Stringer Materials
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=16193
Printed Date: November-18-2024 at 4:24am
Topic: Stringer Materials
Posted By: jbenbri
Subject: Stringer Materials
Date Posted: January-02-2010 at 7:51pm
| I saw a psot recently discussing the possibility of using lvl for the primaries but can't seem to find it. Anybody tried this? |
Replies:
Posted By: SNobsessed
Date Posted: January-02-2010 at 9:16pm
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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. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: eric lavine
Date Posted: January-03-2010 at 1:01pm
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i did see some ply laminated together and used as mains, Denmark guy ------------- "the things you own will start to own you" |
Posted By: 8122pbrainard
Date Posted: January-03-2010 at 7:55pm
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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. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Gary S
Date Posted: January-03-2010 at 9:44pm
Hey look who dragged himself thru the frozen tundra to go get internet access! 0 out, 10 feet of snow and up hill both ways.
 ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: 8122pbrainard
Date Posted: January-03-2010 at 11:06pm
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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. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: jbenbri
Date Posted: January-04-2010 at 12:49am
| Thanks Pete. I've e-mailed you before with a couple of questions and I am heading toward a complete stringer job. I live just south of Atlanta so I can check out Sweetwater that Buffalo used. I just started looking at Lowes and they looked at me kind of strange when I asked about the Douglas fir. Remembered that I had seen some discussion about the LVL which they can get me with no problem and it is 5 minutes from the house. The CPES and epoxy will be used for sure. I will get some pics up this week hopefully. Right now I am trying to get the foam out so I have a couple of weeks at least to figure out wood. Thanks for the help. The info here is great. |
Posted By: DAY_TRIP
Date Posted: January-04-2010 at 1:32am
| 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. |
Posted By: jbenbri
Date Posted: January-04-2010 at 1:49am
| I'll check it out as well. Thanks. |
Posted By: jbenbri
Date Posted: January-04-2010 at 2:00am
| Would I laminate it together to get the width and length needed? |
Posted By: Fl Inboards
Date Posted: January-04-2010 at 12:46pm
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Anyone in the Atlanta Area have a line on Doug fir? ------------- Hobby Boats can be expensive when the hobbyist is limited on their own skill and expertise. 1993 Shamrock "fat" 20. 2008 Nautique 196 5.0 |
Posted By: 8122pbrainard
Date Posted: January-04-2010 at 1:37pm
Jody, Check out Sweetwater. I think they do have a web site that Greg linked at one time. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Fl Inboards wrote:Posted By: Fl Inboards
Date Posted: January-04-2010 at 2:31pm
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Thanks Pete,
Sweetwater had full dimential and I have a planer. I ordered and stocked up on doug fir lumber will take a trailer up on Friday when I go to the AWSA southern region meeting. ------------- Hobby Boats can be expensive when the hobbyist is limited on their own skill and expertise. 1993 Shamrock "fat" 20. 2008 Nautique 196 5.0 |
Posted By: inglesideshawn
Date Posted: January-04-2010 at 5:52pm
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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 ------------- 1989 nautique |
Posted By: 8122pbrainard
Date Posted: January-04-2010 at 6:16pm
Ben, Be very carefull if you go with one of the plywoods even the Meranti. You must keep in mind that every other ply of a plywood the grain is in the wrong direction for the longitudinal stress of a typical stringer in a boat hull!! Even though I'd say the original solid Fir stringers are over engineered, the plywood will be basicly 1/2 the strength. Splicing ply together to get the length needed makes the situation worse: IE, if you laminate 3 pieces of 1/2" together to make up the original 1&1/2" thickness, you only end up with 2/3rd's the strength at the splice point then less by 1/2 with the grain direction problem. The advantage of LVL is all the plys are in the same direction!! The disadvantage is it is thicker. 1&3/4" instead of the 1&1/2" plus it is slightly heavier. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: BuffaloBFN
Date Posted: January-06-2010 at 12:01pm
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Sorry I missed this.
http://sweetwaterlumber.com/default.htm - Sweetwater Lumber ------------- http://correctcraftfan.com/diaries/details.asp?ID=2331&sort=&pagenum=12&yrstart=1986&yrend=1990" rel="nofollow - 1988 BFN-sold "It's a Livin' Thing...What a Terrible Thing to Lose" ELO |
Posted By: DAY_TRIP
Date Posted: January-08-2010 at 12:10am
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. Everything is in metric. I don't agree that it is half as strong but that is not worth arguing. My barefooter hasn't folded in half yet so that is a good sign 
I built composite stringers on my ski nautique just to say I did and that was 10 times the pain in the neck. |
Posted By: 8122pbrainard
Date Posted: January-08-2010 at 10:25am
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. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: eric lavine
Date Posted: January-08-2010 at 10:34am
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I always go back too, some of these boats havnt had stringers in them for 10 years and went unnoticed, because of length i have laminated ply together in different brand boats but have no way going back to check the progression. the biggest thing i kept in mind was waterproofing the sht out of it, Im not condoning this method in any way, i removed mush that was in there for years and felt at the time balsa would even of worked. i too also go back to balsa cored boats, once wrapped it is very strong and light....but like anything once water gets to it... ------------- "the things you own will start to own you" |
Posted By: eric lavine
Date Posted: January-08-2010 at 10:35am
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8000 thats alotta BULL SHEETING ------------- "the things you own will start to own you" |
Posted By: 8122pbrainard
Date Posted: January-08-2010 at 11:00am
Eric, this is very true especially with a Balsa boat. However, with the typical ski boat I don't think anyone really knows how much of the strenght comes from the glass over the stringer VS the stringer itself. I do know that in the early days of the glass hull the stringers were the main strength. They weren't even covered at all and simply attached to the glass hull with small strips of glass/resin. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: jbenbri
Date Posted: January-08-2010 at 9:15pm
| 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. |
Posted By: 88Bishop
Date Posted: January-08-2010 at 10:14pm
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I am in Kalamazoo, MI, and I have a stringer replacement job waiting for me as soon as the snow melts. I am having a great deal of trouble locating doug fir around here, anyone in the area have a suggestion? I was thinking I would just use yellow pine, but the lvl sounds like a good option too. Unfortunately budget is an issue, paying $400 to ship lumber from Oregon is out. I am going to cover it all in epoxy, how much does the type of wood matter if it is sealed up? ------------- |
Posted By: 8122pbrainard
Date Posted: January-08-2010 at 10:27pm
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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:
------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |