Prisma Preform?
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=19316
Printed Date: November-13-2024 at 9:47pm
Topic: Prisma Preform?
Posted By: Ranger
Subject: Prisma Preform?
Date Posted: September-03-2010 at 8:43pm
|
I have an 86 SN which I am planning on restringing this winter. I've read every post that I can find on the subject, but have only found a couple on composite stringers. I came across the Prisma Preform product and talked with the President at the company for about an hour. I do not have a cost estimate yet, but the product seems to be something I should consider.
Most people use wood for obvious reasons, but has anyone looked at the Prisma products? What are your thoughts? Thanks in advance |
Replies:
Posted By: YooperSully
Date Posted: September-03-2010 at 10:40pm
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My question would be.... Are these made for active or in active stringers? Active being something that's going to take the torque, flex, and weight of a V-8 on them, and inactive being the secondary's that are there for shape and strength of the hull and floor.
I stumbled across a similar product in West Systems catalog, but concluded that they wouldn't be sufficient for direct drive. Who knows.. I could be wrong. If they are what the owner/president claims, does the math work out? I guess what I mean is do they have the height you need so that when applied your main stringers are at the right spread for your engine? What about your engine mount bolts? Do you need to epoxy fill these and if so how much strength are these going to have when all they are held down to is foam? Believe me I'm a supporter of composites, but I don't think this is the right one for your application. ------------- 87' 2001 |
Posted By: Ranger
Date Posted: September-04-2010 at 1:46am
|
All good comments. I have similar concerns about the load carring ability of these, but they are being used in other OEM applications. So maybe I'm not educated enough on the subject.
According to the company, they will design the stringer to my height without any problems. As far as the engine cradle, I would have to insert either wood or another composite material to bolt to. But again, they say they do it with other manuafactures all of the time. I don't have any manufacture names, but I am sure that I can probably get them so that I can confirm how they work. I know of another project that is in process of using them and they are suppose to be sending me some links to others that I can check out. So far, I have only seen them in one outboard application, but again, I'm told they are in inboards as well. I know that I am more familiar with wood and I would rather return it back to factory spec's, but I also know that I should make sure that there isn't something better out there. |
Posted By: tuna_tugger
Date Posted: September-04-2010 at 3:09am
------------- Don Liberman |
Ranger wrote:Posted By: BuffaloBFN
Date Posted: September-04-2010 at 10:58am
That was my reasoning as well. I went back very close to factory with my boat; and on recommendations from this site, I used CPES(clear penetrating epoxy sealer) on all of the new wood. Several here have used it and I think all agree that it's good stuff. I think it'll outlast me unless I leave it like I found it. 
 ------------- 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: Ranger
Date Posted: September-05-2010 at 12:56am
|
Thanks for the replies. After a little more research, I think I am going to stay with douglas fir. The boat has lasted 24 years so far, and I am sure it will last at least that much more when I am done.
I spent about 4 hours with a local boat repair shop today and the owner sat down with me, pulled out several types of materials and went over in detail the complete process. I have already completed a couple of other boat restorations, but the information I gained from someone who has been in the business 40 years, was priceless. Thanks again. |
Posted By: tuna_tugger
Date Posted: September-05-2010 at 3:02am
------------- Don Liberman |
Posted By: BuffaloBFN
Date Posted: September-05-2010 at 10:16pm
Do tell! ------------- 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: Ranger
Date Posted: September-06-2010 at 1:16pm
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According to him, he would use all doug fir, even on the secondary stringers. In other words, no pine. He scribes in each stringer tight to the hull. After he has each stringer dry fit, he builds jigs to keep them in place. To set each stringer, he starts with 2 strips of 3 oz. mat under each stringer. Where each length of mat meets, tear the edges so that they intertwine for a stronger joint. Set the stringer and clean up any excess. After a good 1 or 2 day cure, he then does a layup a 3 oz mat with 22 oz cloth over the entire stringer. Sometimes, he will split the 3 oz mat into two 1 1/2 half oz layers, but lay's them up at the same time. He will take the mat and cloth 3 to 4 inches on the bottom of the hull on both sides of the stringer. Once he has all of the stringers done, he will then lay mat and roven in the hull between each stringer, essentially tying everything together. The mat and roven goes between each stringer and up the hull sides at least 6 inches.
