Stump strike repair (Was: Oh, Glassman...)

[tdonoughue]

@Glassman...and others who are good at fiberglass...

So, this is what I did to my boat this weekend:


I believe that this is mostly a gelcoat injury, but on that big hunk on the right, the underlying fiberglass is impacted a little. I *think* I can clean this up, remove loose pieces and rough edges and just apply gelcoat to fix. Agree? Or do I need to do something more with the fiber, do you think?

 

[RightStuff]

That'll buff out.

P.S. I'm not good at fiberglass.

 

[robert843]

Ouch how did you do that?

 

[swatski]

Gel coat is a pigmented resin normally associated with molding process's of construction, so is the first coat applied to a female mold. Simple sailboat gelcoat is usually the cheapest marine resin but if your boat is a higher end model (sic), gel coats can be either epoxy or poly resin or whatever. Then you'd have to ask the manufacturers exactly what to use to replicate their gel coats.

You are in luck as Spectrum is the manufacturer for Yamaha gel coats, and they will sell you the right stuff over iboats.

I don't know what resin Yamaha uses for their fiberglassing, but it is not your daddy's fiberglass boat. I would stick with the Spectrum stuff and not experiment. Wonder what others think.
(MHO)

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[swatski]

As far as surface prep - I would go wide over the entire area, not try to patch individual dings. Almost easier that way, but you may need some sanding power tools.

I'm waiting for @Glassman - curious what he will say about all that. This is exciting! (please don't take it the wrong way!)

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[tdonoughue]

Ouch how did you do that?

There are two events that could have caused it, but I believe that the most likely was taking off without picking up my box anchor... Thus the larger hits about 12 inches apart. Oops.

As to the gelcoat--I already have the Spectrum color matched stuff from a repair a few months ago.

As to the prep--yes, the plan is for the entire area. If you saw it up close and personal, you would see that most of that cracked stuff will probably come off with my pocket knife. So, yes, taking it down with the dremmel or a sander will have it down to the glass on the first pass.

And don't worry, @swatski . I understand the excitement. If you can't laugh at yourself and learn from a mistake, you go through life very unhappy. I try not to go through life unhappy.

 

[Ronnie]

Why not just file a claim with your insurance company? Are you concerned that the time to repair will kill a big part of your remain season, just want to tackle it yourself or is it something else? Sorry this happened to you but admire your attitude about it.

 

[tdonoughue]

Good point, @ClemsonTiger . Boat was on the water all weekend, probably like that. So nothing is happening until later in the week once it has had a chance to dry out in some nice Texas heat. And I will be using your dryer trick.

And, no, the boat is officially out of service until the repair is complete.

That said, I would be interested in your recommendation on repair. Believe it or not, the glass only looks impacted at one little spot on the right. About the size of a dime, maybe a little less, is broken on the surface (about 2 mm or so). Certainly not all the way through.

 

[tdonoughue]

Why not just file a claim with your insurance company? Are you concerned that the time to repair will kill a big part of your remain season, just want to tackle it yourself or is it something else?

Oh, I still may do that. That is in large part why I wanted the opinions on what the repair would entail. I already have the gellcoat and need the practice on using it. Plus, when you do it yourself, you can be sure it is done to your satisfaction. Finally, I would of course hate for the boat to be out for the rest of the season with this injury. If I can repair it next weekend or so, I could be out my boat in a couple weeks.

All that said, if it is too big or won't be safe, I probably will file it... I just prefer to save dealing with insurance companies for when I really need it.

 

[swatski]

Ok, well before I state the following let me preface it by stating it is only my opinion based on history, experience and fiberglass & gelcoat characteristics/properties.

1. All brand new boats right off the factory floor will absorb water (through the gelcoat and fiberglass).
2. The rate of absorption is dependent on the quality of fiberglass manufacturing process, quality of gelcoat resin and the amount of or lack of imperfections.
3. Water/Moisture will combine with uncured resin and dissolve cured (good) resin.
This means that if water/moisture penetrates through the gelcoat and into the fiberglass at an apex amount (different for each boat/situation), your hull will literally deteriorate from the inside.

Now, if your willing to accept the above then proceed reading. If anyone feels the above is incorrect then stop reading now and don't bother responding telling me why it is wrong...I'll go ahead and concede now that you are right and I'm wrong.

