Cutting Open our “New Hull”: What Could Go Wrong? | Step 386

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[@AntoineGrondin]

For your delamination: (1) peel ply may leave a wax residue in place, so secondary bonds require cleaning (2) if the surface was fully cured, you need to sand it before bonding to it again, peel ply helps but isn't enough (3) you need to prewet the fabric before laying it down, don't lay it down dry. Your hired pros are using a lamination table; they saturate the fabric full of resin on a plywood sheet on your floor, before then moving the wetted fabric in place. This ensures a good bond. You didn't do that.

[@Rivondo]

I spotted point #3 during the time lapse portion of the crew working inside Uma. Professional gang, there. Worry not

[@stevenpoels4639]

Oef this comment save the project....❤️

[@jacobsquires859]

I was going to point out the same thing as your #3. Their process wasn't entirely the same as the crew working inside the boat. If they want piece of mind try doing it again but fulling wetting the fabric before laying it down. It will be a way different outcome.

[@pierremitham2964]

They also didn't saturate the peel-ply when they made the initial piece. leaving some of the waxes UNDER the peel-ply on the surface of the resin. They needed to dewax the surface and then grind to key the surface. You can see the pro's peel-ply was saturated. Saturating the peel-ply makes "its resin" part of the overall layup allowing the waxes to "float" to the surface above the peel-ply

[@jortfaber4719]

Yeah of all comments of this video i think this is probably the issue

[@valeriylulchenko6734]

I just finished restoration of my sailboat Ecume de Mer 1975, and what I found was - any repairs of fiber glass with polyester resin on a top of polyester body doesn't have chemical adhesion at all. (Fisical only) Any new layers of fiberglass with polyester resin can be easily delaminated from the main body. What I investigated is for restoration of the old boat recommended the use of epoxy resins. In my case I used classical west system, 4 times more expensive, but it gives you structural and strong adhesion with old polyester body.

[@allenrees3456]

We have nothing to add except words of encouragement. As sailors on the west coast of Canada who rebuilt an Ingrid 38, we are so impressed by your self-sufficiency and your capacity to navigate your way out of bad situations. During our rebuild, we used only epoxy resin whenever we had to do glass work, so I have nothing to add as possible problems or solutions (and I'm certain that whatever I would say, you have already considered it); you are much more adept at figuring things out than I was and I am certain that, in the end, you will solve this problem just as you've done countless times in the past. All the best.

[@pauleohl]

The bond failure may be a drama ploy. Many years ago I damaged the bottom of a 21 foot runabout (built by the now long defunct T-Craft) when a trailer roller collapsed on land. I could hear the glass cracking as the hull developed a large dent. When we got the boat off the trailer the dent came back to a fair shape. We repaired it from the inside with multiple layers of glass mat and woven roving and vinyl ester resin. The patch was about the size of a large pizza. That repair lasted at least 8 years with no problems when we sold the boat.

[@fogllama]

Thank you for building a model of the process. I don't think many folks would go to that trouble to illustrate the details.

[@TheMachoGabacho]

I love the empty hull. I used to remodel houses for a living, and my favorite thing was walking into a room that had been gutted down to bare framing. I always felt like the possibilities were endless!

[@lawrencejones1517]

Uma was born under a lucky star to have you as her crew! I've been watching you for several years now, and have seen the many projects that you've done to update and improve Uma. You really are pulling out the stops to make her the best she can be! This really is giving her a new life! Good on you!

[@adamhearn9368]

Fantastic informative video as always. I much prefer this style of video compared to the RAW video last week. Looking forward to the progress 🤙

[@ianstewartmowat3594]

My best message for you is from my experience. Mistakes happen. They represent loss of time and money. But they are not usually catastrophic. You are resilient and will find a different way forward. Just keep on keeping on. Good luck. We all love you. Ianxxx

[@uuugberns]

You can imagine how happy it makes me to see you working on your lovely boat again. Thank you very much!

[@porterbrass]

Great model for testing. Your boldness to search for truth makes you stronger each time you’re faced with a challenge. (There’s a catchy saying for that). 😅 You will persevere.

[@bishopkinlyside8477]

Hi guys, I’m so excited for you both to see Uma getting put back together I know it’s going to be awhile before she’s back in the water but I’m so happy for you both and the people that are watching the channel. Keep up the good work love and appreciate you both and especially this wonderful yacht Uma , Clifton from Australia

[@Edmund_Mallory_Hardgrove]

I like that you stuck with Uma. I've really enjoyed watching your channel since you work building her out the first time to go sailing. What's really cool about your channel is it's one of those sailing channels that appears accessible to to people with more modest funds. ...not that what you're doing it is cheap, it's just that it seems attainable.

[@sockeyevoyages8840]

Agreed! 100%.