After the bottom is done, he would use 3/4 inch ply for the entire deck. Seal the bottom of the ply with at least 2 coats of resin. The deck should be a couple of inches short all the way around the perimeter. Be sure to set the deck on 3 oz mat strips where the deck comes in contact with all of the other members. Then take mat and cloth tabs and glass to the sides of the hull. After it cures, then lay mat and roven on the top of the deck. He also had very strong feelings about foam. He said, don't do it. He feels that if any water gets trapped under the deck, nothing good can come of soaked foam. He is an old school guy that has been around the block. He doesn't like composite stringers and doesn't like to mix the resins within a boat. He won't use epoxy on a vinylester or polyester built hull. I know this might stir things up a bit, but it's what he said nonetheless. He also doesn't like to use any fillers or putties unless he absolutly has too. He feels that putties under glass weakens the layup. He cut materials and built small mock ups for me while we were in his shop. He showed me some rebuilds that were in process and was very helpful. He even had one of the guys go through and show me each tool they use for each step of the job. I should tell you that he knows that I am not buying anything. I contacted him through someone I know who hires him as an expert witness for insurance clam losses. Although, some might disagree with his steps, he is very knowledgeable on the subject. |
Posted By: tuna_tugger
Date Posted: September-06-2010 at 5:34pm
------------- Don Liberman |
Posted By: Ranger
Date Posted: September-06-2010 at 7:15pm
|
Yes, I would probably agree. I think I'm kind of like that to in some ways. Were creatures of habit.
But, to be fair. If I was involved with as many cases as this person was over the years. I too, might form a strong opinion that certain things will work and certain thinks shouldn't be done. |
Posted By: tuna_tugger
Date Posted: September-06-2010 at 7:38pm
------------- Don Liberman |
Posted By: Ranger
Date Posted: September-06-2010 at 11:26pm
|
He only indicated that he has had several failures in his shop due to composite stringers. He showed me one that was in his shop when I was there. The stringers were delaminated from the hull and looked pinched. It didn't look like he hit anything from the outside however.
In addition, I think he has testified on a few cases with high speed hulls that came apart. I can see where his experience could form an opinion that says stay away from composite stringers. That obviously doesn't mean that it can't be done, just his experience. |
Posted By: tuna_tugger
Date Posted: September-07-2010 at 3:16am
------------- Don Liberman |
Posted By: tuna_tugger
Date Posted: September-07-2010 at 3:19am
------------- Don Liberman |
Posted By: Ranger
Date Posted: September-07-2010 at 1:16pm
| No I haven't. I would think that composite strings would be lighter when the layups are finished, but how much? I don't know. Like I said earlier, I am getting ready to restring my 86. I should weigh the fir stringers and see what it is and do a comparison. |
Posted By: tuna_tugger
Date Posted: September-07-2010 at 1:30pm
It would be an interesting comparison. I am going to contact Steve Smith of Smith and Company and get his imput on how best to laminate to existing fiberglass. We all know wood will rot, look at how many of us are redoing older CC. I still am leaning to composit stringers and bulkheads. I only know of one boat that is still made with wood stringers and transom and that is the 19" Donzi Classic. They tried composit but it changed the sound and handling to much so they staid with the original design they have been using for about 20 years. It's an incredable boat that does about 73mph before it starts to chine walk. I went to the factory and had one built for me when I turned 40 and it was an awsome boat. ------------- Don Liberman |
Posted By: TRBenj
Date Posted: September-07-2010 at 2:05pm
