1989 BFN Rebuild
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=33685
Printed Date: November-17-2024 at 2:36pm
Topic: 1989 BFN Rebuild
Posted By: Ski Oz
Subject: 1989 BFN Rebuild
Date Posted: May-26-2014 at 12:00pm
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I am in the middle of a complete rebuild of a 1989 BFN with 454. When I bought the boat I knew it had motor problems (water had gotten in cylinders). Turns out it had slipped a rod bearing, but was otherwise okay. Rebuilt the motor and had the transmission overhauled as well. Just I was about to put the motor back in I notice some real soft spots up by driver seat. I knew that meant stringers and foam (I had been reading tons on CCF from all you guys). So rather than put the motor back in an worry about it, I bit the proverbial bullet and cut into the floor. I found exactly what you would expect - wet foam and rotting wood stringers. Well that's how I got here! My plan is to do a composite rebuild using Coosa Bluewater 26 and use polyester resin rather than epoxy (seems like overkill and a lot extra expense from everything i have read plus it helps justify the cost of the Coosa). At most I would only like to foam in the front section back through the drivers seat. What I am trying to work out now is how to best layout the stringers and supports w/o foam. You will notice in the pictures below that the 89 BFN had the following: - Main stringer - made from a 2x4 and is 10'-6.5" long. The Engine cradle rest on these. - Secondary stringer - Probably made from a 1x10 as it is 8.5" at it tallest point. It is 13'-10.5" long. - Third stringer - Could have been made from 1x6 stock. It was pretty much destroyed and came out in pieces, so I haven't measured this. I would like to use Coosa 1/2" x 3 layers to build the mains. For the Secondaries I could use Coosa 3/4" but from other builds I have seen here the secondaries were eliminated in favor of cross member support (re Another BFN Rebuild). How important is the third stringer (which I haven't seen in any other rebuilds or pictures)? Should I just duplicate what is there and replace and put in a coosa floor for stability? Would love to hear your recommendations... Finally - one more question. How is the ski pole in front of the engine laid in? Can I just cut it out? (I broke the bolt off trying to get it out. I drilled the bolt out but was still unable to extract the Pole. Figure if I can get it out on the bench it will easier to repair...) Cheers - Mike  Boat when I bought it.  I think oil might be a better choice to run in here...  This is when I found the soft floor  First reveal after floor removed...  Here you can see all three stringers  Rear View before the foam removed  Here is where I am as of today... |
Replies:
Posted By: SNobsessed
Date Posted: May-27-2014 at 12:35am
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Sounds like a good plan. Just for info, epoxy resin is stronger & has a much longer pot time, so it is easier to work with. More money, upfront but after you are done you won't regret using the better material. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: TRBenj
Date Posted: May-27-2014 at 10:42am
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That 3rd set of stringers is a new one to me- there was no such thing in our 79. I haven't seen anything of the sort in any of the other bfn rebuilds either. Are you saying there were no ribs and bulkheads to speak of? That is strange, they seem to do a fine job of keeping the v-hull in the shape of a vee. It seems strange for cc to have switched construction techniques so late in the boats run (90 was the last year). I wonder if the boat had been restrung previously? If you've never worked with the different types of fiberglass before, I'd highly recommend epoxy. Not only is it stronger and less apt to absorb water, it's also a lot easier to work with. That alone is worth the extra cost on a project this scale. The cost shouldn't be appreciably higher- check US Composites for materials. Oh, and a '89 would have been built with vinyl resin (ame4000) not poly- so I'd use that as a minimum. I'm not sure if poly will stick to vinyl... I know it doesn't stick to epoxy. Epoxy sticks to everything. |
Posted By: uk1979
Date Posted: May-27-2014 at 5:02pm
