After You Punch A Hole In The Hull

Ahoy from good ol 3440!   My Flying Scot has a neato depression just off the centerline of the hull to set the crutch when you are all done sailing.  This works well for experienced folks.  But summer before last we took our beautiful yellow boat all the way to Traverse City Michigan where she was the queen of the lake.  But the boat ramp was mainly for ski-boats and in the hurry to cross the highway at the head of the ramp to fetch the security of the parking lot, I failed to see the limb of the Oak tree that was trespassing overhead, and you guessed it, parted my forestay.   Turns out the mast on a Flying Scot is tremendously strong.  Enough so that it Karate Chopped right through my boom.   Really, you could hardly see a scratch on the mast.   Got a new used boom.  Back in business, busy losing races.

This spring I was cleaning the hull and noticed a star shaped set of cracks aft.  No big deal.  They will match the other thousands small cracks I have.  But when I noticed small dribbles of water, I knew I was in trouble.

Today I removed a 3" round section of gelcoat, and the first layer of fiberglass.  You can push on the edges of the gelcoat and glass and it flexes.  There is a void between those two layers and the upper layer.  Totally out of my depth here.  I know I need to dry it out.  But  help?  Is there plywood core this far back?  I don't seem to see any.   Should I just pack the void with stranded glass and gelcoat the surface?  Is that a good fix?  Any thoughts would be appreciated.

Further:  I removed more of the exterior.  There is a large 3/16" gap between the outer glass and glecoat and the inner hull.  Bilge?  There is some small amount of waterlogged dis-integrated plywood in this space.  There is a 3"x3" section of thick Glass, perhaps thrust bearing below the crutch socket.  Since this bit of plywood is shot, does this mean that all the plywood is wet as well?

Any suggestions for investigation or repair is appreciated.


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Comments

Deck Crack

James

I assume that the crack is on the aft deck. The core is made of balsa, which loves to absorb water if allowed to do so. I had 2516 a while back which had a crack through the hull from her previous owner. The balsa core was wet and the area for repair was far more extensive than I thought. We got her back together pretty well as we went in from the floor as opposed from the outside in and replaced the damaged core and reglassed it all back. Deck repairs can be tricky and the best suggestion is to contact Flying Scot Inc.

You need to be more specific

You need to be more specific - pix help.  If you're refering to the aft deck - and there is that much 'mush', chances are... and you're not going to want to hear this, that a lot, most, or all of your aft deck's core is wet.

If you're not handy, then I would recommend finding someone who does fiberglass repair to assess and repair the damage.  Or, an experienced FS owner.

The forward deck, the aft deck, the side decks, the floor are all made in a sandwich construction of, from the top: gelcoat, laminate glass/resin, balsa wood, laminiate glass ( the floor does not have a gelcoat top ).  This layup creates great strength and lightness.  FS' are built like tanks.  This will last for a very long time... AS LONG AS WATER DOES NOT GET IN TO THE WOOD...  If water gets in, the balsa turns to mush quickly - the strength and structural integrity are gone.  And, if you encase the wet wood with a half-assed repair, that wood will rot lickety-split.  Unfortunately, almost all I have read says that wet wood will not dry - so it's gotta come out. 

The repair must be done right. 

I would take a screwdriver - hold the metal shaft in your hand and use the plastic handle as as a sounder against the cored areas.  Knock a cored area you know is solid.  Hear that nice ping? - it's a solid sound and feel.

Now, take the scredriver and knock the area where you know its wet - hear that thud ?  That's a delaminated area - where the wood is wet, or mush and not holding to the (2) layers of glass... Knock the screwdriver further away from the thud to where the thud sound starts to 'tighten up' - that's where you're getting back to healthier core ( this can still be wet and will still need to be removed ).  Once you get back to a nice ping sound - you can assume that the area is either 'good' or marginal...

I've done extensive repair on these boats and although it is not rocket-science, it does take a certain level of skill and commitment to repair.  And, at the time, I seemed to have more time than money !  If you have some money - PAY to have it repaired - so you can maximize your sailing time !  However, I would make sure the rest of the boat is OK before you start because every area where there's a through deck fiting is highly suspect for allowing water into the balsa...  Check the chainplates, the jib sheet block on side decks ( if equipped ), the boom crutch hole via the SS fitting through the aft deck and the boom crotch resting point in the floor, to name a few...  

I have 'potted' with epoxy every through hole in my boat 'cause once you do this type of repair, you never want to do it again !

Good luck !

 

 

 

Hull Not Deck

Yes, I should have been more specific.

The crutch nearly pierced the hull, certainly shattered everything leaving through the resin and gelcoat cracks.

The main question is the wood back aft "connected" to the main balsa of the hull.  If so, then then I am pretty sure all the balsa is shot.

Yes - the wood under the boom

Yes - the wood under the boom crutch support is balsa, I'm sorry to say and a design flaw.  I've seen many a boat with a wet floor due to the boom crutch wearing the glass in the area away, typically from a boat on a mooring where the boom moves around and transfers that movement to the crutch where that slowly digs a hole into the core where rain water makes short work of the core into mush... 

How long was this hole exposed to water ?

