It's bare glass under centerboard section. The Hunter production crew could have cut it off, but then, there goes the price point...
The core and FRP is "floating" around the centerboard trunk.
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Parting out H170 in AZ
- Thread starter Mik
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The core and FRP is "floating" around the centerboard trunk.
Using @txjim info I have started putting the repair plan in action.
Stage I is to test pull the core up to the Luran and look for gaps, Then drill any new cores for low spots. I'll also drill several small holes for spreading glue in more locations. While the core is dropped I'll fill the gaps with adhesive. I'll try using compressed air to blow in some water and adhesive per crazy dave's suggestion. Then, raise the core.
I picked out a glue...Loctite PL 3X premium. Its a moisture cure Urethane glue much like 5200 and gorilla glue. The best glue for this scenerio is actually any "MMA adhesive", but the cost is brutal and the working time is too short. 3M 5200 is the next choice, but was concerned it might not stick to plastic for the long haul. Epoxy would spread nice and probably stick really well, but the reports are it is brittle and cracks with movement.
The application of adhesive will begin when the two part 4lb urethane foam is delivered.
Stage II will be the pouring of foam structural columns under the deck as soon as full tension on the deck is applied. These will substitute for "stringers".
The tension required to pull the floor up is pretty high so I'll leave the clamping system tight until the colum supports are fully cured.
It been amazing reading and studying everyone's posts for the ACP construction and putting this plan together. Thank you!
Ill report back after the clamping system is released.
Fun fact: The starboard side deck core is almost twice as thick as the port (cracked) side. The core thickness is not consistant.
Stage I is to test pull the core up to the Luran and look for gaps, Then drill any new cores for low spots. I'll also drill several small holes for spreading glue in more locations. While the core is dropped I'll fill the gaps with adhesive. I'll try using compressed air to blow in some water and adhesive per crazy dave's suggestion. Then, raise the core.
I picked out a glue...Loctite PL 3X premium. Its a moisture cure Urethane glue much like 5200 and gorilla glue. The best glue for this scenerio is actually any "MMA adhesive", but the cost is brutal and the working time is too short. 3M 5200 is the next choice, but was concerned it might not stick to plastic for the long haul. Epoxy would spread nice and probably stick really well, but the reports are it is brittle and cracks with movement.
The application of adhesive will begin when the two part 4lb urethane foam is delivered.
Stage II will be the pouring of foam structural columns under the deck as soon as full tension on the deck is applied. These will substitute for "stringers".
The tension required to pull the floor up is pretty high so I'll leave the clamping system tight until the colum supports are fully cured.
It been amazing reading and studying everyone's posts for the ACP construction and putting this plan together. Thank you!
Ill report back after the clamping system is released.
Fun fact: The starboard side deck core is almost twice as thick as the port (cracked) side. The core thickness is not consistant.
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I use to put cloth down on the cockpit floor with boards on top. Then I placed weights on top of the boards and let the glue or adhesive cure for at least 24 hours.
Contrary to 5200, I do not recommend it for a variety of reasons. First you have to drill too many holes which is not good causing additional time and cost. Secondly, you cannot spread it with air very well unless using high pressure and that will damage the boat more. Third, I have seen it not settle down evenly very well. I could go on but Hunter Warranty would not use 5200 as an adhesive. Of course this will create a firestorm but I did try and do not recommend this
Contrary to 5200, I do not recommend it for a variety of reasons. First you have to drill too many holes which is not good causing additional time and cost. Secondly, you cannot spread it with air very well unless using high pressure and that will damage the boat more. Third, I have seen it not settle down evenly very well. I could go on but Hunter Warranty would not use 5200 as an adhesive. Of course this will create a firestorm but I did try and do not recommend this
I do not believe that is the case. Please see the 2-part write up on repairs made to my motor mount -
https://hunter.sailboatowners.com/mods.php?task=article&mid=11&aid=100114&mn=170
https://hunter.sailboatowners.com/mods.php?task=article&mid=11&aid=100115&mn=170
I did have concerns about heat build up, but applying the glass layers, just a few at a time, did not cause apparent problems.
We need to find what adhesive is used for that grip strip
It was tough to pull off, and still sticky rolled up in the garbage bag. I researched 3M 77 spray adhesive, but there isnt a pourable high temperature version. 3M spray adhesive doesnt hold up to high temps brought on by sunlight. I tried to spray a camping matt to the seats but the glue got runny in the heat. The grip tape never suffered that issue.
Epoxy is on order with 404 filler. This will be used for placing the cut out panels back. Ive used marinetex with great results on the hull and rudder mount and this will offer more flexibilty for later repairs. When MMA adhesives come down in price i might change my mind.
I found a left over west system activity kit (101-6) in the paint job box and there is one packet left. Ill test that "neat" against the pl 3x.
Next weekend Ill have to remove the cores from the luran.
Next weekend Ill have to remove the cores from the luran.
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Sorry I didn’t phrase my question very well. I’ll try again, Many of the threads indicate that the plastic welder “Plexus” is the only stuff that should be used to “repair” the Luran skin and I understand why because it’s tried and true. My confusion lies with the fact that you spilled a drop of West system epoxy on the Luran and it didn’t cause any damage plus it stuck so well you cant get it off, so why all the concern about only using Plexus???
I understand that using acetone etc would likely “eat” either the foam or Luran or both but it would seem that a person could just cut out the original damage of the sandwich layup and replace it with normal epoxy layup and fair it into the original sandwich, just don’t use any solvents that would damage the original product???
Here a google SketchUp plan for the new proposed Hydroturf decking. Looks like one full sheet might leave enough for 8 seat pads. Waiting for the samples.
