Question on plywood and other Matl's.

[saltfly]

Gran thanks, that would be much  appreciated. I’m not in a hurry and would like to see what pic’s you take.

Short one thing I’ve learned over the years, and that is to listen to people that know their field. But I’ve also learned that when they are competing with other companies. They will always say what they do is better. To get the bis.

[gran398]

SP, probably its because its what they've always done, what they're comfortable with. My guy up here...his work is right there. But initially this was all new to him. The Coosa Bluewater...first time he'd ever used it. Nidacore too. The divinycell he had worked, as he does aquariums for the state. It all goes back to what they are used to, skilled with. And most of the time, with a family shop....it's "just how we do it."

Can't wait to post the pics of his AC fir transom/stringers. Beefy stuff.

A lot to be said for a quality build....as Seabob eloquently stated, its the encapsulation/glasswork that matters.

edit after the post:

Salt, thanks, you got it, pics this week

[seabob4]

Eloquent?  Eloquent?  Damn, them's fightin' words...


BRB, gotta go look it up...

[gran398]

Eloquent?  Eloquent?  Damn, them's fightin' words...


BRB, gotta go look it up...

It means you have way with words, you know, elegant

[Callyb]

The one thing I didn't see mentioned in this discussion was the fact that these boats were built with polyester, and polyester is not completely water resistant. That is were most of the rotting transom, and waterlogged foam issues come, not to mention folks drilling and screwing holes without proper sealing. I'll be starting on mine soon and plan to use Okoume plywood throughout. the key is total and complete encapsulation, wich can be taken with a grain of salt depending on who is doing the work.

I actually just sent an email today (to a member of the forum), and we are having this same basic conversation (foam vs. wood). First of all, the way I see it the fir that was put in the transom of my boat is still there today, so 46 years aint too shabby.  I also don't think I'll be around another 46 years so wood it is. Plus the cost of foam vs. the cost of wood vs. the weight difference equation drives me towards the wood.  

In case ya didn't notice, my vote is for the wood...  

But, I figure the guy spending the money should be the one to decide what goes in his boat. My opinion is just one of probably millions on the interwebs!

[gran398]

Cally, good post. Glad you're back too

The poly isn't the culprit on the transom rot. Neither is the internal plywood.

If they could have somehow built boats without bilge transom drains....none of the transoms would be rotten.

The bilge transom drain...the outer brass SLEEVE is the culprit. They didn't have 5200 back in the sixties/seventies...Life Caulk (polysulfide) was the status quo. So on the install, they bedded the sleeve to the exposed internal transom plywood core with the best they had, polysulfide caulk or the equivalent.  Had 5200 been available, probably wouldn't have mattered over the course of forty years. Eventually, the seal on the sleeve deteriorated/broke.

So the boat is in the water, with the lowest part of the boat leaking water. Directly into the plywood.

Water seeks it's own level. The water gradually makes its way up to water level (waterline level) through the years. A slow process. The more the hull is in the water...the wetter it gets, and the faster it happens.  Once the water, through osmosis...rises upward through the transom.. the heavier the boat gets, going lower. Pressure increases...water rises faster, up through the plywood core.

And the water is trapped. Rot sets in.

We look at the rebuilds today, all of the soft mush is at the bottom. Closer to the top, sometimes wood is left. But most of the time, the boys are describing pulling out what is left with their bare hands. a fully saturated old transom...300 pounds gone.

On the rebuild, leave the rear fiberglass transom skin on if possible. Serves a few purposes. Keeps the hull shape intact and stable...gives something to build to....and if you're into "classic" ....keeps your imbedded hull numbers preserved.

[saltfly]

Gran, you are right. When you use to using something, and have for a long time, you become very good at using it.

callyb Now there is a point that does get pasted over once in a while. I’m not using polyester, even though all boats are built with it and it is still a good product. I’m using vinylester, which is stronger then polyester and I believe it resists water better then polyester. It cost a little more, but no were near as costly as epoxy. i almost for got. I'm also using 1708 biaxial glass. I'm getting it for $9 a yard, so I'm ordering 20 yards. I'm not using it all at once. but at that price. I'm going to get it while I can.

[seabob4]

I need wires, then I'll be happy...

[gran398]

Just make sure they're .040 gauge like mine. You won't regret the extra .2 cents per wire.

[Callyb]

Damn Scott, I started typing that and had to walk away for a little while, stupid work getting in the way of me b.s.ing on the internet...anyway my point is I wouldn't have rehashed some of the points you had already made.

[gran398]

Naw, all good Cally!

Got the girl all tucked in for the winter?

[shortpants]

Gran your absoulutely right regarding how shops just do it there way and I understand that completely having been in construction prior to my job now.  From speaking with the guy that did my transom it did come down to cost and weight for me at the time.  My transom is solid as a rock after having used to pieces of 3/4 ply with bonded with resin, after holes were drilled in each piece for the resin to seep into them for a tighter bond.   The problem was application of the wood as experienced by me recently!  The prior shop installed all of the thru-hull fittings without either waxing each hole or even putting a little resin to seal the wood prior.  Also, the id**t used at least one plastic fitting below the water line and don't hold me to this but, I wouldn't be surprised to save money that poly-caulk was used instead of 5200.  Now, at the shop it's at now those issues were discovered and will be sealed correctly adding to the longevity of the wood that's in there now.  

I will say that a friend of mine poured his transom and I always noticed his boat sat lower in the water then mine.  About a month later he called me and sounded like that car window commercial, "and crack!"

Wow, look at me more then two posts in a month!!!  Hate computers..lol

[dburr]

Walt the key to me is cost and weight.

It seems the vast majority of the folks here are custom one off builders with the propensity for doing the best job they know how.  I am pretty sure that what CB4  wrote about proper application and encapsulation will apply to anything that a member attempts because we want to do it right and most likely will do “just a little more” because none of us wants to get back in there to fix it again.. Rybovich has been glassing over cold molded cedar strips since like 1950 with fantastic results.  Scotty’s point about the drain tubes and polysulfide is right on, especially when the dang outer flange on the drain tube corrodes off..

Bit of a ramble..


I like epoxy and wood because I have used them to build skiffs and kayaks.  I used vynalester and AC to do the deck of an old Formula..  If I have to do the transom of the Osprey I am really interested in the pour concept, I don’t know squat about other then I have read here but I will learn some more before I pull the trigger with the goal being the lightest weight and highest strength with the least disruption of the surrounding area(maybe pouring isn't the ansewer..) .

I think it boils down to what do you want to work with and what result do you want?  Our boats are gonna out live us because we care about what we do to them, so previous history with water intrusion will probably not be an issue.

This doesn’t answer the question but as I am dulling up the saw blade I think I’d rather smell burnt cedar rather than melted plastic..

 

[slvrlng]

Hey saltfly, are you getting the 1708 in 50" width? Check the price on this link if you haven't ordered yet.

http://uscomposites.com/specialty.html

[seabob4]

Poured transoms.  Always reminds me of one day at the plant...

My Cuban buddy Tony is prepping a transom on an Explorer to hang a motor, drilling the engine mounting holes.  He comes over to me and says, "Bobby, come here."  I follow him over and his drill is hanging from the bit in the hole.  He pulls at the drill...and it springs back in the hole!  WTF?!..Pulls hard, and out comes a finger of a yellow rubber glove wound around the drill bit!  Starts digging, gets another finger and various pieces of that glove...

At least no real fingers were inside of that glove!