BYYB Forums

Ok, here's last years repair.  At first it didn't look to bad, until I pushed a finger through the wood with very little resistance.

  I pulled out all the punky soft wood, made sure I had good solid wood around the edges.
Stringer along the bottom had some bad spots but was mostly sound. Cleaned everything real nice and made a patch to fit.  The patch material was a little thicker than the original.  I used a backer board and countersunk all the screws.  I also used 5200 all around and between the backer board and the patch.  Let the 5200 cure for a week (had to make a west coast run). 

  When I got back, sanded the patch flush with surrounding wood.  I used fiberglass marine body putty to fill/smooth. Let it cure overnight then sanded smooth and painted.  (I use an oil based exterior house paint).  Let it sit for another week, then took her out sailing.
 
  Sailed the whole season (at least one day per week) then put her in her winter home. She sits in my folks barn for winter so no water intrusion at all while in storage.

  This year I've retired from truck driving and have much more time for sailing and maint on the boat.  I sanded all the old varnish off all the bright work and refinished it.  Gave the whole boat a good paint job. Rebuilt the rudder box/tiller, built a new hatch for the companion way. Cleaned and regreased wheel bearings and other maint jobs on trailer.  This all took about 3 week and my repair from last year still seemed fine.

  Now I've been sailing this season and discovered soft wood just to the left of last years repair, and the bottom hull is soft from the inside (outside still feels hard, but probably the fiberglass shell.

  There is water behind the pant and soaking the wood.  I think it came in through the screw holes that hold my transducer. (forgot to seal them after I screwed them in.)

 

More pics of last years repair.

Are you using epoxy or polyester?

Hi Paul,
  Thanks for responding.  I understand your question. I've read several of your posts regarding regular ol' bondo type body putty.  So when I went shopping for materials to effect this repair, I came across the filler (made by bondo) that is marine specific, supposed to be waterproof, and fiberglass impregnated. (lots of fiberglass strands in the raw mix)  It does have a cream hardener that looks exactly the same as the bondo body putty.  I guess I'm not sure other than it's not what I understand as "epoxy".  It smelled the same as fiberglass resin that I've used for other things. (had a clear liquid hardener that you only used a few drops per once).

  The actual area of the previous repair is still sound. Just a small area just to the left, in the 'original' wood.  I did trace the water back to the screw holes that I made to hold my depth finder transducer (I know fishfinder : )

    Also the stringer that was mostly ok is now very soft and spongy and about a 6"x5" patch just forward of that stringer on the bottom is also soft. 

    I guess I'm asking, is there a better way to make this type of repair?  The patch with a backing plate was ok. Now I'm looking at a part of the stringer and hull bottom.

  It's all in the lazerett area, so even if I use a backing plate on the hull bottom appearance won't be effected, but will it be strong enough?  And how to replace that stringer piece to give strength to that whole corner? 

Yep, you've used polyester resin. Polyester resin is easy to check, as it stinks to all hell, compared to epoxy and requires MEK as a solvent. Polyester just doesn't stick to wood very well and this is part of the problem. The stuff you bought is called "Boat Resin" and this is reinforced polyester (micro and larger 'glass fibers). Polyester isn't waterproof on wood.

This is probably what you have:



or



Epoxy cures these issues and there's lots of information about it's use on various projects. Epoxy is waterproof on wood, in fact really the only thing that is and also act as an adhesive and coating too.

Thanks Paul,

  Yep, that bottom picture is exactly the stuff I used.........

  I guess I get to research epoxy now. Do you have a recommendation?  (and I tried so hard to use the right stuff in the first place, after reading your posts about body putty.....)

Log onto Bateau.com and check out their "Marinepoxy", which is one of the cheapest around. It's a 2:1 mix so easy to use and they sell some supplies too.

Next, download the free "Epoxy Book" from SystemThree.com and the "User's Guide" from WestSystem.com.. Lastly download the PDF version of the Gougeon Brothers book > http://www.westsystem.com/ss/assets/HowT...061205.pdf <, which is going to provide a good idea of the proper techniques and processes used in the industry.

Thanks a  bunch

  Off to study