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The test pull is complete and its pretty obvious that I'll need at least 5 stringer colums added. Moving to the bow i found that around the centerboard housing the flexing is minimal. The core is attached to the centerboard closer to the bow. Two disc were not attached, two were well attached. I pryed one off the foam and it was hard to remove. One puck I left attached to foam. I was going to drill a bunch of small holes for glue but decided instead to take advantage of the larger acces to lift the luran up for injecting glue in a star pattern out from tbe circumference. Its going to be better to glue the pucks back and fill the small gaps versus filling and leveling 3/8 holes.
I have till the weekend to storyboard the forms for the columns.
I have till the weekend to storyboard the forms for the columns.
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These may come in handy at some point - https://www.amazon.com/Calculated-I...ocphy=9012008&hvtargid=pla-492693528949&psc=1
Also available locally at Home Depot - https://www.homedepot.com/p/Calcula...VSr3ACh1b4QGsEAQYAiABEgLufPD_BwE&gclsrc=aw.ds
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Yea, I probably didn't explain my foolishness very well either.
When I first did the repair, I was unaware of Plexus (or Devcon) being recommended as the only real good choice to use. I was unaware that it was recommended to not use epoxy. So... I just took some stuff that I had on the shelf, left over from deck repairs on a motor boat, & had at it. It turns out that my success was better luck than planning. It seems that I accidentally stumbled upon a specific epoxy that works with this material. Either that, or the fact that my boat never sees real big temperature changes means that my limited environment allows my foolishness to live on borrowed time. Since my boat is just one example, it's kind of hard to pin down all the facts of what might happen in a slightly different situation. But so far, seeing is believing. Your mileage may vary. I'm just reporting what I did & what I have seen.
Those are cool. I want one in the car trunk and another in the hurricane box.
How would you use this for the deck? From underneath?
Do you still have the West System containers you used and if so can you post what “version” of product it is?
Your recommended approach to the original poster is in line with what we are both “attempting”
to say In the OP case it looks like the entire floor is very damaged so just build a new one using epoxy layup techniques and attach the “seam” to the ACP.
If it’s an area where the Luran skin has delaminated then use the “spray in glue” approach to recreate the original sandwich
I am wondering if thermal buildup of normal epoxy (West System etc) would cause the Luran to actually melt. If you dropped a spot of it on the Luran and it didn’t “harm” it maybe normal epoxy and glass could be used “on top” of the Luran skin to fix cracks as long as your careful about thermal buildup????
The little airbags are interesting, I had a lock the keys in the car event and the roadside assistant showed up with one of them. Stuck it into the top of the door between body and door, inflated it and then stuck a thin bar in the opening, hit the unlock button and she was in. I notice that the description said they have a firm “plate” so they might not fit into the holes Bobbyfun cut out
The little airbags are interesting, I had a lock the keys in the car event and the roadside assistant showed up with one of them. Stuck it into the top of the door between body and door, inflated it and then stuck a thin bar in the opening, hit the unlock button and she was in. I notice that the description said they have a firm “plate” so they might not fit into the holes Bobbyfun cut out
I’m a little stuck on the West system solution as I did my first ding repair with the Plexus product yesterday. Very short work time ( no more than 5 minutes) , incredibly strong fumes and thick consistency so tricky to work with compared to my experience with West system stuff.
@Hunter216 it doesnt have to be plexus. The term to research is "MMA Adhesive".
There are tons of companies breaking out into this market. There are different formulations for longer worktimes and thinner inconsistencies. They are all high dollar though and small quantities.
Epoxy (west, total boat, marinetex) all work great on dings and dock rash. It adheres to the luran well, but as others have said, doesnt alter the luran at all.
If you have a chance, look at the technical sheet for plexus...very little gap coverage, 1/8 inch. it not supposed to be used as replacement substrates. Its for bonding substrates together.
In the future, one will wave a scanner or the area, edit the point matrix, then send the results to a 3d printer loaded for acrylic. The replacement part will then be glued on.
There are tons of companies breaking out into this market. There are different formulations for longer worktimes and thinner inconsistencies. They are all high dollar though and small quantities.
Epoxy (west, total boat, marinetex) all work great on dings and dock rash. It adheres to the luran well, but as others have said, doesnt alter the luran at all.
If you have a chance, look at the technical sheet for plexus...very little gap coverage, 1/8 inch. it not supposed to be used as replacement substrates. Its for bonding substrates together.
In the future, one will wave a scanner or the area, edit the point matrix, then send the results to a 3d printer loaded for acrylic. The replacement part will then be glued on.
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Yes the scanner / 3D stuff already in existence is amazing and will only improve.
Thanks for the clarification on the "normal" epoxy and Luran compatibility.
Just throwing out an idea that builds a little on JI's mini airbag suggestion. To lift the deck could you use a tire tube(s) inserted in the holes and then inflated in the air space?
There is nothing under core to push against. Its a giant cavern under the deck. I cant imagine what to place in the large gap that would also be recoverable. The deck is about 10 inches off the hull.
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.
So my “theory” is to jam a deflated inner tube of appropriate size down one of the hole saw holes and then somehow push or pull it around until it lies flat on the inner surface of the hull, inflate the tube and it should equalize itself in the available space and while pushing down on the inner hull FRP it would also push up on the inner surface of the “deck” FRP which should push the floor up, sort of acting like a stringer. If you needed to remove it just deflate and pull it out of the hole. If it’s not in the way of anything leave it in for some structural support. Just don’t put the boat in an unpressurized plane or it would likely explode