It sounds like this guy has a long history in the business, but he's certainly not on the cutting edge. Im no fiberglass expert, but I have done a bit of reading and have restrung boats with both wood and composites. Here are just a few comments. -It sounds like he uses a thicker lay up under the stringers (2 layers of mat) than he does up the side of them (1 layer of mat, 1 layer of cloth). Im not sure the thicker layer underneath is beneficial. The thinner layer up the sides would be far from "overbuilt" in terms of thickness or strength. Ive always used somewhere between 3-7 layers to tie the stringers to the hull, regardless of the stringer material. -Ive heard of the not-mixing-fiberglass-types school of thought before, and Im not sure I understand it. If vinyl and epoxy are both superior in their adhesion, strength and osmotic properties (even when used to attach to poly), what is the downside of using them besides cost? -Not all composites are created equal- its a generic term. They will vary in weight, composition and strength. Some are purely foam based, some are a foam/fiberglass mix, some consist of other polymers. To lump them all together is a bad idea- some work better than others for certain applications. Fiberglass itself is actually a composite- and there are some manufacturers (Malibu, etc) whose stringers are hollow. -The role of "fillers" and "putties" can be very important in working with glass as well. Again, these are generic terms and not all of them are created equal. Sawdust or talc will not offer the same type of strength as aerosil-cabosil or milled fiber. When used for adhering materials together or to make a fillet for glass to follow, they can significantly increase the strength of the layup. Ill defer to the experts here who have more experience than I do... but those are just a few talking points. Remember that most OEM boat builders have gone to composite structures, and collectively they have done a lot more R&D on the benefits than the re-building industry. If composites (when designed and installed properly) werent superior, I suspect most boats would still be built with wood. On the other hand, using wood is a tried and true method with a long history... so using it (and following the factory design) is probably the most straightforward method. ------------- |
Posted By: Ranger
Date Posted: September-07-2010 at 8:27pm
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I agree with what you both have posted. Very good points. For me, I think I will stay with the wood stringers since it was the way the boat was originally designed. My decision was also based on my familiarity with wood and not just advice from others. I don't have the resources or the time to do it twice.
I think we all form opinions based on our experiences. This guy is sharp, but definitely not a cutting edge type. But to each their own! He believes very strongly on what he does and once he is done, he doesn't get them back. Pretty good business model for the most part. Is he missing the boat? (Excuse the pun) Probably, but he is putting out quality work that most people are quite please with. Further, I don't think I have every met anyone that was willing to give a half day to someone he just met. I appreciate and respect the person quite a bit, even if he doesn't look towards the next level. |
Posted By: tuna_tugger
Date Posted: September-07-2010 at 8:30pm
Best of luck with your project, take pictures and keep us informed. ------------- Don Liberman |
Posted By: Ranger
Date Posted: September-07-2010 at 8:49pm
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Thanks, I am thinking I might start a little sooner than I originally thought. I was in the process of changing the fuel filter and the bracket fell off in my hand. I tried to reinstall it and all got was rotted wood on the end of a lag bolt.
I was hoping for one more trip, but now I'm a little worried. I don't need any more gel coat cracks to deal with. So, I am contemplating on canceling the ski trip with the Nautique and make it a bass fishing trip. I also have a Ranger that my boy and I fish from. Or, I might just cancel it all together and get started. I am the type of person who won't hardly stop until it's finished and I'm feeling a little itchy to get it going. I will try to keep everything documented and post a string, but it's not something I'm typically good with. I'll give it a shot, but I need to come up with a clever name to start the string. Any ideas? |
Posted By: tuna_tugger
Date Posted: September-07-2010 at 9:04pm
------------- Don Liberman |
Posted By: Waterdog
Date Posted: September-07-2010 at 10:20pm
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The only reason not to use epoxy resin is money. If your doing the labor, roughy 2/3s the cost, - well shame on you for using polyester.
