Cracks in Bilge area-21' SC

[megmac]

Hi,
I purchased this boat late last fall, first time boat owner. One of the projects I wanted to tackle this winter was replacement of the inspection covers and bilge cover on deck. The bilge area needed a good cleaning so I've been tackling that today. While cleaning I discovered two fairly good size cracks and need to know if it should be a concern. I don't want to install the bilge cover till Im certain no work is needed. Thanks in advance for advise.

 

[Brent]

The boat is constructed with piece of wood to serve as bilge pump platform and is gelcoat. Try opening up the cracks, let dry with a fan blowing directly at it. Check for soft spots by hand or use moisture meter. Fill back with gelcoat or white epoxy or fill with resin then gelcoat, or paint the area. It looks bad but isnt


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[warthog5]

First let me congratulate you with your pix posting. If everyone on the internet did it like you did it would save a LOT of time and understanding on questions.

The boat is constructed with piece of wood to serve as bilge pump platform and is gelcoat.

Maybe? Yes some boat they throw plywood in there but from what I've seen ,Parker uses a bunch of Coosa Board....The bilge in my boat had it in several places...It was a '95 model.

Coosa is a Composite panel ....It's Gray in color....It's a combination of plastic's and fiberglass. It does NOT rot.


This is a Perfect spot to learn about fiberglassing technices

 

[megmac]

First let me congratulate you with your pix posting. If everyone on the internet did it like you did it would save a LOT of time and understanding on questions.

The boat is constructed with piece of wood to serve as bilge pump platform and is gelcoat.

Maybe? Yes some boat they throw plywood in there but from what I've seen ,Parker uses a bunch of Coosa Board....The bilge in my boat had it in several places...It was a '95 model.

Coosa is a Composite panel ....It's Gray in color....It's a combination of plastic's and fiberglass. It does NOT rot.


This is a Perfect spot to learn about fiberglassing technices

Thanks Wartog5, I agree Photos always help. I do photography work on the side so guess its in my DNA...ha So, do you think I can just grind out a bit and backfill with maybe Marine-Tex? Thanks

 

[grouperjim]

It is what Brent said it is.......plywood glassed over on the top and edges (usually nothing on the bottom) and is used to secure pumps etc..

The wood retained some moisture and has swollen which is what you see there. Easiest thing to do is nothing. It is cosmetic.

If it were my boat I would grind the plywood out and replace it as it was done at the factory.

 

[warthog5]

So, do you think I can just grind out a bit and backfill with maybe Marine-Tex?

Yes....That would be easiest thing to do.


I have in the past.....But would not in your case here....... If it is Plywood there and I'm in to replace pumps and float switches....The discover the the wood is pretty rotted....I cut the old out and replace it....

I want you to note.....It's not a 90deg cut.....but a 45deg.....This allows the glass that goes over it to conform easily.

 

[megmac]

So, do you think I can just grind out a bit and backfill with maybe Marine-Tex?

Yes....That would be easiest thing to do.


I have in the past.....But would not in your case here....... If it is Plywood there and I'm in to replace pumps and float switches....The discover the the wood is pretty rotted....I cut the old out and replace it....

I want you to note.....It's not a 90deg cut.....but a 45deg.....This allows the glass that goes over it to conform easily.

Hi, yes I think it might have to be replaced. There is almost total separation on that top surface. I unscrewed the pump and flow lever and can lift the gel coat/fiberglass layer right up. Can only assume it's rotted bad. I was thinking maybe a piece of pvc plate or another material the epoxy/glass would stick to would be better. Are you saying the plate has a 45 degree chamfer to allow the fiberglass to lay down better like in the diagram I've provided? thanks

 

[warthog5]

Yes..... Just like your drawing.

For what it's worth.....I prefer the Rule A Matic Plus float switches....They have a cage around them. Keeps crap from getting stuck under them.

It's hard to get pieces of Coosa Board, unless you know someone that has it and is willing to sell you smaller pieces.
You can redo it with Plywood....But you take special precautions. I've done this quite a few times.

Cut the piece you want and bevel the edges out of plywood. Then lay your pump and float switch the way you want them. Mark the holes. Note you do want the float switch sideways as it is mounted now. Mounting it 90degs from the way it is and the hinge in the back will cause the pump to come on everytime you jump on the throttle....


Now drill thru the plywood with a larger bit at those marked holes. So lets say your going to screw the componets down with a #10 screw......Drill the holes a 1/2in or 5/8in.....Then tape one side and fill the holes with epoxy /Cabisol mix.......Cover the plywood with a layer or 2 of cloth . You want to be able to see thru it where you filled those holes. Now bond that back into the hull. But drill your pilot holes first for the pump and float switch.....This will isolate the plywood if a screw leaks and water can not get back to the wood.

