FIXING FIBERGLASS MISTAKES!

When learning how to work with fiberglass, something to keep in mind is that any mistake can be fixed ;-)! Last video I knew that I messed up on the bow, so this week I'm showing how to correct it.
Hopefully this will be helpful and take a bit of stress out of a few of your projects :-)!
The Dust collector thingy: www.oneida-air...
Support the companies that help to make these videos possible (their products are the best otherwise I would not be using them!!) Learn more about them below:
- Totalboat: bit.ly/2X4wT0ZT...
- Alexseal Yacht Coatings: bit.ly/2tdNzZKA...
- SoftSand Rubber Nonskid Discount 10% OFF when you use code BWT10
www.softsandrub...
* Order Total Boat Supplies HERE and Help Support Boatworks Today with your purchase!:
bit.ly/2E1a0or
** Looking for help with your project? Check out my Patreon page for consultation options!
/ boatworkstoday
*** Need help choosing the best resin for your project? Download our fiberglass Resin Guide:
bit.ly/2PCr72e
**** Subscribe To This Channel!!
www.youtube.co...
***** Shop our Amazon store for the materials used in this video!
www.amazon.com...
There is additional content and ad-free versions of these video’s available for Patreon supporters! Please click below to find out more!!
/ boatworkstoday
#BoatworksToday #TotalBoat #Alexseal

[@matthewcuccia7671]

I love how he didn't side step to get the 2nd camera out of frame, it's a diy project with a single person filming. Oddly Keeping small details like that in the final edit is humblingly refreshing.

[@geoffreybrown3332]

I really appreciate your teachings Andy, I currently have a small boat project going on at the moment, with some glassing, spidering and gel coat. Before finding your channel I did not have a clue, I now feel confident to get the job done, might not be the best job in the world, but it will be good enough to get this dinghy on the water and give me much pleasure fishing, soo thank you 👍🍻

[@josephk2958]

Great vid, Andy! I appreciate you for taking the time to show and explain how to fix faux pas that are a little more common to we amateurs.

[@aaronpetterson2207]

Love that you include the "not so ideal" parts of your repair. Very helpful

[@18ftLyman]

The stem is an area that takes a beating on any small boat, and if the entire hull required lamination there may be weak spots in the radiuses at the stem and around the dagger board hole and at the edges of the transom. This project should include critical examination of those areas. On to the laminating of the stem area, yes, a torn strip is the best method here, although the strip used is a bit too wide. Since there is fresh fiberglass on each side of the stem, the bond is primary; fresh to fresh. A narrower strip can be used, remembering that a feathered edge should be ground to about a 7 to1 width to thickness minimum should be used. The strip's torn edges only have to be a little wider. More glass than that becomes harder to hide during finishing, especially the further away from the turn of the shape at the stem. If I was wetting out that patch, I'd probably would start by rolling on resin right down the length of the repair on the narrower strip and then wet the edges gently with one end of the roller, again lengthwise. I wouldn't want to start dragging material away from the turn of that shape. That would make the repair thinner. The narrower strip will lay down better and require less tearing in darts. The glass on this shape shouldn't be worked until the wet out is fairly thorough, when the glass turns translucent, clear-like. Wrinkles that begin at the turn of the shape and lead outwards can then be patted down with a wet brush to flatten the repair prior to rolling-out. I normally use a 2" natural bristle varnish brush, after you are through destroying chip brushes, you might come to really like the varnish brush. I use a 3" roller (3/8" nap) and a gallon water jug with part of the top cut away leaving the handle, this has worked for me since the 50's. Speaking of that long time, I've had the opportunity to teach laminating allot over those years, and I've found that watching someone do the work is about the best way to learn it. Just writing about it or telling someone is second best. This Boatworks guy knows quite a bit about the trade, more people first starting out with these projects need to watch. And if you've never put catalyst to resin before, start small, one square foot small.

[@lifeofdave1237]

Fantastic education 👍 we all make mistakes, but as you say fiberglass is great as it can be easily sorted out. Currently renovating my Shetland here in England and have learned loads from watching your Chanel and putting it to practice. It's my 1st boat and needs loads of work, it's a challenge lol but great education. Thanks Andy, keep up the good work.

[@Stoneface_Garage]

Nice work. I had to tear out some work this week for cure failure. I suspect it was old MEKP. A video on these types of issues would be appreciated

[@Thewrightstuff777]

That was really cool giving Zach’s Garage a shout out for his snappy trick!!!