If you've done your homework you know it's SUPERIOR. Amine cured epoxie are the toughest, a little finicky sometimes (amine blush) but worth the cusin'. Douglas Fur - lasts a long time and with epoxy resin you & I won't have to re-stringer it. Coosa board IS much better and if your inclined to use it, it's as good as it gets today. Fillers & Fillets - Do add strength and I'd "bed" EVERTHING attached to the hull / substrate in epoxy & MILFIBER. 2,4,6 inch glass tape to bond the stringers / bulkheads. Foam - I can swim pretty good, on a average lake I'm not using it that's just me, BUT on a costal boat flotation is a MUST. It may save your life... ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: tuna_tugger
Date Posted: September-07-2010 at 10:34pm
------------- Don Liberman |
Posted By: Keeganino
Date Posted: September-08-2010 at 2:32am
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Read Tim's another BFN rebuild for more coosa ------------- "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: tuna_tugger
Date Posted: September-08-2010 at 3:12am
------------- Don Liberman |
Posted By: Keeganino
Date Posted: September-08-2010 at 12:21pm
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Here it is http://www.correctcraftfan.com/forum/forum_posts.asp?TID=16014&PID=237063#237063 - Another BFN ------------- "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: Ranger
Date Posted: September-08-2010 at 1:23pm
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Waterdog,
I don’t necessarily agree that the only reason not to use epoxy is money. Some people have different opinions which have nothing to do with one’s wallet. To be honest, I haven’t decided what resin I’m going to use, but money has nothing to do with the decision. I do know that I will not use Polyester, but I have entertained the idea of Vinylester. I would agree the Douglas Fur lasts a long time, but I would also say that if the boat was designed to either prevent the build-up of water or provide a method for the water to escape, than you won’t have to restring it regardless if you use epoxy or vinylester resin. For example, my last restore was a mid 80’s skipjack that was built with wood stringers and polyester resin. The stringers and hull were as strong then as the day it was built. But the hull was designed so that no standing water was ever trapped inside the sealed compartments. I know that a lot of older hulls have issues; Grady White’s come to mind. But I believe if the boat is designed for the particular materials used, than the wood in the hulls should outlive both of us. Now that being said, I realize that the bond strength of epoxy is far superior of vinylester resin. But what I haven’t come to terms with, is the long term effects of mixing resins. I’m still digging into it. Another issue I have, is that I want to gel coat my deck and bilge. Why? Because I will most likely go with a carpet system that will look original, but not be glued to the deck and I don’t want carpet below my seat pedestals. A gel coated finish will outlast almost anything else I put down. But, gel doesn’t like epoxy, so.... Maybe it’s my saltwater background, but I want something that looks and feels original, but with the added functionality of the today’s techniques. So, like I said. The money has nothing to do with the decision. It will be based on what I think will be best for my project. Regardless of which product I use, I am confident that I can rebuild the boat better than it was from the factory and it will easily outlast my ever aging tail. On another note. I decided to cancel my trip and start on the project. I removed everything from the boat last night and the engine is ready to be pulled. I'll build a stand this evening to set the engine and tranny and hopefully get it pulled tomorrow night. With any luck, I whould have the deck and foam removed by the end of this weekend. Thanks for the comments |
Posted By: JoeinNY
Date Posted: September-08-2010 at 1:57pm
|
I do agree with Waterdog and his opinion (based on experience and research) that that only significant reason not to use expoy is money. I too have used poly, and vinyl, and epoxy on many many projects (including many where I had to grind off the old poly or vinyl to do the repair again) and like Andy the waterdog am well aware of issues (some real some inflated) of putting gel coat over epoxy.. but they pale in comparision to the benefits and ease of use of epoxy. Guys who rebuild these boats for a living will often push poly or vinyl but they don't live with the boat afterward.
Like you have heard from Tim and Andy... if money is no object... coosa is a great product.. the company eh.. but the product is exceptional. Douglas Fir is certainly an amazing material as well, and yes a well designed install with Fir and Vinyl will last most likely indefinitely.. but I would still say for the effort involved Fir and Epoxy is minimum... ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: Ranger
Date Posted: September-08-2010 at 3:14pm
|
I understand what you are saying and agree with most of it. All I am saying is that the money is not the deciding factor for me. I have the money to go either way. I'm just not sure which way I am going..... yet.
