Ok! good to know! Sounds like Epoxy would be best for the deck areas that are cracked up, to keep the expansion similar. I'll try to get away without using glass matting, but right now, I just don't know the extent of it all. I'll be bringing the boat home from the pole barn soon. I'll peel up the black non-skid, and figure out just how messed up it all is. I'll likely post some pics of the mess here to get your/others feedback. Thanks!
Plastic Hunter Crack Repair
- Thread starter H216sailor
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- crack hunter 216 repair
wait what?
If you plug down coin fir ma300 use that. That is a far superior product Use epoxy as a last resort.
Epoxy doesnt work as well as ma300 and epozy CANNOT be used where there is flexing. Thats why its reinforced and used with filler. Stuff snaps like a jolly roger candy without support.
BobbyFunn, I read in one of your other comments about making plugs: " If the luran is detached from the foam at those cracks then inject adhesive about an inch on both sides, underneath" This must be what you mean by "plug down coin fir ma300". When I get the boat, and really know the situation, I'll post some pics. Plugging it down rather than using epoxy is a welcome suggestion. I see that epoxy would just be a brittle, and futile waste of time. I think I saw in one of your other projects that you used fiberglass & polyester resin on a deck area. I suppose that would be the way to go, rather than epoxy, for a larger deck area. Correct me if I'm wrong. Is fiberglass w resin more flexible? I like your image of the jolly roger candy snapping. Totally convinced me not to use epoxy. Stay tuned. I hope to get the boat home next week, and get into it.
Im going to shut up now.
If you are going to spend the money on the MA adhesive, stay away from Epoxy or any other adhesive.
Epoxy/Resin by itself is "paint". Add glass and it becomes more rigid and the stress is distributed. I think the goal is to actually use as little resin as possible when putting a layup together.
Haha! No! Please don't shutup! I need all the mentors that will tolerate my questions!! I will stick with the MA . Thanks for the input.. So much to learn about this stuff, and I haven't even ground off the old stuff yet! Fortunately, I found the Methylacrylate for a lot cheaper than Plexus.. I'm getting tighter as I grow older. Pictures when I start grinding !
It is a mistake to believe that you will get a decent adhesion from anything but MA or depending 5200.
Glues need a 'rough' surface to allow the molecules to catch and hold. The Luran is too closed, no holes, even when sanded. If you just try to glue epoxy to the surface I would guess over time it will peel off.
While there may be times when epoxy will work fine that depends on how it is used. The MA adhesive will no break free even if the expansion rates are different as it has bonded to the surface and is linked together.
Glues need a 'rough' surface to allow the molecules to catch and hold. The Luran is too closed, no holes, even when sanded. If you just try to glue epoxy to the surface I would guess over time it will peel off.
While there may be times when epoxy will work fine that depends on how it is used. The MA adhesive will no break free even if the expansion rates are different as it has bonded to the surface and is linked together.
Shorefun! Thanks, I'm getting the picture. I ordered the Methylacrylate a few days ago. 10 x 50ml cartridges. I will keep in mind when I'm grinding off the cracked places so that I don't go too deep. Even though I found a less expensive supplier, it is still pricey. This boat has been repaired before, as you can see on the bow photos. I won't really know what with until I grind some of it off. I'm suspecting that the repair was made with fiberglass, not methylacrylate, so do you think I will have to grind all of it off, down to the foam, or just enough to make a topping of methylacrylate?
Got it, thanks! I will know so much more when I start peeling,,, carefully. Thanks for your suggestions. I should be getting into it all this coming week.
Here's a few pics from my first day at this crack repair. The previous fiberglass repair made it interesting. I tried a heat gun first, but too much made it easy to dig into the ACP, and too little didn't do anything. So I peeled it off, sanded it down to the ACP. I'm assuming that the "V", or river bed one creates for the Plexus should not go so deep that it gets to the foam, but for the drilling at the end of the cracks, I went to the foam. The hardware was bedded on some sealant, so the screws into the support below were solid. Happy about that!! Anyway, that's how far I got today! So far, so good!
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Grind deeper as you want it very thin at the bottom. After you fill the cut u you if use a spreader to level and force through the bottom. While it may not happen fully along the crack, some will get through and bind the back side. Plus the deeper cut gets wider and makes more surface area. You do not need to get the glue to the end as the spreader will move some down. If you have perfectly level glue it shrinks and will curve down some.
Makes sense, now that I think about it. Why weld only the top portion of the crack. Widening the crack nearly to the bottom of it would insure more complete contact (like you say, "surface area") with the glue. Also, I know that this Methacrylate heats up considerably when it "goes off" to create the weld. I'm guessing that more material is better than just a hair line of it, for facilitating the chemical reaction. I know that too much is not good also, as one can melt the surrounding Luran. A final finish coat will probably need to be applied after the initial weld shrinks down. Thanks for the advice. Waiting for the weather to warm up, and dry up now. Do you know if I need a minimum outside temperature to apply the Methacrylate? I should get my shipment today. Maybe it will tell about minimum temperature on the package. Thanks again!
That bow section is pretty bad. The cracks between the mounting hardware suggests the previous owner filled the rotten holes with something. Luran has no redeeming quality here, It probably delaminated off the foam. Purly cosmetic if delaminated.
Id cut all that luran off except for about 1-2 inches above the deck joint. Go back enough to get most cracks. Put some fresh wood (sealed) back in the foam, cut into the front cuddy and put a G10 backing plate in the hull space. Get a access port to seal it up. You might be able to pull the luran off and then reattch with 5200. MA will be hard to spread everywhere and set the luran back on. Still need MA to fix those cracks if reusing.