[@ZachsGarage1]

Could it be?! Is Andy watching my videos?! I will have to up my quality! 😂

[@mille1cw]

@@ZachsGarage1 Wow, very cool when your favorite boat restoration guys give each other shout outs!

[@walter2990]

While watching the earlier video, I'd wondered what you were going to do about tying in the glass at the bow. Now we know. Thanks for the video, but we'd still have loved to see you gelcoat it! Keep in mind that you have many fans, in this awful pandemic, who are living vicariously through YT videos, and especially yours! Stay well!

[@zacharyirving5080]

Thats what I appreciate about your videos, when you mess up you not only do a demonstration on how to fix it, you also admit you made a mistake and dont try to say something like "oh i set this up on purpose to show you....."

[@bobdelaplage690]

Thanks brothef, i did 2 polyester courses, and am working with it regularly! I learn from u thanks, it kind of comes back and motivates! Thx!

[@JAR2.0]

Excellent video! Timely and very helpful indeed. I feel that your fix was in fact the best option for finishing the seam at that high stress point of the prow (cutwater).

[@pezpengy9308]

as usual you're right... doing things in proper steps in important! i.e: wake up early on sunday, straight to the couch to watch your latest video, comment and thumbs up to uprank in youtube algorithm.... THEN start life. yep.

[@boatworkstoday]

Just as how Sunday morning should be ;-)!! Thank you!

[@lancehenthorn17]

I have always enjoy working with fiberglass. As you said you can always go back and fix the mistakes. I really like watching your videos. Always a chance to learn new stuff. The only down side for me is the videos are to short. Lol! I do understand you have other things going on besides the you tube videos. So needless to say I can't wait for the next video. Have a great day!

[@shawnpowell4618]

Hey Lance.. I have a question for you.. I have a Maxum 3700 SCR and it did not come with a radar arch.. The previous owner took it off.. I have NO idea what he was thinking.. But it is gone. So I found a 3300 SCR radar arch that I bought for $200. That was a God send. But there was a 14" gap between the older radar arch and the newer one being smaller stretching across the boat.. I cut it into 2 pieces and now going this week to set it up with a support board in the middle between the two sides and putting it on the boat and then start filling in the middle with plywood I am guessing.. How should I approach repairing this with fiberglass between the gap? I am seeing videos of fiberglassing this or that, laminating with fiberglass and fixing holes.. But nothing that is a gap of 14 inches.. Where could I find these answers and make sure the radar arch is strong and sound as it can be? Thanks..

[@williamediger3193]

Chopped strand glass has no structural integrity to speak of and just forms a protective barrier. Keels are often covered with a layer of chopped glass then a layer of biaxial weave laid over at a 45 degree angle so the strands cross the peak at 45 degrees instead of 90. The first layer covers all the chopped with some extra, then one or two layers less wide to taper the area up to the peak so fairing is good. Some even use Kevlar as the woven layers for the added protection over the keel that the Kevlar provides. All this allows the woven layers to cross the peak of the keel and smoothly lie so no bubbles or voids occur. That is how the guys make smooth edges to wings and such on aircraft and proved much more structural integrity to the areas. Just a thought.

[@ronaldrice1600]

Liike this guy. He keeps it simple yet i swell informed. Tells you stuff other guys leave out.

[@ajcates9136]

We are a marine dealer and you help me move from bodyman to boat man thanks 🙏 just taking it all in. I am getting some total boat fairing compound too !

[@RTD1947]

Andy, would you take a quick moment next week and explain laminating resin, why it needs gelcoat (with wax) to cure. What is going on with the two products? When do you cure resin? How long do you work with it before you cure it ? Can you do anything with resin after it’s cured. Just explain the two products and how and why. Thanks Andy, love the channel.

[@mylespeabody9310]

Needs wax to create an air barrier in order to fully cure. You can buy finishing resin or add or own wax to poly laminating resin or gel coat without wax. At a beginner level, I purchased finishing resin and gel coat with wax just because its less work/measuring for the beginner

[@finbarrryan7085]

Great vids Andy. Am bringing a Squib back to life over the winter and your step by step process is spot on.

[@4englishlies875]

Great video Andy, I do think that the so call mistake you made was on purpose so that you could show how to fix any mistakes that anyone could make. Thanks for doing more work than you would have just to show us any mistakes made while doing fiberglass can be fixed.not many would do that and just try to talk about it instead of showing. Love your channel!!!!!!

