Trojan Boat Forum

Unfortunately the damage has been done... you should have done it in sections, say 1/4's so that the top skin would have held the profile. Once you removed all of the top skin you removed the support from above. The reason to work in small sections is because you want to maintain the shape and allow to work from above.
Of course that information is no good to you now but let's see how best to recover from that error.
I would suggest you shore up the salon roof back to flat from below using 1/2" plywood panels pressed up against it and held up by poles..... that way you can tell from the underside of the plywood that you have removed the sag.
Then go back to the top, chisel out all bad balsa from ontop of that lower glass membrane, sanding it smooth and replace 1st layer of balsa (crosscut) bedded in epoxy and thoroughly wetted from above. Then replace the middle skin of glass several sheets and add the second layer of balsa like the first and putting several sheets of glass over that then you are back to gelcoat anti skid on the top to finish it.... like new.

I would do it in sections (approx: 3'x3' max) working from the back of the bridge to bow till each layer is completed (so working in two or three sections, whatever you are comfortable with).
Hope this has given you some idea on how to recover.... you will likely get the crown back but if not you can also do this with more glass sheets down the centre of bridge to make it higher.
If you puncture that bottom skin make sure you patch it before wetting with epoxy as it will run out the holes.... especially around the light above the doors.

Just an update. I was able to get the crown or bow back into the inside of the saloon. I shored it up with 2x6's and plywood. Seems to be back to original contoure.
The reason I cut the entire section out two fold. First the water intrusion was so bad and covered such a large area that it was collapsing in. And second was i had to open until I found dry core.
Today I removed about 2/3 of the adhesive (like iron) that was used to keep the inner layer (ceiling) to the first layer of glass together. It looks like I will have a nice smooth surface to start building from.
It looks like they used 1" balsa as the bottom layer and 3/4" balsa as the second layer. I have 2.25" total distance from ceiling layer to finish gelcoat.
Looking at the prices of the balsa, seams pricy, almost 800 for 20 2x4 sheets.

Glad to hear you got the bow back... I suggest you check with Beacon about core thickness.
I believe it is 3/4" balsa both layers. That is what I found with mine working in small sections. Two 3/4" balsa with epoxy is more than 1 1/2" and then you have the glass matting between the layers at least 1/8" then the top layer glass matting at least 1/8" , allowance for epoxy thickness then anti-skid gelcoat layer... that is pretty close to 2 1/4" in my mind.

I understand why you thought you had to look for dry core... but it would have been better to clean out smaller sections and repair them then continue moving on to adjacent areas.... since one is using crosscut balsa core sheets the blocks are held together on the sheet and one can work from a wall edge and stop in mid space without any problem.
I know this is a deck but you can see the bottom layer on forward left and the top layers already done below and to the right of it.

Not a Fun Job for sure .

To say the least, it was a little overwhelming when I first cut into it. Now after cleaning the damaged core and glass out, it makes since how it was constructed. This project does not allow any corners to be cut. I'll have to pay the price if I want it to be as good or better than new.
To answer your question Jeff, yeas I plan on making repair only from the top, I want to keep the inside in tack.
One more question, should I stagger the 2x4 sections of balsa to get a stronger top surface. Meaning first layer running bow to stern, and the second layer port to starboard if that makes sense?
Thanks for everyone's input. Rick

Bubbabuda wrote:One more question, should I stagger the 2x4 sections of balsa to get a stronger top surface. Meaning first layer running bow to stern, and the second layer port to starboard if that makes sense?
Thanks for everyone's input. Rick

You are using blocks of crosscut balsa? If so there is no difference in strength or rigidity in either horizontal direction. The grain is running top to bottom of your deck, so nothing changes when you lay the sheets front to back or left to right.... the strength and rigidity is from top to bottom of your deck which is what you want.

wow, weird illusion on those pictures, it does look like an old barge because it appears to be 50' wide!

I recently repaired some coring on my engine hatches doing the same thing on a much smaller scale. I would say that between the two of us, we have both extremes of balsa core repair covered.

Good luck, you're on the road to recovery now....

Bob

Bubbabuda wrote:unfortunatly, the junk barge is the bridge. See why im in deep....

Why no use Divinycell instead of Balsa?

Won't rot or absorb water.