Fiberglass patch bilge pump area

[Monterey276]

Looking for some advice on patching this correctly.

I discovered a crack in the gelcoat where my bilge pumps/switches mount. I initially was just going to grind out the crack and put some marine tex in there to fill it. After I opened it up though, I discovered a lot of water underneath there, it was squirting up when I’d push down next to it. The boat was built with a piece of wood, I think it’s probably 1x4, in this spot. I assume it’s designed that way specifically for the pumps and switches. Anyway, I cut out an area in the center and have had a fan blowing directly on it for a few days. I’ve grinded down the surrounding area just enough to get the gelcoat off.

Did I prep this correctly? I have CSM, some woven fabric, and polyester resin to make the patch. Not sure how many layers yet but I plan to just make it the same thickness as before.

Any suggestions or tips appreciated

 

[Scott Danforth]

that piece of wood will still be wet a year from now. dig it out and replace it.

 

[Monterey276]

that piece of wood will still be wet a year from now. dig it out and replace it.

Yup, it’s gone. There was water underneath there so I cut it out (mostly). I guess I just grind everything back further right. Cut a new piece of plywood and use some thickened resin to bond it in place and then glass over it?? Should I grind back the gel coat on the insides of stringers to tab it in further back?

 

[todhunter]

Grind back a big enough spot to glass, coat wood (I recommend using mahogany / sapele) in resin and let dry, PB in place, cover with a layer of glass, gelcoat, and you're done. Don't go crazy with tabbing. It doesn't need to carry a load.

 

[Monterey276]

Grind back a big enough spot to glass, coat wood (I recommend using mahogany / sapele) in resin and let dry, PB in place, cover with a layer of glass, gelcoat, and you're done. Don't go crazy with tabbing. It doesn't need to carry a load.

Thanks a bunch, this is very helpful. Getting after this today

 

[airshot]

I would take a good look at the other wood in your hull. If one piece was rotted, there will be more ! That wood is the skeleton of your hull, without that skeleton, your hull will fold up. Better to be safe than sorry......

 

[Monterey276]

Thanks a bunch, this is very helpful. Getting after this today

Here’s what I got now. I was going to wrap this piece of plywood in resin and CSM first and let that set up. Then mix up some thickened resin to bond it in place and do the layup right afterwards. I have both woven and CSM and using polyester resin. Then do gelcoat before it completely cures right? Give it a couple hours to set up? One thing I noticed was the gelcoat was really thick down here. Do I just wait for it to dry and then do a couple more coats of gelcoat?

 

[Monterey276]

I would take a good look at the other wood in your hull. If one piece was rotted, there will be more ! That wood is the skeleton of your hull, without that skeleton, your hull will fold up. Better to be safe than sorry......

Yea I’m well aware. This project all started because of a leak at the transom assembly. Those repairs are done and I’m going to bilge paint down here before putting it all back together

 

[todhunter]

I really would recommend getting a piece of rot-resistant wood like sapele to use instead of pine plywood. Your local hardwood supplier should have some (a piece that small will only cost a few dollars), and it won't rot nearly as quickly as that pine will.

Just coat it in laminating resin, letting it dry between coats - no need to wrap it in glass. 2 coats should do it, as long as there are no more dry spots after the resin cures. Mix a batch of PB, and PB the wood in place. Fillet with the PB around the edges, then while still wet, lay some glass over it with laminating resin. After that cures, 2-3 rounds of gelcoat rolled on should be plenty.

 

[stresspoint]

paint some resin or gel coat over that ground back area , get some 5200 and bond the pump strainer strait on the floor, clip the new pump on and go boating ,
the reason for the pump being on the log of wood is for lazy people that don't keep there bilge free of leaves and crud.

 

[Monterey276]

Turned out pretty good I think. Find out for sure tomorrow when I go back to see how it cured

 

[1985 Century Mustang]

Turned out pretty good I think. Find out for sure tomorrow when I go back to see how it cured

Good job