Thoughts on approach for wrapping the stringers

Hi Folks. I’m a long time lurker but have now begun a new project that I’ll be needing your advice and thoughts on.

It’s a 21’ Eliminator Daytona tunnel hull that I’ve recently picked up and have started working on.

First up is to lose the itty bitty and hole ridden stringers.


I’ve got the stringers out now and first up is to replace them with some 5/4 x 4” clear straight grained Douglas Fir. I talked to Bob Leach (founder of Eliminator) and he said they typically used 1” stair step material but he couldn’t recall building one with such small stringers like what I have (¾” by 1 ¼”).



In theory I think I could do this fairly easily but I have one wrinkle. This boat has beautiful Balsa floors on the outboard side of the stringers and I would like to preserve them.

My thoughts are to use West System epoxy as I have had some great success with it in the past but with a desire to make it as clear as possibly, I’m a bit apprehensive.

Here’s some pictures to give you and idea of the hull shape





Also, here is a conceptual approach of what I would like to do.



Black represents the shape of the hull…….

Blue represents the stringers………

Green represents the location of the Balsa floor….

And Red represents my thoughts of wrapping the entire area in glass.

My thoughts for needing to wrap the entire area is to get the strongest bond without having an unsightly seam right on top of the Balsa floors BUT, if you folks feel that is overkill, please let me know.

It’s important to note that for the most part, the stringers only serve as attachment points from the motor well forward and I will again be cutting them down to approximately 1 ¼” tall. I only need the 4” height back by the motor.


I’m all ears. Thanks so much for any advice you would be willing to provided................John

 

Generally, even if you had the seam halfway across the balsa, once you sanded it back smooth and reapplied the varnish, you would hardly see the join.

Is the balsa deck exposed to the sun ?"

Is the balsa deck varnished ?

 

John ,Your idea is exactly what I had in mind of doing, but I found that the flowcoat on minewas so cracked up that I neeed to go deepe, so I decided to just remove the ore entirely and start over. It is a good thing I did because the balsa had alot of soft and real dry spots in it.
If You have looked at gone greens CP from PB I liked the way that they pre glassed the stringers and the just tabed them in. I often wonderd is just tabing them was strong enough. The only problem that I dont care for is to see the tabbing on the full length of the stringers. But it did come out nice. I just really liked the idea of pre coating the entire stringer. I think it made for a much clearer look and finnish.
Did Bob Leach happen to say what laminate schedule and material weight they used on the stringers and balsa core?
I am planning to do what you are showing in Your sketch ecept to extend the glass down into the center sponson , to cover the flowcoat cracks after grinding them out, to give it a fresh layer, I am then seriously thinking of covering the center sponson area from stringer to stringer, mostly for astetics ..H

 

Thank you for the reply Watson. The deck is exposed to some sun so I'll likely need to cover it. The manufacturer had flowcoated over the Balsa and I am likely going to do the same.

Hi Hal!
Yah, these floors are beyond perfect so I really want to try to save them. I agree on the looks of Randys stringers. By precovering all the stringers and bulkheads it does look very nice and clean and I too wonder if just tabbing them in would be okay versus going all the way like we both are talking about. Specially since the stringers really only are providing someplace to mount things too and the vertical walls are providing all the structural strength.
Unfortunately, when I talked to Bob I totally spaced on asking hem the weight and schedule they used. I've started to do some trial runs on some scrap 1x4 wood and some material I have left over from the Brendella. Assuming the material is close to the same weight as the original, the thickness compares to about 3 layers of cloth or 2 layer of cloth with 1 layer of matt. Not scientific but I wanted to see if I could recreate the thickness. The problem is I dont recall the weight of this cloth and matt I have. Grrrrr

 

One more thing guys....

This is an ex-outboard boat and will converting over to a jet so I have no need for the 1 1/2" transom. I would like to swap that out to something less heavy.

What's the best approach to removing the transoms? You can see a seam running right to left in the pictures.

Thanks again

 

I've moved this thread to the fiberglass forum. Thanks