|
Posted By: Waterdog
Date Posted: September-08-2010 at 9:49pm
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Ranger,
If your going to use Prisma Preform products I'd talk to somebody about using Vinylester resin. The resin may melt your stringers. Make sure the chemistry is compatable. I have no idea - but look into it. I just looked at Prisma Preforms website the stuff is made with polyester resin - Right ? I thought you said you were going to stay away from polyester. ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: Ranger
Date Posted: September-08-2010 at 10:17pm
|
Waterdog
They were what I was considering, but I have decided against it. I made the decision and mentioned it in an earlier post. I saw the product and was curious of what some of the members thought about it. I am going to use either epoxy or vinylester. I know what most on this site would recomend, I just want to make my decision based on what I need. Not what everyone else does. Further, I was only trying to make the point that cost was not the deciding factor for me. |
Posted By: Waterdog
Date Posted: September-09-2010 at 10:19am
|
Ranger,
This is pretty good info. http://www.redrockstore.com/resin.htm - http://www.redrockstore.com/resin.htm ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: Ranger
Date Posted: September-09-2010 at 1:54pm
|
Yes, I have read that article and it's very compelling. I have also read allot at the boat design forums and find some very compelling evidence for epoxy. However, it seems that for every few people that are adamant about epoxy, there are several that are adamant about vinylester. Both views have good solid points.
I really believe that both have their place and a good repair with vinylester would be appropriate and adequate for many of us. If I was to do my stringer job with vinylester, I'm sure it would last at least my lifetime. However, I do not have a controlled environment and I am thinking that epoxy will be more forgiving in my application. So, I am leaning that way. I like the superior adhesive qualities and the additional flex that epoxy provide. I still need to do a little more research on epoxy manufactures and the number and types of layups. So I'll keep digging. What would you suggest with regards to manufacture of epoxy and number of layups? I appreciate your posts. I know what you prefer and think the data behind your experiences are worth more than the comments alone. In other words, the links to articles and such are helpful. If you haven’t guessed, I'm not very good at following the herd unless I have a reason to go that way. No disrespect intended. |
Posted By: TRBenj
Date Posted: September-09-2010 at 2:11pm
|
Ranger, by all means, dont simply "follow the herd". Hopefully you stick around long enough to figure out who to listen to and when on this site. There is far more collective knowledge here than any one person can hold... whether the topic be wood boat building, fiberglass questions, carb rebuilding, prop selection, skiing tips or anything else, I think you'll find that there are various experts on most topics here that have already done a lot of the legwork for you, and will freely give you good advice. I like to do my own research too, but there are many members here who I will blindly take advice from, as they have much more experience and knowledge than I could hope to attain in any reasonable amount of time on any given topic.
Do continue to push the envelope and investigate new materials, techniques, etc- but dont discount the advice given here, or consider getting input here as a sign of weakness. I would highly recommend you utilize the search function- there have been several composite builds (and many more with wood) with different cores and types of fiberglass used. Make sure you select the search option to view threads that are more than 6 months old (Any Date). ------------- |
Posted By: tuna_tugger
Date Posted: September-09-2010 at 2:23pm
------------- Don Liberman |
Posted By: Hollywood
Date Posted: September-09-2010 at 2:23pm
There is plenty of Kool-Aid to go around!  ------------- |
Posted By: Ranger
Date Posted: September-09-2010 at 3:38pm
|
TRBenj
Yes, I have used the search function. Probably more than I should. I have so many saved threads, they start to get confusing. Not to mention it takes me half the day to read them. I find that my daily work starts to play second fiddle. On another note, the nautique is gutted and ready to pull the motor. I was going to pull it last night, but my tractor doesn't have the reach I need to get over the engine. So I'm calling some rental yards today to see what I can find in the way of a Cherry Picker. I'm hoping that I don't have to pull the wheels off the trailer and lower the beast. I do have another option, I could back it in the barn and use one of the metal beams, but if my wife sees a boat in her barn, I'll be looking for an RV to sleep in. |
Posted By: Waterdog
Date Posted: September-09-2010 at 7:20pm
|
When I pulled the engine in my boat (86-2001) I used a automotive cherry picker. I pulled the tires off the trailer and set it as low as possible on jack stands. With the cherry picker boom all the way out it just reached the center of the boat but it worked just fine. The engine is way up in the air when you clear the gunnel with the oil pan! ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: charger496
Date Posted: September-09-2010 at 7:32pm
| I hear everyone saying to use fir for stringers. Whats wrong with using CPES coated white pine? With the proper fiberglass layup, isn't the wood just a design redundancy, and just something to bolt the motor to? |
Posted By: Ranger
Date Posted: September-09-2010 at 7:48pm
|
I just picked up the tallest cherry picker that I could find. I think it goes to about 8 feet, so if I drop the tires on the trailer I should be fine.
