Plastic Hunter Crack Repair

[Shorefun]

My thoughts on this mess.

The cracks at the bow look like stressed plastic cracks. Just because it was molded deep and likely experienced temp variations causing stress. The plastic is smooth across the surface so nothing is displaced.

The screws are like what 3" or 4" long? Right

If you can crank them babies down tight, even if they are a bit loose half way, it is going to hold. Not like you are going to stress this out in 20 knot winds much.

I say MA the cracks, Maybe drill some holes and glue the loose floor here and there to tighten it up, put down some light colors anti slip tape (it is expensive to get the right stuff, but there are cheaper alternatives), tape up the sail and go sailing.

The boat wont sink if it breaks and you are not going far just going for fun.

In the end, there would be someone who would buy the parts on the boat for what you have into it.

Honestly, The boat will likely get more cracks here and there over time, glue them up. So long nothing is falling off it will work. I think it is pretty obvious you can sink a lot of time and money in the boat if you want to and you still have a plastic boat that will have issues. I think keeping it simple and minimal money into the boat is a wise course of action. I got a VERY good deal on my boat ($500) for boat and trailer so it was worth picking up. I would MUCH rather have a fiberglass boat as any repairs you do you know will work and nasty surprises are less likely to happen. Really these plastic boats are pretty crappy and they best avoided unless they are cheap. You got yours cheap enough, I believe so long as the screws will hold tight the parts will hold together. Fix the cracks and go have fun. So long as it holds together you can always resell for more then $500.

 

[Rictifyit]

Well, it's all ahead Full! I got my Methacrylate yesterday, so all I need is a dry, warmer day to start filling cracks! We have a break in the rain so I took off the tarp, and screwed in the 2 inch screws about half way, and all is firm. Nothing moves when I wiggle them, except the whole boat! I'm satisfied, and I agree, it's time to get this thing going, and on the water!
Shorefun, I agree with everything you say. "Fix the cracks, and go have fun" !!! Sounds like a great plan to me! I appreciate your interest in my little plastic project! Have a great day!

 

[Rictifyit]

Haha, you thought the bow was bad. Attached are after, and before pics of what mess I uncovered today. The Mast hardware, was pretty solid, but the Luran below is unattached to the substrate, and bouncy. The mast screws were mushy, but did not spin. One pushed up some mirky water when tightened, so I assume that at least part of the wood below them is rotten. Nearly the entire deck is somewhat bouncy, and unbonded in varying degrees. The cracks by the other hardware, that I unearthed by grinding off the fiberglass repair are not just cracks. There are voids under the cracks, as you can see by how far my scraper is buried. In one spot I can see under the Luran, into the void. The support wood seems solid.
So, I have no fantasy about fixing this properly. Meaning tearing up the deck, replacing wood, etc., etc. It would just never end. What I think I want to do is inject something under the Luran, in-between it and the foam, to give it support. Something that would harden up, and fill up the void enough to fix the crack above it. I'd use some expanding foam if I knew of any that actually got stiff enough to offer support, but I am not aware of a product like that. I'm wondering if any of you know what I should inject/force under the Luran? Once I have it supported from underneath, I can fix the crack with Methacrylate. If it lasts a few years, I'll be happy. If it lasts for a few weeks, I will just see how far I get, or sell the trailer.
My brainstorm for fixing the mast hardware screw holes is to lift up the Luran, drill out the rot, and fill it with Marine Tex to create a new place to screw to. Or, I could just fix the crack, screw it back in, try not to spin the screws, and bed it on top of some fast cure 5200. All that hardware has to do is keep the mast base from moving laterally really.
My goal is just to keep the thing afloat, and sailable, not pretty. So I need to know what you guys would use to somehow inject in under the Luran?

Editing this post now: After thinking about this, I suppose if I just inject some Methacrylate into the spaces, that would do the trick. Drill in some plugs too. I was thinking I needed more volume.
Funny how a couple beers can make one think clearer.

 

[Hunter216]

Hunters approach to building Luran boats was to have a layup of FRP then foam and then Luran. They inserted small sections of wood in the foam layer in specific areas so they could use screws to attach the hardware from the outer surface. Fast, relatively inexpensive manufacturing.

As I see it you have two “levels” of repair.
1) Areas where hardware is mounted
2) Areas of the deck that are “spongy”

The “common” problems are
1) Water gets into the wood either through a crack or past the screw and rots the wood so the hardware can tear loose
2) The Luran layer separates from the foam (spongy area).

If you think about repairing the type 1 areas try to picture a 6 x 6 inch square of thin plywood with a screw in it, hard to yank the screw out but the square would be pretty easy to move around. Now take the square of wood and embed it into a big chunk of foam, makes it harder to move around. Now consider that the wood is rotten so everything gets pretty sloppy. Foam has no holding power for the screws and a small plug might seem strong initially but would
likely tear out or start to move. In other words if the area where the screw embeds is not strong enough you have a problem.