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Just something you may wish to conceder , using HDU board in just one thickness with extra build up on your cloth/glass around the stringers or build up in layers with cloth in-between, from what I been shown Coosa is great light weight but so is the foam in it too, HDU is much denser, so fixing/through bolting is much less of a pain. This is one available but there are others around, would think if you’re in FL there be plenty around used by the Theme Parks Builders, Boat Builders, Sign guys... as always it will come down to cost as its no cheep but it’s easy to work/cut, we been using a European one for a year now and been surprised how well it works even on CNC routers. http://precisionboard.com/applications/hdu-marine-board/" rel="nofollow - HDU Board This may well be the same type Hasbeen Skier guy used on his BFN rebuild. ------------- Lets have a go 56 Starflite 77 SN 78 SN 80 BFN |
Posted By: Ski Oz
Date Posted: May-27-2014 at 10:26pm
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Thanks for the responses! I am a newbie at this boat building stuff but have always loved correct craft and just couldn't let a potential gem like this one get by with out some serious care and attention! 3rd Stringer - From everything I can tell this was all original and the first time the floor has been up. No ribs - just long stringers and foam. I am leaning toward just recreating the stringers as in the pictures and covering with 1/2" Coosa - maybe 3/4" under the front area. Seems like this would be easier than custom building/fitting the the ribs in aft sections. Epoxy vs Poly - I really hate to spend the extra bucks but you make a good case - particularly with respect to ease of use. I have done a little fiberglass work but may moons ago. Quite a different product selection these days. HDU - Very interesting. Will it take a lag screw like wood? That could be a real bonus. Any idea how it compares price wise to Coosa (1/2" is $265 for 4x8 sheet)? |
Posted By: SNobsessed
Date Posted: May-28-2014 at 12:02am
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There is an even more important reason to use epoxy - The factory resin was epoxy ('89 was the 1st year for this) so polyester wouldn't bond well to the base material. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: Ski Oz
Date Posted: May-28-2014 at 12:30am
That definitely sold me!! Though my pocket book is crying :( The knowledge on this forum sure goes deep - thanks that could have been a big mistake... |
SNobsessed wrote:Posted By: bhectus
Date Posted: May-28-2014 at 9:50pm
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Michael, if you haven't found this thread yet, it will be very helpful in your stringer project. Lots of great useful info with pictures to help guide you: http://www.correctcraftfan.com/forum/forum_posts.asp?TID=9543&PN=1&title=weeding-the-pumpkin-patch" rel="nofollow - Greg's (BuffaloBFN) Pumpkin Patch rebuild ------------- '02 Ski Nautique 196 w/ 5.7 Apex bowtie - Sold '87 Barefoot - sold '97 Super Sport Nautique - originally custom built for Walt Meloon '97 Ski Nautique '83 SN 2001 |
Posted By: Ski Oz
Date Posted: May-29-2014 at 3:39am
| Thanks I did read it and plan to go back and review it some more. I find if I do some work on the boat and then go back to re-read sections,I get a better understanding. Do you know what year his boat was? I am looking around for info/pictures closer to year model . |
Posted By: kapla
Date Posted: May-29-2014 at 6:24pm
IRCC its an 88 bfn... ------------- <a href="">1992 ski nautique |
Posted By: Ski Oz
Date Posted: May-30-2014 at 2:54am
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I found one thread on here for a 1989 ski Nautique rebuild. Its stringer configuration is not the same as I found in this 89 BFN which had a 3rd set of stringers. Can anyone confirm if this is factory correct? Also I am still trying to get the center pylon out. I was able to slip the engine cradle up and off but twisted the bolt off that holds it in the cup base. How is the base installed? Is it just glassed in and can I grind it out to remove? Thanks - Mike |
Posted By: 8122pbrainard
Date Posted: May-30-2014 at 7:20am
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Mike, The cup at the keel is glassed in so it can be ground out. The pin in the cup can be a PITA it get out since CC put the cup down instead of up so water collects in the cup causing rust. This is just another one of CC's fantastic design engineering problems.  They didn't even consider putting in drain holes in the cup nor did they make it out of SS!!!------------- /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: uk1979
Date Posted: May-30-2014 at 10:27am
