Epoxy snapped and stripped. Now what?

I snapped my bamboo laminate stringerless epoxy about 1’ from the nose this weekend.  Since I was landing one at the time the water got between the cloth and polystyrene and delammed most of the bottom.

Since I’ve snapped this board before and broken the nose off I should probably consign it to the tip, but I need the practice working with epoxy, so I’m thinking of getting it surfable again.

The delam tore chunks out of the blank.  How do I fill these and smooth the bottom again?  (a microbaloon mix or fast n final or something else?)

The bottom is 1x4oz, which is patently not enough.  I’m thinking of cutting the bottom to the rails and laying in a bamboo veneer with 2oz or 4 oz  under and taking the cloth for a full wrap.  Then finishing with a full lap of 4oz over the veneer.  

Lastly, How do I cut the lam neatly, especially around the fin plugs?  Just a craft knife or can I try thin cutting disks designed for steel in my mini grinder?

Much apprecated

Red

 

 

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The delam tore chunks out of the blank.  How do I fill these and smooth the bottom again?  (a microbaloon mix or fast n final or something else?)

The bottom is 1x4oz, which is patently not enough.  I'm thinking of cutting the bottom to the rails and laying in a bamboo veneer with 2oz or 4 oz  under and taking the cloth for a full wrap.  Then finishing with a full lap of 4oz over the veneer.  

Lastly, How do I cut the lam neatly, especially around the fin plugs?  Just a craft knife or can I try thin cutting disks designed for steel in my mini grinder?

[/quote]

Hi Red - I did a rebuild of a GSI Walden Magic stringerless epoxy that was snapped in half.  How big are the chunks?  Pics would be good.  According to another thread, chopped glass and cabosil makes a good filler.  By mini grinder do you mean dremel-like tool?  That sounds like it would work good. 

I cut the rails off about 1 1/2" by 12" long on each side, centered on the break, epoxy glued a redwood 2-by in place, and shaped it to match.  Then I did two layers of glass on the bottom repair area, in a diamond shape, the second layer larger than the first.  I sanded and feathered, but you can still see it just a bit in the right light, it looks fine 'tho.

On top I cut the bamboo (or whatever it is!) veneer back, cut a swath of foam out of the middle, added about a 40" beefy cedar wood stringer with epoxy glue, then veneered back over with thin redwood strips just epoxy glued in place, then sanded and glassed over the deck.  4 oz. for everything.

Then I just painted with an appliance epoxy spray paint.  Tough stuff, but still scratches easier than resin.  But good enough.

It sounds easy when I say it like that, but it was actually a lot of work.

Thanks for that. Sound like you did a good job.

I fixed a snapped to deck in a similar board by feathering back the veneer and sticking a veneer patch on top, doing a full lap and then smoothing the edges.  The veneer did leave a raised bit on the top deck, but this was under deck grip so it doesn’t worry me.

I looked at the board again last night.  I think I will do a microballoons mix and use it to stick the peeled bottom deck back.  I might throw it in a bag or just use kling wrap to pull it down (not sure how to deal with the concave - maybe an old towel to pull into the concave).  I may glass the the rails with 3" tape. Then I will do a full lap 4oz on the whole bottom deck and see how it ends up.  Sure my concave will end up a bit deeper, but I don’t think materially so.

4 weeks ago it looked like this:

snappage and delam

2 weeks before kneeboard world’s and I didn’t like my other boards.  So I made up a slurry of microballoons and epoxy, and coated the delam section and got it lined up and popped it in a vac bag.

rocker table and bag

I started off using a venturi vaccuum and my compressor

venturi vac

, but then it got late and I had to switch to the much quieter fridge pump system. 

I’ve put boards in bags on rocker table before and ended up with a flatter rocker because the vac bag can pull it flat.  So I used a high-tech solution to keep the board on the table.  Dial in foreground is vac guage from auto parts store, reading 10" or so:

board on table under 10" pressure

The nose was a bit out of alignment, so a dwang and a couple of clamps and some more microballoons epoxy: (It’s not impossible that I did this before sticking the delam back - I forget)

The wax paper does a great job of keeping the finish smooth.  Thanks for the tip, Swaylockians.

Here’s how the bottom looked out of the bag.  The mess at the nose is from a previous crappy repair effort

Then I threw a layer of 4oz on and a cheater coat. It ended up pretty heavy (like a solid store-bought PUPE)

The next day I sanded it back in the am, loaded it and 3 other boards on the roof of the car.

I only surfed this board on in the week-long comp and came away with one of these:

2011 world's trophy

3rd 50-55’s (biggest division - we’re all old farts). Trophy art by Dave Fincher - renowned local ceramic artist

Not bad for a board that’s been snapped 3 times, weighs a ton and has lost all its spring.

Hey Red

3rd in the World in any division is a huge effort , Congratulations.

With your venturi vac does the compressor have to run continuously  or can you use something like a mac valve to cycle it.

I started with the old fridge compressor setup till I scored a twin pump liposuction machine, always wondered about the venturi idea.

Now it might be time to make a replica and retire the old girl.

Cheers

Mooneemick

Nice result!

The compressor runs almost continuously with the venturi because the air blows out all the time.  I set the compressor to 50psi in the tank and it shuts off when it hits that, but soon kicks in again as the air pushes out through the venturi.  I’ve been contemplating a one-way valve and a switch set up but haven’t got there yet. I think the best solution is to use the venturi to pull the bag down, then switch to an electric vac pump to hold vac.