The spongy areas might feel weird but probably don’t have an impact on the sailing ability of the boat. Fixing the spongy areas requires getting enough adhesive under the Luran layer, spread out and then weight on top until it cures. There are documented approaches here using Gorilla glue, air compressors, Loctite adhesive, removing areas or Luran and then sticking them back down.

@BobbyFunn and @Shorefun and several others have sorted this out through trial and error.


I would suggest that you should at the least ensure the forestay, mast step, mainsheet and rudder are firmly attached and/or you have a plan in place if they should fail on the water.

 

[BobbyFunn]

The mast tabernacle also keeps the centerboard up. Thats an easy repair. Same as motor mount.

Believe it ir not if you peeled all the top deck luran off and replaced all the rot underneath and lifted the deck foam, you have an great family lake boat.

I hit a powerline on the way to a ramp once, the forestay snapped. It was the H170. The mast comes down in an ugly way right into the cockpit. I have visions of your jib, furler and all with 3 screws still in the hardware macing your jib crew.

As you are towed to the ramp you raise the centerboard only to have that spin wildly to whoever it pulling the centerboard line

 

[Rictifyit]

@Hunter216 Really? It's a piece of plywood that the screws are in? Wow, I would have at least thought it was 5/4". I get a clear image though, so thanks. Yes, it's a problem. The wood base for the forestay hardware is solid, and so is the rudder. I'll lift up the Luran where the mast step sits, and go from there. The mainsheet hardware feels good, but I haven't tested those screws yet. I lost my motivation today after seeing the extent of this mess, but these forum responses revive my interest. Tomorrow I'll get at it again if it's not raining,,, Thanks! As for the spongy deck areas: I'm going to not worry too much about those for now, but I'll look for the posts about Gorilla glue, etc.
@BobbyFunn Your image of getting "maced" by the mast is unsettling. I hope no one was hurt when your forestay snapped. The story is motivating to at least do one's best to make things as safe as possible.
Thanks to all for your help, and interest in my project. I'll keep you posted.

 

[Hunter216]

@Hunter216 Really? It's a piece of plywood that the screws are in? Wow, I would have at least thought it was 5/4". I get a clear image though, so thanks. Yes, it's a problem. The wood base for the forestay hardware is solid, and so is the rudder. I'll lift up the Luran where the mast step sits, and go from there. The mainsheet hardware feels good, but I haven't tested those screws yet. I lost my motivation today after seeing the extent of this mess, but these forum responses revive my interest. Tomorrow I'll get at it again if it's not raining,,, Thanks! As for the spongy deck areas: I'm going to not worry too much about those for now, but I'll look for the posts about Gorilla glue, etc.
@BobbyFunn Your image of getting "maced" by the mast is unsettling. I hope no one was hurt when your forestay snapped. The story is motivating to at least do one's best to make things as safe as possible.
Thanks to all for your help, and interest in my project. I'll keep you posted.

I don’t know for sure what wood was used on any particular model, but if you consider mass production - plywood would be a reasonable choice. I was trying to help you visualize the construction process and what can happen when water invades the layup. It doesn’t really matter as any piece of raw wood exposed to water, heat, cold will rot. Check the photos of the muck that @BobbyFunn pulled out of his 170, no way that’s going to hold a screw. The classic approach to attaching hardware is to have a backing plate, bolts etc.

I know you indicated you are on a lake and won’t sail hard, you could probably recover from a failed rudder, maybe not so much if the mast comes down. Maybe the wood still has some integrity so the screws “feel” OK, hard to say.
As the saying goes your boat, your choice.

 

[Rictifyit]

@Hunter216 You did a great job of giving me the image of what's below the Luran! I'll find out what's there, because even the mast step hardware needs to be secure. I'll probably peel up some of the loose Luran, and check it all out. @BobbyFunn did a repair once where he drilled out the rotted wood, and replaced it with Marine Tex. Then drilled it to make a new home for the screws. Not perfect, but he said it worked for 3 years, so I'll consider that as a plan.
Yep, no metal backing plates on these boats.
I've been reading old posts for the last half hour. I found the info about Gorilla Glue, 5200, Air, etc., and found it motivating. Thanks for the suggestion. @Shorefun has been a big help with my project. Very grateful to be tackling all of this with the help of sailors that have done it first!

