To fix or not to fix

[Keith Knecht]

A friend of mine has a 222 Walk Around that had some gouges in it when he bought it.  During an extreem low tide he added a little to, or should I say, removed a little more from the existing "scratches" along the keel.  There is some debate going on as to whether this is cosmetic damage or if it should be repaired to preven water intrusion. Hope the pictures are good enough to see the detail.  What do you think?  

[Joey]

First, I am not a boat builder, so I will defer to the experts here.  But I have been around this stuff most of my life.  The Holiday Inn Express I was in last night helped too.

I would visually checked the area for cracks. If there are none, remove the bottom paint around the damage, rough it up with 80-grit sandpaper, and fill the gouge with West System Epoxy. However, if you are at all unsure of the integrity of the core where the damage is, you have two options:

1) Use a moisture meter
2) Drill a small hole to let out any water. (you are going to epoxy the area anyway)

After mixing the epoxy, add enough colloidal silica thickener to make the consistency like peanut butter, then trowel it on to to fill the gouges in the boat’s bottom, using a piece of wax paper to keep it from sagging, and creating just enough surface tension to hold the epoxy in place until it cured.

Since the repair was below the waterline, a simple coat of bottom paint would complete the repair.  or if you wish, polyester gelcoat to match his boat’s gelcoat color would complete the repair.

[slvrlng]

Even easier,  Sand as per Joey and check if the glass fiber is exposed. If it is exposed coat with some poly resin. Let cure. Then another coat. Then
go to Wally World and get some Bondo-glass. Mix as directions state and fill hole just slightly below the edge of missing gel. Wipe off any excess around the gouge with acetone within 10 minutes of applying ( this makes it melt off the gel very quickly, if you wait too long it locks down and is harder to remove). Sand with the 80 grit again to level it out and rough up the surface. Then coat with your gelcoat of choice. Make sure it is finishing gel with the wax in it. If there is a true crack in the fibers, that is more than just some missing gel, follow joeys directions. I have used this method on my 222 several times and so far has worked really well. The hardest part foe me is matching my color of gel, Ivory Mist, what a pain!

[Georgie]

Keith - everything I've ever been told or read indicates that fiberglass with exposed glass fibers WILL absorb water and is not waterproof.  That said, a structurally reinforced area like the keel is probably laid with several separate layers of glass at the factory such that the porous glass fibers themselves terminate within the layup and do not connect, and the amount of water that is transported internally is minimal at most.  Regardless, the glass is not "waterproof" and probably should be resealed (of course, as I say this I have a 14 inch section of my keel that's been exposed for two years and bothers me every time I look at it).

Regarding repairs, I RARELY post contrarian opinions and truly hate doing so , but I gotta disagree a little guys.  I used to do this type of repair constantly when maintaining the FJ's (racing dinghys) at University of Rhode Island's sailing center.  Unless my eyes are deceiving me, those photos show nothing more than classic gelcoat "chafing" or chipping along the keel.  The glass there is usually extremely strong, so unless there's a major structural issue I don't see, I don't think you don't want to add epoxy (which may be incompatible with future gelcoat or glass repairs) to the mix on a white hull that doesn't even seem to have bottom paint on it.  My personal (simplified) plan of action would be: 1) grind out any loosened glass fibers with a dremel and coarse sanding or grinding bit.  Don't take any more glass out than necessary.  2) Fill any DEEP gouges with a poly-resin based glass-fiber infused product available at most glass shops.  3) After sanding any filled gouges in the glass , tape off and prep the repair area w/80 grit paper, wipe well with acetone, and patch the gel with thickened matching gel (cabosil has worked well for me as a thickener) to a height greater than all of the surrounding finish. 4) Sand progressively finer until satisfied (I have no idea if the waxed gel is necessary if you'll be sanding anyway, but it probably couldn't hurt - especially if it keeps the sandpaper from gumming up   :evil: ).  

Suffice it to say I believe in keeping with the original chemicals/materials unless forced to do otherwise.