Applying gelcoat over the damaged area is better than doing nothing at all; however, there are superior repair options. Will a bandaid work? Yes, but it will not heal the wound.

The damaged area needs to have the gelcoat sanded down to the fiberglass. The exposed fiberglass has to be smoothed/sanded then subsequently repaired. Gelcoat can then be reapplied.

The chipped rough edged fiberglass will allow water to be more easily absorbed overtime and so will gelcoat that is just simply applied over it.

Bottom line, once the damage is done...there really is no reversing it. That area will forever be a weak spot for water absorption over time. Luckily, most people do not own the boat long enough for it to be an issue...assuming they repair the area properly.

This is why you should never purchase a used boat that has visible home repairs or shade tree mechanic fiberglass issues. Yet another reason to repair the area properly...your resale value will take a significant hit...assuming the next purchaser knowns anything about boats.

 

[swatski]

And one more thing. Now, that I have already identified myself as an a$$, LOL, in all seriousness.

The shelf life of Spectrum pastes/kits is 6 months or so. For a job like this, I would want to use fresh (best even unopened) package of both resin and catalyst, not very expensive, relatively speaking. That is one of few things that are critical and will affect whether or not your job cures completely. You want your reagents as fresh as possible and your volumes measured as accurately as you can, perhaps erring on the side of too little MEKP catalyst if in doubt.

I can not see how or why you would want to incorporate anything else than a high quality gelcoat into this repair. In fact, I can see how any such attempts would be detrimental to your results, both cosmetically and long term.

Yamaha fiberglass and gel coats are most likely polyester based, maybe epoxy, maybe polyvinyl, maybe something else (I don't think anyone outside the company knows the chemistry). Obviously, Spectrum does as they produce the gel coat. Either way, with these kinds of resins you can only get chemical bond when they are still tacky/not completely cured. Everyone knows it, and you are past that point (as that only applies co-production). Which means you will have to rely on a mechanical bond.

So - for example - if you try to "strengthen" your repair/fiberglass with a layer of epoxy (which binds well to cured poly resins) you will be asking for problems with your gelcoat (which is polyester based and does not bind well to epoxy)... And so on. In my view, it would create more problems than it solves.

The easiest and essentially foolproof plan, in my view, is to use good surface prep and then fresh Spectrum kit directly onto the shallow gouges of you wound, followed by the customary sanding/polishing scheme.

My 0.02.
I am hoping real experts will chime in, as I would like to learn and verify my own views. I have enough experience to appreciate both difficulties but also beauty of gelcoat restoration, as over the years I have (almost) apprenticed and also attempted/failed/succeeded in numerous fiberglass restoration projects.

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[tdonoughue]

Thanks, folks.

This mostly confirms my plan (subject to more expert advice). Sand this bit down to the glass. Dry out the area well with some heat (hairdrier/heat gun). Clean with acetone and my toothbrush. Let dry a bit, then Spectrum gelcoat. Cover with plastic and let cure. Sand and buff to a fine finish where you cannot even see what happened.

I agree that this will be leaving a weak spot. That said, I do not know anything that can be done about it. Whatever water has gotten in there already has. I can only dry it best I can. Even were I to take it to a pro, they could only dry it as best they could. And yes, the bond with the new gelcoat will not be as good either. But again, short of trying to replace the glass or add epoxy (which causes more issues), there is no real way to address that issue.

Though I have had this thought: anyone put more than one Keel Guard on their boat? I could cover the secondary apexes with one, too. Heck, I could cover the bottom of the boat with them... Ok, probably not. <sigh> Guess I will just have to start pulling up the anchor before it bites the bottom of the boat.

 

[tdonoughue]

Sweat?!? No sweat! It will get the glass wet! Aaaarrrrgh!

(hehehe--sorry, I couldn't resist )

 

[Speedling]

I recommend taking to a shop because of all the aforementioned stuff.
I would also recommend using something like a West Marine epoxy in there to make sure that the fiberglass doesn't let water soak through any further than it has. I would see if you can get to the inside of that so that you can repair it from inside, but I don't really think you can.
Perhaps the shop can give you a little discount if you get everything out of their way and make it easier on them.

