71SN Stringer
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=16621
Printed Date: November-18-2024 at 3:45pm
Topic: 71SN Stringer
Posted By: FrankT
Subject: 71SN Stringer
Date Posted: February-23-2010 at 11:08am
I have been using the Wakeslayer and Keeganino threads as a reference as I undertake my own stringer replacement and I thought I would post some pictures as I move forward. This is my current status, dry fitting the stringers. Most of the PITA work is done and time permitting I am hopeful to get them set within the next two weeks.
FrankT |
Replies:
Posted By: TRBenj
Date Posted: February-23-2010 at 11:21am
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Frank, looking good!
Before you attach the stringers to the hull, I would recommend grinding the old gel out of the bilge where the new glass will attach (at least 6" along the stringers). Attaching glass to glass will be a much better bond than glass to gel. I found the gel to be thick and brittle on the BFN... so I ground every last bit of it out. One trick that I remember hearing was to glass the underside of the water channels before placing the stringers in the boat... much easier than glassing in place and upside down! ------------- |
Posted By: FrankT
Date Posted: February-23-2010 at 11:35am
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I intend to rough up the existing glass. Hopefully this will be the last of the PITA work. I am planing on glassing the stringers before I put them in with 4oz fabric and epoxy. I will try to post some pictures of this process.
FrankT |
Posted By: Okie Boarder
Date Posted: February-23-2010 at 1:04pm
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Looking good!
It's interesting to me to see all the notches the Nautiques have compared to my Supra. |
Posted By: WakeSlayer
Date Posted: February-23-2010 at 1:08pm
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Looking good Frank!
I agree with Tim on getting the gel out of there. I got about 95% of it. Assuming you are using CPES and covering with a coat of epoxy, I am not sure you need to glass the entire stringer before you put them in. Glassing the drains, however, will make life much easier. One thing about the drains is that I think it will be a lot easier to round them at the corners a bit. Corners are a biatch to glass. I am glassing over the drains and notches entirely and then grinding them out. Measuring and cutting holes in the fabric accurately is pretty much, for me, not happening. A grinding bit on the dremel is a hell of a lot faster and less frustrating. I do think the water intakes are going to be in your way too. They are easy to remove, and will be sealed better when re-installed with 5200. I am curious about the larger notch where it appears you from motor mounts are going to be. What was there before? What engine did you have. My mounts sit on top. I assume the larger notch further forward is for your pylon mount. I still have to figure out what to do there. Keep the pics and updates coming!!! Mike ------------- Mike N 1968 Mustang |
Posted By: FrankT
Date Posted: February-23-2010 at 2:35pm
I do have two notches. From the rear the first is for the engine mount. The engine is a 318 Chrysler LA and it site down about an inch. I have an angle bracket that sits between the mount and the stringer which will allow me to bolt through the stringer as opposed to just down into it. The second notch is for the pylon support. I will be using a piece of white oak for this. On the outside of the stringer I will be laminating another piece of white oak, about 30" long, that runs from the engine mount to the pylon mount for additional support.
FrankT |
Posted By: WakeSlayer
Date Posted: February-23-2010 at 2:40pm
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I would be curious to see what you are talking about with the mount. Is this something you are through bolting prior to installing the stringer?
My mounts sit on top and will just be lagged deep into the stringer on both the motor and the trans. ------------- Mike N 1968 Mustang |
Posted By: FrankT
Date Posted: February-23-2010 at 4:56pm
Here is a picture of he mounts. Left is the front and right being the rear. Not certain if the front angle bracket is factory or not. It came out with two lags but I am going to weld in studs at the engine mount and lag into the stringer in front and rear. On the side of the angle I plan on bolting through the stringer. The rear should be the same as yours. I plan to install it the same as the front.
