Boat hull @ keel is thin - need to thicken

[frozenokie]

I'm ready to do the stringers and floor of this hull when weather permits and I noticed while cleaning out the hull that I could actually see the sunlight through the keel of the hull!!! It's a strip about 2 ft. long and 3/4" wide, right beneath whwere the new stringer will be going. After closer observation, it obviously is from running the boat upon a sand shore, or any kind of shore for that matter, and has rubbed the underside a little thin.

My plan was to layer the inside of this area with fine hair fiberglass/resin and going a couple inches larger all around the area and going up to about 1/2" thick. I've used this fiberglass on other things up to 1" thick. When cured, it's as hard as a concrete. I really don't feel the need to do anything to the underside of the keel since I plan to apply a keelguard also. Would I be making a mistake in using the fine hair fiberglass/resin? Should I just use the fiberglass matte and resin?

Thanks for any advice!

 

[oops!]

Re: Boat hull @ keel is thin - need to thicken

im not sure what you mean by using "fine hair" glass....

glass comes in all types and thicknesses.....

if you go to hull extension in progress.....last page...ondarvr just did a fantastic post on glass and resin......it can help....

but your right....it needs fixing...

cheers
oops

 

[erikgreen]

Re: Boat hull @ keel is thin - need to thicken

Keep in mind that fiberglass resin properly applied is translucent.

I can see light through unpainted hull sections as much as an inch thick.. it's surprising how much light gets transmitted.

It won't hurt to reinforce the hull, but be aware it may not be needed. I'd think it unusual for a hull to be abraded away that much unless it was parked on the sand every day for several years.

I know this because I've had to grind out a hull with a power grinder and 36 grit disc... it's not easy

Erik

 

[SgtMaj]

Re: Boat hull @ keel is thin - need to thicken

Mine is the same way, yet it still has an in-tact original paint job. It kinda freaked me out when I first saw it, too. I'm planning to lay down a strip (maybe even two if I'm up for it) of woven roving over the inside of the keel, and a keel-guard over the outside as well... just to make absolutely sure it'll stand up to being bashed against that boulder I won't see comming.

I wouldn't think that it needs to be 1/2" thick though.... but as they say, whatever floats your boat... sorry, that was a bad pun. Seriously though, if you would feel better with a 1/2" layer, go for it... you'll have the strongest keel short of the Nimitz class carriers.

 

[oops!]

Re: Boat hull @ keel is thin - need to thicken

yeah ...hey ...wait a minit here.....

eric is right.......

frozen....what kind of boat do you have?.....

another test you can do....is try to flex the spot.......i mean...dont hit it with a hammer......but try to push on it with your hands......see if it flexes.

but the boat is yours...if you feel better glassing it...glass it.....

im going to add a full 28 oz cloth to the entire inner hull of mine...then glass the stringers in.....

 

[frozenokie]

Re: Boat hull @ keel is thin - need to thicken

Hey Oops - I have a 1979 18 ft. Laser Bass Boat with a racing style V-hull manufactured by Laser of Grapevine.

Fellas -
What homed me in on the suspected thin area is the light shining through it where it does not shine through anywhere else on the entire hull. When I say shine through, I mean excessively. Plus, it's exactly where the heavily rubbed area is on the keel. So, it really caught my attention. If all I need is a little roven and glass, then that's what I'll do. "Less work is better when it'll suffice" is what's in my book

Expecting more freezing rain/sleet for a few days Just tappin' my foot waiting to start. Looks like it'll be a few more days or weeks.

By the way, how do I post photos? I can post these to help explain what I'm seeing.

 

[frozenokie]

Re: Boat hull @ keel is thin - need to thicken

Hey Oops - Here are some photos of my boat until I can get another sunny day to get better ones. Before I can get some of the restore stuff, I have to downsize my files in order to post here. I'll be working on it.

 

[SgtMaj]

Re: Boat hull @ keel is thin - need to thicken

Fellas -
What homed me in on the suspected thin area is the light shining through it where it does not shine through anywhere else on the entire hull. When I say shine through, I mean excessively. Plus, it's exactly where the heavily rubbed area is on the keel. So, it really caught my attention. If all I need is a little roven and glass, then that's what I'll do. "Less work is better when it'll suffice" is what's in my book

AYUH, exactly like mine.

On mine though, they (or someone) added some roven woving everywhere but the keel already, and when they did, they used a translucent resin instead of a transparent one. So the light doesn't shine through the rest of it, but it shines through really well all down the keel. I'm like you though, I want to know it'll last through a few bashings with rocks or logs, etc. So yeah, go for reinforcing it. Sure it may not need it, but it's not going to hurt anything if you do, and it's not going to cost a whole lot. I would think 2-3 layers of roven woving would be more than sufficient on the inside though, especially if you're planning to put an external keel guard on.

 

[drewpster]

Re: Boat hull @ keel is thin - need to thicken

Beaching wear is very common, especially in runabouts, and I had to repair my tri-hull due to the same problem. In my case the gelcoat had worn through exposing the laminate underneath. I used a screwdriver and was able to push right through the keel at its sharpest point.
I had no easy access to the inside of the hull at the keel so I had to do the repair from the outside.
Basically I ground away all of the soft and loose glass. Let the area dry for a reasonable period of time. I then filled it with resin and fiberglass mat building the area from the inside out. (a slot about an 1"x10') I finished the keel by rough grinding the profile I wanted and covered the whole area with cloth. I then used a plastic trowel and spread gelcoat over the area and sanded it smooth. My guess is that the keel at the repair ended up about 3/8" thick. I have owned and used the boat for about 5 years without a problem.

 

[frozenokie]

Re: Boat hull @ keel is thin - need to thicken

Hey Oops - Here is that hull/keel photo. See the white in the middle. That's the thin area I'm talkin' about.

Frozenokie

 

[SgtMaj]

Re: Boat hull @ keel is thin - need to thicken

The white steak between the two big white pieces, right? Yeah, definately reinforce it. Like I say... it can't hurt to reinforce it.

 

[frozenokie]

Re: Boat hull @ keel is thin - need to thicken

Yep, that's it. And I'm with the rest of ya'll in reinforcing it. Consider it done, err almost done anyway.

Thanks to all for the replies. I'll be posting more photos of my progress and my problem areas. Hopefully I don't have many more problems like this one arise even though it's a small one

Keep in mind, I'm new to the pic posting. But I'll get the hang of it

 

[oops!]

Re: Boat hull @ keel is thin - need to thicken

as far as pic posting goes...it looked good on my puter...

and that is one slick lookin craft....does it come with a drag chute?

yup....reinforcement time.....no big deal.....

use the matt...roving...matt..roving sandwich method....

youll be done in a fwe hours after grinding......check the trread on minimum safety for grinding to see what you need...rough and scuff it good.

is it also rubbed fron the outside? is the glass visible?

if so ....i would fix that as well before adding the keelgaurd.

if you need help with that too....were here

cheers
oops

 

[weweber3]

Re: Boat hull @ keel is thin - need to thicken

I am in process of replacing all stringers in a late 60s Crestliner. I have read about the hull "hooking" if I take out all the stringers. Part of this process is to lay a layer (or 2) of glass down to thicken the bottom of the boat as well as up the sides.

So... how do I make sure the hull doesn't become damaged? Brace from the bottom? How about when I glass the bottom... can't really walk on either?

Thanks for the advice.

-Bill