96 - 208 Soft spot over gas tank

[Kevin p]

Hi all,
I have a 96 Grady white adventure and the cover over the gas tank is spongy, not sure how to proceed in fixing it, I do not like stepping on it and try to avoid it making the boat seem a lot smaller, so it needs to be fixed without breaking the bank. Anyone have their cover fixed and how did you do it? I love the boat other than that but not sure how to proceed having it fixed. (Supports under the cover or having it) reglassed,) Thanks in advance for suggestions.

 

[seasick]

Is the tank panel removable ( screwed and caulked in place). Some years the deck was one piece and to remove the tank, the deck had to be cut.
Having a removable tank lid makes the job easier. In all likelihood the coring is rotten. If the outside of the lid is not creaked, it can be rescored and reused. There are threads on deck repairing
On a not to positive note, if the coring is rotten there may be additional issues with the bulkheads and stringers. Only an inspection can tell for sure. To do a complete inspection, the tank should be removed and then you have to decide if the tank should be replaced. It is 26 years old. Even if the tank is not replaced, if you pull the lid, you may want to replace the fill and vent hoses
The cost to do these tasks depends a lot on how much of the tasks you feel you have the skills to tackle.

 

[Hookup1]

I'm not familiar with that model. Some pictures of the deck would help. As Seasick said - there are lots of posts on this topic - it's a common problem with the older Grady's. I did my 1997 Islander a few years back and documented it here.

 

[DennisG01]

Kevin, since you said "panel", can we assume it is a removable panel?

But, as others have said, there are plenty of posts on this topic - both here and on the web, in general. It's a pretty straight forward repair... cut the bottom skin off, get rid of all the old wood, use epoxy or polyester to glue the new core in place and either euse the cutoff piece of glass or just lay a new layer of 1708 over it. Be sure to do this on a perfectly flat work surface. It's also best to cut the wood (if that's your choice of core) into some smaller pieces to avoid air pockets between the top glass layer and the core.

Cores... regular plywood, marine plywood, Coosa (and similar)... I actually used (as an experiment, so I don't recommend it) foamboard insulation from HD... it's been about 6 years now, though!

 

[Willy-C]

I recored my ‘92 Grady tank cover a few years ago with plywood blocks, mat and epoxy. It came out rock solid. Cleaning out the cover I found wood right up to the edge, water intrusion followed the screw holes in the original cover, so I tapered the edges and around the inspection holes and filled those areas with epoxy and cabosil so no screws into the wood now.

 

[Kevin p]

I recored my ‘92 Grady tank cover a few years ago with plywood blocks, mat and epoxy. It came out rock solid. Cleaning out the cover I found wood right up to the edge, water intrusion followed the screw holes in the original cover, so I tapered the edges and around the inspection holes and filled those areas with epoxy and cabosil so no screws into the wood now.

Thanks for all the replies I pulled the cover yesterday and definitely looks like it needs to be recored . There was water dripping out of it but dry around the tank and everywhere else.I do not have space to work on this myself or I would attempt it.I need to find someone in the Boston area to do this. Any suggestions would be appreciated. I found one local but won't even look at it until next spring.other than that panel the rest of the boat is solid so I would love to get this done.any ideas on pricing for a repair like this?
Thanks

 

[Hookup1]

I would use epoxy not polyester for the repair. I used one-piece Coosa board composite. Marine plywood squares are ok too but it should be saturated with resin. I vacuum bagged the Coosa board in to compress everything together and get the air out. Support was added last and glassed in. All holes are oversize drilled fill them with thickened epoxy and re-drill to correct side. This is complete overkill but the hatch will outlast the boat.

 

[seasick]

Hookup mentioned an important issue; If the back of the tank panel is not dead flat, you will have bonding issues if you use a single piece of wood. Since composites like Coosa can flex. Using a vacuum bag puts a lot of uniform pressure on the Coosa helping it form to the lid surface. . If using plywood, you will need to cut smaller pieces to fill the inside of the panel.
I am not sure if the two ribs on the underside of the lid are sized to hold the tank. They may be there only for rigidity but in either case make sure you know there dimensions, especially there height before you chip out the old coring if you plan to do that yourself.

 

[DennisG01]

Polyester is a perfectly fine choice for this repair. It's MORE than strong enough so the extra strength of the epoxy isn't a "need". Boats are built out of polyester. However, personally, I would use epoxy if I was doing it indoors due to much less smell. It's also a little easier to work with - especially if you use a "system" like Hawk or West Systems. But poly is much less expensive. In the end... either one will work just fine.

 

[Hookup1]

Polyester is a perfectly fine choice for this repair. It's MORE than strong enough so the extra strength of the epoxy isn't a "need". Boats are built out of polyester. However, personally, I would use epoxy if I was doing it indoors due to much less smell. It's also a little easier to work with - especially if you use a "system" like Hawk or West Systems. But poly is much less expensive. In the end... either one will work just fine.