[@mattpedersen1312]

So that delamination looks like a secondary bond failure. If the original "Hull" section was covered with plastic or peel ply or you used a resin with wax, then it was air inhibited and the chemical bond sites just aren't there to make a primary bond. The prep you did on the hull, with the interior surfaces all sanded down to glass is the right way to do it. You should get a good bond there. Best to lay the CSM layer down first, rather than the Biax. Another thing that can contribute to the failure is that what you tested may not have been full strength - it takes about three days for a resin to cure completely. I think you're going to be okay when it comes to the work you're getting done on Uma.

[@micheldawes1]

@30:57; As one of your previous commentators mentioned, the peel ply has a wax residue that needs to be cleaned off, or it will act as a release agent (Similar to a silicone release agent) and I admit that I am definitely NOT a shipwright, I would have sanded between lay-ups, to key the surface, to help with mechanical adhesion. No matter how much abuse you give her, Uma has infinitely better structural integrity than she had before your refurbishment!

[@animapulcra9205]

Peelply has generally silicone as release agent. In the aircraft industry we've had several mishaps with both surface contamination and tool contamination. In your case I presume you don't use a resin with wax as that is the main reason why peelply is needed sealing of the curing resin from the atmosphere. Mechanical prepping of a silicone surface is a dead end it just drives the silicone contamination deeper into the surface. Low pressure grit blasting with aluminium oxide grit is the preferred method cleaning such surfaces. In your case there's not enough information distinct the model from the hull.

[@idreecemian2192]

Thanks for showing us what how not to do, we have seen and remembered all the steps of laminations side by side inside UMA and outside in the open, a big thanks for showing how mistakes can be made and then prove it as well. Geez you are so good at educating by deliberately making mistakes that other can do without knowing, love you for doing what you do. From Melbourne Australia 🇦🇺

[@tonystites2134]

Since I was picky on the last one I just wanted to tell you that you nocked this one out of the park. I loved the short you made from the last one also.

[@SailingOfka]

we are a few steps behind you... for now we have dismantled the interior of the yacht. We keep our fingers crossed for you. You can do it!!!

[@wanderingontheway7303]

Tough moment, you guys. No advice, not an expert at anything related to glass work, but full sympathy and trust that you'll figure it out!

[@joncozzi1701]

I love the stairs onto the boat. It drives me nuts seeing folks go up and down ladders on extended boat project. Every thing you two do is done top flight, bravo!

[@raireva4689]

Nice ending😊....you should be directing thrillers 😮

[@sailingrolima]

Great video and storyline as always 👏🏻

[@forrestwebb6182]

Great job, as always, explaining complex stuff in a fun, down-to-earth manner. I'm sure you'll figure out this delamination situation!

[@robertlhoyt9775]

What a great edit! Excellent lesson for learning and correcting!

[@andersnilsson6625]

For that very reason (polyester does not glue so well to polyester) we recommend in Sweden that all repairs are done with epoxy. 🇸🇪😄😀💕

[@PanceriMarco]

it glue in a well keyed surface... i didnt see they preping the survace

[@juergenschoepf2885]

I would never have done anything else in my boats. Sure, Polester is cheaper but that's not worth the risk.

[@PanceriMarco]

well cleaned, corse grit sanded and cleaned with acetone have amazing adehsion

[@rodbrandon8598]

Nonsense! Polyester has approximately 480 psi bond adhesion strength to cured polyester. As long as the bonding surface is adequate area, and prepped properly, the repair will be at least as strong as the original hull. Any stronger is no real benefit. Improper prep will cause epoxy adhesion to fail too, so that must be removed from the repair strength equation. If the interior hull surface is 28 m^2 (43200 sq in), just a rough guestimate, the adhesion strength of an interior polyester skin, applied properly to the existing hull, would be in the area of 43200 sq in x 480 psi = 20,736,000 pounds. This is simple math an FRP expert should be able to complete in seconds. Please advise why any more strength than what polyester resin could provide would be required or warranted in any way, at about 3 times the cost? Don't listen to everything you read (intended) especially from an epoxy manufacturer produced instruction guide. Of course they will promote the use of their epoxy product everywhere. They are in business to make money, and their marketing communications staff are getting paid big bucks to help sell more product. Whereas any FRP expert worth there salt will advise, NOT REQUIRED, NO REAL VALUE (for any repair application where the somewhat greater adhesion strength is of no real benefit). That said, I use epoxy where the additional secondary bond adhesion strength is needed for the instant application, and that is maybe 3% of all the FRP work I do. Using epoxy where polyester will more than suffice has serious implications. It takes far longer in process time, it has serious temperature issues, it is extremely dangerous as airborne particulate (if not fully cured), and even a small repair patch pretty much commits to using epoxy for any other subsequent repair in contact (without jumping through hoops and unnecessary risk of adhesion failure), regardless of size or unnecessary cost, unless the original repair is ground out and redone with polyester, before the new polyester repair is applied. I do use a lot of epoxy barrier coat over polyester resin FRP hulls and repairs, but that is a completely different issue, and still a much more economical, safer, and better solution than performing FRP substrate construction or repairs with epoxy. Quite frankly, I don't think epoxy should even be sold to amateurs. I can't tell you how many DIYers I have seen in yards grinding uncured (maybe only a day or two after kicking in cold temps) with no PPE whatsoever. Should be in head to toe Tyvek, sealed at every possible opening to skin or lungs, with a minimum organic cannister full face respirator, better yet, supplied air respirator. Even the removal of the peel ply from the vinylester in this video, without the PPE indicated above, is a completely unnecessary health risk, which stands as more proof that amateurs, should not produce KZbin "How To" videos, handling hazardous materials.

