Corsair floorboard blues

Corsair floorboard blues

Joined: September 12th, 2011, 10:31 pm

April 6th, 2012, 10:52 pm #1

Paul (and Dave)--

Your wonderful tutorials on your Sea Skiff projects were plenty honest about the level of challenge, but I never thought I'd get into this degree of difficulty replacing a couple of floorboards in my Corsair Sea V! Removing the rear seat and starboard side paneling was a snap, neatly exposing the floorboard I intend to remove first. Lo and behold, the floorboard is essentially BUILT into the boat. Unlike my old 26' Cavalier Cutlass, which had nicely visible screws and trim washers holding down the nautolex-covered plywood sheets, the Corsair's floor is something out of a horror film!

While the smaller panels in the center of the Corsair are easy to remove, with visible screws and trim washers, the longer plywood floor sheathing (7.5 feet) in the main cockpit section appear to be fiberglassed into the sides of the hull. The inboard edge of these large sheets is countersunk-screwed (covered in putty) into the under-deck framework and the (deteriorated) Nautolex is applied OVER those screws and stapled willy-nilly to both the edge of the plywood sheathing and, in places, to the framework on which the sheating rests! Yikes! Or, as they say in Minnesota, "Uff Da!"

This photo shows (rather fuzzily) the Nautolex staples driven into both the floorboard sheathing and the framework beneath it:


This photo shows the edge of the starboard sheathing as it meets some fiberglass mat that curves out from the side of the hull. There is a 2" x 2" wooden strip (for attaching the lower edge of the inside wall panel)on the seam, but even with its screws withdrawn, it does not seem willing to be removed easily. I suspect it was epoxied/resined into place.


Did you guys encounter this? If so, how did you deal with it? I'm ready to take a skill saw and cut the sheathing along the edge of the 2"x2" strip. Hints appreciated.

Best,

Cliff
Quote
Like
Share

Mike Watson
Mike Watson

April 7th, 2012, 12:44 pm #2

It appears to be the same method that is on the SS. If your floor boards are rotted there is little choice other than ripping it out. I just went after the glass that was laid on top of the boards with a narrow pry bar and peeled it away from the top layer of the plywood then trimmed the left over glass. No reason you could not skip this process and just cut it with a saw of of some type and clean up the leftovers later. Don't cut all the way through so you have a pattern. Glassing it back is easy.

Of course what you find underneath is the unknown. I found the wood support pieces that run the length and lay on top of the stringers to be rotten and had to be replaced. This include the 12x12 steel plates that supported the pedestal seat bases that were rusted. These were replaced with aluminum. The originals were threaded to accept the bolts but I will just be using the molly's that are now available.

Good luck and wear gloves!
Quote
Share

Cliff
Cliff

April 7th, 2012, 3:51 pm #3

Mike --

Many thanks for your observations. I think your approach to the problem has merit.
Still interested in weigh-in from Paul and Dave, who did this with their similar Sea Skiffs. Also, anyone else who has tackled this type of project.

I saw your treatise on the pedestal seats. Good work!

My Corsair has traditional helm and companion seats with hinged backs and support rods with rubber "feet."

Thanks, again, Mike foryour comments.

Best,

Cliff
Quote
Share

Rich Duane
Rich Duane

April 7th, 2012, 9:37 pm #4

Cliff,
Paul and Daves boats are a little different then the 67 and 68 models when it comes to the support system of the flooring. In Pauls index you can find some pictures of my boat when I started to correct
these problems .
While you are in there you might take a good look at the lower supports as most have really deteriorated.
I am replacing mine with Coosa Board. It is a light weight composite material I am also using it for the floor.
When I get mine uncovered I'll get more pictures posted.

Regards,
Rich
Quote
Share

Cliff
Cliff

April 7th, 2012, 10:18 pm #5

Rich --

Many thanks for your input. So far, the support framework for the flooring on my boat seems intact, but I haven't seen it all yet!! And the sad thing is that 80 per cent of the plywood floor sheathing itself is in good, solid condition. It's just in a few spots that serious rot has attacked it, thus it must be replaced. If I could cut out and replace a small piece, I'd do it, but I need to entirely replace the Nautolex covering vinyl, and therein lies the problem!! I see the only way to accomplish this is to replace the entire plywood piece(s) so that I can cover it with new Nautolex.