I did this method in a LOT of places on my Parker....Especially in the hardtop where there is balsa core.


Then paint that block with Epoxy paint or Gellcoat it and it will look like factory and Never rot.

 

[Drop top chicken box]

Remove the plywood, clean up the area real well, grind back to virgin glass and 5200 a square of HDPE/ starboard down and fasten to that. Done for good, nothing to rot ever again, at least in that 1 sq/ft area.

Im replacing a fuel tank as we speak and learning a lot about the "really solidly built" Parkers. Fantastic boats dont get me wrong but they are far from immune to very basic issues. Its a shame that a few minutes worth of work wasnt done to prevent all the things im dealing with

Some of the very disconcerting things ive found are:

large almost continuous voids beneath all of the stringers and bulkheads, the wood was held in place by dabs of adhesive then glassed over, spaces between the adhesive completely hollow

Piping for fuel/ vent lines wasnt glued, this lead to water draining straight into the foam and filling the port compartment, weeting the wood, freeze thaw damage

Plywood under tank was not adequately glassed over so it absorbed water that was directed into the fuel tank compartment by the PVC fuel/ vent line

Pipe leading from cabin compartment to rear bilge compartment was very poorly sealed and allowed water up in to the bulkheads, there is not even a need for this pipe, both compartments are pumped anyway

Stringers and bulkheads were so poorly glassed on top that the glass only attached on the very top and lifted right off the sides almost everywhere ive opened

In my opinion the best thing these boats have going for them is the heavy construction, lots of roving and thick hulls, everything can be wet and freeze and thaw for years like a Grady and the important parts wont fail enough to cause complete failures.

 

[MadGar]

Remove the plywood, clean up the area real well, grind back to virgin glass and 5200 a square of HDPE/ starboard down and fasten to that. Done for good, nothing to rot ever again, at least in that 1 sq/ft area.

Im replacing a fuel tank as we speak and learning a lot about the "really solidly built" Parkers. Fantastic boats dont get me wrong but they are far from immune to very basic issues. Its a shame that a few minutes worth of work wasnt done to prevent all the things im dealing with

Some of the very disconcerting things ive found are:

large almost continuous voids beneath all of the stringers and bulkheads, the wood was held in place by dabs of adhesive then glassed over, spaces between the adhesive completely hollow

Piping for fuel/ vent lines wasnt glued, this lead to water draining straight into the foam and filling the port compartment, weeting the wood, freeze thaw damage

Plywood under tank was not adequately glassed over so it absorbed water that was directed into the fuel tank compartment by the PVC fuel/ vent line

Pipe leading from cabin compartment to rear bilge compartment was very poorly sealed and allowed water up in to the bulkheads, there is not even a need for this pipe, both compartments are pumped anyway

Stringers and bulkheads were so poorly glassed on top that the glass only attached on the very top and lifted right off the sides almost everywhere ive opened

In my opinion the best thing these boats have going for them is the heavy construction, lots of roving and thick hulls, everything can be wet and freeze and thaw for years like a Grady and the important parts wont fail enough to cause complete failures.

Chicken box, I followed your repairs and your work looks very thorough and well done. I just want to mention though that the voids between stringers, bulkheads and the hull are done on purpose. This ensures that all the loads from the hull are transmitted through the stringers evenly. If the stringer was resting on only a couple spots of the hull before you glassed them down you could end up with concentrations of the load = "hard spots". If there is just a small gap everywhere and the stinger touches many times all around,t hen you do not worry about it. Hard spots can cause serious problems and crack the gel coat. I probably am not explaining it very well but google stringer hard spots and you’ll see a ton of info on why you leave gaps between hull and stringer.

 

[warthog5]

large almost continuous voids beneath all of the stringers and bulkheads, the wood was held in place by dabs of adhesive then glassed over, spaces between the adhesive completely hollow

You should read some boat building books.....In particular "Hard spots" in a Hull.

 

[750line]

What I did with mine.

 

[pelagic2530]

Remove the plywood, clean up the area real well, grind back to virgin glass and 5200 a square of HDPE/ starboard down and fasten to that. Done for good, nothing to rot ever again, at least in that 1 sq/ft area.

For the record, 5200 isn’t going to bond well to Starboard/HDPE unless it’s flame treated; even then it’s not great. It’ll sort of work, but glass over Coosa is probably your better bet.