Definitely make sure it's dry first like Joey mentioned.

Lewis - is bondo-glass poly-based and does it have comparable hardness?  If so, then I apologize completely for being "contrarian" as I realized after I completed this post      that you weren't talking about "bondo" per-say, but rather a nearly identical product and process to what I was proposing.  

If I am wrong and there ARE structural issues, then please void my response and listen to the pro's!  

[gran398]

Georgie, you're on the money regarding incompatibility between poly/vinylester and epoxy.

Lew is referring to the two-part product body shop folks around here call "kitty hair" .It is like Bondo but infused with thin fiberglass strands for strength. It is polyester resin based.

[Joey]

First, please... I am not disputing anyone's statements, I am attempting to learn something, so please don't take offense to my reply.

I also found this.. that talks about the different types of resins.

http://www.masepoxies.com/How_To/About_ ... sters.html

I get it, most production fiberglass boats are made with polyester resin. I have also found epoxy is a wonderful material for repairing polyester fiberglass boats. One reason for this is the ability of epoxy to form a stronger mechanical bond to a damaged laminate than polyester resin. Epoxy also provides a better moisture barrier than polyester resin.  I even had multiple instances of success getting polyester gel coat to adhere to a properly prepared epoxy repair (even though lot's of people say no).


Like I said in my post, I am not an expert nor a boat builder.  So I need some help here, please as I ask out of ignorace.  Based on the differences between the resins, why would you use a polyester resin on the keel?  It seems like the weaker candidate.

[Capt. Bob]

I feel it boils down to form and function.
I can't argue the "gel will/will not adhere to epoxy theme" due to inexperience.
My keel has the same wear except that it isn't visible like Keith's friend's hull so...

Out of site, out of mind and following the "epoxy is stronger" thought, I repaired mine with same. If Keith's friend wishes to return the hull to all it's past glory then from what I've read, George and Lew's approach is likely to yield the better chance, though as Lew stated, matching 30+ year old gel coat ain't easy.

If the wear is likely to reoccur, I think you have a strong point in using a repair that would add extra protection in that area, again why I used epoxy on my section of keel bottom and the repair is not visible. Six of one and a half dozen of another. If indeed the gel would adhere to the epoxy, then that would be the best of both in form and function.

[slvrlng]

Yes the Bondo-glass is ploy based. Yes it does use a red cream hardener just like "bondo". No, Scott it is not like kitty hair. It has a much finer grain and is much easier to sand than either kitty hair or bondo hair which both have fairly long strands in them. the reason I mention the Bondo-glass it is readily available at Wally world and is about 13 bucks for a quart. It is also waterproof due to all the short strands of glass in it. The only issue i have had is the fact that when mixed it turns a really nasty brown color, thus the need to get the excess off. It gets hard enough that you can drill and tap it for screws. It is also very quick set, you really have to get it on there and worked quick!

[gran398]

This stuff I'm talking about is green, it has coarse hairs in it. It probably doesn't sand very well.

So Lew, I was mistaken in my take of the product you describe, and hope there are no hard feelings regarding my misconception of your product or potential liability on your end for recommending such product :alien:

A vinyl keel guard can be installed once the repair is completed if so desired.

[Joey]

If indeed the gel would adhere to the epoxy, then that would be the best of both in form and function.

According to this, gel will adhere to epoxy.

http://www.westsystem.com/ss/assets/Upl ... yester.pdf

[slvrlng]

I tried to do this on some areas when I rebuilt my tank hatch. In places it took the gel a really long time to kick and in others it did quickly. This is why I switched to the Bondo-glass for any spots I will be putting gel on. It could have been the reaction from the amines in the epoxy hardener as they state. Not sure just got tired of all the waiting for it to kick when I can do a bunch of places with the other all in one day.

[Keith Knecht]

Thanks guys for all the advice! It's greatly appreciated.

[seabob4]

Marine-Tex and off you go...