Keel patch?

[lvl]

After my first day of sanding my transom skin I found a shotty repair. I took the grinder to it and it was gray in color and looked like it was leaking. As you can se in the pictures i still need to grind out more due to the cracks in the resin.

First way I thought I could patch it was to tape cardboard to the bottom and pour in peanutbutter mix. ( Like the one opps used on his hull extension project ) My concern with this is how well will just a resin mix hold up? Will it be to brittle?

My next thought was start with some CSM on the inside and build it up from the outside using alternating layers of CSM and roving. My concern with this is how to keep the angle on the bottom of the boat. How many layers could I put in at a time?

Thanks in advance
From the inside looking down the transom

Looking at the back of transom

Lookin up through the hole from the outside

 

[Bondo]

Re: Keel patch?

My concern with this is how to keep the angle on the bottom of the boat. How many layers could I put in at a time?

Ayuh,... Sand it to a Straight line along the keel/ bottom to a Straight line down the transom....

Use Glass, not putty...

 

[Greg Mrozinski]

Re: Keel patch?

Lv,

You definitely need to fully glass that hole inside and out. I wouldn't worry too much about maintaining the final shape. That area needs to be ground out more on the outside to create a gradual easing of the edge. You can start with a layer of CSM on the inside to build against. Then add layers to the outside to build to the final layer. Then add a few layers to the inside. I recommend something along the lines of 1708 for the repair. When everything is built out, grind smooth and flush.

 

[lvl]

Re: Keel patch?

Thanks for the input and I'll post pics as this will be the first thing i need to repair before moving on to the transom.

 

[lvl]

Re: Keel patch?

Got my 1708 and two diffrent weight csm in the mail this week. I plan on sanding and starting the patch this weekend.

Any suggestions on how many layers of 1708 should go on in one lay up? They will be pretty small peices.

Should I let the layer of csm on the inside fully cure before starting to layer the 1708 from the outside?

Sorry for all the question but this will be my first shot at fiberglassing. BTW I'm using polyester resin.

Thanks

 

[Yacht Dr.]

Re: Keel patch?

Hello lvl..

4-5 layers of 1708 at a time..as soon as the layup starts to cool down put some more on before it completly hardens.

Let the inside mat gel up..stiffin..not completely cure then layup the outside.

YD.

 

[lvl]

Re: Keel patch?

Went out today with the intention of sanding the keel to a more gradual angle.Ended up sanding and removing all the wood from the billage area.

So I found three wood strips on each side about 2 inches wide and 1/2 inch thick laminated in the floor. They were totaly soaking wet and rotted. Dont know how they got like that is the problem. I think I remeber hearing somewhere if a lamination had an air pocket in it, then it would build condensation that would turn into like an alchol type liquid that would eat the fiberglass away from the inside. Is that pretty much right? The laminations had all kinds of air pockets and dead glass in there that could of caused the rot I'm thinking. What do you guys think?

My next question is do I need to replace the wood with wood? Could I just layer biaxial cloth in there to build it back up to where it was? Now that I took all the wood and glass out I can see a light spot right down the center of the keel in the back should I be worried? I am thinking that is because I took out so much wood and glass.

Let me know if more pics would help I could post if you guys need.

Thx
Sorry for such a long post

 

[lvl]

Re: Keel patch?

Here are some pics to go with the above post.


2 hours of grinding

Looking at the bulkhead in front of the billage area

The yellow arrow is the hole I drilled the other hole was there. The floor on the inside of the bulkhead is lower than the billage area floor. How will the water ever get out if the floor is lower behinde the bulkhead?

 

[lvl]

Re: Keel patch?

Anybody?

 

[Yacht Dr.]

Re: Keel patch?

Hello lvl..

When you "drilled" how was that wood coming out ? .. wet.. blecky..

Looks like your transom is starting to fail ( wet ).

YD.

 

[lvl]

Re: Keel patch?

The transom core has already been removed. The pic with the yellow arrow is the what I thought was a bulkhead at the front of the bilge area. It turned out I pulled up the deck and its a stringer running from port to starboard. The good news is my boat has no wood in the stringers its just fiberglass.

The bigger question was do I need to replace the 6 strips of 1/2 inch by 2 inch strips that were laminated ( very poorly ) in the bilge floor? Would just laying biaxial cloth be enough. I did plan on putting back as much cloth as it takes to get back to the original thickness.

If i do need to replace the wood could I just put two bigger pieces. One on the port and one on the starboard side bilge floor.

Thx

 

[Greg Mrozinski]

Re: Keel patch?

LV,

Nice work so far.

From the looks of it you may not have to replace that wood at the base of the abeam stringer. Not sure why it was even put in but my guess would be that it was some sort of attachment to set the original in place. Once the stringer was laid and glassed it served its purpose.

I suggest removing the wood completely, grinding out that stringer hull joint and retabbing abeam with 1708. That should do it.

 

[lvl]

Re: Keel patch?

Um... I'm not quite sure what an abeam stringer is. The wood that was removed was from the floor in the bilge area. There was not a stringer in that area.

Correct me if I am wrong but is the bilge area the spot on the inside of the transom that would fill with water that gets in the boat?

Would it need to be put back in this case?

 

[lvl]

Re: Keel patch?

Realy could use some help on this. Not sure if I need to put back in wood strips in this hull floor or would roving do it? I would hate to put in roving or mat to find out it will not be good enough.

Thx

 

[Yacht Dr.]

Re: Keel patch?

Hello lvl..

I am suprised nobody chimed in here..

You have a unique resto here...

You have gutted the stringers and the floor. What Was there does not mean you cant change it.

I would layout your stringers where they were ( not one in the middle of the keel ). You really should support the cockpit floor with something side to side attached to your hull.

It almost looks like there has been replacement of somekind in the past..

Just lay your ply stringers dry..your supports..and then start glassing it together starting with your stringers..then your supports for the floor ( mark on the sides where your supports are so you can screw the deck down ).

Of coarse leave the keel open for water flow to your drain ( you may have to relocate your drain in your transom.. )

Please use mat first before woving ( or even 1708 ).

YD.

 

[lvl]

Re: Keel patch?

Thx for the replies guys but I think I am having trouble putting my situation into words. So I am going to try with pics.:redface:

This is the best pic I have of the area in question before I took the grinder to it.

Imagine the diffrent colors being individual pieces of 1/2" by 2" plywood strips that were butted together covered by glass

This is the area after I ground out the glass and wood and cut back the deck the bottom of the pic is the outside transom skin.

Again the questions are:
Do you think the plywood needs to be put back in?
Will layers of 1708 be good enough?
If wood needs to go back in could I put back two bigger pieces instead of 8 strips?
Is the area in question called a bilge?

Thx

 

[Greg Mrozinski]

Re: Keel patch?

LV,

Sorry for not getting back to you sooner.

Abeam means running port to starboard or width wise across the boat.

The hole in the forward bulkhead is a drain hole allowing water to flow back into the bildge area from the forward compartments (called a limber hole).

The area you ground out is part of the bildge area and water will most likely collect in this area. I don't know if you need additional pieces of ply in this area or not. I imagine that it was additional support for the deck (floor). If the fiberglass stringers are solid enough and supportive, then just make sure the replacement deck (floor) is thick enough to span that distance with providing good support. I suggest that you create a smaller bildge area in the stern by running a piece of ply across between the two stringers about 12-15" forward of the transom. Put a hole in the bottom of this piece so water will drain from the forward compartment into this smaller area and then install a bidge pump in there. The deck should not cover this area so that you can access the bildge if need be.

1708 will be plenty for this area.