Trojan F-30 soft spot repair

REMorgan · Post by **REMorgan** » Wed Dec 02, 2009 1:17 pm

My F-30 has a soft spot just as you step from the ladder to the flybridge. Has anyone ever made a repair in this area before that can give me some idea as to how to proceed?

ready123 · Post by **ready123** » Wed Dec 02, 2009 7:43 pm

The structure of the bridge below the outer surface is 2 layers of 3/4" balsa with a layer of glass between both.
I suggest you cut out the top layer of glass/gel with a thin bladed saw (jig or angled rotary). You then need to check if it is the top layer of balsa, the lower layer of balsa or both that are wet. It is highly likely that it is the bottom layer in that area.
Have you sounded the bridge floor using a plastic mallet? If you hear a sharp ping then the balsa is OK... if it is dull it is likely wet. The water usually enters at the srew holes of railing supports, console attachment, bridge surround brackets, helm seats and then runs to the back of the bridge due to gravity.
You can also drill test holes with at least a 1/4" bit to a depth of say 4" and examine the state of the balsa that comes out. NOTE It is possible that balsa will have rotted completely away and that you will not get a full 1 1/2" of core with the drill bit.
The repair method is to remove all the wet core by digging it out and then replace with new core. The choice of how to do this depends on how much needs repair.
If it is only that spot ahead of the ladder (which would surprise me) you can just use 2"x2"x3/4" blocks of Plywood coated with epoxy to fill the space and then replace the top skin you cut out earlier. We then covered that patch with one of those non skid pads to make it invisible.

prowlersfish · Post by **prowlersfish** » Wed Dec 02, 2009 10:04 pm

4" ??? you will have drilled all the way thru the next layer of gas plus a inch or 2. I don't belive the core is a inch or so thick at that point on a F30 .its not even 4" total incl glass on my 36
other wise I agree with what you are saying

BTW this is a comon proplem area on the F30 I am sure the water comes in at the ladder mounting

ready123 · Post by **ready123** » Wed Dec 02, 2009 10:12 pm

Maybe 4" is a bit extreme there say 3", 4" works for the floor over the window frames to check if the fore/aft wood rails are wet... one can feel the layers as you drill, surface layer, first core, 2nd glass layer and then second core then final glass layer of the top tub of bridge floor.... then you get to the glass covering the wood core of the salon roof.... that would be further than you want to go.

prowlersfish · Post by **prowlersfish** » Wed Dec 02, 2009 10:27 pm

I did not know they used a layer of glass between the cores ( good Idea) , I never tried to go thru the "next" layer of glass asuming it was the last , Have you run into this on a f30 ? or A F32 ? I hope I never find out on my F36

A layer of glass between the cores sound great untill you relize the bolt holes that let the water in to the core go thru both layers and so will the water . thats why its a good idea to rebed fittings every so often .

ready123 · Post by **ready123** » Wed Dec 02, 2009 10:48 pm

prowlersfish wrote:A layer of glass between the cores sound great untill you relize the bolt holes that let the water in to the core go thru both layers and so will the water . thats why its a good idea to rebed fittings every so often .

I believe this was the standard process for all bridge floors not just the F32 of my experience... they build them like a bath tub in the mold and then flip them over and place on the salon roof.
You are right about the water getting in and hitting both cores. What I have found is that the bottom core can be gone completely while the top core is almost untouched other than the immediate area around the inlet point. I have found a 3 foot square section of lower core wet and some of it completely missing while the upper core was dry. This is because gravity pulls the water down into the lowest core layer and the water travels around that lower compartment area.
I have found that the test drill gives better results than hammer or moisture meter....

That is why in my initial response I suggested that the problem is unlikely to be just there.... as one steps there when going up/down the ladder it moves more than other damp core areas... but other points can be equally wet along the back of the bridge. Both corners tend to be bad too.

REMorgan · Post by **REMorgan** » Fri Dec 04, 2009 4:27 pm

So starting from the top and going down it's gelcoat then fiberglass then 3/4 balsa then fiberglass then 3/4 balsa then fiberglass. Am I reading your post corectly? Would that be a proper discreption of a cross section?

ready123 · Post by **ready123** » Fri Dec 04, 2009 4:37 pm

Correct

REMorgan · Post by **REMorgan** » Fri Dec 04, 2009 5:17 pm

Wow. Thanks