Lay up some cloth and resin to reattach to the foam. Grind off the overlap between new and luran.
In 6 months you may have a new crack between the luran and your new GRF layer. Use MA to fill it back.
Id cut all that luran off except for about 1-2 inches above the deck joint. Go back enough to get most cracks. Put some fresh wood (sealed) back in the foam, cut into the front cuddy and put a G10 backing plate in the hull space. Get a access port to seal it up. You might be able to pull the luran off and then reattch with 5200. MA will be hard to spread everywhere and set the luran back on. Still need MA to fix those cracks if reusing.
Lay up some cloth and resin to reattach to the foam. Grind off the overlap between new and luran.
In 6 months you may have a new crack between the luran and your new GRF layer. Use MA to fill it back.
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Hey BobbyFunn, You are so right about the need to remove all Rot! When I took off the bow hardware, I tested the screws to see if they felt firm as I tightened them. I will do it again before I go further, as I respect your suggestion that there may not be much of anything left underneath the Luran. If it's rotten, then I will likely trash the whole project for a while until I have the time, and motivation to do all the things you say to do. Obviously, you've been there, done that by your thoroughness. I'll test the screws again, and if they feel firm, I'm going to take your original advice from April 5.
Apr 5, 2020
#32
You are up north. If the sails are shot, buy new ones and go sailing with them until the hardware rips out. Sell the sails online afterwards.
Your April 5th approach is more my speed for now as I have many competitors for my time. One being sailing my wooden boat. I only paid $200 for this Hunter 146. It needs a new jib, and I need to find out if it's worth buying a new one. ( the old one can be temporarily repaired) It won't be sailed more than a half mile away from the pier, so if the bow plate rips out, I'll be fine. I can put it back in the barn, and go from there.
Thanks for your suggestions. I have total respect for anyone who has tackled these issues. I am learning as I go, and appreciate your knowledge bank on it all.
I'll let you know how I proceed after I test the firmness of the screws. Ric
Apr 5, 2020
#32
You are up north. If the sails are shot, buy new ones and go sailing with them until the hardware rips out. Sell the sails online afterwards.
Your April 5th approach is more my speed for now as I have many competitors for my time. One being sailing my wooden boat. I only paid $200 for this Hunter 146. It needs a new jib, and I need to find out if it's worth buying a new one. ( the old one can be temporarily repaired) It won't be sailed more than a half mile away from the pier, so if the bow plate rips out, I'll be fine. I can put it back in the barn, and go from there.
Thanks for your suggestions. I have total respect for anyone who has tackled these issues. I am learning as I go, and appreciate your knowledge bank on it all.
I'll let you know how I proceed after I test the firmness of the screws. Ric
You have some tough choices. The foam underneath probably looks fantastic. Both resin and epoxy will stick to that foam for another 20 years. Before placing hardware back set a couple screws in about halfway, then wiggle them loose. If the luran moves, you are in trouble. If not, then you have several years left. I initally fixed my rudder by injecting epoxy. It was super tight to the end. The luran was flexing with the "repair" causing it to flex and crack. Focus on shielding the luran from becoming structural.
I see, if I put the screws in half way, wiggle them, it will tell me if it's all still bonded together. Thanks, I think I have it, and will test it out before I start filling cracks with Methacrylate. One question: I assume that what you mean by "fixing your rudder by injecting epoxy" is that you filled the screw holes with epoxy first, and then screwed your rudder hardware in. Is that correct? Or do you mean that the Luran was flexing above the foam because it was not bonded to the foam, and injecting epoxy between them firmed it up nicely? I'm a little confused, as usual. Also, what do I do with the hardware screw holes? If I determine that it's all pretty solid, and go ahead with the crack repair, should I set the screws in first so the holes don't get filled up with Methacrylate, or let them fill up, and drill them out just a bit before I set the hardware? Or should I fill them up with epoxy first??? or what? I'm thinking what should I use for a "Loctite" sort of adhesive to make sure when I set the hardware that the screws are setting down into an adhesive that will lock them in nicely. I wish I wasn't such a novice at this stuff. I really am enjoying the learning process. I wake up in the morning thinking about it.. Am I now a Boat Nerd??
You dont want to inject anything in the original screw hole. If the screws wiggle you need to rebed the mount. You cant rebed without knowing if the substrate is solid all the way through. The last thing you want to do is allow the luran to bond to the substate you screw into underneath.
You do this wrong and youll have a snot of glue injection spread out into rotton screw threads. The snot will form a tight bond to the luran and loosen from the substrate. Itll work for a couple years.
I redrilled the holes, reamed out some rotten wood, then filled with MarineTex. Then drilled new holes. It lasted three years before the luran started to crack spreading out of the holes. I had a glue snot pretending to be a "nut" on the luran.
You do this wrong and youll have a snot of glue injection spread out into rotton screw threads. The snot will form a tight bond to the luran and loosen from the substrate. Itll work for a couple years.
I redrilled the holes, reamed out some rotten wood, then filled with MarineTex. Then drilled new holes. It lasted three years before the luran started to crack spreading out of the holes. I had a glue snot pretending to be a "nut" on the luran.
Ok, Great! I get the picture. Knowing how you fixed the rudder screw holes is helpful. Marine Tex would work well for that once the rot is gone. I'll keep the screw holes open. Thanks!
That repair i made (filling rotten space with marinetex) was shotty craftmanship. I tore that garbage out then fixed it correctly.
Yea, I can see that, but it lasted 3 years. I may reviewing all this with you in the future if my repairs go South. 3 years would be good for now.. Stay safe!