[@ChrisCripps-nv9bw]

good argument for a metal hull

[@kimphilley621]

"We know how we like to trim Uma" was your answer when I asked about Stability. You are Architects both of you. You know all about structure, foundations, load bearing etc. Stability on a boat refers to Righting Moment, Pitch-poling, and Knockdowns etc. When you add weight which you are, and considering all the cruising gear you put aboard to go all the places you all cruise....Perhaps you do have a Marine Architect among all the engineers involved in your project to answer these important questions. If so might make an interesting Video. I am just a silly old 70 year old ex Tugman who wonders...Best wishes

[@IrishAcres]

Have not stopped by for a while, I come by in your boat is out of the water and stripped clean and you’re rebuilding. How exciting what an incredible Journey. I’m gonna have to tune in here now and watch a little bit. Take care and God bless you.

[@jerrychandler657]

Great job building the model.

[@blukisandrzej]

It's fine. Now you can take your new boat out of the mold with just a few knocks.😊

[@davidwebb4904]

Like a butterfly emerging from the chrysalis .

[@niakros]

wait what!? a YEAR!? In my mind it was just like yesterday you started repairing Uma 🤯🤯

[@gaiaocracy]

right?!

[@gwebster6600]

Only these two can take a year to do bugger all.🤦‍♂️

[@RAEckart22]

@@gwebster6600 For some reason quite a few sailing channels are at this pace now

[@ApexWoodworks]

@@RAEckart22 it's the reality of life.

[@greenharoguys]

Where are they going?

[@adamhenderson001]

AH!!!!! NOW I get it! Very informative, thanks for ALL the HARD work to enlighten this farmer from Indiana.

[@se2103]

Your videos(you two) make me smile 🙂

[@chucksohm7213]

I believe this is referred to as a 'cliff-hanger'. I'm guessing the last video scene shot was followed by much texting. Keeping fingers crossed.

[@SailingUma]

Hours on the phone with every boat builder we know.

[@singularityscan]

@@SailingUma Cant wait to see what condensed wisdom you gained from them in the next video and how it will influence the build!

[@jarchdm]

I build fibre glass bows as a hobby and the same problem shows up there, it's hard to get fibre glass to stick to fibre glass unless you use some expensive epoxy. I have to wrap the limb with fishing wire but that's of course not a solution for you guys. Really hope you work it out.

[@matthiasvonmutius9264]

Hi probably you already checked your footage, I am quite sure you contaminated your "hull" piece with something oily and did not use peelply... It looks very much like that. I hope the crew working on the real boat sanded and degreased thoroughly before laminating. Sanding after degreaser is important as well because you avoid rubbing the contamination into the substrate. I hope you find a good explanation for your mishap. Matthias fixing my trimaran in Greece at the moment.

[@carldombrowski8719]

​​@@SailingUma As others mentioned, the pro's did it better by wetting the sheets in resin first. Also, as you have a hull in a hull, a little delamination doesn't do anything - all is fixed in place, and the waves and piers will still be stopped by old and new layers. A leak could cause a small issue between the layers, but once the water is out, you could inject some glue before fixing it. Also, you can't put too much force perpendicular to the hull - a shelf, for instance, should be attached to the ribs, not just the walls. Good luck!

[@rogerbayzand4455]

According to Shane from Young Barnacles KZbin Chanel who is a composite technician, peal ply does not leave a surface that is ready for new laminate, it needs cleaning with acetone and sanding to remove the residue from the ply. I think he said the peel ply has silicon in it to stop it sticking and enabling it to be removed after the resin has cured.

[@SailingUma]

Don’t know who that is. But the people we know who build boats for the last 30-40yrs laminate directly over the surface after the peelply is removed. That’s what peel ply is for.

[@lordhydromage6614]

yikes

[@KeithCarmichaelInFL]

I am definitely not against keeping the surface smooth in the final product. But if you let it cure, it needs to be scuffed before it can be adhered to properly by the next layer. I hope that is the only issue you run into. I would strongly recommend taking a rubber mallet to the ribbing you just had done. It would be terrible to discover an issue in the base structure of your vessel after you rebuild the entire boat! Sometimes it’s better to take the hit early!

[@mckenziekeith7434]

@@SailingUmaShane is an expert. He works on high-dollar racing projects. I don't think he advocates using acetone, but peel ply does leave little particles of material behind after you rip it out. It is recommended by experts like Shane to sand lightly after removing the peel ply for best adhesion. But I am not sure what is going on with your layup. It came off so easily it was almost like there was a layer of mold release between the stringers and the "hull". I am sure the pros doing the stringers will not have the same problem. But I do agree with others that epoxy may have been a wiser choice.