Mike, You got me thinking on bolting straight into HDU so tried it out on a off cut (2 bonded together) we use here....Spec is a fine grain 15lb HDU 2’inch thick which I lag bolted (4in) up through a steel plate into the edge of one layer of the off cut around centre with a strap hanging 119lb off it....no pilot hole just wound it straight in with a wrench. My thoughts, yes you can screw into HDU coarse thread needed....can strip/over tighten 4’inch lag bolt @ around 15lb in the sense that it just turns with the HDU rides over the threads not stripping out like metal. If I were to use on a stringer project would go for 30lb + if using HDU to lag into only....wood screws also work well into HDU with coarse threads and would use longer screws/lags than in a wood project. There are more test results on the link... under technical with west system bonding. As for cost you will need to call a HDU supplier in the US as we have lots of shipping costs in the UK.   ------------- Lets have a go 56 Starflite 77 SN 78 SN 80 BFN |
Posted By: TRBenj
Date Posted: May-30-2014 at 10:59am
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Roger, it looks like HDU is available in greater densities (up to 75 lb/ft3)... Which one did you run your test on? Coosa is only available in a few, primarily 20 and 26 lb/ft3 (the latter being the choice for stringers). Other than that, I see that both products are closed cell foam based (urethane/polyurethane). Coosa has layers of roving and strand glass built in- I see no mention of that on the HDU. Just curious what makes you think it's a better material, as I don't see anything obvious. The hull shape of a 89 ski nautique shares nothing in common with the BFN, so that is a poor reference for comparing the structure. The bfn hull was unchanged 79-90 so I'm having a hard time understanding why cc would deviate from a proven structural configuration late in the boat's run. I'd be inclined to say yours was altered a some point, but it's tough to be sure. The larger v-hull Fish Nauique had 3 sets of stringers but also had a number of ribs and bulkheads, as commonly seen on v-hull boats. I find it very strange that this particular boat is lacking that seemingly important element. If be inclined to rebuild it with those features added back in. |
Posted By: uk1979
Date Posted: May-30-2014 at 1:28pm
Tim, As I said in my post above the off cut I used is fine grain 15 lb on test...you are right to point out all Coosa is a HDU with glass on each side (not sure if there weights are with or without glass)but for many Coosa is not readily available around the world, HDU is and as you will be adding glass over it you can fine tune the Core (HDU) to suit their needs/application, over cost availability in the US or around the world, it’s just another option to play with. Better or not will always be down to execution/spec but more important there are more than one way to go. ------------- Lets have a go 56 Starflite 77 SN 78 SN 80 BFN |
Posted By: TRBenj
Date Posted: May-30-2014 at 1:44pm
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The site timed out and lost my whole post... No way am I typing it all again! The highlights: 1. Coosa has glass throughout in layers, not just on the outside. 2. Coosa is available in greater lengths and thicknesses so 1-piecing the mains should be an option. 3. The original poster is in Florida, no? (Despite his misleading screen name). No issues with availability. 4. Set up an account with Composites One and a 4x8 sheet of 1/2" b26 should be <$200 5. Agreed, it's good to have options! Lagging to denser HDU sounds good to me. |
Posted By: Hollywood
Date Posted: May-30-2014 at 2:07pm
If your hull sides don't have cracking then I wouldn't be worried about changing that stringer layout. I was swayed towards epoxy for its superior adhesion, not that stronger is needed, but it will compenste for rookie craftsmanship! I'm rebuilding the same hull and will not copy the many bulkhead design either. Look at any walk through Sport. Substantial v-hull up front, ski locker (no solid floor) and lastly no deck providing support either. ------------- |
Posted By: Ski Oz
Date Posted: May-31-2014 at 2:15am
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The plan this weekend is to get the pylon out, do some more grinding on the starboard side (I like the idea of doing one side at a time) and ponder which composite material to go back in with. I really like the idea of being able to use lag bolts, particularly on the engine cradle to mains and the seat to the floor. (thanks for the test UK!) Not having worked with either, I wonder which is easiest to cut/shape? I am in S Florida - West Palm Beach area. Though I did live in Australia for bit around 2000 that's not where the Oz comes from. I am an older Gezzer Engineer (electrical) who has a reputation for being the guy you call when no one else has been able to fix it (and the customer is usually ticked off!). Well the younger techs' pinned the name Oz, from Wizard of Oz, on me. Naturally, when they saw Video of me barefootin on my 60th birthday comments like " the Oz skis too but without skis!" popped up. All good fun. I bought the BFN a short time later, signed up on here and well, it just popped in my head.... |