DennisG01 - I respectfully disagree on polyester for a repair. Polyester sticks well to "green" polyester when laying a hull up (chemical bond). For repairs epoxy "sticks" well to cured polyester (mechanical bond). It doesn't smell, easier to work with (pot life) but is more expensive. You wouldn't want to build a boat with epoxy but for repairs it is the right choice.

 

[DennisG01]

DennisG01 - I respectfully disagree on polyester for a repair. Polyester sticks well to "green" polyester when laying a hull up (chemical bond). For repairs epoxy "sticks" well to cured polyester (mechanical bond). It doesn't smell, easier to work with (pot life) but is more expensive. You wouldn't want to build a boat with epoxy but for repairs it is the right choice.

No worries, Hook - all good!

Poly does, however, work extremely well for repairs. Most yards and many pros will use poly - especially places that do lots of this work. By far, poly is the most widely used product in the industry for repairs. I use both - probably epoxy moreso than poly - but that's more for the ease of mixing factor and smell factor.

 

[SkunkBoat]

https://www.greatgrady.com/threads/deck-hatch-re-core-265.32638/

As boat projects go, this is a good DIY project. All of the ugly is hidden underneath...
The worst part is the grinding clean.

Finding really good plywood isn't easy anymore. Ideally you want "marine grade" douglas fir exterior AB. It has more layers and fewer eyes and gaps.
I had to settle for the best pieces of exterior AC pine that I could find. (that might bite me in 10 years) Don't use pressure treated plywood.

Coosa is certainly a way to go.

This project uses a LOT of resin. Polyester will save you $100s but epoxy is easier. You have to make big batches and get it poured out before it kicks in your bucket.

 

[DennisG01]

https://www.greatgrady.com/threads/deck-hatch-re-core-265.32638/

As boat projects go, this is a good DIY project. All of the ugly is hidden underneath...
The worst part is the grinding clean.

Finding really good plywood isn't easy anymore. Ideally you want "marine grade" douglas fir exterior AB. It has more layers and fewer eyes and gaps.
I had to settle for the best pieces of exterior AC pine that I could find. (that might bite me in 10 years) Don't use pressure treated plywood.

Coosa is certainly a way to go.

This project uses a LOT of resin. Polyester will save you $100s but epoxy is easier. You have to make big batches and get it poured out before it kicks in your bucket.

A 40 or 60 grit flapper works wonders, though, right! It looks like that's what you may have used. I found that to be the fastest. For the squares of wood that were still stubbornly hanging on, I used a combination of a shingle removal tool (long, heavy and has a "scraper" edge) and an oscillating tool to get under the wood.

 

[Fishtales]

I agree with hookup. I did the same. Glassed the coosa board in. Very easy to do. Don’t be intimidated.

 

[Fishtales]

Marlin 300 Aft Deck Cover Repair

I noticed a little brown water dripping from my small cockpit deck piece that resides under the rear seat (when seat folded down) when putting the boat away for the season. The deck piece has an access port as well as a vertical door that swings down to allow access to the aft bilge area. It is...

www.greatgrady.com

 

[Don Davis]

Well I have a dumb question as I know very little about fibreglass other than small repairs on my very small hand made lake boat. Why put any plywood in the tank lid at all? Why not just layer in lots of fibreglass glass and resin to make the thickness needed and forget the plywood altogether? Or is it a strength issue when walking on the lid?

 

[DennisG01]

Sure, you "could" do that, Don. The downside is that it would end up being very heavy and expensive. It would take a lot of glass and resin to do that. The advantage to using a core (plywood or whatever) is that you get strength without the weight or cost. The way the core does this is by separating the top and bottom layers of glass. It's the separation that is the key to the strength. That's why when wood gets too wet, the bond between the wood and glass is lost (and/or the bond between the layers of wood is lost). This allows movement/flex and it eventually gets worse and worse. A wood core is a tried and true method - issues arise when holes are drilled and not properly sealed or when mistakes are made in layup. Synthetic cores are, of course, better - but that comes at a $ cost.

 

[seasick]

IN addition to weight and cost, epoxy resin by itself is very brittle and does not take bending forces well. Your all epoxy filled deck lid will most likely crack under typical operations stresses.
This topic brings up another piece of advice when laminating and that is to not overdo the resin either when using glass fiber cloth or solid core material like plywood , Coosa and the like.
This is one area where more is not only not better but more cam be worse. Using too much resin can create thin layers of fragile epoxy than can stress crack and lead to structural failure. The layers need to be 'wet' but not soaked to the point where liquid resin will pool or form liquid spots