[@alstaubin3699]

Great video series getting ready to do major repair on fiberglass canoe this spring so I need all the tips I can get. I like how you added a full new coat of fiber flass cloth after repairing I hadn't though of that.

[@im4broke643]

Geez...room and board and food I'll come apprentice for a month no pay! Watched the 3 of the sail boat repair...patch hole, reskin and fix skin. Great job, this reminded me why I subscribed before the sailboat.

[@im4broke643]

My offer is serious.

[@pearlcustoms]

Great video! I’m just getting into fiberglassing and this helped me calm down after creating a disaster of a speaker box.

[@chrisrancat2808]

Jeesh you make rolling out that CS glass look easy. Specially when you had to tear into a bit. I seem to get that stuff all over me and everything around me 50% of the time.

[@o.h.w.6638]

So glad that you mess it up so I can learn! Thanks!

[@o.h.w.6638]

On my next boat build video, I’m going to link one of your past videos. If really helped me! Keep up the great work! Appreciate that you don’t cut out the wonky bits!

[@billiondollardan]

Sunday routine is almost finished. First Andy, then Mads. Thanks for the vid

[@fabienh3943]

Oh oh oh...this looks so much easier than it really is 😊😊😊 When you see Federer play, it's also kind of misleading on what to expect when you enter the court...

[@alixbarks]

Alternative: Wet out the mohawk. When green, i.e. gelled and stiff but not hard, cut with a sharp hook knife (carpet knife) right up to the hull. Let harden. Then sand. A lot less dust and flying fibers this way. And, what's with leaving the bow eye in the way? Get it out of there for a project like this.

[@TabulaRasa11]

Have you ever think making online courses about this kind of job? You are legit.

[@j.p.wagner6461]

Andy, thank you for your most-valuable & informative videos. For a fiberglass-work newbee, you've saved me tons of time & money; therefore, new patreon ..

[@ruaraidhmcdonald-walker9524]

“Needs wax to seal a laminating surface”? Right need to go back and find that video then! Was that a dedicated gel coat video I’m guessing? Thanks again Andy, very honest to show how to deal with SNAFUs!

[@MrDanielHawes]

Poly will never cure without being sticky as long as there is air touching it. Adding a wax will allow the wax to rise to the surface before the resin cures acting as a barrier between the resin and the air. That gets rid of the tackiness so that it can be sanded

[@1ocean515]

Very helpful. Thanks for showing how it’s done. 👍

[@boatworkstoday]

Glad it was helpful!

[@familysawchuk5632]

Love your channel. Just wondering why you didn't sand the paint off? Is it not necessary? Please explain. Thanks love your work and explanations.

[@highlinercustomboats1816]

I'd suggest applying a layer of 6oz cloth over the wet matt, which could have been 3/4 oz for the purposes of simply sealing the old surface. Running a squeegee over the cloth then would help saturate the cloth, remove air and go a long way to keeping the subsequent fairing to a minimum.

[@elmeradams8781]

Have you tried a squeegee? It seems like it would just grab the matt, but if it glides good enough it would be awesome.

[@brucewilliamsom5928]

As always...great advice Andy thanks

[@rickaurand5384]

Great video. You answer so many questions. Thank you 👍👍

[@fenderrexfender]

Love the video transition timing. Really keeps the viewer...

[@kevinthompson3380]

I absolutely love watching your videos Hey Andy I have a question how many layers should you put down at once should you put what are the time Inlet cure?? Any advice would be greatly appreciated

[@donpetrey8007]

Great vid Andy nice to see your back at it last Sunday just wasn’t the same

[@MrDanielHawes]

I loath sanding laminating resin. If I ever make a mistake along the lines of that mowhawk i will continue to wet out all of the glass. Once its set, I apply a coat of waxed resin and sand down from there. Any cloth not touching your surface or any airbubbles will come out in the sanding process. Saves on frustration and sanding discs

[@pangrac1]

Yo should use saran wrap to bent that weet fiberglass any way you want over the bow. Easy.

[@berniepatchen9027]

Thanks for the decal Andy!

[@VW.907]

I was wondering the correct way to repair these issues. Thanks.

[@kevinrisher7658]

Total Boat is a great company to deal with! Love their products!!

[@arkeyethenoo]

Great video as ever Andy, did you consider putting narrow strip down the centre before the wide piece basically to keep the whole repair in that area 2 layers thick??

[@boatworkstoday]

It didn't cross my mind at the time, but suppose I could have :-)

[@lynchcreekmuzzy5759]

I thought the same thing...in order to double strengthen that point, but wasnt sure if it would still slightly 'mohawk' the end product.

