MX16 is the balsa core needed?

[capt911]

Have an old 1972 MX16 and noticed there was water under the top layer of glass cloth in the stern very center of the Vee. Last year I cut the center flooring out as it was rotted. Today I started removing the top layer of glass cloth that is only in the center of the boat under the flooring and the balsa core is obviously rotted. Under that the hull is solid layup and appears to look just like what is on both sides of the boat outboard of the floor.

I was wondering structurally how important the coring is in the center of the boat? considering I used it last year probably in this weakened condition and did not have a catastrophic failure. Any advice on how important the coring is just in the center of the Hull?

As I said I am in the process of totally removing everything rotten and will go from there and reglass coring or just layers of cloth if that is the proper thing to do. Any advice would be appreciated.

If I figure out how to post pictures will do so soon.

Thanks in advance for any help or advice.

 

[capt911]

I do believe I have to strengthen the bottom rotted core area under the floor. Time to look for balsa.

 

[Nick616]

Try these guys: http://www.specializedbalsa.com/index.php

I assume they can take care of you - I use them for balsa structure competitions. ( Science Olympiad )

 

[Diplomat82]

Here is a good article talking about balsa cored hulls and the engineering behind it.

http://blog.dankim.com/2010/01/15/grp-materials/

 

[Diplomat82]

Good place for balsa also.

http://www.fibreglast.com/product/end-grain-balsa/Vacuum_Bagging_Sandwich_Core

 

[hgrants]

I am working the baja version of the MX16 (same mold I think). It was a free boat but we all know there is no such thing. I gutted it and also found most of the balsa core soaked or mush. At this point I would have given up on the hull if it was not such a cool boat. Like you, I contemplated my options. The hull without the balsa core is too thin. I considered building up the thickness with resin and CSM but decided it would make the boat much heavier and would use up a lot more resin and CSM. I decided to go with the balsa core as it will cost about the same and it will be as it was built by the factory. I ordered my balsa core from Fiberglast. Their shipping was much less than other suppliers I looked at. The nasty work is grinding down the inside of the hull where the balsa core was laid down with resin. I would not skimp on making the hull at least as strong as it was when originally built as that is dangerous.