Thanks, again, and please do post some pics when you dig a little deeper.

Best,

Cliff
1968 Corsair Sea V 20' inboard
Quote
Share

Dave Krugler
Dave Krugler

April 8th, 2012, 12:57 am #6

Cliff- Rich is absolutely right that the construction of my and Paul's boat differs from yours. The outboard edges of those 7ft long floor panels on my boat and Pauls sits on and is screwed to an oak stringer that is glued and screwed to some plywood side splashes as shown in my pictures below. Also when Paul and I covered the floorboards we glued the Nautolex to the top surfaces of the boards, wrapped it over the edges and stapled the folded over material onto the bottom of the boards. The boards were set into place in the cockpit and then screwed to the supports. Pictures below should give an idea of how that went. I have no clue why they glassed the boards in on your boat. Is that the original setup or did someone else re-do the boards before you got the boat? I know mine were redone once becuase of the amount of Douglas Fir house lumber I tore out of it. I hope this helps. If you need more let me know...

Dave

The oak stringer on these side splashes is what the outboard edge of our floorboards sits on and is screwed to.









The side trims cover the screws and side splashes.


The glue I used is indoor/outdoor carpet glue from Lowes or Home Depot.


The Nautolex installation, I used stainless staples.




Quote
Share

Cliff
Cliff

April 8th, 2012, 3:18 am #7

Many thanks, Dave --

I recall looking at your and Paul's photos and having a pretty good feeling about tackling the floorboards on my boat. Now you can understand my chagrin when I discovered what a nightmare I was up against once I removed the side panel.

I think Mike Watson's suggestion is the best approach: basically separating the 'glass from the plywood with a small prybar, removing the floorboard, duplicating the floorboard and recovering it; and reinstalling it, this time simply with external screws. He wisely suggests "wear gloves." Sheesh, this is much bigger than I bargained for.

On your question about whether my oddball flooring may have been done by a previous owner, I don't believe so. It looks like "factory work" to me. The fiberglass on the inside of the hull matches in color and mesh with that of the fiberglass mat that curves out from the hullside and is epoxied to the floorboard. Even the screw holes on the inboard edge of the sheathing is fastened with numerous brass, countersunk screws that are professionally covered with putty. Also, the mechanic at my marina says he has encountered very similar construction on other CC boats, and he simply cut the floorboard out with a skill saw set at a depth only a hair deeper than the board width (3/4" in this case).

Thanks, again, for posting your photos. They're great, and I wish my boat was designed that way.

A couple of questions--for now -- what paint did you use for the wood frames and the back of the floor sheathing? Also, I have a quart of Nautolex adhesive. Will it adhere to an unpainted side of 3/4" marine plywood?

Wish me luck!

Best,

Cliff
Quote
Share

Joined: July 15th, 2005, 8:09 pm

April 8th, 2012, 1:28 pm #8

Hi Cliff,

Dave, Rich, Mike, have given some good tips. In this case I think the best thing to do is pull out the entire aft flooring and toss it. Put in new structure (I used white oak) and then put down a 1/2" (not 3/4") floor of marine plywood on top, with either a nautolex if you can find it, or some other marine vinyl or perhaps even a topping like Jerry used. There are plenty of vinyl products that would stand up in this use, many of which have been used on vinyl top automobiles. A light color will be best of course.

