Piling Bites Sailboat-Advice Requested

[BrianW]

In Pensacola, we had a big blow the other night. I was out of town and not available to secure her in advance. The end result was that one of my dock lines broke and the boat rode up on top of a short piling and the it took a chunk out of my Hunter 26. As you can see from the photo, most of the damage was at the hull joint. There is also a straight 1-foot long crack just above the chewed out joint damage that goes all the way through. I also have some rubrail damage. I would appreciate some advice from some of you who have experience in fiberglass repair. I don't have fiberglass experience but am willing to try. My questions:
(1) Should I try this repair myself?
(2) How much of the damaged area should I cut back for the repair
(3) Should I treat the joint as a single piece (one repair surface) or separately repair the upper part and the lower part of the joint?
(3) How should I repair the crack above the gouged-out area?
(4) Is it possible to buy just a section of rubrail track that will match fairly well instead of a buying a complete rubrail and channel set for the whole boat?

Thanks in advance for your help! BrianW

 

[sailingdog]

Brian-

That's a pretty nasty repair to cut your eyeteeth on in learning to fiberglass. Since you have no experience doing fiberglass work, you probably want to leave this to the professionals. If you have insurance, I'd recommend biting the bullet and having the insurance company cover the repair and paying your deductible.

That said, if you do decide you want to tackle this, you'll probably want to use epoxy resin and fiberglass cloth to re-build the damaged area, rather than polyester/vinylester resin. IMHO, epoxy is a bit easier to work with than polyester/vinylester resin for the novice. Epoxy is also better for doing structural repairs IMHO, since it has far better secondary bonding (adhesive) characteristics than do either polyester or vinylester resin. Epoxy also has greater tensile strength than polyester/vinylester resins. However, epoxy does have two significant downsides—first, it tends to break down under exposure to UV so has to be painted or gelcoated; second, it deforms thermally at a lower temperature than either polyester or vinylester resins—so needs to be painted/gelcoated a light color.

I would recommend treating the crack and the gouge as a single repair, since the taper for either repair would encompass the other. You'll want to taper the fiberglass back by grinding it out to a 12:1 taper. This means if the laminate there is 1/2: thick, you'd want to taper the repair back over a radius of SIX INCHES (12 x .5" = 6).

Wash the fiberglass well with TSP or some other strong cleaner/degreaser before grinding it. Otherwise, you may find that the grinder has embedded contaminants into the ground back laminate, and that makes it much harder for the repair to bond very strongly.

Also, since this is a hull-deck joint, you'll probably have to treat the upper deck repair and the lower hull repair as a single repair, unless you want to remove the deck from the hull—didn't think so. As a side benefit, glassing over the hull deck joint here will help make the repair stronger as well as reduce the chances that the repaired area will leak.

After grinding the tapered area, you would build the area back up using several layers of fiberglass cloth and epoxy resin. West Systems website and several books, like those by Don Casey, et al., will have a more detailed description of this process.

Finally, you can probably order a small segment of the rub rail, but IMHO, you'd be better off replacing the whole rubber piece on that side of the boat. If you replace just a section, and hit it just wrong coming into a dock or something, it might tear off more easily if it is a separate smaller section. As for the rail itself, just replace what is damaged.

BTW, you'll have to remove and re-bed the stanchion in the photo, since the tapered area for the repair will include the area that stanchion is mounted to.

Once the epoxy and fiberglass has cured... you'll want to sand it and fair it using thickened epoxy. Then you'll want to either gelcoat it or paint it. I'd recommend going with gelcoat, since painting it would probably mean you should paint the entire deck... and that's probably more of a pain than you want to deal with.

I hope this helps.

 

[Tim R.]

To be honest, Brian, this is not a beginner FG repair. That is the area that seals the deck to the hull and repairing it properly is necessary to ensure a watertight and cosmetically accurate reapir. I have a fair amount to experience but I would leave that to the pros. Have your insurance company pay a professional to do it right and you will never notice the repair. That being said, the rubrail should not be too complex for a good DIYer. Rubrail is usally sold by the foot so you should be able to buy a piece but there will always be a seam and not look original.