 

[Hunter216]

@Hunter216 You did a great job of giving me the image of what's below the Luran! I'll find out what's there, because even the mast step hardware needs to be secure. I'll probably peel up some of the loose Luran, and check it all out. @BobbyFunn did a repair once where he drilled out the rotted wood, and replaced it with Marine Tex. Then drilled it to make a new home for the screws. Not perfect, but he said it worked for 3 years, so I'll consider that as a plan.
Yep, no metal backing plates on these boats.
I've been reading old posts for the last half hour. I found the info about Gorilla Glue, 5200, Air, etc., and found it motivating. Thanks for the suggestion. @Shorefun has been a big help with my project. Very grateful to be tackling all of this with the help of sailors that have done it first!

No problem, lots of helpful sailors here and for that matter everywhere, pretty supportive group - unless you race

Parting out H170 in AZ

What other boats share the mast and boom sections? Looking for a boat that needs a mast but nothing interesting popping up. Everything is in super condition - except for the cockpit fiberglass. Mik

forums.sailboatowners.com

I would recommend this thread again, mainly because it lines up with the way I tackle a problem If your trying to glue one thing to another Luran to foam in this case I like the idea of being able to see what Im doing. Cutting the Luran off in a 4” circle lets you know for sure you get coverage on the disc area and however far underneath the uncut area you can reach. You said you didn’t care about cosmetics so might be worth considering.

 

[Rictifyit]

I will read that post again. I've read many twice, and find that I glean new insight each time. I haven't done it yet, but it seems that cutting off a piece of Luran is not a big deal since the Methacrylate will bond it back together. Thanks! More reading now

 

[BobbyFunn]

Haha, you thought the bow was bad. Attached are after, and before pics of what mess I uncovered today. The Mast hardware, was pretty solid, but the Luran below is unattached to the substrate, and bouncy. The mast screws were mushy, but did not spin. One pushed up some mirky water when tightened, so I assume that at least part of the wood below them is rotten. Nearly the entire deck is somewhat bouncy, and unbonded in varying degrees. The cracks by the other hardware, that I unearthed by grinding off the fiberglass repair are not just cracks. There are voids under the cracks, as you can see by how far my scraper is buried. In one spot I can see under the Luran, into the void. The support wood seems solid.
So, I have no fantasy about fixing this properly. Meaning tearing up the deck, replacing wood, etc., etc. It would just never end. What I think I want to do is inject something under the Luran, in-between it and the foam, to give it support. Something that would harden up, and fill up the void enough to fix the crack above it. I'd use some expanding foam if I knew of any that actually got stiff enough to offer support, but I am not aware of a product like that. I'm wondering if any of you know what I should inject/force under the Luran? Once I have it supported from underneath, I can fix the crack with Methacrylate. If it lasts a few years, I'll be happy. If it lasts for a few weeks, I will just see how far I get, or sell the trailer.
My brainstorm for fixing the mast hardware screw holes is to lift up the Luran, drill out the rot, and fill it with Marine Tex to create a new place to screw to. Or, I could just fix the crack, screw it back in, try not to spin the screws, and bed it on top of some fast cure 5200. All that hardware has to do is keep the mast base from moving laterally really.
My goal is just to keep the thing afloat, and sailable, not pretty. So I need to know what you guys would use to somehow inject in under the Luran?

Editing this post now: After thinking about this, I suppose if I just inject some Methacrylate into the spaces, that would do the trick. Drill in some plugs too. I was thinking I needed more volume.
Funny how a couple beers can make one think clearer.

You might actually do well with 6lbs density 2part foam. Drill half inch diameter hole running along the length of the seats about 3 inches away from them, about 1 foot apart. Pour in the high density foam. There is a gap under the luran on the deck and the foam angles down to the center. The foam will go diwn the holes then run and expand towards the centerboard. Some might run off the core then spill into the hull by the centerboard. This will bond the luran back to the core and should hokd until you crush this.

 

[Rictifyit]

Hey, that picture looks good! Yeah, That 2 part foam is wild stuff. Saw that kind of thing used to secure fence posts. I like your plan. 1/2 " holes, pour it in, let it expand!
After I opened up that big crack by the mainsheet hardware, I see that there is intentionally some void where the Luran goes from horizontal to vertical in a corner. Must be the same thing near the seats. Not sure if I'll get to all the delaminated Luran this Spring. We'll see. The priority is sealing up all the cracks, and getting the hardware set good. Thanks for the suggestion! Do you have a name of the product that you are referring to by "6 lbs density 2 part foam", or if I search on that, it'll be obvious ?? Thanks again! You've been a big help!

 

[Shorefun]

The tabernacle is less of a problem. The screws are only in shear, it does not even need screws they could just be steal pegs so long as the bottom of the mast can not slide around.

The spongyness. I tried the Gorilla glue and do not like it, though I think you really want to do that in the sun on a warmer day. Part of my problem I think it was too thick to move around because it was colder and not in the sun. I do not like gorilla glue because really does not stick the Luran very good. I question how long it would stay good. I like the the 5200. You drill a small hole and inject it. It makes like a 4" disk and because it is flexible and does stick well to the Luran I think it makes a good choice to glue the floor to the foam.

