Replacing Cabin Floor Tips

[bonkle]

How are my searches yielding so little on this topic? It seems like rotten floors would be rampant on a boat forum. I have quite a large section of rotten plywood (with a most likely fake teak veneer) above the bilge section of the boat. I think I plan on replacing the center section of floor (outlined in blue). This section is bordered framed by fiberglass "bulkhead" that separate it from the bow berth and galley floor sections. Orange is comprimised floor and red is completely rotten floor. So the questions:

1. Does the furniture (couch on port, table/benches on starboard) have to be removed? How is this done?
2. Can I use a synthetic product like plastic deck boards? It seems silly to have plywood (even if it's treated) above the bilge. That just seems like the optimal environment for rot.
3. Any tips out there to help make this a success?

And a general question: why is there a grate at the foot of the stairs? It seems that hunter went out of their way to design it like that. Is it simply a floor mat of sorts to keep the interior clean?

 

[ggrizzard]

Pull up the grate. Sweep floor debris into grate well. Vacuum the well.
Smile, you've got a clean floor.

 

[dlochner]

There are 2 fundamental ways of building a boats interior, stick built and pan built.

The interiors of stick built boats is constructed from individual pieces of plywood and other woods and assembled in the hull. The interior can be disassembled with a screwdriver. This type of construction has some structural and design advantages, however it is an expensive way to build the interior because of the large amount of skilled labor that is necessary. High end semi-production and custom boats tend to be stick built, Sabre and some Tartans are good examples.

Most production boats, Catalina, Hunter, Pearson, etc. tend to use pan construction. In this method the interior is built of fiberglass as one unit in a mold and then placed into the boat. The wood sole you see is likely ¼" veneered plywood that is glued to the pan. One way to tell what kind of interior you have is to look at the settees, is the front wood or fiberglass? If wood, is it wood on the inside under the seats? Removing it is probably tedious (I have never tried) and involves scraping and cutting the wood until it is all out. Once out new plywood could be installed or a synthetic substitute.

Depending on the damage, it may be possible to remove just the outer damaged veneer and then install a synthetic over it.

 

[Johnb]

Use the search function and enter sole rather than floor. You will find loads of articles.

 

[bonkle]

Use the search function and enter sole rather than floor. You will find loads of articles.

That's much better, thanks! This isn't as common of a project as I expected.

There are 2 fundamental ways of building a boats interior, stick built and pan built.

The interiors of stick built boats is constructed from individual pieces of plywood and other woods and assembled in the hull. The interior can be disassembled with a screwdriver. This type of construction has some structural and design advantages, however it is an expensive way to build the interior because of the large amount of skilled labor that is necessary. High end semi-production and custom boats tend to be stick built, Sabre and some Tartans are good examples.

Most production boats, Catalina, Hunter, Pearson, etc. tend to use pan construction. In this method the interior is built of fiberglass as one unit in a mold and then placed into the boat. The wood sole you see is likely ¼" veneered plywood that is glued to the pan. One way to tell what kind of interior you have is to look at the settees, is the front wood or fiberglass? If wood, is it wood on the inside under the seats? Removing it is probably tedious (I have never tried) and involves scraping and cutting the wood until it is all out. Once out new plywood could be installed or a synthetic substitute.

Depending on the damage, it may be possible to remove just the outer damaged veneer and then install a synthetic over it.

I'd say that mine is stick built from the sole up. I suspect that if I were to gut the interior down to the fiberglass, the bottom of the hull (well... top of the bottom of the hull) would have a grid of fiberglass "stringers" to mount the sole to. It looks like this floor is not all that wide. I'd have to pull the two settees and couch. which shouldn't be too terribly difficult. This pic (not my boat) makes it look like a fairly easy project, but once I'm inside the boat, it sure seems daunting.

There's definitely no fixing the bad parts though. It's rotten all the way through.

 

[dlochner]

That's much better, thanks! This isn't as common of a project as I expected.


I'd say that mine is stick built from the sole up. I suspect that if I were to gut the interior down to the fiberglass, the bottom of the hull (well... top of the bottom of the hull) would have a grid of fiberglass "stringers" to mount the sole to. It looks like this floor is not all that wide. I'd have to pull the two settees and couch. which shouldn't be too terribly difficult. This pic (not my boat) makes it look like a fairly easy project, but once I'm inside the boat, it sure seems daunting.

There's definitely no fixing the bad parts though. It's rotten all the way through.

You have a pan. There appear to be a few places where the settee is supported by a plywood panel, however, look at the aft end of the V-Berth and under the dinette seat on the starboard side, that is what a pan looks like.

What you are calling the "top of the bottom of the hull" is the pan. The pan is laid up on a male mold with gelcoat on the out side which will be the top of the pan.

When you look in a locker of a stick built boat you will see something like these photos. In this photo you can see the balsa coring in the hull and the top and front of the setter is plywood. Not sure if can be seen well in this photo, however, the front of the settee has fiberglass tabbing securing it to the hull.

In this photo you can see the weave of the glass cloth. The locker has been painted so you can't see the balsa core. If you could see under the shiny white parts of your boat you would see raw glass similar that in these photos. Besides, Hunter would not be able to meet their price point if the interior was stick built.

 

[bonkle]

You have a pan. There appear to be a few places where the settee is supported by a plywood panel, however, look at the aft end of the V-Berth and under the dinette seat on the starboard side, that is what a pan looks like.

What you are calling the "top of the bottom of the hull" is the pan. The pan is laid up on a male mold with gelcoat on the out side which will be the top of the pan.

