PDA

View Full Version : Crocker Deck replacement and possible replanking



Woodonwater
08-30-2007, 03:47 PM
You all will have to forgive my newbie status. I am quite sure you have debated this issue ad nauseum, but nevertheless, I need to broach it again.

My Crocker 37' ketch, Tamara, is new to me and has a very rotted deck. Actually, to be more precise, the 1+" mahogany deck planking comes off in your hand, but the 3/8" ply under it is actually in decent shape. There are a very few places where it too is rotted, but it must have been installed well. There was a skrim or canvas over the ply. (It was built in early 1940's).

The deck beams all appear fine. I originally intended to keep the original ply, clean and rough it up, and epoxy another layer of say 1/2" marine grade ply over that and then glass it. Now I am of the mind to pull the ply to be sure of stopping all rot. I will have better access to install new silicon bronze chainplates in place of the badly rotten iron ones as well as access for painting and cleaning up the deck beams, etc. I can also pull all the iron deck nails/screws and replace with hardwood dowels/sweet screws or whatever they are called. I prefer to install the deck with bronze, even thought he hull is iron fastened. Above the water line and not in the hull is okay to change fastener material?

So here is the planned system at this point: I epoxy down the first layer of new 1/2" marine ply onto the deck beams. Where the deck meets the cabin top, I add shelfs onto the outboard side of the carlin to get a positive connection at the cabin side of the deck for the ply. I leave the thin strip of old 3/8" ply between the cabin sides and the carlin (The cabin sides are 1 3/8" mahogany), unless I can reasonably dig out this strip of old ply and cram in new mahogany shims between whatever fasteners will be in the way. I really don't want to pull the cabin top off!

Then I run another layer of 1/2" ply over that first ply in an even bed of epoxy. Then I glass over that. Then, when money allows, I would like to set 3/8" teak planking over the glass in the popular "fastenerless" method, as a veneer. I am told this holds up well, and is lower maintenance. How much lower, and what will still be required on a yearly basis is unknown to me. I have never owned a boat with a teak deck.

I have gotten a boatwright to give me an estimate to perform the re-decking (sans teak) for under $5,000. As an aside, the previous owner of my boat was a shipwright, and he had planned to add 5/4 baltic birch plywood. He ordered about 11 sheets of the stuff in 5' square size (I think it's a metric size actually) Great plywood, and the seller will sell it to me at a discount. (The previous boat owner died, and I got it from the heir). The owner did things well, when he did them, but this choice I don't fully understand. The sections will be short at 5', leaving lots of joints and the thickness will be difficult to install. The decks are fairly flat on Tamara, but not totally. (I will link to pics right after the Labor Day week end, for a better idea of all this).

Although I don't like the idea of two layers of ply, with potential voids, I also don't like the idea of the ply not respecting the sweeps and curves of the deck, gentle as they are. I am told I need at least 3/4" of deck for this size boat. I could even go (2) 3/8" layers for even easier install, right?

The other order of biz is to add back on a bulwark/toe rail which is missing. My thought is to have the bulwark step in slightly (about 3/16"), but continue the line of the hull. Also, I would like to add a 1x "plank" to butt the ply into, so the edge of the ply is nowhere near the water. The bulwark would sit on this strip and over the ply and would fasten at an inboard angle to hit the carlin at the edge. I'll try to post a picture/sketch.

How does all this sound?

donald branscom
08-30-2007, 04:37 PM
Dont epoxy the covering to the deck beams!

What if the deck ever needs work in the future. The next owner would have to chisel or grind it all off WOW what a bitch. Don't do it.

Just remove the covering make sure the deck beams are good and then screw down the new wood. Then cover with fiberglass cloth and epoxy. Make sure the edges are leak proof. Use caulking that can flex a little.

I would use stainless screws in the deck NOt bronze.
Bronze and steel do not mix.
You can even buy square drive 316 stainless screws at some hardware stores now. they are used for outdoor decking.
Skip the marine store expense.

I would not pull all of the deck up at once because the boat could loose its shape. I would replace in sections, like maybe the bow area, then stern then middle. Like that.

Two layers of 1/2 inch ply and then mahogony strips !
Too much. You better find a boat wood worker to help you with this project. You are in way over your head it sounds like.

That covering board between the carlin and the ply is called a stopwater.

By the way that 5 foot square ply is usually sold to cabinet shops.

Woodonwater
08-30-2007, 07:17 PM
Well, so far I have found three qualified boat repair people/shipwrights to consult with and do some of the work, in addition to discussing it on this forum and reading books and reading Wooden Boat magazine back issues and being an Architect and a woodworker....so..no, I am not "in over my head" thank you very much. I am embarking on a learning process, and hopefully the final solutions will be right for the boat and right for the pocket book. Your input was otherwise very helpful, but if I miss the mark on the first round, I don't need insults, just helpful advice. (Or maybe I need a beer, come to think of it :) )

Regarding deck thickness. I would agree that it seems too much. However, the consensus so far is that 3/4" structural decking is a good idea. If I do the 3/8" veneer teak, it will not offer much structurally, since it is glued down with no fasteners. I suppose it will stiffen things, but I also may never do the veneer. Perhaps one 3/4" ply sheet is appropriate and bendable to the gentle curves? I will ask the people doing the job, given what curve they see on the deck.

Thanks.

donald branscom
08-30-2007, 07:43 PM
Well, so far I have found three qualified boat repair people/shipwrights to consult with and do some of the work, in addition to discussing it on this forum and reading books and reading Wooden Boat magazine back issues and being an Architect and a woodworker....so..no, I am not "in over my head" thank you very much. I am embarking on a learning process, and hopefully the final solutions will be right for the boat and right for the pocket book. Your input was otherwise very helpful, but if I miss the mark on the first round, I don't need insults, just helpful advice. (Or maybe I need a beer, come to think of it :) )

Regarding deck thickness. I would agree that it seems too much. However, the consensus so far is that 3/4" structural decking is a good idea. If I do the 3/8" veneer teak, it will not offer much structurally, since it is glued down with no fasteners. I suppose it will stiffen things, but I also may never do the veneer. Perhaps one 3/4" ply sheet is appropriate and bendable to the gentle curves? I will ask the people doing the job, given what curve they see on the deck.

Thanks.

I was not insulting you. If i was saying this to you in person you would know i wasn't. But since you can only read the words the communication is less than perfect.
It sounds like you you are doing it right and getting your ducks all in a row.
when things are over my head i ask for help also.
And sometimes the expert will say to me "looks like you don't know what you are doing" and I say I yes can you show me?

Would you post some photos of your boat?

Woodonwater
09-04-2007, 06:55 PM
Thanks. I am sure you were not insulting me. (I think my blood sugar was low or something) Anyway, life isn't interesting unless you get in over your head once in a while, right? This project will take much assistance and I admit there is alot of it that IS over my head, plain and simple.

The galvanic actions of different fasteners and alloys of fasteners above and below the waterline are making my head swim, for example!

I will attach pictures of my Crocker #125 very soon. I have to sort out the best method to do that for easy viewing.

Thanks again for your help.

James