[@SVPearler]

​@SailingUma the company that Shayne Young worked for, did testing on peel ply, found problems bond to a peel ply finished surface. Shayne worked on America's Cup boats and Volvo around d the world boats. He has done some amazing carbon work on his own boat. Like carbon chain plates, front beam. He has redesigned their rudders with winglets, to reduce the length but not efficiency. Does Gunboat deliveries. The O'Kelly's have interviewed him as well.

[@jesseroland5561]

Congratulations! Im sure it feels really great in your soul to see her taking shape

[@sockeyevoyages8840]

Oh my! Great edit for this cliff hanger! Really looking forward to your next episode. I, too, am glad you are sticking with Uma. She has carried you far, through so many adventures, and learning, which we are grateful that you have shared. You've received plenty of opinions/advice. While re-fairing a 61 foot motor-sailor, 30 years ago, a batch of epoxy did not get enough catalyst. We discovered this when we came to work the next morning and it had not cured. We scraped it off, sanded, and carried on. Sh*t happens. You two rock!

[@cluso9985]

Boat builders use closed cell foam such as Divinicell. If moisture gets into the foam it does not soak into the foam. I also agree that it would have been better to put a layer completely over the hull, using a specific glue (sorry, cannot recall its name) and vacuum it to the hull. Then glass over that. Then it would only be necessary to glass in the bulkheads, and a rib mid height around the hull. Use this to rest your bench tops on.

[@anthonygillesse7242]

Vinyl ester does not bond with polyester, best bond is epoxy to polyester with a well prepped surface of the hull. Who ever suggested using vinylester should have gone back to engineering school. The sizing of the frames and stringers are overkill, it takes too much volume out of the interior. Smaller scantiling of frames and more glass to bond them into place. 🇨🇦

[@Sagan_Starborn]

Agreed with all you've said. Those stringers and ribs are WAY too big. They'd have gotten a better result with 25mm foam sheets with tack gaps between the sheets to bond the inner skin to the outer while leaving the foam sheets inside for insulation. The rib and stringer model is weaker and uses much more space, and doesn't have the insulation properties of the foam sheets. All that needed to happen was to watch how the big boat makers do their composite foam sandwich hulls nowadays to see how superior that is. Also here in Australia there's a guy with the "Life on the Hulls" youtube channel who is single-handedly building a Crowther catamaran in foam sandwich.

[@robertrosenzweig6693]

Vinylester does bond with polyester!

[@calmauric8218]

Uhhhh yeah it does. Polyester and vinyl ester bond really well

[@robertrosenzweig6693]

Poyester does not bond to vinylester!! But the other way around works.

[@rodbrandon8598]

Not true! Vinylester does bond to polyester quite well, and perfectly adequately for this application. The key take away should be, there was no real reason to use vinylester (commonly used by builders for underwater hull sections to reduce the risk of osmosis, having no control over the dealer or purchaser barrier coat application). Isophthalic polyester resin, would have been perfectly adequate for this application, and the pros (speed, cost, allergy safety, convenience) would have certainly outweighed the con, that it's secondary bond strength is a bit less than epoxy, which would have absolutely no real bearing in this scenario, due to the huge amount of surface area covered.

[@KenDavies-qv3fs]

You two are fantastic, at best.

[@ettoreperrone9147]

Thank you for the valuable content!

[@CJLeTeff]

What you have to consider is that you’re applying a tremendous amount of force to a very very small area with the hammer. To apply that same force to your boat hull you would have to sail full speed into rocks. 👍👍🎉🎉🎉🎉🎉🤘🏻🤘🏻

[@rodbrandon8598]

False! Lift the boat wit ha crane, set it down on the keel / cradle pads, crash over a wave at 6 knots. The forces can be incredible. You are correct that a hammer blow places significant force over a small area, but a proper secondary bond layup, should provide much greater adhesive strength than shown here.

[@raymondwhitford433]

I believe that you should lay in filler to give the inside corners a 20mm radius, this allows the glass to bend through 90 degrees without cracking.

[@cluso9985]

Yes, definitely fill in the corners with a radius.

[@charonstyxferryman]

Any cavity absolutely *must* be filled with something. If one is working with epoxy resins, it's a thickened epoxy. In a research article I read that it's thickness of the sandwiched material which make the composite material really strong, meaning that voids are weak points. The material on both sides of the sandwiched layer does of course need to have a sufficient thickness.

[@larryoutdoor]

The eyes are a window to the soul. A smile is a mirror to the heart.❤

[@znerol1]

excellent demonstration of destructive testing, and now on to the solution...

[@bgonz3599]

Not good results from your test piece. Sorry to see that. On the positive side, you're still in time to do something about it. I would try prying a piece off of the actual hull to have a better idea as to how strong of a bond is there. Good luck.

[@colinhogan5469]

Awesome video. Your model failed because you didn't sand your "hull" piece before glassing the ribs. Awesome to see so much progress! It must feel good.