On areas where you can lift the luran you might be able to slip in a bit of fiber glass behind the crack. Then make sure you grind down far enough that when you fill with MA you make some come out the back side. You could try to wet it with the MA and slide it in place, but I did not see having enough time to work that and glue the crack before the stuff in the mixing tube set. When you work the glue after you put in the crack with a scraper you end up forcing some through. This will get into the glass and make a bit better of a repair. This is what I did for the long flat crack in the forward storage area. It was long and easy to make enough room to slip in the glass.

 

[Rictifyit]

I read your posts when you were trying out Gorilla Glue and 5200. Thanks! My thoughts are the same about the mast step. The hardware just holds the mast from moving laterally. The forestays do the work.
I got some 5200 fast cure in the mail today, so I might use that when the weather breaks again. Thanks for your thoughts! Very Helpful!

 

[Crazy Dave Condon]

You could also cut fiberglass into small pieces putting it in the crack using the common term in the industry plexus

 

[Rictifyit]

Good idea Mr. @Crazy Dave Condon ! I went with Fast Cure 5200. 1. Because the voids that need filling are extensive, and MA may be lower viscosity, and spread out too much. Although it would probably work nicely with Fiberglass cloth, forcing in 5200 was just a lot easier. I hope it works. It seems to have set up well, except in some very thick parts that are still curing. I forced it in a few bouncy places also, and they seem very stable now. 5200 is costly also, at nearly $30 bucks for a 10 oz tube, so my next tube is going to get used sparingly. So, I'm using 5200 to support the Luran, filling voids, and gluing it to the foam, and will start knitting the cracks back together soon, with MA. I entertained the Gorilla Glue idea for re-gluing the plastic to the foam, but the 5200 was the simplest/quickest/less process. Drill a hole, force it in, tape it, and put some weight on it. I'll know in the long run if it works well. Thanks for you suggestion! I will post some pictures soon. Don't want any of you to get bored.

 

[Shorefun]

I think I paid like $20 for the normal 5200 at Ace hardware and I think they had the fast stuff at the same price.

Also keep in mind West Marine will price match. I have gone in with an amazon price and showed them my phone and got it at that price. One case was some $30 epoxy for $15.

 

[Rictifyit]

Cool! Yes, at Ace, a 10 0z tube is $26.99. I bought it from amazon for $27.84. Not every day Ace beats another price. Love going to Ace though!
Good to know about West Marine! Wish there was one close to me. I'm really having fun repairing this boat! The weather here (Chicagoland) sucks, so I moved the boat into the garage today, and put on a heater. Hope to MA all the cracks by the end of the week. I got the MA, but stupidly ordered the wrong mixing tubes. Due to the people on this SailboatOwners site, I've receives a lot of knowledge from people who have "been there, done that", and it's made it easier, now that I've gotten deep into it. Stay safe!

 

[BobbyFunn]

I read your posts when you were trying out Gorilla Glue and 5200. Thanks! My thoughts are the same about the mast step. The hardware just holds the mast from moving laterally. The forestays do the work.
I got some 5200 fast cure in the mail today, so I might use that when the weather breaks again. Thanks for your thoughts! Very Helpful!

The mast tabernacle does double duty of holding the centerboard up. Even as you drive over bumps on the local roads. Its easily over 150lbs of force pulling the tabernacle sideways. The two front screws are keeping the tabernacle from rolling off while you have the mast suspended for the road trips.

 

[Rictifyit]

@BobbyFunn I remember this comment about the mast hardware doing double duty to hold up the centerboard. The image of it bouncing along on a road trip emphasizes the need for this thing to be solid. I'm wondering if it would be wise to find a way to secure it better for a trip.
Here's some pics of how I repaired the mast hardware. @Hunter216 was correct. It's plywood below it, and it was like a sponge!
Before I installed the Oak piece ( replacement for the 5/8" rotten plywood), I soaked the substrate plywood with a 2 part epoxy wood hardener called Rot Terminator. When I screwed down the Oak, a good part of the epoxy was displaced around the Oak because I purposely cut it a bit smaller than the original plywood. The Rot Terminator is low viscosity, and cures slowly on purpose so it is absorbed into questionable wood. I had let the substrate plywood dry for a few days first, filled the holes with toothpicks, and covered up the PVC support with duct tape so the epoxy wouldn't spill into the void ( which I found about 2 cups of water in when I unearthed all of this). The Oak is permanent now, and today I plan to fill up the voids around it with fast cure 5200. We'll see how that all works out when I start filling the cracks with MA later this week. So far, so good! Thanks to all for you helpful suggestions, reminders, and comments! You have made this more fun than I ever expected! Ric