be buffed out to a nice shine.  The pieces I'm using are .090" thick.
 
 
 
 
 
 

A photo of the finished aluminum pieces that have been painstakingly cleaned of varnish, cleaned of the now infamous 'black paint' and then shined back up.
 
 
 
 
 
 

Probably an old race incident fractured this frame in two right down the middle.  It then had wood braces nailed to each side and another wood brace nailed to the top.  All of this was mushed together with some type of old marine sealant.  When everything was scraped away I was left with the original frame.  I decided to go with a sandwich of 6061-T6 aluminum so it would match some of the other cross bracing in the hull.
 
 

The aluminum for each sponson has now been fitted, holes drilled and countersunk.
 
 
 
 
 
 
 
 

Agitator Part 4
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