[@mylespeabody9310]

Have you used plascore in any builds or repairs? A how to video on nidacore (plascore) would be awesome. Keep up the great work.

[@jamesrahn8339]

Great explanation of everything... especially great choice of music!

[@westieBrucedavidson]

Gussset I think word you were looking for Nice work mate

[@djuracki]

Andy, Great work and realy great tutorials. Only question is, why you didnt remove that U-bolt? Best regards

[@wolfgangz4407]

Curious as to why you used total boat gelcoat instead of alexseal. You seemed to praise the alexseal immensely in a previous video. And thanks soooo much for your videos! I've been learning quite a bit and is going to come in handy on my 85' 4 winns deck boat rebuild!

[@boatworkstoday]

Alexseal is a paint, not a type of gelcoat :-)

[@wolfgangz4407]

@@boatworkstoday Thanks for the quick reply, tho mine wasn't lol. Sorry. Guess I misunderstood that video. *sits back and nods head* "Yes, master." (still learning)

[@kamoboko86]

I can't understand why you didn't remove the bow eyelet ring and glass to the tip of the bow. It takes 5 minutes to remove.

[@boatworkstoday]

Hindsight lol :-)

[@kamoboko86]

@@boatworkstoday Yeah, we've all been there. Since I got your attention I wanted to say I really love your videos and I'm proud of you for taking the leap to quit work to make videos. So many people have learned alot from you. This video made me think of how you could teach people to fix botched jobs. For example fixing something the wrong way and showing how to make it right. Like a bad epoxy ratio mix. Or improper tepreture when painting or laying glass. Etc. Fixing a mistake is way harder and people feel like there is no hope after that. God bless man. And keep up the good work. Leedy from Japan. 🇯🇵

[@tcar3654]

I've learned so much from watching your videos, took the plunge on a complete transom replacement of a 1974 Mako 20cc and took your advice on the total boat epoxy which I am very happy with thus far.

[@jons6125]

Uk we have emulsion and powder bound csm. Emulsion is cheapest and most common.

[@horstkotte6114]

I love seeing professionals making mistakes. It's sort of motivating in tolerating my own mistakes and especially in this case it shows that owning your mistakes is actually helping to speed things along. Most beginners probably would have tried to glass in the Mohawk and got frustrated twice, first by trying to tame the mess while the resin starts kicking and then again when sanding down the glassed mohawk. The professional just laughs at himself and chooses not to enter the dead end ahead / skip two unnecessary steps.

[@kimberlyjacobsen4148]

Lovely video Why don’t you add a window on the bucket? That way you can see if it’s full?

[@svdoinitright7519]

Andy, TotalBoat epoxy question. I was resurfacing teak handrails, so cleaned them up and tried to coat with Totalboat 5:1 epoxy, prior to varnish. The epoxy just fisheyed tremendously. I wound up sanding everything, cleaning it again, and reapplying. Same effect. At that point, I changed plans and went to straight Cetol with fantastic results. I'm wondering if the epoxy can go bad. It's only a year or so old, but could have been in freezing temperatures for a night or two last winter.

[@boatworkstoday]

Did you wipe the bare wood down with acetone prior to applying the epoxy? The oils in teak can cause the eyes :-/. Also I'd probably try their 2:1 as it's a bit more flexible than the 5:1. Epoxy should last a very long time; even if it freezes a couple times, but as long as the job got done and you're happy with it, that's all that matters ;-)!!

[@svdoinitright7519]

@@boatworkstoday The first time, I just used soap and water, the second time I used acetone. It is a project boat, primarily to learn repairs, so I'll try the 2:1 next time

[@PFLEONARDI0906]

Great video, thanks for the tips on the relief cuts on such a difficult transition area. Have you worked with Carbon Fibre cloth? I think that would be a great vid. Once again thanks!

[@mickfisch96]

Thanks Andy. Great information as always 👍🏻⛵️

[@Starboatbuilder]

Hi I have been waiting - great is having the next installment. Perfect. Still do not why you did not use 1/2 oz cloth Great project , your kids are lucky

[@tomlockwood6599]

Andy, I'm rewatching this one. I realize it's older but, why did you leave the bow eye on while glassing the bow? I'm currently doing a 14 ft hull.

[@jonmckinney3981]

Always love these videos. You have single handedly taught me so much

[@spedobill]

❤could you have used a epoxy resin?