Tonight’s goal, pull the motor and tank. Everything is loose, so it shouldn't be a problem. However, my son has baseball practice from 4:00 to 7:00 and I'm not willing to miss it, so I will be at it a little late. |
Posted By: 8122pbrainard
Date Posted: September-09-2010 at 8:01pm
It's the same reason SPF has a different rating for construction compared to Doug Fir. ------------- /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: tuna_tugger
Date Posted: September-09-2010 at 8:05pm
You can only get pine in 1"x plus it is not as strong it is considered a soft wood, only dor decoration and trim. If you are going to use wood fur is the only wood to use. It is strong and a little flexable. ------------- Don Liberman |
Posted By: charger496
Date Posted: September-09-2010 at 8:20pm
| I've seen hollow stringers built for these boats (I forget who did that on one of the rebuild threads here). With 2, 4, and 6 inch strips bonding the sides and hull, and mat and cloth overlays, it seems like balsa wood would do the trick. Is the wood important if the fiberglass is providing the strength? I have.... a friend who is trying this theory on his boat. Not with balsa, although think of the weight savings! Lets call him "challenger 496"... |
Posted By: 8122pbrainard
Date Posted: September-09-2010 at 8:20pm
Not true at all and the reason for the SPF lumber rating. ------------- /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: tuna_tugger
Date Posted: September-09-2010 at 8:23pm
Ok I stand corrected but I wouldn't use pine except maybe for a boat your going to use in a pond. ------------- Don Liberman |
Posted By: tuna_tugger
Date Posted: September-09-2010 at 8:26pm
To scarry for me. You need some one smarter then me for that answer. ------------- Don Liberman |
Posted By: Ranger
Date Posted: September-09-2010 at 8:46pm
| Although I decided to stay with fir, I just received my Prisma Preform sample kit. This stuff is sweet. I can see where it would save a ton of time in replacement of stringers. However, I think I'm still a little unconfortable about the product. Especially when it comes to setting a 351 on two of them. Maybe someone else will tackle the job with the product, I would love to see it used. |
Posted By: BuffaloBFN
Date Posted: September-09-2010 at 8:59pm
|
What bothers you about it?
I have several layers of mat, cloth, and biaxial on my fir stringers and still wonder how they take the punishment. Great discussion! ------------- 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: Ranger
Date Posted: September-10-2010 at 2:15am
|
What bothers me the most is the crush strength when bolting the engine cradle to the stringer. From what the manufacture tells me, I can place a small piece of wood in place of the foam stringer under the cradle. But I don't think I would like to have a composite stringer with a chunk of wood in the middle. He did say that they have several other type of composite materials that will also work. But I haven't push it any farther.
I really think it's just the unknown of "what if" that scares me. On the other hand, the product is very nice. The foam is very dense and does look like once it is glass into the hull would be very strong. They sent me a sample of each product type and they come with the glass already on the stringer with the proper size tab. You completely wet it out and lay it in. Much easier than scribing a pice of fir in. All the notches and such are cut with a razor knife. There are a couple of U-tube videos that are very good to watch. But they are about selling the product, so they are obviously showing the good points. I would be a little more willing, but I have only found 1 boat being rebuilt with these. The manufacture primarily sells to the OEM industry, so I know the product is in allot of boats, I just don't know which ones. Check out the video's and website and let me know what you think. |
Posted By: 8122pbrainard
Date Posted: September-10-2010 at 10:02am
No name, The preferred method I feel is best for bolting into composite is to drill out the area of the bolt with a 1" to 1&1/2" hole saw before any glassing. The hole is filled with thickened epoxy and then glassed over. Engine mounting holes are then located and drilled. On the blind holes into the tops of the stringers, the holes are drilled and tapped (long shank tap). Stainless threaded rod can then be epoxied in with about 3" to 4" of thread engagement. ------------- /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: September-10-2010 at 11:30am
Pete, I agree that your prescribed method would be an improvement over lag bolting into a foam based composite... but I would think that through bolting would be superior to lagging regardless, no? ------------- |
Posted By: 8122pbrainard
Date Posted: September-10-2010 at 12:07pm