Posted By: Ski Oz
Date Posted: May-31-2014 at 2:52am
I have a supplier here in West Palm but his price is around $265 for 1/2" (in stock) and $525 for 1-1/2" (all 4x8 sheets). I noticed Composites One has a distribution branch in Miami - about an hour and 15min drive for me. Definitely worth it if one can save 25%. To your point about the ribs: I am still thinking it through but with out the foam in the aft sections I will need something to replace that support. Maybe not as many ribs as you did but at least enough to add support and hold the floor. One bulkhead just forward of the engine and maybe one about halfway back to where the hoses turn up - let the foam do the rest... btw - Do you sleep? I saw a post at 4:20am! Mike |
Posted By: TRBenj
Date Posted: May-31-2014 at 9:53am
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Petes an early riser and the forum software is off by ~45 min, hence the early timestamp. Both Coosa and the HDU roger linked to are foam based, the Coosa has layers of fiberglass as well. Coosa is very easy to work with- you can cut and grind it with regular wood blades. I traded messages with joe about your stringer configuration- we agree that it's really only viable if you keep the foam. Anywhere you want to leave it out, I'd be putting bulkheads or ribs every 12-16". Coosa holds screws just fine, especially if you have a layer of glass on either side. This is how we mounted the seats. Mounting the cradle using lags is a little more dicey- I'd through bolt it. It would require a fairly basic structural change- both BJ (hasbeenskier) and I have done this on our composite structure BFN's. |
Posted By: Ski Oz
Date Posted: June-23-2014 at 10:14pm
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I have been spending quite a bit of time working on revising the stringer design while I grind and grind and grind... Not to mention this is the worst time to work outside here in florida as it hot and very humid! The following is some CAD work I have been doing. |
Posted By: Ski Oz
Date Posted: June-23-2014 at 10:26pm
 This is the original layout (left) vs. Plan (right)  Here's how the Stringers workout  Here's how they layout on the expensive Coosa Board. I thought about putting another stringer past the first main bulkhead (similar to what Benj did) but wasn't sure. I am going to block out between the main and secondary and not put back foam and floor here. That way I can through bolt the engine cradle. The ones on top that bolt down, I plan on drilling out an oversized hole and filling with epoxy. Thought I would then drill and tap threads in it and go that route. Foam wise I was thinking I would do that just fore of the bulkhead at the end of the stringer. Not sure whether I will foam aft or not. Crazy question but has anyone ever considered using stryfoam?? |
Posted By: JPASS
Date Posted: June-23-2014 at 10:57pm
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Cool exploded view. If I ever have to do my stringers, I'm gonna give you a buzz. ------------- '92 Correctcraft Ski Nautique |
Posted By: Ski Oz
Date Posted: June-23-2014 at 11:03pm
Could someone help me identify the device in the picture below. I was in the bottom of the Bilge by the prop shaft. it has 2 wires on it but was not hooked to anything. I have since scraped it off (it was only attached with a bit of putty) and removed it. just curious??? Am I being bugged, Mr. Snowden? |
Posted By: Ski Oz
Date Posted: June-23-2014 at 11:07pm
I have to give cudos to TRBenj. He did it originally in his BFN rebuild. It sure helps when you want to lay things out... |
Posted By: SNobsessed
Date Posted: June-24-2014 at 12:03am
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Someone here pointed out that stryofoam + gasoline = napalm. The marine foam is expensive, but it may save your life someday. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: Ski Oz
Date Posted: June-24-2014 at 12:27am
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[Knew there had to a reason...it's definitely waterproof and bouyant though! I keep debating with myself about the foam... On one hand I want to avoid any possibility of rot yet if I do a good (careful) job and use the better c!osed cell foam I should have minimal issues. I figure I will pass the boat to my grandkids (13 & 8) one day and it might save them... Probably do the foam. |
Posted By: Hollywood
Date Posted: June-24-2014 at 2:28am
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That is a pod for a depth finder. You are making a lot of work for yourself with all those pieces. Not so sure on tapping threads in epoxy. ------------- |
