200XF Tank replacement - Soft deck plate

[inletcomputerworks]

I'm replacing the tank on my 1981 Aquasport 200XF. I got the tank out relatively easy however, once I got the cover off I've noticed the deck plate covering the tank was pretty... 'spongy'? It feels pretty soft when walking on the nonskid.

I really don't want to grind out the old plywood and glass in new marine plywood. This boat is pretty old and I don't forsee a multidecade relationship here.

I'm getting a new aluminum tank welded up but I want a way to stiffen this deck plate.

I was thinking about running 27" 1 1/4" x 1/8" aluminum angle iron across the whole coffin and having the deck plate rest on that. It would have 4 of these brackets installed the width of the coffin. It would also have on each side of the coffin a drilled L bracket that is screwed into the coffin. The angled aluminum would be bolted onto the L bracket with recessed aluminum bolts. All of this would be in a perfect world perfectly aligned and flush.

Does anyone see any reason why that wouldn't work? Also, how do I attach the bracket to the coffin wall? Can I use aluminum 2" lag screws? You think that would be too soft of metal? I don't want to mix stainless screws with my aluminum brackets correct? Also, my coffin goes from 27" width down to 20" width.. So it tapers down.. When fabricating these brackets I'd have to take that into account.

[mshugg]

What do you plan on screwing the angle iron too.  You’ll be putting a lot of stress on those lag screws, and if the core is shot, 1 brace may not be enough. 

Truth in advertising, I’m a do it right, do it once kind of guy, but it seems to me that replacing the core isn’t really a big deal.  With an oscillating multi tool Cutting the core out and cleaning The underside of the lid is less than a day.  It would take a second day to cut and glass in the core, and a third day to slap some bilge paint on the underside.  depending on your glass experience, that  may be a tad optimistic, but you’re sPending hundreds of dollars on the new tank.

A second option that would be even easier would be to inject penetrating epoxy into the rotted core.  There are lots of examples of this Deck Repair on this website.  Hopefully someone with better knowledge on CAS can post some links to those. 

Whichever method you choose, repairing the core will be superior to a jury rigged brace, and not much more difficult.

[captaincahill8]

mshugg is correct. If you even just cut the core out dropped in some plywood and glasses it up it will do a much better job in giving you a solid deck. Even if you are only going to use a non marine grade plywood with polyester resin it’ll provide more support.

If it’s the cutting and glassing that is spooky for you take a few hours and watch BoatWorksToday on YouTube. He has some recoring videos and working with different resins  and glass.

Best of luck. And we are here for help, I wouldn’t have been able to rebuild my boat with out that channel.

[inletcomputerworks]

I have replaced plates before on hatches, but it was a much smaller job.

I do have another question... Once I pulled the tank and cut the fill and vent line, I see they went back to aluminum nipples.
If I wanted to replace the hoses on the other end of that nipple, how would I access them? I see one inspection port on the starboard side, kind of near the gas fill but closer to the vent. No clear line of access to hook up the new fill line. This is a 1981 Aquasport 200XF. It appears the gas & vent line run under a hatch then up the gunwales to their respective ports.

Any suggestions?

[inletcomputerworks]

My other thought was, I bought a 3 foot house cleaner, ran it up and down the gas fill and up the nipple. Cleaned it really good and got all the gunk out of it. When I flush the line with water, it comes out clear with no particulates. Perhaps I can keep the existing line?

[mshugg]

Getting that fuel fill out is a huge pain.  My deck was completely removed and still it took way more time and energy than I wanted to spend.  There are some tank replacements, both as stand alones and complete rebuilds in threads on CAS.  Maybe Capt Bob, or someone else who really knows their way around these pages can point you in the right spdirection.

If you decide to leave it, be sure there is no sign of fuel leakage from the fill.  The foam around my fill was saturated with gasoline, so there was no way that I was leaving any part of the fuel system in place.

[Capt. Bob]

MS is correct. It ain't easy so....

Here's an idea what you're up against.
https://classicaquasport.com/smf/index.php?topic=3850.msg23933#msg23933

https://classicaquasport.com/smf/index.php?topic=14157.msg140864#msg140864

One thought, link to pics is broken
https://classicaquasport.com/smf/index.php?topic=8477.msg69668#msg69668

https://classicaquasport.com/smf/index.php?topic=9956.msg87432#msg87432

https://classicaquasport.com/smf/index.php?topic=6789.msg48839#msg48839

Hopefully these will give you an idea of what to expect and so thought on approaching the removal.

Good luck.

[inletcomputerworks]

So upon further inspection this tank has definitely been changed before. I can see the foam around the fill and vent has been broken apart. The vent has been replaced with aluminum oddly enough. The fill house is also not in foam. However, I don't see how they attached the aluminum fill nipple... Perhaps they attached the nipple to the hose then ran it through the coffin, to the gunwales and up?  Very odd... How do I determine if the fill hose is shot?
I put my phone in there with the light on and it looks okay I suppose?

[inletcomputerworks]

Just want to follow up on this, my friend suggested I put two layers of 1708 down on the panel with epoxy. Worked like a charm, it's a lot stiffer now.

[RickK]

Congrats.