FrankT |
Posted By: Keeganino
Date Posted: February-23-2010 at 5:00pm
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Nice pics Frank and great work. You are ahead of me by light years! My wood was supposed to be here yesterday but now is coming at the end of the week. I have a local supplier that I am getting all my glass from, but not sure yet if they have the epoxy I need. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: WakeSlayer
Date Posted: February-23-2010 at 5:06pm
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Interesting. I will dig up a couple pics of my mounts tonight. When I asked about how you were through bolting, I had something else in mind. Were these original? Or do you think someone fabbed them up to get around stringer rot??
I did something kind of similar with the trans mounts on the Mustang. I drilled a backing plate to match, and then alternated which way the bolts went so in the unlikely event that something got loose, I would still have the ability to tighten half of them, which would be more than adequate to hold them. ------------- Mike N 1968 Mustang |
Posted By: Keeganino
Date Posted: February-23-2010 at 5:29pm
My mounts have holes that look like you could through bolt them horizontally to the stringers. Cant see the holes in this pic but you can see how the mounts go down along the inside of the stringer.
 ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: FrankT
Date Posted: February-27-2010 at 8:19pm
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My son and I glassed one side of the stringers today, 4oz cloth and 2:1 epoxy. Hopefully tomorrow we will flip and do the other side. Plan is to set into the hull glassed and only have to do the fillet within the boat.
I mix epoxy by weight and total weight applied on both stringers was about 400 grams. Assuming two coats on each stringer, 4 total, a conservative estimate of epoxy is 3200 grams, 7 lbs., less than a gallon. 
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Posted By: WakeSlayer
Date Posted: February-28-2010 at 1:07pm
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Frank,
You are not going to glass the stingers in? I think you need to for strength. Also, no CPES? Did you put a couple coats of epoxy on the stringers prior to starting the layup? The secondaries look raw. I did look and my mounts are the same as yours, I just don't have the plate. I would be interested to hear if others with that year of boat have them, or if them were added after the fact to combat stringers starting to rot. ------------- Mike N 1968 Mustang |
Posted By: BuffaloBFN
Date Posted: February-28-2010 at 1:35pm
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If you through bolt a stringer and maybe glass a floor over it, how do you pull the engine and how do you set it on a stand? ------------- 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: SNobsessed
Date Posted: February-28-2010 at 2:37pm
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Greg - I think a typical design is to have a threaded bolting plate on the back side of the stringer - it has to be retained such that it doesn't drop when all the bolts are out! ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: FrankT
Date Posted: February-28-2010 at 3:36pm
The stringers will be glassed in. I intend to thicken some epoxy up, make a fillet and then glass over this with three layers of fiberglass tape, 2-3 inch pieces offset about an inch and then 1-6 inch to cover it all. This will give me three layers of 7oz at the joint which will be significantly stronger than the original detail. I am glassing the stringers up front to try to avoid glassing them within the boat. I did not thin and prime the stringers. The US composites product is very thin and the fir soaked it up quite well. All we did was lay out the cloth, weighted it, and then used a plastic trowel to wet it out. It worked quite well, smooth, bubble and wrinkle free. Once it's dry will trim the excess and use some narrow strips to seal up the cut outs. The stringers will get another coat or two brushed on as well. All I am trying to do is seal up the stringers and I normally wouldn't even glass them but the more I worked with the fir the more concerned I got as the grain is somewhat inconsistent. The cloth does provide some strength but what I am really using it for is to proved a good uniform thickness of epoxy. The engine mounting plate may have been added at some point but I don't know for sure. The welds don't look that great but the hole punchings look like a manufactured product. FrankT |
WakeSlayer wrote:Posted By: FrankT
Date Posted: March-15-2010 at 12:36pm
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Finally set the stringer last night. It took quite a bit longer to grind than anticipated. It would appear that Correct Crafts tolerance was not very tight and at several locations on the secondary stringers ½” of resin had to be ground out.
In my opinion you have to stabilize the trailer. It flexes and moves quite a bit and lowering the boat makes getting in and out a lot easier. 