[@aaronbeyette3140]

was wondering why you use gel coat with wax to cure instead of adding wax to the resin?

[@skiscuba2]

I have a question about putting two pieces of fiberglass board together do you have a video I haven’t found it. I’m doing a deck repair where I removed the top skin and cleaned out the rotten Bohl Cell core and now I’ve replaced the skin over the top of the new core . trying to find the best solution for putting the two seams together

[@bruiser6479]

another interesting video. Thanks very much.

[@matt5george]

In a 1979 sunhatch the engine stringer need to be fixed they had wood with glass over them. Over years wood rotten and now needs to be fixed. Can I replace hard wood and pour a glass slushy with tearing mat up into pieces and then pour the mixture in and around the wood to fill in? What glass and resin or poly do I use? Help? Or bad idea?

[@projecttrawler]

Love the videos, ive learned so m7ch from you but i have a question, What oz chop strand should i use for waterproofing the inside of a shower on our yacht..

[@str8chillin18]

I need this video right now 😅

[@leonard5995]

Would it be okay and look good if you sanded the hull down after that glass was laid and applied paint rather than gelcoat? Would it look a lot different?

[@bobcutlip9448]

If one wanted to extend the fiberglass to both sides of the bow eye all the way to the terminating edge of the bow, could you tear a hole in the mat and place over the eye and resin all of it instead of doing it the way you did it?

[@chuckhoover5269]

I need to refiberglass the keel of a Skipper 20 for bother strength and waterproofing. Does chopped strand fiberglass add the protection I’m looking for versus woven?

[@drewmccabe2687]

I have a Rebel 16 I want to fix/paint the hull. How did you you turn the boat over? ha

[@badfishmarine2085]

Great video as always Andy. What sander is that you're using?

[@BirdDog.]

Like to have seen that gel coat process. Can you link a video to where you’ve done that?

[@willrogers8454]

Great episode! Question...can I use PVA to help cure resin that may have been a little light on hardener? I found some tacky spots after a couple days.

[@wokmajik]

Hello! When you're laying down CSM and are painting it instead of gel coating it, do you sand it smooth prior to painting? Fair it? Thanks in advance

[@shawnpowell4618]

Hey everyone... Listen, I have a question.. I have a Maxum 3700 SCR and it did not come with a radar arch.. The previous owner took it off.. I have NO idea what he was thinking.. But it is gone. So I found a 3300 SCR radar arch that I bought for $200. That was a God send. But there was a 14" gap between the older radar arch and the newer one being smaller stretching across the boat.. I cut it into 2 pieces and now going this week to set it up with a support board in the middle between the two sides and putting it on the boat and then start filling in the middle with plywood I am guessing.. How should I approach repairing this with fiberglass between the gap? I am seeing videos of fiberglassing this or that, laminating with fiberglass and fixing holes.. But nothing that is a gap of 14 inches.. Where could I find these answers and make sure the radar arch is strong and sound as it can be? Thanks..

[@richardtharp1608]

What Products will Help me Repair a few Spots in my Old boat Hull .. The Bottom of the Boat is a Mirror of the Outside.. Fiberglass Outside with thinner Glass inside with Water soaked into the Middle "stuff", or can I Repair with some type of Filler, Please Sir??

[@thegrumpytexan]

Andy, is there a good book you can recommend that explains the different types of resins, gel coats and mats - and when to (or not to) use them?

[@boatworkstoday]

it's not a book per say, but I do have a guide for download that covered the different resins, when and where to use each that might be helpful :-) www.boatworkstoday.com/product/fiberglass-101-download-guide-choosing-the-right-resin-for-your-project/

[@highlinercustomboats1816]

Fiberglass Boatbuilding for Ametuers by Ken Hankinson. By far the best resource for composites in general and boats in particular.

[@thegrumpytexan]

@@boatworkstoday Definitely going to download it - but I'm also interested in when/why you would use chop strand mat vs. woven fiberglass as well as the different types of gel coat and their applications. Thanks!

[@bobadam7021]

I want to do this to fix my 8' dinghy which I've had for almost 40 years. I'm a little concerned about the added weight of additional layers of glass and gelcoat.

[@whitecompany18]

Don't be , a few patches won't change its draft , even if you use five kilo of matting and a gallon of resin as it's spreading the ten kilos out evenly . My dinghy was a cheap fibrecell boat and I added three layers of chopstrand to the inside, overkill yes but I added nearly thirty kilos to the hull in total in resin and matting and the water line has barely changed.