Posted By: Ski Oz
Date Posted: June-24-2014 at 2:46am
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Thanks that was driving me crazy trying to figure that out. I guess if I were more of a fisherman I would know that. Lots more work but I have to agree with earlier comments that it will be much better when done with bulkheads and ribs. At my age (61) I likely won't ever do this again! |
Posted By: TRBenj
Date Posted: June-24-2014 at 8:56am
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Yep, lots of work but I see no other viable option without the foam. If there's no wood in the structure, it obviously can't rot, but water always seems to find a way in no matter what you do- and I hate the idea of carrying around waterlogged foam. We added just enough foam in the nose to ad a little buoyancy in case the boat swamps... But leaving it all out is an option too. You can put more on the underside of the deck if you're worried about floatation. Anything that goes under the floor should be the pourable closed cell type, IMHO. Looks like a good structural plan. What are you doing for the floor? Have you tweaked the secondary stringer height to compensate for the 1/2" change in floor height if you're using Coosa? Your delux interior bases might not adapt to a change in height nicely. I don't see any details for drains between compartments or scallops for motor mount bolts... I'm assuming you just ommited those details in your drawing but have given them some thought? I think you can lay out board #1 a lot more efficiently to minimize scrap. If you have enough through bolts going through the side of the stringers, you can skip the ones going down from the top (we didn't use any). |
Posted By: Ski Oz
Date Posted: June-25-2014 at 3:37am
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Great feed back! Floor - Planning similar to what you did. From the Ski pole to the dash I would do 3/4" coosa and 1/2" elsewhere. Also, add 1/2 piece at the ski pole. For the removable hatch behind the engine, I am thinking 3/4"x4 glassed and sistered to the secondaries set 3/4" below the top of secondaries (this in lieu of the 90 degree alum angle bar in the original). This will will provide a ridge for a hatch (made of 3/4") to set on. Stringer height - It is probably wasteful but I measured both the mains and secondaries at their highest. On the coosa sheet layout I was going to cut the along the full length at this width. Then I would use, the ones I removed (managed to get the starboard out with little damage and intact) as a pattern after I put the coosa ones together full length (the scallops would happen in this step). From there, I would do final adjustment/trimming to height to compensate for the floor and some buildup of glass. Drains - To be honest I really did not put a lot of thought into the drains. If I do it in the aft sections so they would drain into the bilge, how big a hole do you make? Did you fit some kind of tube or small pipe between the stringer and hull to make sure it stayed open when bedding and glassing it in. Layouts - Fully agree I can get it more efficient. still playing with it... Engine Cradle - I should have thought of that - it is so obvious! (while i slap my forehead and say "Duh!"). I do have one question though. Did you have to do a lot of adjustment on the engine and xmission mounts to get it to line up properly with the prop shaft? I am going to try an get it as close to original heights as possible but was not sure how close I need to be... Overall - this was my first cut at a plan so I could get a better idea on materials. I want to shop the material a bit as I have several local suppliers (including US Composites) right here in my "backyard". I did go ahead and buy two 1/2" sheets of coosa ($210 ea) but haven't cut yet - maybe this weekend. |
Posted By: 8122pbrainard
Date Posted: June-25-2014 at 7:32am
Use a toy balloon to fill the hole after laying in the glass and resin. I'd suggest about a 2" diameter. ------------- /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: TRBenj
Date Posted: June-25-2014 at 8:59am