What we did was to dry set the stringers first and then made several braces to hold everything the way we wanted. The braces in the front and back fit tight to the sides of the boat and hold the center line. Then we cut some legs and temporarily raised the jigged stringers about 18 inches so we could apply the epoxy underneath. Then we unscrewed the legs and lowered into the boat. After that we created some fillets with some plastic spoons. We may have some touch ups after the braces are removed. 
Here are some of my epoxy tricks. I like to use old coffee creamer bottles for dispensing epoxy while mixing. The spout allows small amounts to be poured and they clean up well with a paper towel. To mix larger quantities I make a mixer out of a dowel and flat piece of wood, this is part of a paint stick, and an electric drill. I reuse anything plastic for mixing. Taller cottage cheese containers work well if you are adding silica. I mix epoxy by weight and graduations are not necessary. 
FrankT |
Posted By: WakeSlayer
Date Posted: March-15-2010 at 1:16pm
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Looking good Frank.
I totally agree on the loose tolerances. I used a pretty good amount of filler between the hull and stringers in a couple spots. Mine were cut exactly like the originals so it was a factory thing. ------------- Mike N 1968 Mustang |
Posted By: Okie Boarder
Date Posted: March-15-2010 at 3:35pm
| Looking good. Interesting to see how you glassed the stringers. What's the reasoning behind using weights to "pull" the glass tight? Does this give a better bond than just rolling it or using a squeegee? |
Posted By: FrankT
Date Posted: March-15-2010 at 5:14pm
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We weighted to pull the fabric tight and eliminate any wrinkles or bubbles. We used 4oz fabric but if you feel heavier is better the same came be done with 8oz or multiple layers. The other advantage is keeping the surface horizontal is it allows better buildup per coat and eliminates any runs. On the secondary stringers we are doing the layout, then glassing, and then going to do our cuts. This should be quicker and better.
FrankT |
Posted By: FrankT
Date Posted: March-22-2010 at 12:35pm
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Make some progress but time to work on the SN is sometimes hard to find. Spoon fillets are done and half of the joints are taped. Tape detail is two layers of 3" offset about and inch then both covered with a piece of 6". With the drainage slots we basically have six locations about 4 feet long. Secondary stringers are rough cut but need to be sealed and glassed before they get set. Once everything is taped in a another cost of epoxy will be brushed on.
FrankT 
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Posted By: FrankT
Date Posted: March-31-2010 at 11:54pm
Some updated pictures. Primary stringers are in and taped. Secondary stringers are being glassed. Trying something different on these pieces as I intend to cut the notches and drain holes after they are glassed.
FrankT |
Posted By: connorssons
Date Posted: April-01-2010 at 1:17am
| Frank! boat looks great your almost there. |
Posted By: WakeSlayer
Date Posted: April-01-2010 at 1:19am
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Looks good Frank!
When do you think you will be done with the stringers? It is getting nice out!! ------------- Mike N 1968 Mustang |
Posted By: kapla
Date Posted: April-01-2010 at 1:28am
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no foam i guess...looking good!!! ------------- <a href="">1992 ski nautique |
Posted By: FrankT
Date Posted: April-01-2010 at 11:34am
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I am hopeful to get all the sub-floor and floor back in by the end of April but free time is the issue. If I am lucky the secondary stingers will get set on Monday evening as it takes 4 days to pre-glass.
FrankT |
Posted By: FrankT
Date Posted: April-06-2010 at 11:46am
Pre-glassed secondary stringers are in and fillets complete. Will hopefully find time to tape the joints this weekend. Once this is done the old floor line, kept as a reference point, will be ground smooth and the sides prepped for new carpet. I will be picking up some white oak for the floor battens and the pylon brace.
FrankT |
Posted By: WakeSlayer
Date Posted: April-06-2010 at 12:26pm
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Looks like you are making good progress Frank.