[@EpoxyCircus]

Half right

[@lawdawg1942]

@@EpoxyCircus and the other half? Cleanliness next to godliness? 😛

[@peterihre9373]

That ending was the best cliffhanger. Can't wait until next week but not worried about Uma 😀👍

[@ghost307]

"Second best thing". Nice save, Dan.

[@posterestantejames]

Hmmm... food for thought. Interview the engineers and their response when they saw this. Curious about what they have to say.

[@theunknownunknowns5168]

"Where we're going we are going to need it": Dan Step 386. Conjecture. Southern Hemisphere. Most ocean per dirt Hemisphere.

[@henryrossouw930]

Glad to see Uma is slowly but surely coming together again.Hope delamination of your model doesn't put doubt in your boat.

[@drjasper100]

Very informative episode.

[@nickprice235]

dont worry what you did is fine , they would of sanded the hull before hand so layers key in to each other . i used to build the T60 at sealine international ltd based in the uk

[@samuaarnivuo4113]

I bet that the Dunning-Kruger study was based on the comments written to this video.

[@SailingUma]

😜

[@kankama1]

There are a lot of clever comments re the problems with peel ply, the concern over secondary bonding of polyester laminates and the need for good surface prep for polyester laminates - not much over inflation of self worth that I can see.

[@CaptainShack]

I've learned so much from this channel.

[@dboboc]

Yeah; what NOT to do.

[@CaptainShack]

@@dboboc Can't agree with that. They have done more than most with far less.

[@bobmat53]

The boat that should never had done what it done but by faith Uma did more than you ever think with a boat can do would love and joy with faith keep up the great job with lot of love❤

[@circacire1118]

The surface was not ground back on the model so the keying between the layers will contribute to the bond.

[@richarddickson3211]

Was the first flat panel , peelplyed, or ground- sanded before putting the foam on? Q from a retired boat builder.

[@jimfisk4474]

Hi Y o u T w o, Love watching you, rebuild your boat. And so much that goes into it. Been watching for a long long time. Thanks so much for bringing us Along and catch you. Next weekend.❤❤❤

[@pierrec1590]

Fantastic job!

[@matswilliams1058]

So sorry for the faild model structure. The video is so well and informative done! Thank you for sharing it ALL. Hope that you finde the reason for the delamination a.s.a.p

[@papataffy]

My layman guess is that you need to sand the surface first to make the bond stronger. Also I would expect that they would make a filler with at least 20mm radius because glass is known for disliking sharp corners, you should not force it into 90° angle.

[@KeithCarmichaelInFL]

I was REALLY worried about the hot glue! That creates an air pocket AND adds another chemical into the layers of fiberglass (never a good idea).

[@davidwebb4904]

Informative, as-is how NOT to do it….

[@davidwebb4904]

@@KeithCarmichaelInFLHot glue is not structural, at all.

[@KeithCarmichaelInFL]

It’s not a question of structure, it’s a question of chemistry. Hot glue releases solvents as it cures, solvents act in questionable ways when reacting to other solvents. Notice the way the bond of the fiberglass became brittle and broke AFTER the application of hot glue in the process.

[@theromihs]

I like what you are doing with the hull. Seeing as you are doing all of the reinforcing, will you be building composite chain plates to replace the inferior stainless chain plates? The "insta" delamination of your sample was most likely due to a poor mechanical bond of the rib & stringer lamination. You did not sand the surface of your sample hull, like was done inside your hull.

[@inneshutton3716]

There is no mechanical bond it's a chemical bond that's failed here.

[@mckenziekeith7434]

@@inneshutton3716 there is no bond of any kind now. LOL.

[@mazdarx7887]

@@inneshutton3716 It's a mechanical bond as the sample plate was cured befor the addition of structure and laminations. In order to get a chemical the lay-ups have cure together while the resin is still reacting. OR to get a partial chem bond after layup has cured, sand then wipe with stryene ( sometimes MEKP works too)

[@johnrussel4483]

Waiting for the next step….. have fun!

[@davenghiem364]

I'll bet there are other viewers like me, who've worked on boats, who read your video title, did a WTF, and saw your intro, and are watching with wide eyed, slack jawed, "holy crap they're doing wut?!" thoughts in our heads. I absolutely love, LOVE your working on the boat videos. I learn so much!

[@pmnfernando]

there is actually a difference between going from big to small or small to big. if you go big to small, which is the best practice, you make sure that the first layer has FULL contact with the substrate, the subsequent layers on top will help in reinforcing whatever it is you want to reinforce/build. if you go small to big, there is only a percentage of "next layer" that will contact the hull/surface. going big to small is how one should be laminating over thru hulls holes that one needs to plug. same principle is applicable everywhere including your lamination over the foam core pieces this project is pretty cool to watch and i cant escape the ironic notion that, whilst we get new materials and techniques, we still resort to basic, millennia old, ways of building/reinforcing boats, as shown by your new frames which resemble traditional wooden boatbuilding i reckon the delamination is due to not having enough cure time, its not your first time mixing resin so that shouldnt be the problem either since it cured, that leaves us with contaminants being present, bad surface prep. also, the nature of impacts and what is the expected behaviour of grp doesnt really align with such "precise" impacts like you did with the hammer. ive been glassing a bit in the course of my refit and in one ocasion i noticed i could pull out the end tail of a bit of "dry cloth", effectively delaminating it by hand, but only for a couple of cm. i also noticed that this situation would improve overtime, as you let the resin to fully cure.