Tim, I guess I wasn't very clear - The 1 to 1&1/2 holes I mentioned are through the sides of the stringers. From the top, the holes should be 1/2 to 3/4" for a 3/8" threaded rod. Yes, bolting through the stringer is superior to the lagging but the thicked epoxy plugs are there to prevent the foam core from collapsing and to distribute the load. It's easy to do with a engine cradle but more work without a cradle since you need to set the engine, locate the holes and then pull the engine to drill them. Still, I would recommend the threaded rod (not lags) epoxied in from the top as well. You want the cradle to sit tight on the top of the stringer, I'd even go to the point of laying down a decent bead of 4200 under the cradle. It would really help with the distributing the load due to the large surface area. ------------- /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: JoeinNY
Date Posted: September-10-2010 at 12:26pm
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On the subject of balsa wood or hollow stringers.. it is possible but not directly applicable to these boats IMHO. The factory lamination schedules and certainly most that have been done here rely on the wood for strength, and heavily so. Using the coosa product gives you a replacement for the wood that is nearly equal in terms of strength but has much better rot charecteristics and is lighter. If you use it as a direct replacement with similar layups and materials as factory I doubt you would ever have a problem. Most would use better materials and additional layers along with the coosa and end up with something better in every way than the wood system replaced for similar or less weight... but greater cost and labor.
I have also done a correctcraft with non structural foam in the stringers/floor.. actually I used a couple types of foam that vary in terms of how much structure you can count on them for, the main stringers while not hollow might as well be. I used polystyrene foam, and while you can make some interesting laminates with it using glass and epoxy it will disolve instantly when contacted by gas or many other solvents that can find thier way into your bilge, if you are actually counting on it for strength your someday going to have a boat that falls apart. It will allow you to build up a laminate without building a mold first though. Next up the list of cores is a lightweight material that can be considered structural but will rely heavily on the bond to the laminates on either side to maintain the strength of the system. Balsa falls in this category, and if you keep it dry is a legitimate choice for a boat building material (although rarely used in any below the waterline situations these days), another popular choice and the other product I used in my mustang build is Divinycell which is a rigid PVC foam. The biggest issue with Divinycell and I would expect the biggest issue with the prisma product (but don’t know as I haven’t held it in my hands or read the cut sheets) is how you attach anything to it. You cant just screw into it obviously and by its very nature you need to spread all loads evenly across the product using the fiberglass skin, anything like coring out a section and filling with glass creates a stress concentration. You are better off glassing on a tab and being careful about using multiple overlapping layers to hold it down. This is a particular problem in an inboard flat bottom boat… but in many boats with V hulls and no real need for structure to hold the engine through most of the hull I would think the prisma product would be very doable. Coose overcomes these limitations not simply by the added density of the foam but also by the glass fibers that interlock the foam, there is really very little chance of pulling the foam apart and delaminating with coosa once you have a good surface bond. I am thinking of taking on a Stuphen I/O rebuild and while I am not a wood guy the coosa is really overkill for the front of that boat, it would still win out over a divinycell rebuild because it would be cheaper and far less labor intensive… but the prisma product at the right price might be a viable alternative in that application. Anyway this is not cut and dry stuff, anyone who wants to spend way too long talkling about it feel free to give me a call sometime and you will get as much opinion as you can handle on it .. mixed with a few facts... ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: Ranger
Date Posted: September-10-2010 at 1:33pm
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8122pbrainard,
Why would you call me “No Name”? I’m new to this forum. Am I suppose to list me name somewhere? My name is Jeff by the way. My screen name that I listed is the name of my bass boat. JoeinNY, This is great info and I appreciate the response. |
Posted By: 8122pbrainard
Date Posted: September-10-2010 at 2:26pm
Jeff, No offence was ever intended so I hope you will take it that way. I, as well as a couple others will use the "no name" term on occasion when members don't add their first names in their profiles. On CCfan, we have a tendency to use first names rather than screen names. I do apologize for not explaining this when I used the term. I usually do! 
