Stringer Materials

Shelby,
I'd go with the LVL before the SYP just because of it's known strength properties. No matter what is used, this is true with any wood:

8122pbrainard wrote: I do not know if the engineered has ever been used but I certainly feel it sure would be a great option. Strict and careful use of CPES and epoxy just as if you were using Fir would be a must.

Thanks for the help guys. I hope to finsish foam removal this weekend. We'll see, we have had record cold temps this week. Removing foam is bad eneough and hard to get motivated when it's 30 degrees.

8000 thats alotta BULL SHEETING

jbenbri wrote: Would I laminate it together to get the width and length needed?

DAY_TRIP wrote: Exactly. I used two pieces of 3/4 on the mains only to get the 1-1/2 width. On the barefooter the mains are very small (3-4" tall). I glued them together with epoxy and wood flour. I tried to look at the engineering properties of the plywood so I could tell you the difference in strenght between the solid material and the ply.

Jim,
I too have looked for stress modulus figures without success and the reason I've always stated plywood strengths in rough terms. I wish there was more info out there!

Ben,
Yes, Jims boat hasn't bent in half yet but I again caution you with splicing ply together to get the lengths needed as it is my opinion that this is bad advice. Think about this analogy: Would you laminate two pieces of 3/4 ply together with a splice in the middle and use it for a 2x component in you house like for a roof rafter or joist? That's even worse than using 3 laminations of 1/2" ply.

The first signs of stringer problems will be gel cracking.

Also, wood flour is a low strength filler usually used for a final fairing compound because it's easy to sand. High strength fillers such as Cabosil and micro balloons should be used on structural work.

Sorry I missed this.

Sweetwater Lumber

this company replied with a email that has some interesting composite products, they said that the can cut 16ft pieces of product on their router table..when i was doing my stringers long pieces were not avalible.... think this the stuff in malibu boats..






Bryan Emerson

National Accounts Sales Rep

SpaceAge Synthetics, Inc.

ISO 9001:2000 Registered

Cell 701-866-9041

Home 763-208-2196

www.spaceagesynthetics.com

Fl Inboards wrote: Anyone in the Atlanta Area have a line on Doug fir?

jbenbri wrote: I live just south of Atlanta so I can check out Sweetwater that Buffalo used.

Jody,
Check out Sweetwater. I think they do have a web site that Greg linked at one time.

Would I laminate it together to get the width and length needed?

I used Meranti BS1088 (AKA Hydrocore) plywood for my stringers in the barefooter. No problems at all. I have also built an entire boat out of the same material. Far superior compared to normal "marine grade" ply. I talked to a naval architect and he recommended it. Very stable, engineered and manufactured to tight specs and easy to use.

Yup, made it!! Not much snow but in the negative teens the past couple mornings. 6.6 hours without power but the back up generator came in handy. Lost my phone service at the same time the power when out. I've got a feeling the underground took a hit when the early 70's 22K underground electric blew next to it.

Ben,
Chris is correct that I was the one who mentioned using LVL but that was as a alternate when someone was having a hard time finding the Doug Fir and wanted to stick with using wood. I do not know if the engineered has ever been used but I certainly feel it sure would be a great option. Strict and careful use of CPES and epoxy just as if you were using Fir would be a must.

I think Eric is referring to the guy in Denmark who use what looked like "Baltic Birch" ply. I would be concerned with it. I know birch has a extremely poor rot resistance and I'm not to sure if the plys are bonded with waterproof adhesive. Any epoxy coating failure or water from a poorly sealed fastener would be a problem.

I think Pete Brainard discussed the possiblity of using micro-lam material, but I don't think anyone actually used it yet. The doug fir is tried & true, so most guys are sticking with that. If you seal up the new wood correctly, the stringers will last along time.

Some guys are using Coosa board, but that is more involved.