When you look in a locker of a stick built boat you will see something like these photos. In this photo you can see the balsa coring in the hull and the top and front of the setter is plywood. Not sure if can be seen well in this photo, however, the front of the settee has fiberglass tabbing securing it to the hull.

View attachment 214992

In this photo you can see the weave of the glass cloth. The locker has been painted so you can't see the balsa core. If you could see under the shiny white parts of your boat you would see raw glass similar that in these photos. Besides, Hunter would not be able to meet their price point if the interior was stick built.


View attachment 214993

Ah I see. I didn't think about the v berth. I figured the top pan was a structural thing as opposed to interior design related. I guess it could be a combination.

 

[dlochner]

Ah I see. I didn't think about the v berth. I figured the top pan was a structural thing as opposed to interior design related. I guess it could be a combination.

The pan is a structural thing. Beneath the sole there are beams molded into the pans. On stick built bolts there are frames glassed into the hull. The sole is supported by timbers or floors like the ones you see in this photo. On this particular boat, a Sabre 34, the subsole is glued and screwed to the floors and then a ¼" teak veneered plywood is glued onto of the subsole. On a pan built boat all of these components are molded in one piece and then set into the boat before the cabin liner and deck are installed.

 

[bonkle]

The pan is a structural thing. Beneath the sole there are beams molded into the pans. On stick built bolts there are frames glassed into the hull. The sole is supported by timbers or floors like the ones you see in this photo. On this particular boat, a Sabre 34, the subsole is glued and screwed to the floors and then a ¼" teak veneered plywood is glued onto of the subsole. On a pan built boat all of these components are molded in one piece and then set into the boat before the cabin liner and deck are installed.

View attachment 214994View attachment 214994

I think I get it. Stick built has a wood frame and the hull is built around it. Pan built is a two piece deal... hull and structural pan that are glued together.

 

[dlochner]

I think I get it. Stick built has a wood frame and the hull is built around it. Pan built is a two piece deal... hull and structural pan that are glued together.

Almost. Both stick built and pan built hulls and decks are built about the same way, in a female mold. It is the interior that is built differently.

 

[RitSim]

I had to replace several plywood risers that were water damaged. I drew them in Draftsight (AutoCAD equivalent) and Chesapeake Lightcraft was able to CNC route my parts out of 18mm waterproof plywood with Sapele veneer. My only issue was trying to match the stain. The veneer would not accept any stain. I finally tinted the varnish and got it matched.

 

[kloudie1]

The settees are fairly easy to remove. They are screwed to the floor (sole) with cleats (wooden bars) .. The top of the settee is the tricky part because it is screwed into the side panel cubbies . The screws can be reached through the ports in the side panel. The veneered plywood rests on the structural grid. I think it is attached with screws that have bungs to hide them. The ply is 1/2 or 5/8, I can't remember. Attached shows the floor panels from the H-34 which is very similar to the H-31 in construction. In the 34, the panels go aft under the sink island ; I don't know if they do on the 31, but if so, it may be possible to shorten the new panel at the grid support. ( EDIT I see from your picture of the 31 that the sole probably stops at the aft grid crossmember.. probably easier to deal with) These are from a forum member's H-34 project.. sorry I don't remember to give him credit for the excellent pictures.

 

[Benny17441]

You can use 3/4" marine grade plywood, stain and give it a hand of clear polyurethane.

 

[Crazy Dave Condon]

Was this boat built by a manufacturer and if so, can you provide manufacturer, model and year of boat?

 

[rgranger]

His dashboard tile says it is a Hunter 31

 

[bonkle]

Sorry icudda sworn it was in my signature or something. It’s a 1984 Hunter 31.

Edit: It's in the banner on each post. That can't be seen on mobile apparently. I added it to my signature.

 

[smokey73]

You have a lot of options if you are going to remove all of the cabin sole with a range of cost from $$ to $$$$. You can get marine grade plywood, cut it using your original pieces as pattern, then stain it and protect it with a durable finish.

I found that Minwax "gunstock" colored stain was the closest match to the original teak portion of the flooring. You'll have to experiment with different stains or mixes of stains on some scrap of the actual stuff you buy to get the color you want.

You can get marine grade plywood of the appropriate thickness and then use a synthetic teak and holly vinyl type covering to give you the original look. (there are plenty of posts on this on this forum). Probably the easiest and most durable if you like that look.

You can buy teak and holly veneered marine grade plywood, cut the pieces using your original as a mold. This is closest to the original but pricey. I purchased marine grade teak and holly (I only needed one 4X8 sheet) from eastteak.com/teak-plywood/ which is between Columbia SC and Greenville SC so I could pick it up myself. One 3/4 inch 4X8 sheet was still neary $400 per sheet. They normally sell only wholesale but I sweet talked them into selling me 1 sheet if I picked it up myself. I sanded down the original sole (hardest part of the job and not necessary if you are replacing it all) and then experimented to get the stain to match with the original. I then finished the whole sole with several coats of Daly's ProFin. It is not perfect but I am very happy with the project. I'd recommend the ProFin over a varnish but that is your call. Here is a picture of the finished project. See if you can figure out which piece (just one) was replaced. The"blue" things are reflections from the light from the hatches.

 

[Carl sv WINDROSE]

Found a mixture of Minwax stains, two parts Golden Oak and one part Gunstock gives a pretty good match for the teak plank cabin sole in our 2013 Marlow-Hunter 40.