 

[Ross]

If you decide to make the repair yourself, replicating the shape will be your biggest challange. It looks to me like it is mostly chopped strand and the rubrail was just a cap for the down turned lapped joint. In addition to the books mentioned also Alan Vaitsis book Fiberglass Repair is the best I have seen. I have three others and I turn to Vaitsis for answers. I think that vinylester resin will be more compatable with gelcoat than will epoxy. Don'y try to make do with a grinder get a proper one with the assortment of disks that you will need.

 

[sailingdog]

Ross-

Just FYI, West Systems did some testing with gelcoat and epoxy-resin fiberglass... and gelcoat does work on epoxy. I wouldn't use vinylester resin for a structural repair like this because its secondary bonding characteristics aren't that good.

 

[Ross]

Ross-

Just FYI, West Systems did some testing with gelcoat and epoxy-resin fiberglass... and gelcoat does work on epoxy. I wouldn't use vinylester resin for a structural repair like this because its secondary bonding characteristics aren't that good.

That is good to know. My experience has been mostly with polyester resin (about 50 gallons) and only a little with epoxy (2 or 3 gallons) and none with vinylester. I know that polyester spilled on a freshly ground fiber glass surface defies removal except by grinding.
I set my engine beds with epoxy and fiberglass on some carefully prepaired polyester hull structure. I bonded my deck to the hull with fiberglass and polyester elimanating the hull-deck joint and closed a couple of picture window size original openings with glass and poly resin. I doubt that anyone could find a weak bond.

 

[LANCE ON CLOUD NINE]

Consider using a long flexible batten to help form a mold

for the lower lip edge. Something a little bigger than yard stick material. Butt it up to the bottom of the lip on either side of the damage area. Hold it tight to the hull with 3M double face mounting tape. Coat the top edge with a good releasing agent.

 

[sailingdog]

Ross-

If the boat is relatively new, then the chance of polyester/vinylester resin finding a decent number of open bonding sites and creating a primary (chemical) bond is fairly good.

However, as boats age, the resin in the hulls cures continually, and the older the boat, the fewer bonding sites that will remain, leaving polyester/vinylester resin to attach mainly using the much weaker secondary (adhesive) bonding. On older, thicker hulls, there's a better chance of having available bonding sites, since they're generally higher in resin content than more modern layups.

Epoxy has much better secondary bonding characteristics, and as such is much easier for most novices to use, and works better than will the polyester/vinylester resins.

 

[Franklin]

I just tackled a few fiberglass projects including repairing a hole in my hull that went all the way though. This I can tell you: 1) sharp curves are a pain 2) any mistake you make can be fixed as you just grid it out and start over 3) a drill with a few griding pieces will work fine and sometimes better as you can get small griding stones 4) make sure you get your gelcoat from Hunter (Hunter white) 5) gelcoat is resin with color so the norm is to use resin when dealing with gelcoat.

If you try it yourself, at the worst case, you learned a lot, wasted a couple weekends and a couple hundren dollars and had to hire somebody else. Best case, you learned a lot, know how the boat was repaired, and saved a couple thousand. Also developed confidence in doing fiberglass repair and you will look at your boat in a different view...like...what else can I fix. I've fixed a lot of little problems with my fiberglass after I fixed the hole in my hull. Had my friends not talked me into doing it myself, I would have never fixed all those other things and they would continue to annoy me.

I say "give it a try" as you have much more to gain then you have to loose.

 

[Ross]

I just tackled a few fiberglass projects including repairing a hole in my hull that went all the way though.

If you try it yourself, at the worst case, you learned a lot, wasted a couple weekends and a couple hundren dollars and had to hire somebody else. Best case, you learned a lot, know how the boat was repaired, and saved a couple thousand. Also developed confidence in doing fiberglass repair and you will look at your boat in a different view...like...what else can I fix. I've fixed a lot of little problems with my fiberglass after I fixed the hole in my hull.

I say "give it a try" as you have much more to gain then you have to loose.

A good right angle grinder is a very useful tool and they last for years. A gallon of vinylester resin is less than forty bucks and a yard or two of glass cloth might cost 15-20 dollars. The worst you can do can be undone in twenty minutes. I say go for it. Us ester resin , but first read the books, get the tools play with some scrap. Make an apple pie from fresh apples and a bag of flour and sugar if you want something to challange you. By comparason fiberglass repair is not so bad.