 

[swatski]

I recommend taking to a shop because of all the aforementioned stuff.
I would also recommend using something like a West Marine epoxy in there to make sure that the fiberglass doesn't let water soak through any further than it has. I would see if you can get to the inside of that so that you can repair it from inside, but I don't really think you can.
Perhaps the shop can give you a little discount if you get everything out of their way and make it easier on them.

@Speedling not to question your judgement, but are you sure you would want to use epoxy for a permanent repair of this kind of damage in a poly(whatever)fiberglass hull? I have to say I am completely perplexed. Wonder if you would care to elaborate on the rationale.
One could, conceivably, soak/impregnate exposed fiberglass with a variety of things to waterproof it but why? Nothing will bind like the (chemically cognate) gelcoat from the original manufacturer... Am I missing something?

At any rate, I will take my answers off the air. Good luck @tdonoughue! I'm sure your boat will soon be as good as new, whichever way you proceed.

 

[Murf'n'surf]

I would use a grinder to grind out all of the damaged loose material. Your repair area will be twice the size of the current damage once it's feathered out. The deeper gouges may be filled with a fairing material such as 3m vinyl ester filler or marine Tex but it's important to keep this filling lower than the gel coat. You'll need to leave enough depth for enough gel to coat the entire area.

 

[Speedling]

@Speedling not to question your judgement, but are you sure you would want to use epoxy for a permanent repair of this kind of damage in a poly(whatever)fiberglass hull? I have to say I am completely perplexed. Wonder if you would care to elaborate on the rationale.
One could, conceivably, soak/impregnate exposed fiberglass with a variety of things to waterproof it but why? Nothing will bind like the (chemically cognate) gelcoat from the original manufacturer... Am I missing something?

At any rate, I will take my answers off the air. Good luck @tdonoughue! I'm sure your boat will soon be as good as new, whichever way you proceed.

I was thinking of the epoxy in the back, not in place of gelcoat for sure! Replace some of the fiberglass but use the epoxy along the inside around the damaged area and so from in to out you have epoxy, glass, gelcoat. The epoxy strengthens the area since it was now no longer continuous fibers and it also keeps moisture out. Problem is it keeps moisture in as well so it needs to be very dry.

 

[tdonoughue]

Ok, so here is today's update:

Found out last night that my brother and his boys are coming in town this weekend. So.... if I can have the boat operational, that would not be required, but would be optimal. Plus, I thought about much of the wisdom provided on this board and decided to give it a go. I figure that at least cleaning it up can't hurt as long as I don't do more damage. So, with the boater's Hippocratic oath ("Do no harm") in hand, I went off to the boat.

I started with the scraper. Turns out that the reason that much of the gelcoat did not come off is that it is really attached on there. Basically the scraper got a couple of larger hunks and some little stuff around the edges. Certainly not the type of area I was looking for in a repair. Basically it looked very much the same as that original pic.

So, I broke out the grinder. I went very slowly and gently, being sure not to hit the unintended parts of the boat with that nice spinny disk. And I got:

It cleaned up really much better than I expected. Lots of smooth fiberglass. A couple of spots where the strands are separated. And one crack, seen here (you can also see some of the separated strands to the right of it):

I broke out the epoxy and latex gloves at that point. I decided the main thing was to get epoxy in that crack. Then I put some anywhere that looked like it might have some hint of a void. Finally, I used my finger in the glove to push the epoxy flush before it cured. Now it looks like this:

That is where we leave our intrepid hero this evening. The plan tomorrow is to sand up some of the epoxy to make sure there are no drip parts, clean it up with some alcohol, dry it out good and try to get some gelcoat on it. Stay tuned.

 

[Murf'n'surf]

Now is the time to remove any sharp edges on the gel coat. Blending the new gel into the old requires no sharp edges.
Hard to tell looking at your photos on my phone. Also, don't be afraid to sand further out...... It will make for easier blending so you don't see a bump where the repair is.

 

[tdonoughue]

Yes, that was the object. I may have missed one or two small spots, I guess. But tomorrow when I clean up the epoxy, I will have a chance to double check those.

That, and, I strongly believe that the bottom of the boat was put on the bottom for a reason. And it wasn't so everyone could inspect it.