Transom Rebuild on 13' Water Bug

I picked up a 13' Water Bug earlier this year at a price that as too good to let go. I knew when I bought it that the transom would need to be replaced. I just didnt realize that it would need it so soon. After only a couple runs with an 8hp Johnson, I noticed a couple stress cracks and the transom felt a little spongy.

After doing a good bit of research online, I decided to get started. I ripped out the old transom and it was not pretty.
Here are several pictures of the damage and demolition process.

http://s838.photobucket.com/user/kitchens2197/slideshow/13ft%20Water%20Bug

I will be replacing the transom with 3/4" water resistant OSB and I will try to upload pics throughout the process. I know there are already several threads about this topic, but since this is my first attempt at this, I will take any suggestions you are willing to offer.

Thanks

 

I'm not sure if you are familiar with the stuff or not but I had planned on using Advantech. Its a subfloor material that I have seen withstand several months in the weather with little or no signs of wear or rot. I was mostly concerned with the potential for water damage. Vibrations never crossed my mind. Its pretty tough stuff but Im new to this so I will take your advise and pick up some plywood tomorrow.

Also, I have encountered what should have been an obvious issue. I'm not exactly sure how the old wood was installed due to its condition when I removed it but it did cover the entire back end of the boat. Since the transom is narrowest at the top, I'm not sure how to get the new transom in as a single piece. Would it be best to install this as two pieces or one piece as large as I can get to fit?

 

I haven't been able to find very much information about these boats. The design was was based off of the Gheenoe. My boat was made in Brooklet,Ga but I have heard of other Water Bugs being made in other towns in Ga. Im not really sure of anything else. Im hoping to run across someone here that has a little more information.

 

I agree that a single piece would be better but I'm having a little trouble finding a way to get it in there. If you notice in the pictures, the interior shape of the transom is not the same as the exterior. On either side of the boat, there are foam filled boxes(for lack of a better word). If these were not in the way this would not be an issue. I would really like to avoid cutting these out. The plywood that came out matched the shape of the exterior of the transom. The interior shape is a good bit smaller because of those boxes. Any ideas on how to get it in as a single piece?

 

I wasn't able to figure out another way to do it, so I cut out a section of those boxes on each side of the boat. I cut my plywood to shape and finally got a tight fit after a little sanding here and there. I coated my wood with resin and now I am waiting for it cure. I have a heater in my shop but with the temps we are have around here now, it will take a little longer that usual to cure. Hopefully I will be ready to move forward with the installation of the new wood this weekend.

 

Im almost finished with the transom rebuild. I got the wood in there and put on a layer of fiberglass cloth. After a couple days I reinstalled thoae "boxes" and then out on another layer of cloth. I hope to get the rough edges knocked down and cut some new boards for mounting the motor today. Its looking pretty good so far. I will try to update the pictures to show my progress.