stringer lumber

there is a gouge in the foam that you can stick your pinky in just about the whole length from something, definately not just a failure.

Not a piling. Laminate failure from a bad initial layup aggravated and failure initiated by hydraulic erosion. Latent Manf. defect. Lets hope his adjuster is as clueless as most seem to be. That boat is totaled. I am sure glad none was hurt.

Correct. No epoxy whatso ever. I didn't drill holes all over either, all I did was two coats of poly resin over the lvl, then I coated them in 1 oz. mat, then 3/4 mat before they were layed into the boat. This was the best I could come up with once I ruled out the epoxy. It wouldn't be fair to say that he talked me out of epoxy. It was more of a choice of convenience. He was willing to get me all the epoxy that I wanted but he had the drums of poly on hand. I knew if I needed a bit more that it was convenient to just go and pick up what I needed instead of waiting for the ups man to show up. To be honest if I had to pay more for epoxy, the project probably wouldn't even be finnished this year.
On a different note about foam or no foam.
I kicked the idea around for the year and a half that I had my boat torn apart and decided to put it back in. Yesterday a friend of mine sent me a picture of his boat. He had just left from filling up at the local marina, about 500 yards out he felt a hesitation and the boat rocked slightly, 3 seconds later the passengers where screaming WATER. He throttled down and headed towards shore. By the way this is a Mastercraft from the late 90's by the time he got to shore the water level was calf high in the boat. Long story short. He hit something in the water and from the front wakeboard tower support all the way back to about 6 inches short of the transom his hull is torn open. It's a gash 3 inches deep through the glass and into the foam. The glass on one side of the gouge is missing about 8 inches x 9 feet. The culprit is believed to be an old dock pylon from the shipping days of 80 years ago. Pylons were placed in the water then beams were bolted to the top in order to build the docks. After years the beams would rot off leaving 16" or so of bolt protruding from the top of the pylon. Down the lake people are putting in a new 6 slip dock where these pylons are. They must of moved a few to get their new structure in and released one out into the shipping canal. The whole thing was probably under water a couple of feet leaving the bolt and head a few inches under the water because none of the 5 on board seen anything in the water. But regardless if that boat didn't have the foam in it it would have never made it back to shore. So for me personaly if my floor only last 15 years because I put foam back in it then so be it. If my boat was foamless and then I saw how quick an accident like this can happen and what it can lead to, I wouldn't have one moment at ease out on my boat.

YooperSully wrote: CPES is an epoxy product. So if I'm laying poly over the top of it, it isn't a compatible combination.

Roger,
When you said "I bought it", I wasn't sure what "it" was! Yes, you are correct that poly will not stick to epoxy. The CPES is the "primer" for epoxy resin. So, this person talked you out of going epoxy all the way. Way back, I thought you were going epoxy.

Did you end up using his method of drilling holes all over the lumber so you got some penetration of the poly?

YooperSully wrote: I bought it but didn't use it on my boat. My whole project was done with polyester resin instead of epoxy so it wasn't compatible with my build.

Roger,
It was this statement that got me going! Did you misunderstand the compatibility issue? What isn't epoxy compatible with?

BTW, my next CC will be the bridge erector.

Gary,
The exact same thought crossed by mind. The Donzi's a pretty light weight and actually not built very well. Maybe the "old timer" needs to turn some Donzi's into ice breakers!!! I think the years of him using the poly has gotten to his brain! The bottom line is he is doing cheap repairs using cheap poly. Epoxy not compatible? I'd wager to say he hasn't ever used CPES ether. Drilling holes in wood for penetration??

I bought it but didn't use it on my boat. My whole project was done with polyester resin instead of epoxy so it wasn't compatible with my build. But he had never heard of it. When he gets into big pieces of wood such as transoms he'll pepper the marine ply with 1/8" holes in a 3" grid then he'll two coat it with poly resin. This guy grew up in the marine industry building Donsi (spelling) boats. Off shore racers. Boats that do 80+ over choppy ocean waves. When I explained my project to him in the beginning I was planning on using epoxy. But after talking to him I switched to poly resin. One comment that sticks with me that he said was " are you trying to rebuild a ski boat or are you trying to build an icebreaker".

I also used lvl's in my rebuild. I ran them through a planer to get them down to a 1 1/2". The boat builder that I purchased all of my supplies from only rebuilds stringers with plywood. He doesn't lam them together how I thought he would instead he cuts them into strips and then stacks them adhered with resin until he gets to the height of the original stringer. He's been using this method for over 25 years now with no issues.

Depending on the composite, your glass layup schedule is more or less important. Coosa (specifically high density, like the bluewater series) is a core material with good strength, but poly foam (the method I used) is not structural, thus your layup schedule is critical.

Plus when using a composite like Nidacore, the builder must remove and backfill or sleeve the material any place a fastener will be attached.   Last, compression forces: wood holds up better to compression than many composites. Hence you have a little more room for error with wood as a novice builder than with SOME composites.

LilRichard wrote: composite is the way to go... But it's a less forgiving methodl than wood.

In what way?

True, not like Mako made any inboards using that method. Or Shamrock.

http://www.classicmako.com/forum/topic.asp?TOPIC_ID=17843

LilRichard wrote: Brainard, yes, you scarf the ply. If moisture isn't the problem with treated, what do you suggest is? Prior to using it for my deck I did some pretty good research on the topic - of which I will dig up and provide.

I just did some research a well. Lot's of technical papers out there o epoxy bonding treated.

Here's an interesting comment:

"Limitations of pressure-treated plywood
Many people ask about the value of pressure treated plywood. Often, pressure treated plywood is heavily warped. This is primarily the result of the high temperature and rapid moisture take up during processing. Some plywood delaminates during the process. In addition, some pressure treating methods incorporate water repellant materials. These materials can easily jeopardize bonding so you won't be able to glue or paint the plywood successfully. Generally speaking, pressure treated plywood may be acceptable for house projects but not for boats."

I'll stick with the CPES and epoxy method for plain old wood!

LilRichard wrote: Regarding the strength, so many boats were made factory with ply stringers it would take all day to list them.

How many were inboards?

Brainard, yes, you scarf the ply. If moisture isn't the problem with treated, what do you suggest is? Prior to using it for my deck I did some pretty good research on the topic - of which I will dig up and provide.

Regarding the strength, so many boats were made factory with ply stringers it would take all day to list them. But I can tell you one right off the topof my head: Makos. They are a hell of a strong boat and all the 70s - 80s boats were made with ply stringers. They had rot problems just like Nautiques, but I never saw one rebuilt with a broken stringer that wasn't rotten. I'd argue that those hulls take way more abuse than a freshwater boat. You'd fracture the hull lamination beforen you'd have to worry about the stringer giving way.

Once again, not trying to stir the pot, but there are many ways to skin a cat.... And I think suggesting one way only is leaving something on the table.

I used LVL, which from what I have read is just laminated Douglas Fir strips, in my project. I am very pleased with the way it turned out. The LVL is a little thicker than the 2X stock but there is plenty of room in there for it. Taking it out on a test run weekend before last the boat was stiff as a board and handled the chop so much better than before!!

As far as using the ply, it could be done but I would be worried about getting everything laminated together. If I was going to go through that much work I believe I would go with Coosa board. It would not bee that much more expensive that Marine grade, but you would never have to worry about rot again. Plus others here have used it before and would be able to help you if you have questions.