Welcome to CCfan. I hope you become one of our regular members. ------------- /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: Ranger
Date Posted: September-10-2010 at 4:31pm
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I don't take any offense to it, but was puzzeled. But I added my name to the profile.
Thanks for the welcome. |
Posted By: TRBenj
Date Posted: September-10-2010 at 7:29pm
Joe, I totally agree- except for the hollow stringers not being applicable to these boats. I was surprised to find out that Malibus have hollow stringers. I actually reached down under the engine on one at the boat show- I could reach the backing nuts. Im sure theyre built seperately from the hull on their own mold- so it might not be the easiest way to rebuild a boat, but I would think its doable and apparently its suitable for a high powered inboard ski boat. The layup was over 1/4" though... maybe closer to 3/8", if memory serves. ------------- |
Posted By: behindpropeller
Date Posted: September-10-2010 at 7:32pm
I think you are over estimating the amount of strength required in the stringers. That motor is sliding the hull through the water, not stopping against a brick wall. ------------- |
Posted By: Keeganino
Date Posted: September-10-2010 at 7:47pm
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My take on it all is- "Why try and re-invent the wheel?"
Doug fir, epoxy, follow the prescribed layup, use CPES and 5200. Its the equivalent to a rubber tire over a wooden one. Its already better than the original layup. ------------- "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: 8122pbrainard
Date Posted: September-10-2010 at 7:49pm
Tim, We'll get you a pair of swim fins and you can then push a boat from the swim platform to see how much thrust it takes to get it up on plane!! I don't feel they really "slide through the water".
Also, don't forget that the stringers handle the shock loading from the hull going over waves as well. ------------- /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: behindpropeller
Date Posted: September-10-2010 at 7:49pm
Depends who you are....what you are trying to do. If CC didn't "re-invent" the wheel would they still be in business? ------------- |
Posted By: JoeinNY
Date Posted: September-10-2010 at 7:56pm
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The current correctcrafts have hollow stingers for all intents and purposes as the foam filling is not going to be an issue. And obviously I have a basically hollow system in the mustang... I simply meant it is not a easy direct conversion. Going down a smooth lake is not the load you have to worry about. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: Keeganino
Date Posted: September-10-2010 at 8:21pm
Don't really see your argument here. This is a rebuild. You see this conversation in virtually every rebuild thread. Do I have to use this? Can I use that? Would this work? Its all beating a dead horse. Sure if you have unlimited time and resources build it out of coosa, carbon fiber, and kevlar. It makes me laugh when I see guys spend $10K trying to get one of these hulls over 60mph. There is only so much one can do to improve the wheel. Opportunity cost- is it worth the extra time and money when you could be doing something else with it? Point of diminishing returns- All the time and money in the world will only make it better to a point. Just saying. It will never be a 100mph offshore boat no matter what you do. ------------- "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: JoeinNY
Date Posted: September-11-2010 at 5:11am
Well I dont see the arguement here either.. true it will never be a 100 mph offshore boat.. it will always have much more class than that as it is the premier inboard available.. anyone with a wallet can take an offshore i/o to a hundred...but it takes taste and dedication to get an inboard to 50. As for laughing when someone spends 10k to get one of these boats over 60.. that has nothing to do with the topic at hand. If you want to rebuild a boat so that it has no wood and no chance to rot again it will not cost you 10k nor will it get you anywhere near 60.. so start a seperate topic to talk trash as it is not applicable here... as for diminishing returns.. definitely a reasonable arguement when you start to spend 400 percent to get a 10 percent improvement you are no longer in the logical range.. but that is when it gets to be a hobby and not an investment. Bottom line is that it doesnt take 10gs to make your boat rot proof, and there is no 10gs of fiberglass work that will make your boat go 50 much less 60. It is completely reasonable to use wood and poly in your rebuild but is it better than a no expenses hold coosa and epoxy rebuild... no, smarter can be argued but better no.. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: Keeganino
Date Posted: September-11-2010 at 5:23am
I think we are agreeing. I am just being devil's advocate here. Pushing the limit is the name of any game. I am just saying its a ski boat... Mine does 50 mph and its stock. ------------- "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 |