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Did you check with composites one? I'd probably skip the 3/4" in the front floor if I were to do it again. 1/2" wth glass on both sides is plenty strong with supports every 12". The extra care that needs to be taken to account for that extra 1/4" of thickness is a real pain. Doubling up in the area of the pylon where the floor spans the bilge isn't a bad idea, but less of a concern for you than us, as you pylon simply passes through it (ours through bolts to it). 3/4" on the removable panel isn't a bad idea, though we doubled up 1/2" on ours. You might want to add the angle aluminum for support, as holding up that 3' wide panel with only 2 strips of 3/4" seems dicey. I'd put some thought into your drain plan. Remember that a drain will allow water out of a compartment but it will also let it in... That is the downside to draining everything to the bilge. I have seen inaccessible under floor drains plugged up with debris from the bilge (leaves, etc) and cause a compartment to hold water for an extended period of time. So go with large drains (2" as Pete suggested) on all "blind" drains. On our bfn, we drained cavities together but not to the bilge and it's worked out well for the most part. We left access points that we check periodically instead. Drains between accessible cavities (mains and secondaries for example) can be smaller since you can see that they're stopped up and probe them if necessary (we did 1"). The balloon idea is neat but probably not necessary with the Coosa. Since everything will be pre-glassed prior to install, you can glass them then, or just give them a coat of resin once installed. Since you're not making any major changes to the main stringers and are reusing your cradle, just put it back in the same place and you'll be fine. There is quite a bit if adjustment In the PCM mounts to allow to align even if you're off a little bit (nailing the lateral location will be more important than the height- but this shouldn't be hard if you're not moving the pylon). We made major changes to stringer width/stance and height, and custom built our cradle (didn't have one originally) so we had a lot more "figuring" to do than you will to get engine placement in the ballpark. |
Posted By: Ski Oz
Date Posted: June-26-2014 at 10:48pm
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Sorry to be a little slow on the response. I was buried on a rush project at work... Anyways - I noticed that Composites one was located in Medley Fl (e.g. Miami) which is 1H 20min from my house. I found Merrit Marine and they were reasonalble and 10 minutes from work. The time savings alone is worth it to me to spend 10 to 15 bucks more per sheet... Floors - I have a bit more spacing (15") aft of the end of the main stringers but 12" forward of that. That's close enough for me to follow you advice/experience. For the area around the pylon, I guess I thought you had beefed it up a bit due to the wider berth between the secondaries rather than pylon support. Do you think 1/2" is enough? On the Aluminum angle for the removable panel, what did you end up doing? Lot's of screws with 5200? Drains - Thanks for prodding me on this. I went back and spent some time re-reading your post/plan on the subject and reviewed your pictures. I like/get what you did, though I am not real clear on the battery box access (I read your later lessons learn post). Did you not put in the planned drain from the bat box to the bilge? Has its access port work out? Keel - I noticed you put in a keel stringer. How important do think that is? Cradle - I should be okay here as I am taking much care to put it back in same location by doing one side at a time so it lines up with the old. With the available adjustment it sounds like I have some room for error... Thanks again, for taking the time/patience to share you expertise/knowledge - It is greatly appreciated!!! Mike |
Posted By: TRBenj
Date Posted: June-27-2014 at 12:26am
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I'd double up the half inch just where it spans the bilge at the pylon. No need to go full width or put 3/4" up front- I'd say it's overkill. We did not put a drain between the battery box and bilge. I could not find a solution that I trusted that would have been easy to route through multiple bulkheads. We did keep the port hole facing the front as an access point. The problem I reported about the battery box collecting water is true, though it was probably not a major contributor to the water we found in the hull (I later found a small hole from the grinder). I'd probably relocate the access point to somewhere elevated, or at the very least at floor level, so as not to facilitate water intrusion. Having access to inspect and drain those cavities was a great idea nonetheless- I wouldn't consider going without on a boat with sealed compartments. We removed wood from the keel up front. We made it a little taller and extended it rearward, but no major changes from the original configuration. I think I mentioned adding some blocks to the sides of that piece so as to "catch" the screws from the forward tracking fin- even if remove they wouldn't leave a through hole. If yours didn't have wood there it's probably not critical to add though. |