Try the scedriver thing on the floor - you'll get a good idea how far that water went.  The other bad thing is of you live in a freeze zone, then the water and freezing can be even moire destructive ( think glaciers, ice etc. )

 

 

Sailboat Hull of Fame

Now we know why we get to sail the best sailboat around.   Despite sitting in the lake in a boat slip for 18 months after cracking a hole in the aft hull under the crutch pole and seeping in water, the only damage is 3 sf surrounding the crutch pole socket.  Harry will rest easy this summer iced tea in hand knowing that he doesn't have to replace all the balsa core of 3440 as a "fun" summer project.   I am pretty sure this will be relatively a "do-able" fix.

I drilled 8 test holes from the standing hull surface and found dry-as-a-bone balsa wood in my drill bit.  My moisture meter is reading 4% moisture, confirming my observations.

 

The only moist wood starts about a foot from the crutch hole depression.  So the small amount of water getting in was limited to this one area.

 

Many thanks to those that posted!  I'll post my plan for repair, and steps to the success.

 

How To Repair The Hull

This are the Repair Steps as I imagine them, celebretory Gin and Tonic in hand:

Cut out upper layer of gray hull walking surface with surface saw set to 1/4".

Remove remains of wet balsa core.

Dry hull with forced air dryer.

Scratch up the exposed Fiberglass exterior hull inner layer for better bond.

Apply setting bed of resin:  Total Boat Polyester Resin.

Apply replacement balsa into wet resin bed.  Let Harden.

Sand new balsa for fair surface with palm sander, leaving course 60 grit surface.

Apply generous wet resin bed.  Make sure it gets inbetween voids between balsa blocks.

Apply course woven fibreglass into wet resin.

Apply generous wet resin atop woven FG.  Allow to Harden.

Sand for fair surface, leave a course grit surface.

Apply unwaxed Gelcoat layers one and two.

Apply waxed Gelcoat top layer with matching multi color?, and slight sand added for non- slip?

No clue about that last step.  I have no idea how FS finishes the inside of the hull for a standing surface to not be too slippery.

Am I missing something?

 

Gin and Tonic in hand - I'M A

Gin and Tonic in hand - I'M A DARK RUM AND PINEAPPLE GUY - PICK YOUR POISON

Cut out upper layer of gray hull walking surface with surface saw set to 1/4".

Remove remains of wet balsa core. CAREFULLY SO AS TO NOT GO THROUGH HULL.  A PROPERLY USED CHISEL USED UPSIDE DOWN WORKS WELL.

Dry hull with forced air dryer. NOT SURE HOW WELL THIS WILL WORK - USE A HEAT LAMP TOO.  BE CAREFUL I.E. FIRE HAZARD

YOU REALLY SHOULD DO THE 12:1 RATIO CREATING AN ANGLE BETWEEN THE GOOD, SOLID AREA TO THE DAMAGED AREA - LIKE SCARFING A JOINT...

Scratch up the exposed Fiberglass exterior hull inner layer for better bond. CLEAN WITH ACETONE WELL FIRST THEN USE 80 GRIT OR MORE

Apply setting bed of resin:  Total Boat Polyester Resin. TAPE OFF CLEAN, GOOD AREA.  APPLY 'LAMINATE' RESIN WITH PAINTBRUSH. PRECUT 2 LAYERS OF MAT TO FIT YOUR HOLE IN THE FLOOR.  WET OUT MAT AND LAY IN YOUR HOLE.  PLACE PREFIT BALSA ONTO THAT. PLACE WEIGHTS, SANDBAGS, OR BRICKS ON TOP OF BALSA TO HOLD IT DOWN WELL - LET KICK AND HARDEN FOR DAY.   

Apply replacement balsa into wet resin bed.  Let Harden.

Sand new balsa for fair surface with palm sander, leaving course 60 grit surface. SAND BALSA TO BE LOWER THAN FLOOR SO WHEN YOU GLASS ON TOP IT WILL THEN BE LEVEL

Apply generous wet resin bed.  Make sure it gets inbetween voids between balsa blocks.

Apply course woven fibreglass into wet resin.

Apply generous wet resin atop woven FG.  Allow to Harden.

Sand for fair surface, leave a course grit surface.

Apply unwaxed Gelcoat layers one and two.  SKIP THIS

Apply waxed Gelcoat top layer with matching multi color?, and slight sand added for non- slip?

No clue about that last step.  I have no idea how FS finishes the inside of the hull for a standing surface to not be too slippery.  YOU'RE NOT GOING TOP GET IT MATCH PERFECTLY.  A PRO COULD. YOU JUST WANT IT TO BE STRUCTURALLY SOUND AND LOOK GOOD

Am I missing something?

BE CAREFUL NOT TO USE TOO MUCH RESIN - MORE IS NOT BETTER.  THE RATIO OF RESIN SHOULD BE 'JUST RIGHT'.

 

IF YOU GET A COPY OF THE WEST SYSTEM'S MANUAL ( ITS LIKE A MAGAZINE ) ON GLASS LAY UP - YOU WILL BE ALMOST A PRO !  ITS $5 ?

Thanks For The Great Ideas

I think this is some great advice.  I printed out the West Manual, and will start studying hard.

Or have the factory do it

depending on where you live. You may want to have the factory do it.  If you factor in all materials and time, it might actually cost less, and it will be better than new.

Phil Scheetz

FS 4086

Fleet 163, Nockamixon Sail Club