Parting out H170 in AZ

[BobbyFunn]

Did you abandon this idea?

Yes. I just want the deck repair done so i can start on the motor mount and then the rudder mount. I sail from and to the docks so i hardly even bring the motor any more.

It would be noticable to have that mass off center. If there was more space by the rudder mount that would be better. A recessed watertight tank would also fit great in the cuddy cabin, but then longer, thinker cables would be needed.

 

[JimInPB]

...
On the other hand...Near the mainsheet swivel, it is 1foot from the skin to the hull. Might be ideal for placing a recessed battery case there...then use that big hole for using adding and removing expansion devices. Then sink the recessed battery box to seal the hole.

I like that idea, a lot. Two smaller batteries could provide balance. The low CG would be ideal.

 

[BobbyFunn]

Got the 4lb foam today!

Got the forms made up for each core and labeled. It was pretty simple, measure 5 strips 3 inches wide(some arbitrary amount), then roll and tape at a line 25.128 inches from one edge (8 inch diameter). Then measure how deep the hole is from the bottom to the bottom of the core, and subtract about 1 inch. Cut a strip to the measurement then roll a new tube inside the top collar nice and tight. Done.

I remembered to take some pictures looking forward from underneath. Nothing interesting more hollow space. The view is from the port side next to the mainsheet swivel, looking forward. The centerboard trunk is to the right and the deck is above. The bench is to the left. You can just make out the weird shape that holds the port jib cam.

 

[Hunter216]

#105 resin & #205 hardener. I think the ratio was 5:1

Thanks for that. I’m also sort of wondering if there is something different about the “model” of West system you used as your results are positive.

However I’m convinced that a thin layer of clear (non-additive) epoxy is not a good way to glue the Luran to a foam substrate as it is too brittle by itself to handle any flex. Sort of like the difference between cement and concrete. If the epoxy was used in a layup with glass thick enough that it takes flex out of the mix then the Luran might stick as it becomes more of a surface coating than an integral part of the sandwich.

Learning about MMA and the Loctite products and their ability to form a strong bond to the Luran has been enlightening.

The results documented have also convinced me that epoxy doesn’t harm either the foam or the Luran, a person just needs to be cautious of thermal buildup and to not use solvents commonly used with epoxy to do surface prep or cleanup.

 

[Hunter216]

Got the 4lb foam today!

Got the forms made up for each core and labeled. It was pretty simple, measure 5 strips 3 inches wide(some arbitrary amount), then roll and tape at a line 25.128 inches from one edge (8 inch diameter). Then measure how deep the hole is from the bottom to the bottom of the core, and subtract about 1 inch. Cut a strip to the measurement then roll a new tube inside the top collar nice and tight. Done.

I remembered to take some pictures looking forward from underneath. Nothing interesting more hollow space. The view is from the port side next to the mainsheet swivel, looking forward. The centerboard trunk is to the right and the deck is above. The bench is to the left. You can just make out the weird shape that holds the port jib cam.

Keep us posted as to your progress. The “telescope” form was a true Macgyver!

 

[BobbyFunn]

Tomorrow's the big day for raising the deck and applying adhesive. While that is drying ill start on the rudder mount.

I rubbed a sharpie all over the area then sanded until just the cracks were left. can see the Marinetex hole patches i made. Looks like the cracks may have been repaired by a previous owner and they came back. My repair was still holding tight, but the cracks spreading on top were making me nervous.

What's interesting is the marinetex repair shares the same crack as the luran. Rudder mount repairs are common and there's already some good threads on that so i wont bore anyone, but note that this crack looks the same as the picture of the OP's boat.

That upper rudder gudgen is longer than the bottom so there is more twisting going on up top. I see if i can order so high density backing plates. I wonder if a good repair actually hastens cracks...

Revelation to me probably obvious to most..Hardware should never touch luran. The MarineTex allowed the rudder forces to transmit directly to the luran only. Must leave gap bigger than bolt, and fill gap with flexible sealer

 

[JimInPB]

...
...The results documented have also convinced me that epoxy doesn’t harm either the foam or the Luran, a person just needs to be cautious of thermal buildup and to not use solvents commonly used with epoxy to do surface prep or cleanup.

I am not certain that heat from the epoxy reaction would have damaged either material. I was cautious & chose to not take the chance.

 

[Hunter216]

I am not certain that heat from the epoxy reaction would have damaged either material. I was cautious & chose to not take the chance.

My comment on thermal buildup is also just based on caution, one layer of wetted glass at a time, wait until the reaction of the resin and hardener has calmed down before adding the next. When I first tried glassing and before I knew better I had some mixed resin that I had in a soup can “go off”, pretty intense reaction!

Your cautious approach likely didn’t expose either the foam or the Luran to any more heat than it would get on a hot day.

I was also thinking about the drop of epoxy sticking so well to the Luran and had another theory. Maybe it’s on a area with zero flex so the bond between it and the Luran is strong enough to resist efforts to dislodge it???

 

[Shorefun]

NO SHARPIE!!!!!!!!!!!!!!

If you intend to paint or glue you NEVER NEVER EVER use Sharpie.
It will not allow a bond of just about anything. I learned the hard way. I had some sharpie on a car panel I was painting and watched it part the paint. The only cure was to go back to metal and remove the sharpie.

Later I had some sharpie on a wall. It does the same for Latex paint.

You must make sure all the sharpie is gone, really gone before you attempt gluing or painting.

I have since run across others with the same experience. This is something many people in the antique car hobby has found out the hard way.

 

[BobbyFunn]

NO SHARPIE!!!!!!!!!!!!!!