[@matthewsellers82]

The big V small is an old argument. Somebody once said Boeing recommend one way Airbus the other

[@pmnfernando]

@@matthewsellers82 the gougeon brothers suggest big to small, those fellas know their stuff i would say

[@britboy20002]

Big to small avoids air bubbles at the boundary, less chance of voids and quicker to laminate.

[@4everB2]

Vinylester is used to encapsulate a woven fabric, build in one piece or layed up when still tacky. It's not glue, it doesn't bond well to resin that has already cured. For that purpose you use epoxy, especially for structural work. Bonding of polyester or vinylester or cured materials heavily relies on sanding the surfaces as rough as possible. Still it won't come close to epoxy.

[@mazdarx7887]

Dude, where did you read that? Vinyl has been used in boat building since the 50's and has been used in all building stages. Sand to remove blush and clean. Then, just before additional layups, dampen area with styrene or MEKP to reactivate and give a partial chem bond along with the mechanical bond. The industry has been doing it for years, too thick a layup overheats , then you got real serious problems

[@4everB2]

@@mazdarx7887 The fact that you have to reactive the laminate says enough. And good luck trying to reactive a 50 year old laminate. And I wouldn't be too sure they even doing that on Uma.

[@starshiphappens5136]

Peel ply has additives in it so you can pull it off. Some of that material always remains after peeling. It is essential to sand after removing peel ply. A wipe down is also recommended, mostly to get rid of the sanding residue. That said, the bond for such a 'contaminated' surface is usually much stronger. So I agree with some of the previous comments, that the laminate was not wet enough.

[@Degenhardt450]

What you have made is an “ I “ beam with the ribs and stringers. This is the best method to build strength.

[@timevans8223]

When laying up new glass onto existing polyester, you use epoxy. The mechanical bond is stronger. I was wondering why you went the route of ribs rather than layering up 1 inch core to the inside of the empty hull? This would give you a stiff hull without the intrusion of ribs into the space. It would also give you insulation.

[@sylvano44]

You still have to sand and clean with acetone even if you used peelply no?

[@JOHANDOMEIJ]

@@sylvano44 It depends on how long you waited after curing the base you're glassing onto. Polyester will release like a wax onto the surface after curing, which acts like a mold release for the next layer, like in this example. If you put the next layer down before the old layer is fully cured however, you can get proper cross-linking, and this isn't a problem. How long you have depends on type of resin, amount of hardener, temperature, etc. This waxy layer is why you wash with acetone between layers. But even so, polyester on polyester will not crosslink if the bottom layer is fully cured: Meaning that you will never get a full chemical bond between layers, if one of those layers is allowed to fully cure before the next one is put down. All that is then holding the layers together is Van der Waals forces. Sanding or using peel-ply helps getting a rough surface with a larger total surface area for the Van der Waals forces to act upon. Epoxy is better for this, which is why it is generally recommended to use epoxy for repair-work to get full strength. Epoxy is much more expensive though.

[@robm.4512]

@@JOHANDOMEIJThanks for writing this down, you saved me risking repetitive strain injury from tapping furiously on my phone screen. Perfect explanation and well written, I’ve nothing to add. Cheers, R. 😎👍🍻 (Marine Engineer, Ret.)

[@sylvano44]

@@JOHANDOMEIJ I am currently installing a bow thruster on my sailboat and using epoxy. I am very happy to have chosen epoxy after seeing how easily it took off.😳

[@renelise1]

Ho shit Polyester we use it to built not to glue, Epoxy do this job Glue.

[@williammuseler5542]

You did not tie the new ribs into the keel stingers, and you did not overlap them. This creates a hinge point for failure.

[@robertbiron]

I was thinking the same thing

[@JonRenner]

Because the rib to hull joint is sound and the stringers are sound themselves, I'd suggest sanding the stringers wherever they intersect with the ribs and then drilling holes through the stringers and into the ribs where they intersect, and then filling these holes with rolled glass cloth that extends from inside the ribs to the newly sanded areas of the stringers ... and add resin until everything is saturated.

[@JustPlayGamesUK]

Smart idea for a video to keep us in the loop 👏👏👏

[@fantastic_voyage]

The reason for the delamination is the peel ply finish you did on the model.....

[@Sagan_Starborn]

I disagree. The peel ply wasn't under the stringer layers. It was on top. The failure was between the hull and the stringer laminate, not between the stringer and rib laminate.