I would not put too much stock in the fact that your floor was done with "professionally installeed putty over the countersunk screws" because many people in the boating world have come from wood boat backgrounds and that is just par for the course. However it may be a factory job, but I don't think they would have taken the cost and time to glass it in like yours, because on a production line it is more of a slap it together operation and get it on the road to the dealer. I will look again, but in any case if your floor structure has soft spots then the problem is most likely larger than you can tell from topsides. Carefully pull everything out, address the structural issues in a manner that a large person will not cause it to fail, and reinstall with marine plywood. Rich mentioned another product, but marine ply is my preference just because it is easy to get and work with (any good plywood outlet will have fir based marine plywood). Now if you have boatitis bad enough where you just must spend a ton of money and have the nicest floor of any Corsair in the world, you could go with teak and holly plywood, and perhaps have all of your hardware plated in gold, but that would be an obsessive waste of money in a utilitarian boat like ours. Crazier things have been done.

regards,

Paul









Quote
Like
Share

Cliff
Cliff

April 8th, 2012, 5:03 pm #9

Paul --

Thanks so much for your thoughts on this, and I add Rich, Mike and Dave to the list, as well. That's the great thing about this Forum: Knowledgeable folks get together to help out one another, and logical solutions are offered. This not only offers an array of options, but more importantly, furnishes the "moral support" needed to make a challenge seem more manageable.

Fortunately, I also have a couple of other things going for me here: 1) I have a good friend who is a licensed master carpenter with familiarity with boats (he owns several), and 2) I was able to score enough white planked Nautolex to do the job on my Corsair. I got ten yards of it, which I think should suffice. (You'll recall it is in 54" wide rolls.) That works out to more than 120 sq ft, with only two long runs of 7+ linear feet by 2+ feet needed.

I wouldn't be surprised to find some rot in the underframe of the floor, but that which is visible so far is very solid. The framework for the rear seat was in excellent shape (no water soaking), and I removed it for refastening and painting -- and to clear the area for work on the floor and elsewhere.

When I do manage to refloor the cocpit, I will make sure I fasten it in such a way as to make it relatively easy to remove, while at the same time making it sturdy and rigid.

I promise to post photos of my progress, and I'll also try to take a few decent pictures of the "possibly factory installed" glassed-in main floor boards before I demo it.

Thanks, again, Paul and everyone for your help.

Best,

Cliff
Quote
Share

Cliff
Cliff

April 9th, 2012, 10:36 pm #10

I've started the process of demo-ing the "built-in" Corsair floorboards. MAJOR job, and not much fun (yet).

Here are some pictures that may help illustrated the peculiar construction of this floor structure on the 1968 Corsair Sea-V 20 inboard.

Starboard panel removed, revealing 3x4 galvanized downspout ventilator pipe glassed into hullside. Also shows forward end of 1"x1" strip to attach vinyl-covered inner panel (at bottom)

This shows glass mat strips extending from inner hull side and epoxied to floorboard and 1x1" inner-panel fastener strip

More detail of glass strips epoxied/resined to edge of floorboard and 1x1" inner-panel fastener strip. Also shows forward red-vinyl-covered bulkhead for inner storage pocket. It, too, is glassed into the hull-side.


With 1x1" inner-panel faster strip removed, prying fiberglass away from floorboard, to which it was epoxied/or resined.

Rotted after edge of starboard floorboard, showing one of the many, many(!) bronze screws fastening this board FIRMLY to the underframe! These screws were hidden beneath a layer of putty AND the Nautolex vinyl covering.

This picture should help orient the viewer to the location of the project

Another "locating" shot


As you might expect, there is some rot in the framework beneath the floor sheathing. I'll be replacing that with white oak per Paul's recommendation. Speaking of Paul's suggestions, I wonder why he suggests replacing the old 3/4" plywood with thinner 1/2" plywood (both marine-grade fir)? Any particular reason, Paul? Lighter, true, but probably not as stiff, right?

My next step is to make a test cut (with pistol grip had-hacksaw) of the fiberglass stripping that attaches the floorboard to the inner hull side. I want to see what's under it, and in all likelihood it will reveal that the hullside edge of the floorboard is ALSO screwed to the underframe. Man,I hope not!

Wish me luck as I burrow deeper into this challenging process. I'm at the point of no return.

Oh, yeah, one last request: What's the grey paint you guys used to paint the flooring timbers?

Best,

Cliff
Quote
Share