1/10 scale hydro sponson bottom issue

[rat350r]

Over the past off season I decided to build three versions of the same boat. U77 Miss Wahoo, U00 Maverick, and U12 Miss Bud. The boats are built from the same Garry Finley plans. All three boats came out right about the same weight at 6 Lbs 8 Ozs give or take an ounce or two. All boats have the same hardware and motors and speed controllers.

Over the past couple of weeks I have run the boats. Of the three two boats are able to run 7 laps full speed and finish with all electronics in the high 90 to low 100 degree temperatures. One boat the Miss Bud U12 no mater what I do to it at half speed it will lift the left sponson and blow over. All three boats have the same CG strut depth and angle and I have tried several props but the boat still blows over.

After watching you tube videos by Scott Meyers outlining building RC boats I decided to apply some of the techniques he uses when he builds a boat. I started looking at the bottom of the boat to see if it was straight. What I found was that the left sponson bottom was straight but the right sponson bottom has what looks like a rocking chair rocker built into it.

In an attempt to fix this I used West System epoxy mixed with their faring filler basically making epoxy body filler. I applied it to the bottom of the right sponson bottom. Once it cured I sanded the bottom flat and now both sponsons are flat and even.

I plan on testing the boat this weekend to see if this makes a difference. If not what do I try next?