[@bdshort]

@@Sagan_StarbornThey used peel ply on the top of the “hull” layer at the end of last weeks episode. I don’t know a ton about doing composites other than what I’ve seen on some KZbin channels (Mike Patey would have done all this with carbon fiber!) but based on the comments I’ve seen from others here, I’m in agreement with those saying their apparent lack of prep (sanding and cleaning) of their hull layer before applying the ribs and stringers is the main culprit. Since the actual boat was ground and sanded down inside, and the pros were fully wetting out the glass before applying it, I don’t think Uma should have the same issue. Hopefully they give them a good whack with a mallet to check though!

[@jonjon-jd6vt]

My Spidey senses tell me you are headed for the roaring 40's.

[@Zt3v3]

Or the screaming 60's?

[@jonjon-jd6vt]

@@Zt3v3 exactly. but I just didn't want to say it. hehehehehe

[@F1v30h1]

I love the safety boots!🤣

[@ylemoine1]

Was about to ask about the added weight and how you’ve planned for the new waterline and then I saw the ending! WOW, now what? I guess we wait until next week 😊

[@cwsmith7366]

When I was watching you hot glue the ribs to the hull, I went uh-oh. They should have been expoxyed in for sure.

[@davidwebb4904]

Lesson #1

[@SailingUma]

Why!? The foam is just a filler to hold the glass in shape while it cures. It has no structural significance to the finale result.

[@davidwebb4904]

@@SailingUma The new glass is attached to the foam. The foam isn’t attached to the boat.

[@KeithCarmichaelInFL]

When laminating any product, using multiple solvent types is always a recipe for disaster. Hot glue releases a solvent as it cures and can take days to complete degassing. Not to mention that when you have a composite construction with air space sealed inside it is not known to turn out well. Even if it’s just from an expansion/contraction difference, it’s going to create a weaker setup.

[@eugenebutrik3398]

@@davidwebb4904 Delamination in a test occurred between the "old" fiberglass of the "hull" and the "new" fiberglass of "ribs". The connection of foam to the hull's or rib's fiberglass doesn't matter at all.

[@Dude_Slick]

Dan's not alone Kika. We all have you on our list of things that make us happy. LOL Don't worry, we like you too Dan. One conclusion the wife and I have come to watching you guys, is that we own way too many couches.

[@CMiltonDixon]

Better to find out now!

[@WitzBlitzTV]

This video open so many ideas,Thanks!

[@Sorarse]

I would suggest making another model but replicating exactly the process being used on Uma. Fingers crossed it won't have the same delamination problem.

[@claverton]

I really like the idea that you are recycling (so to speak) your 50 year old boat rather than going down the easy path and buying a new boat.

[@D-B-Cooper]

They are going to have an insurance problem, you need insurance to get into a Marina or a yard but the insurance companies won’t insure something this old. My friend has a 1969 S&S in great condition and is having a hell of a time. They are going to spend a lot more money on materials and gear than if they bought a new boat and will never be able to sell it for near what they put into it without regarding labor.

[@claverton]

@@D-B-Cooper Hadn't thought of that ... I wonder if ability to insure older boats varies from country to country? I have an early 70's fiberglass yacht and insurance wasn't a problem. No doubt condition and survey report comes into play.

[@claverton]

@@D-B-Cooper You're dead right about not getting your money back on doing up an older boat (speaking from personal experience). This is probably the nub of the reason why most people don't do it, not to mention that it's hard and time consuming to do. Fashion I suspect also comes into play. That being the case, I still wouldn't swap mine (even if I am a lot slower downwind ;)

[@D-B-Cooper]

@@claverton this is west coast US. It’s aluminum and he is a surveyor and captain. He had a real hard time getting insurance to go just a little offshore to clear the Columbia bar. I never got insurance but that has been quite a while now and I also stayed away from marinas. I’m a retired wooden boat shipwright and know the lures of old boats. The fiberglass back then was stronger but those hulls have gained a lot of weight from ingress, at least no blisters.

[@claverton]

@@D-B-Cooper BTW have you been following the Duracell Project? Guy up in Port Townsend doing a great job on a famous old boat, Duracell. It should be a fast passage maker when he's finished.

[@bravofighter]

PLEASE consider starting a shop building shoal-draft pocket cruisers. Older Cape Dory 28 and 30 are so unbelievably well designed, but with modern structure they wouldn’t need to be so thick and heavy, and so they would sail MUCH faster.

[@Frostbbitten]

What a cliff hanger! Hoping it all works out!

[@pironiero]

Your hull is okay, difference between your example and the actual hull job is that you laid up glass on the surface after peel ply without sanding it. And you never do that on structural things, consult with the young barnacles channel. Also you have applied a lot of tiny but powerful hits to the small surface area, and your hull reinforcement is a one big structure with a lot of contact surface which will distribute the laws of most collisions with the dock

[@mloret6745]

Bond the foam to the fiberglass hull and new fiberglass, not hot glue. The foam has compressional value as a monolithic structure.