[@spyridonbaxevanis6479]

Always a great video! Thank you man, i have learned a lot from you! Greetings from Greece!

[@boatworkstoday]

Thanks for watching!

[@L8nightride1]

stress reliefs spots

[@joeponder9668]

Another awesome video Andy!!!

[@61spindrift]

Ok, now I am confused. Just watched your video and one from O'Kelly Tech where he repaired a sailboat keel. Seems yours is counter to his on laying the fiberglass with resin. In O'Kelly's video he squeegeed the resin out as he said the more you leave in the weaker the repair will be. Also stating it is not the resin the makes it strong but, the least amount of resin compaired to the fibers of the cloth. You obviously elected to leave a great amount of the resin and did not try to remove most of the resin with a squeegee. Please comment, both can't be right. Thanks

[@eddjordan2399]

great work.

[@percussion44]

Is that a proper rotary disc sander? I'm trying to find a try rotary sander , not an oscillating sander which is more of a finish tool. I want a hogs off meat type tool.

[@frankpenzica1176]

Andy can you gel coat over total boat polyester fairing compound

[@sufferedenuf]

At the start, I wanted to say, why poly and not epoxy. Glad I watched it through.

[@davetooes6179]

Polyester is needed as CSM has a binder which epoxy can't break down. Thats why generally all epoxy work uses either cloth, woven roving or dynel. Yes I know there is powder bound and even emulsion binder CAN be used with epoxy. Its just an extra layer of difficulty. Generally not to be used on any curved surfaces.

[@ascott6804]

So its better to come back over an area this difficult? Rather than do it all at once? Hope you never change the outro! Never gonna find a cuter one!

[@boatworkstoday]

Sometimes difficult areas are easier to address after the fact as there's less moving parts to contend with, but originally that was not my plan lol ;-)

[@adl2005]

When are you doing the vid on roll on paint that don't need tipping, thanks from UK.

[@JesseG085]

Andy, do you have any recommendations on which paint for an aluminum Jon boat? Preferably something that can be rolled smooth or with a texture for grip. Thanks!

[@garydumoulin6318]

Hi Andy, good video. I was wondering if alexseal primer can be painted directly over laminating resin or do I need to apply a flow coat with wax in it before painting?

[@tamcaj]

What is the percentage of wax in the gelcoat ?

[@mikepruett1745]

ok after this primer ? after gel

[@chrish2996]

Hi Andy. Done like a pro now you have supplies. Great job, as always. Thanks

[@Danbilawchuk]

the music today was great xD

[@sammm7ykjbkjbkjbkjb403]

What sander are you using? And how many rpm?

[@tristan7351]

Would like to see how you did the gelcoat i am busy with a similar project Pls refer me to vids where you do it

[@keithladd2365]

Hi Andy, how can I get to view your gel cost video. I just don't know enough about gel coating. Thanks, Keith.

[@jaaaake777]

I'd be interested to know how much additional weight all those gallons of resin and yards of CSM have added to that poor little boat! I've achieved good results opening out/ zig zagging/ Dremmeling out all the gelcoat cracks and epoxy filling them then repainting hull. Sounds time consuming- but comparable with how you did it time wise and actually cheaper in terms of material used. Then the only additional weight I need to worry about is the weight of the paint. You haven't really addressed the cracks- more partially laid up another hull over the top off them! I'm sure it will look nice whey you're done, and will be more than strong enough- but probably not very nice as a usable boat due to the weight. Note: You can only really do the method I describe above with epoxy, ideally with a heater under the upturned boat during curing. Epoxy's ADHESIVE strength to a suitably abraded cured polyester laminate (an existing hull) is many, many times that of polyester's. Polyester only has passable adhesive strength when laid up wet on wet. So polyester is OK (and of course very cheap) for building boats- not so good for repairing them. (Unless you pour gallons and gallons of it over the problem!)

[@markshag5149]

Why gelcoat? Wouldn't a PVA spray do the same job for less work/money?

[@boatworkstoday]

PVA would also work fine, but for me using gelcoat has some advantages. 1) the color contrast is easier for folks to see on video :-) 2) being a thicker material, gelcoat fills in the texture of the glass making less sanding to get a smooth surface. 3) I don't have to wash off gelcoat with warm water and get sticky PVA water all over the shop floor lol ;-)

[@TechyBen]

Hi, newbie question here, what does the PVA/gelcoat do that the normal epoxy does not? Is it vital for strength/water resistance?