 

[Franklin]

a quart of resin - $17 with hardner x 4 ($68) Yes, you are going to need 4 of them as part of it will be used to mix with the gelcoat and you have a lot to glass once you've grided out everything to a 12 to 1 ratio.

Considering you have to grid out that whole crack all the way through and then belvle out 12 to 1 ratio, you are going to need quite a bit of fiberglass....at least 4 packages of 30"x30" and they go for about $18 a piece, so 4x18 = $72.

You are going to need at least a quart of gelcoat and that's $75 including hasmat shipping.

Now add on the sanding paper, 20 small cheap paint brushes, 10 mixing bowls, 30 mixing sticks, griding equipment, thinner and cleanup stuff, drop cloths, gloves (4 packs a $2 each but worth a lot more for this job), sprayers, mixing stuff to make gelcoat like putty.... as you can see, lots of little things that add up.

Ok...not $200, but maybe closer to $300. BUT...you will never worry about damaging the glass again because you know you can fix it.

 

[Ross]

A good source for resin and wax and other supplies you will need.
http://www.uscomposites.com/polyesters.html

 

[BrianW]

Thank you all very much! I'll probably just sit next to my boat, drink a beer (or two) and scratch my head for a while and decide whether my next move is to go order the Don Casey book or to call my insurance agent. I think if it were a hole on a fairly flat surface, the decision to tackle it myself would be a no-brainer. Thanks again. BrianW

 

[Ross]

Brian , you will be a lot happier with the Alan Vaitsis book. He ran his own yard for forty years. And wrote about 6 books during that time, he knows the subject first hand by experience on and in hundreds of boats.

 

[Maine Sail]

Some data..

Some data I gathered over the years from various sources. There are no specific numbers on the esters because humidity, temp and MEKP concentration can change the actual bond strengths slightly..

Polyester Primary bond strength = 350 to about 450 PSI

Vinylester primary bond strength = 475 to about 550 PSI

Polyester secondary bond (repair work) = 150 to 300 PSI (this range depends on the age of the substrate being adhered to.)

Epoxy bond strength = 1500 PSI and up usually in the 2000 PSI range primary or secondary..

Just for comparison sake.

3M 5200 adheres with bond strengths from 500 to over 700 PSI

 

[BrianW]

Ross, OK on the change to the Alan Vaitsis book, but I refuse to change my position on the beer(s)! Maine, thanks for the technical specs. BrianW

 

[Ross]

Some data I gathered over the years from various sources. There are no specific numbers on the esters because humidity, temp and MEKP concentration can change the actual bond strengths slightly..

Polyester Primary bond strength = 350 to about 450 PSI

Vinylester primary bond strength = 475 to about 550 PSI

Polyester secondary bond (repair work) = 150 to 300 PSI (this range depends on the age of the substrate being adhered to.)

Epoxy bond strength = 1500 PSI and up usually in the 2000 PSI range primary or secondary..

Just for comparison sake.

3M 5200 adheres with bond strengths from 500 to over 700 PSI

Minumum force required to pull a 12 inch polyester/fiberglass patch off a boat: 8.5 tons.
Epxoy patch: 85 tons.
Average weight of boat 4.5 tons
Probably any of them is strong enough.

 

[Warren Milberg]

"Hello, BoatUS Insurance? You'll never guess what happened to my boat today...." Seriously, this is one reason we have boat insurance. Call your agent, get it appraised, get a pro to restore your boat to its original condition. Good luck with this.

Another suggestion: if you live far enough away from where your boat is slipped so that you can't get there relatively quickly in the face of oncoming bad weather, it may be a good idea to always tie it up with double lines, fenders deployed, and always prepared for a blow. The time it takes to undo these preps and go sailing is minimal compared to the inconvenience of repair time, cost, and effort.

 

[Franklin]

Well said Warren. Because I live aboard I see the work dock lines get on a daily bases and I scratch my head as to what owners tie their boat up with. Sometimes I'll put on of my spares on a boat with a note asking them to return it once they've gotten proper lines because I hate to see broken boats.

 

[Ross]

The least costly insurance is money spent on proper lines and ground tackle. If we were to apply the cost of insurance to the security of our boats and to careful attention to our methods would we come out ahead? I haven't been able to get hull insurance for my boat because of its age so I do all that I can to anticipate how and where something might go wrong and make certain it doesn't.