[@CaptainShack]

But the foam isn't what should be holding the panel on 😂

[@Ack364]

@@CaptainShack Didn't expect you here! Who knew my interest in space sims and sailing had ANY overlap.

[@QuinnChada]

The hot glue simply holds the stringer in place. The overlay secures its placement

[@mloret6745]

@@QuinnChada wrong ...the core is structural when bonded

[@mtm101designs9]

Thanks!

[@elgrande1ish]

That sucks! Hope you guys can figure something out! 🤞

[@aadams8419]

I was never a fan of this plan, but this video broke my heart. Hopefully, they figure it out, and it’s not just a cautionary tale.

[@larrybradley7589]

Instead of hot glue, why not put te filler to adhere the stringer on top of the rib. That way, there is no air gap between the rib and stringer?

[@davidwebb4904]

Too late!!!

[@mckenziekeith7434]

@@davidwebb4904 hot glue is fast. You just have to hold the foam there for a short time until the glue sets then you can move on. If they used epoxy or something they would have to wait for it to set up.

[@davidwebb4904]

@@mckenziekeith7434 Hot glue has ZERO structural value.

[@mckenziekeith7434]

@@davidwebb4904 I agree. The foam is also very close to zero structural value. It is just a form for the ribs and stringers. But instead of removing the form, you abandon it in place.

[@mySeaPrince_]

An idea.. where your below the waterline through hulls are.. build watertight boxes glassed to the hull with thick perspex watertight but removable lids.. The reason is through hulls fail. (I can give more details)

[@SailingUma]

We've got a much better solution. But you'll just have to wait and see what it when we get to it. ;)

[@tamaralee4108]

The test results with the peel ply are very helpful. As your test showed, and others have commented, peel ply by itself does not provide best levels of adhesion for subsequent layers, even though this is commonly believed. Glad you have shared this!!!

[@ThomasBussmann]

Looks like the guys inside the hull attached the horizontal reinforcements first (in the first inserted video clips) of the video. That was confusing. Besides I hope that roughening up the old inner hull surface for a better sticking of the additional (new) 2 mm inner hull works.

[@justincase5272]

"And to save even more weight, we've decided to build everything out of carbon fiber over aerogel..." Hey! I'm GLAD you're using more traditional materials! There's a lot to be said for the handling characteristics of that which is light, but solid. I once had a cast built up of overlapping strips of plaster-infused gauze. The strips were roughly 1" x 6". I've often wondered if such an approach wouldn't be strong than you three-play layup. I'm thinking possibly, but the uniformity would be lacking. "Where we're going, we're going to need it." Rendezvous with the Kraken? Your destructive test of your demo model: You didn't sand and prep it between layers. You DID sand and prep your hull. The sanding significantly increases surface area for bonding, and pepping it with an acetone wipe-down removes the uncured layer of resin which interferes with bonding. Final product: "We no longer have any room inside the boat to live, and it's now too heavy to float, but it's STRONG!" Just kidding. :) You guys are doing great! Excellent considerations all around! I especially like your coordinating with multiple sources of engineering input.

[@beakyturbot]

Spot the SAK with custom scales ... sweet. I agree with the comments on delamination. I used to design ballistic protection (using GRP armour at times, as it happens) the weakest part is near the edge. Because both your inner and outer hulls are contiguous structures, any forces will be dissipated across a significantly greater area. As others have said, I think the pros will be achieving a better bond for you, but I don't think you will have an issue either way. It's easy to say "Don't worry" but don't worry. What's the absolute worst that can happen? You end up with a boat inside a boat ;-)

[@dtondee]

I am not a boat guy I just enjoy watching your videos. All I can say "Good luck"

[@billclarke4134]

You cut the model basically in half before you tested it what were you expecting.

[@__NEMO__]

Friends. I noticed, in my opinion, a number of errors that led to low adhesive strength. All work on the repair and reconstruction of boats, even with a polyester hull, must be done not with polyester, but only with epoxy resin! It is more expensive - but adhesion is several times higher. The gluing areas must be cleaned with an abrasive and completely removed from dust with acetone. Moreover, dust one place 4 times, each time using the clean side of a napkin with acetone. The widest layer of fiberglass fabric is always glued first - for maximum uniform contact, all other additional elements of the material are on top of it. The huge contact area you have is not used under the foam block - where the hot glue is. There should also be a layer of fiberglass with epoxy resin adjacent to the body. The shape of the foam bars should be closer to triangular - the triangle is the hardest shape. You can make a model - according to my recommendations to check the difference. I would not save the option that you managed to make in the boat. Good luck and success!

[@rudygomez-lugo2509]

Notice that when u connected ur new ribs u didn’t connected ur glue in between the new connections and reminds me the same approach the boat builder did in ur boat that u discovered make it stronger while investing time and resources, the best to both

[@Dailyroach]

When you bond two materials together and try to seperate them you know you have succeeded in the best possible adhesion only when the bond is strong enough to tear away at what its bonded to . In other words the two layers have essentally turned into one layer . I just hope this is the case for you guys and that it has no delamination .