Seeking advice on seemingly large hull/structural repair! Help please! 1979 Marquis Catalina.

[briangcc]

Not my first choice for flooring - have the same material out in our shop for assembly area dividers and it looks terrible to work with. A cheap alternative would be the rolls of indoor/outdoor carpet you can find at local home improvement stores.

Next option would be the cheapo faux teak (peel & stick) eva foam you can find on Amazon. Some here have used it with good results. I've used SeaDek on my swim platform. Pricey as all get out BUT still looks brand new since install in '18.

It's actually very easy to pull a boat off the trailer....when you get to that point and you are definitely not there as right now the trailer is helping the boat keep its shape.

Lower the tongue as low as you can. Block up the transom with cribbing (wood blocks), jacks, old tires, etc. Now raise the tongue as high as you can and repeat the support process with the bow. Now pull the trailer out from under the boat. You may have to stop and readjust the supports a few times to get the trailer out.

My vote would be once the interior structure is replaced and the hole in the side of the boat patched from the inside, to flip the boat over so you can attack the hole in the side of the boat from the outside. It'll be much easier to do the repair right side up working with gravity as opposed to trying to glass upside down.

 

[CATALINAWineMixer]

@briangcc you make it sound so easy with the removing of the trailer! I am beginning to regain some confidence with this as my biggest headache is to be grinding underneath the trailer so far. I couldn’t have imagined glassing from underneath, plus I have a gravel driveway so my creeper gets stuck a ton, even with a few scrap pieces of fabric material from work laid over the top of it..

We have thinner sheets of the fabric at work ~2-4mm that is much easier to work with.. I am not a fan of the carpet since it traps water and is usually pretty rough on the feet. I can also ask the department that makes the curtains to cut the scraps to my liking for ease of use. Plus it’s water resistant as we also make clean room doors which are meant to be able to be washed down even with harsh chemicals. I got a full roll they were scrapping for free that has a mesh/padding on the back side. Pretty sure this one roll is also marine grade, since it was for the R&D department only.

I was just talking to my neighbor about our city allows it’s residents 8 tire disposals for free with a id that has a residence as the town I live in, maybe I’ll hang onto the tires after all. I think I have 5 at the moment.

 

[briangcc]

I did this eons ago, mid-80's, in my parent's driveway. Stone and grass. It can be done. Rolled the old Tee-Nee trailer out from under the MFG, had a bent axle, and rolled in the new trailer.

What we did to make sure the boat didn't move anywhere during the process, was to tie a rope from the transom to a nearby tree. Used the trailer winch to help with the pulling the trailer back under the boat.

 

[dave8311]

That caulk around the motor mount doesn't look promising.

 

[CATALINAWineMixer]

Spent the evening tearing out the old deck. Holy foam.. so much everywhere and it was wet too. Didn’t realize how big of a gas tank I had until I saw it. It’s gotta be close to a 30 gallon tank!

At first I was discouraged when I I started, then my neighbor lent a hand, and boy did we start chewing through it quick. Thank goodness for him.

The glass job was hideous, there was glass laid over foam and zero screws from the deck to the joists. The previous repair was a chop shot, several pieces of crossmembers didn’t even have a lick of glass on them. The notches for the cross members were cut very large, and again, no screws holding anything in place. What a joke. Dude really pulled a Dr. Frankenstein on this one!

 

[jimmbo]

Carpet can, and will hide, a Multitude of Sins

 

[CATALINAWineMixer]

So true! The glass in the passenger side of the hull beneath the floor is rock solid though, after prying out 4” or so of foam from the open cavity, it didn’t even flinch to a hammer, I do not have a view of the bottom yet, boat seems to have a deck below to house the giant gas tank. It almost looks like there may only be access to the hull from the inside is under the central storage compartment. I’ll try to get a better picture of what I’m talking about tomorrow in the day time.

 

[briangcc]

Make sure you're taking measurements as you go so you can put it back together once the demo and grinding are done.

 

[CATALINAWineMixer]

Make sure you're taking measurements as you go so you can put it back together once the demo and grinding are done.

The deck itself is oddly shaped so my neighbor suggested using flattened cardboard to mock up the cut for the new decking when the time comes, do you thing this will work? I had to make several cuts to avoid catching any wires, gas lines, or the hull, not to mention I wanted to leave any cavities in as good of shape as possible to retain the measurements for rebuild so the pieces were missing several measurements worth of the blade kerf.

I will be making sure the joists are measured before removal. Again, this is all being done with the boat on the trailer at the moment. I am likely going to slide it off after the remainder of the deck is removed prior to cutting out any joist beams. Should I be worried about the structure bending inward or outward or both? I am trying to devise a game plan for the bracing to retain the shape of the hull.