I will be interested to see what you do do for the pylon mount. Mine was mickey mouse welded iron bracket. I imagine I will do something like I have in the Mustang and I suspect you are going to do here. ------------- Mike N 1968 Mustang |
Posted By: FrankT
Date Posted: April-06-2010 at 3:51pm
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I have seen your pictures and will have something similar. There is a flange on my pylon that gets installed under the pylon cross member which actually bolts through the cross member and the plywood flooring. This flange also has a pin the goes through the pylon. The pin location establishes the thickness of the cross member unless I want to re-drill. Did you have this flange?
FranbkT |
Posted By: WakeSlayer
Date Posted: April-06-2010 at 4:14pm
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I have a small round flange on the pylon. The Mustang had a square one on it. I had to bolt that to the top of the crossmember, cut a square out of the floorboard, and then make a square 1/4" piece to cover that so it was flat for carpeting. ------------- Mike N 1968 Mustang |
Posted By: FrankT
Date Posted: April-06-2010 at 4:32pm
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I will have to take some pictures of it and post. From top down I have a round chrome trim ring, the flooring, wood cross member, mounting flange w/pin, and then the socket in the bottom of the boat which is also pined. Getting it to fit up properly is going to be a little challenging.
FrankT |
Posted By: FrankT
Date Posted: April-16-2010 at 11:17am
Making some progress. Floor battens have all been cut, fitted and are in the process of being sealed.
This is the bottom of the ski pylon cross member. Good piece of white oak with a cross grain doubler at the flange location. 
Top of the same. Next set is to fit again and drill the 4 holes for the pylon flange. 
My pylon is pined at the bottom of the boat and pined at the flange. The cross member is sandwiched between the flange and the stainless trim ring on the top. 
My stringers are notched for the cross member and I have laminated a long piece of white oak on the outside of the stringer, goes back to pick up the engine mount and a short piece on the inside. This should give a good surface area to epoxy and screw the cross member in. 
Hopefully will have the time to tape the secondary stringers and get the floor battens epoxied in this weekend. FrankT |
Posted By: Okie Boarder
Date Posted: April-16-2010 at 4:15pm
| It's looking good! Look at all that purdy wood. ;-) |
Posted By: FrankT
Date Posted: May-03-2010 at 8:36pm
It has been a while since I have posted some pictures but work is progressing. All the floor battens are in and sealed. The flooring templates have been made and we are hopeful to set the new 1/2" plywood floor on the weekend.
Battery box detail. Wood piece with returns to hold the plastic box from moving. Floor will be removable from this point to the kick panel. Bilge pump is accessed by removing the battery box. 
FrankT |
Posted By: WakeSlayer
Date Posted: May-03-2010 at 8:46pm
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Sweet. Looks great, Frank.
------------- Mike N 1968 Mustang |
Posted By: Okie Boarder
Date Posted: May-03-2010 at 8:46pm
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Frank,
That's looking really good. |
Posted By: Keeganino
Date Posted: May-04-2010 at 7:28pm
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Great work! I like it. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: FrankT
Date Posted: June-21-2010 at 11:45am
Some additional pictures of the progress. We launched last weekend but didn't have the camera. Still quite a few fit and finish items to perform but at least it is usable.
At the dock. Front and rear panels are removable and still to be carpeted. 
Chrysler 318. Developed a fuel delivery issue on Sunday. Hopefully nothing major. 
Interior reinstalled after a good cleaning. 
On the lift. 
Taking mom for a ride. FrankT |
Posted By: WakeSlayer
Date Posted: June-21-2010 at 1:53pm
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Nice job Frank!!! I haven't touched mine in a while. Makes me want to get back at it. ------------- Mike N 1968 Mustang |
Posted By: Keeganino
Date Posted: June-21-2010 at 7:09pm
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Looks great I love the red deck! ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: Waldo
Date Posted: June-21-2010 at 11:33pm
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Frank nice ride.
Waldo |
Posted By: 8122pbrainard
Date Posted: June-22-2010 at 9:12am
 ------------- /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: connorssons
Date Posted: June-22-2010 at 11:21am
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Love the red!
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