If you intend to paint or glue you NEVER NEVER EVER use Sharpie.
It will not allow a bond of just about anything. I learned the hard way. I had some sharpie on a car panel I was painting and watched it part the paint. The only cure was to go back to metal and remove the sharpie.

Later I had some sharpie on a wall. It does the same for Latex paint.

You must make sure all the sharpie is gone, really gone before you attempt gluing or painting.

I have since run across others with the same experience. This is something many people in the antique car hobby has found out the hard way.

Wow, did not know that. Was falling back on some "dye penetrate" NDT training. Only i dont have fluorescence dye or a lamp.

Thanks! Let me guess...only acetone will remove it :0

 

[JimInPB]

Thanks! Let me guess...only acetone will remove it :0

I get sharpie off with 91% rubbing alcohol. If the sharpie is fresh, it comes off pretty easily. If it is baked on or years old, then a fair amount of elbow grease will need to be added.

 

[BobbyFunn]

My comment on thermal buildup is also just based on caution, one layer of wetted glass at a time, wait until the reaction of the resin and hardener has calmed down before adding the next. When I first tried glassing and before I knew better I had some mixed resin that I had in a soup can “go off”, pretty intense reaction!

Your cautious approach likely didn’t expose either the foam or the Luran to any more heat than it would get on a hot day.

I was also thinking about the drop of epoxy sticking so well to the Luran and had another theory. Maybe it’s on a area with zero flex so the bond between it and the Luran is strong enough to resist efforts to dislodge it???

I can confirm that the manufacturing process (2004) involved applying epoxy on the luran.

There is about a 3/16 in layer of epoxy in the rudder mount. On the back of the rudder where the gudgeon bracket attaches the construction is luran-epoxy-rotten wood-foam-FRP-rotten wood.

The epoxy adheres to the luran and wood well, until the luran is flexed, then it gives way.

 

[BobbyFunn]

It took both tubes of PL3X but its all applied between the luran skin and the foam.

I started by using a syringe to inject some water between the layers and then using compressed air to atomize the droplets. I comitted sacrilege by using a prybar to lift the luran up to get good airflow.

Fun fact...Compressed air between the luran and foam sounds like a balloon jetting around a room.

I then repeated similar steps for all the holes. I placed one full glue gun sqeeze in 8 directions and then, using a kabob stick smeared the adhesive. If the skin was tight i pryed it up with the prybar.

I hustled with the glue so i could quickly install the prepared suspension tension clamp.

With floor pulled up it was also time to put as much weight as i could down on the deck.

Tomorrow ill pour the foam stringers.

 

[JimInPB]

...
The epoxy adheres to the luran and wood well, until the luran is flexed, then it gives way.

Can you please describe in greater detail how the epoxy gave way? Did wet & rotted wood loose it's bond? Did the epoxy crack & fracture with epoxy left on both pieces? Some other mode of failure?

Thanks,
Jim

 

[BobbyFunn]

Can you please describe in greater detail how the epoxy gave way? Did wet & rotted wood loose it's bond? Did the epoxy crack & fracture with epoxy left on both pieces? Some other mode of failure?

Thanks,
Jim

I've seen this twice now with epoxy and luran. When I cut off a luran panel off the rudder mount it had a tight layer of epoxy fuzed to it, the wood was filth so that doesn't count for anything. It was soundly attached. The luran is more flexible than the epoxy so to remove epoxy just bend the luran panel. The epoxy fractures like glass and comes off in assorted sizes. There's always a little bit stuck that needs to be machined off.

I did a test with foam pucks to see if PL3X would work as an adhesive and that was not as easy to remove. The PL3X is more flexible than the luran and moves with the bending.

You can definitely use epoxy on luran. The luran surface has to be roughed up and the epoxy needs fillers and thickness. If the final product is large enough to bend or flex the bond won't last (e.g. deck floors), smaller solid bits like small cracks and gouge repairs are no problem. If the surface doesn't flex it will last a very long time. I have epoxy on the hull to cover up dock rash and the fairing has held up great.

 

[BobbyFunn]

The cores are poured. The deck feels solid. When the suspension system was released the floor didnt go down at all.

2 part foam is interesting stuff to work with. Have lots of disposable containers nearby if working in small batches. I was nervous about the heat generated from the 200ml batch so never poured more that.

Attached pictures of the first column and then the deck with the muffin tops cut off.

Tomorrow ill get the panel and pucks glued on and fared, so i can get the deck ready for the Hydroturf.

 

[Hunter216]

Tomorrow ill get the panel and pucks glued on and fared, so i can get the deck ready for the Hydroturf.

First of all CONGRATULATIONS!

I'm having trouble visualizing how you are going to reinsert/reattach the plugs you removed? Just the Luran skin glued back on the new foam or your going to holesaw and remove the new foam to a depth where the plug fits flush again????

 

[Hunter216]

With floor pulled up it was also time to put as much weight as i could down on the deck.

Everything but the kitchen sink!!

 

[BobbyFunn]

First of all CONGRATULATIONS!

I'm having trouble visualizing how you are going to reinsert/reattach the plugs you removed? Just the Luran skin glued back on the new foam or your going to holesaw and remove the new foam to a depth where the plug fits flush again????

Thank you!

The foam will be sanded down flush to the deck, then the hole saw will drill down to the depth of the luran. A dremel with a router tip will machine out the rest. That leaves a gap for the puck and some adhesive.

The panel and pucks will be flush with the deck.

I probably could just hammer the foam down.

 

[Hunter216]

OK so you are glueing just the Luran layer back on like Txjim did. Does the new foam have memory? If you hammer it down would it try to spring back? It might eventually bulge the circles or more likely the panel up a bit that might cosmetically transfer through to your Hydroturf??