Any other suggestions as far as what I should do? I’m almost contemplating doing a partial restoration instead of an all out restore, I am not confident in my ability or available tooling to remove the front cap and reattach. Is there any pointers on how to go about this?

Same goes for near the transom, since the compartment to the inside of the transom is rather small I am not sure how I can replace it if it is shot.. I’m praying for a miracle that it is somehow in adequate integrity structurally..

 

[JASinIL2006]

I'd be very judicious in what you cut away before you have your cradle built. The last thing you want to do is complete a bunch of restoration work only to find your hull is racked from moving it before cutting away structure.

 

[froggy1150]

When I did mine it was not necessary to remove cap. I had full access to everything. I also didn't need to flip hull either. My trailer has 4 bunks that are straight and flat so hull didn't move and didn't have to worry about getting cap back on. You are 180 to my build so cap off and flip....
When I did my floor I used thin insulation board. Seemed better than cardboard

 

[JASinIL2006]

When I did mine it was not necessary to remove cap. I had full access to everything. I also didn't need to flip hull either. My trailer has 4 bunks that are straight and flat so hull didn't move and didn't have to worry about getting cap back on. You are 180 to my build so cap off and flip....
When I did my floor I used thin insulation board. Seemed better than cardboard

I used 1/2" thick pink foam insulation board, too, when I made a template for my deck. Much easier to work with than cardboard.

 

[CATALINAWineMixer]

What is the point of the “flip”. Is it necessary to flip the boat? If so, what does this accomplish out of curiosity? Is the cradle for the interior structure or the exterior (similar to a boat lift)?

How do I know if the support is adequate?

I have extra materials from building a loft bed so I am trying to see what I can save from buying.

 

[Scott Danforth]

To flip a boat takes lots of help or lots of equipment and rigging.

I just usually worked upsidedown

 

[zool]

Flipping a boat is surely optional, but it does help dial in a hull, and makes things easier, but mostly beneficial to sport boats., plus the pics are cool

 

[froggy1150]

Had builds mixed up. There is one with a gaping hole feet long here somewhere. That one has to flip. Yours is a bow rider and cap needs to come off to do the front the right way but all you need is a cradle

 

[CATALINAWineMixer]

Not my first choice for flooring - have the same material out in our shop for assembly area dividers and it looks terrible to work with. A cheap alternative would be the rolls of indoor/outdoor carpet you can find at local home improvement stores.

Next option would be the cheapo faux teak (peel & stick) eva foam you can find on Amazon. Some here have used it with good results. I've used SeaDek on my swim platform. Pricey as all get out BUT still looks brand new since install in '18.

It's actually very easy to pull a boat off the trailer....when you get to that point and you are definitely not there as right now the trailer is helping the boat keep its shape.

Lower the tongue as low as you can. Block up the transom with cribbing (wood blocks), jacks, old tires, etc. Now raise the tongue as high as you can and repeat the support process with the bow. Now pull the trailer out from under the boat. You may have to stop and readjust the supports a few times to get the trailer out.

My vote would be once the interior structure is replaced and the hole in the side of the boat patched from the inside, to flip the boat over so you can attack the hole in the side of the boat from the outside. It'll be much easier to do the repair right side up working with gravity as opposed to trying to glass upside down.

Do you think the EZ Roller trailer will provide enough structural support for me to cut out some joists and stringers? Or will the boat start to clamshell? Does anyone know? I don’t have a structure to rig with ratchet straps like someone’s picture in this thread

 

[CATALINAWineMixer]

Had builds mixed up. There is one with a gaping hole feet long here somewhere. That one has to flip. Yours is a bow rider and cap needs to come off to do the front the right way but all you need is a cradle

You mean this whole?

 

[Scott Danforth]

Build supports from the trailer frame to the hull. The rollers are point loading the hull

 

[brodmann]

Marine grade plywood is pretty special stuff. As a former Manufacturer's Rep for Georgia-Pacific, I got to learn a lot about the manufacturing process. Marine grade plywood is a A-B grade panel. That means the face is an A grade veneer and back and inner plies are all B-grade or better. So, no voids or open knot holes. This is to make it possible to bend it and have the bend be uniform. Initially it was made specifically for the manufacture of plywood boats where the plywood was bent over a form made of stringers. It was usually made at the same plants that used the same high grade veneers produce BBOES plywood or Formboard. B B grade "oiled and edge sealed" to be used for cement forms. Super rigid and oil sealed so it could be removed after the cement cured. Fun stuff!!