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Epoxy bottoms
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Epoxy bottoms
I have recently seen boats listed with epoxy bottoms which require no soaking. Anyone have opinions on this? Is this a viable option?
- Don Vogt
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Re: Epoxy bottoms
If you use the search function, you will discover a very extensive debate here concerning the 5200 bottom vs. the epoxy bottom. The latter is certainly viable and many people have bottoms done this way. The most prominent proponent of the 5200 bottom is the boat restorer, Dan Danenberg, and he has a host of acolytes. I dont have a dog in the fight as my boat was restored traditionally, but fwiw, I believe the epoxy bottom is superior. Run through the threads and you will become acquainted with the various arguments and can decide for yourself. Good luck!
1938 Chris Craft 17' Deluxe Runabout "Jennifer II"
Re: Epoxy bottoms
Epoxy bottoms are a viable option, as is original style bottom and 5200 bottom. I'm in the process of doing a full bottom replacement on a Red and White Express Cruiser and leaning towards the laminated, cold molded style bottom replacement or the original double planked. I think it depends on how the boat will be used and maintained. Is it a daily user boat that will soak for extended periods or a show/trailered boat used occasionally? Of course when these boats were designed and built they were all considered user boats that would require regular maintenance. The original bottoms are expected to soak up and swell and they do this quite well but your gonna have some little leaks here and there until the planks take up. If your an occasional user and you want a leak free bottom at launch 5200 or epoxy is probably the way to go. The down side to these methods is that any water that gets into the bottom core will tend to stay in and eventual lead to water logging and rot, therefore both epoxy and 5200 bottoms are dependant on full encapsulation to prevent any water AT ALL from getting in. Original bottoms breath and dry out relatively quickly on the hard and dry wood dosent rot. Their all good systems if done correctly and maintained accordingly.
Re: Epoxy bottoms
I can add, that rightly done, glassing or epoxy treatment of a wooden boat will last very long. In my Yatch club, there is a 55' foot ocean cruiser, which was glassed 1959, and it does not show any rot yet.... Though! The owner points out the absolute necessity of the hull to be properly covered and dried out in the autumn. This boat have been in the water summer season on a non coverd slip and stored outdoors in a cold tarpaulin boathouse wintertime the last 30 years...
Cavalier 36' Seastrake 1967 "CillaGreta III"
http://chris-craft.org/registry/viewboa ... at_id=2318
http://chris-craft.org/registry/viewboa ... at_id=2318
Re: Epoxy bottoms
A 5200 bottom does not completely encapsulate the wood so it can absorb moisture and also dry. The use of CPES may slow this down some, but it will still breath. It also remains more flexible. A 5200 bottom is for the most part a traditional bottom where the cloth between layers has been replaced with a rubber compound.
An epoxy system relies on total encapsulation to keep moisture out, but if damaged or poorly done, could trap water in. If done properly, it will be a stiffer, stronger bottom.
For longer runabouts where the flex is part of the ride quality, I would want a traditional or 5200 bottom. For a shorter boat or a cruiser it wouldn't matter.
An epoxy system relies on total encapsulation to keep moisture out, but if damaged or poorly done, could trap water in. If done properly, it will be a stiffer, stronger bottom.
For longer runabouts where the flex is part of the ride quality, I would want a traditional or 5200 bottom. For a shorter boat or a cruiser it wouldn't matter.
Re: Epoxy bottoms
Well said mfine. Another point is that the joint between the traditional side planks and the epoxy bottom is always an issue. The two types of construction are so radically different and tend to be a weak point.
Full epoxy built boats, where they are built all at once and the entire boat is one type of construction dont seem to be a problem but marrying the two types is problematic.
Of course, the worst case is wrapping an original bottom in fabric and epoxy.
Tom
Full epoxy built boats, where they are built all at once and the entire boat is one type of construction dont seem to be a problem but marrying the two types is problematic.
Of course, the worst case is wrapping an original bottom in fabric and epoxy.
Tom
http://www.boatartgallery.com
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
Re: Epoxy bottoms
Mfine and Tom, correct me if I'm wrong, but from what I've read about 5200 bottoms, a proper installation includes the necessity of applying an epoxy type sealer on the outside of the planking as a last step prior to bottom paint. Have you done or do you know of any boats with 5200 bottoms that stay in the water and soak for extended periods of time, and if so, are the bottoms able to dry out like an original double planked bottom when on the hard in the off season?
Re: Epoxy bottoms
The process call for multiple (4) coats of Barrier Coat Primer applied to the planks after CPES and before bottom paint.
Leaving the boat in the water for extended time periods is not recommended - even with a 5200 bottom.
Leaving the boat in the water for extended time periods is not recommended - even with a 5200 bottom.
1953 CC Rocket Runabout "Rocket Man"
- Don Vogt
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Re: Epoxy bottoms
Not sure what you mean here? not a problem for the tradtional bottom over a summer, say 3-5 months. Likewise not a problem for an epoxy bottom.
1938 Chris Craft 17' Deluxe Runabout "Jennifer II"
Re: Epoxy bottoms
Not all epoxy products are the same. In the case of the Dannenberg 5200 bottom, the product used is CPES, which despite the name, does not produced a completely waterproof seal. My understanding is that it slows water penetration and also strengthens the wood fibers so there is much less swelling and shrinking. The bottom is a "no soak" bottom because it does not depend on the wood swelling to make a water tight seal since the 5200 layer will keep the bilge dry.
Re: Epoxy bottoms
After over 30 years of doing 5200 bottoms I have yet to see any problem with leaving them in the water indefinitely. Does anyone know of a problem? I havent ever heard of any but I would be interested in hearing about them.
Tom
Tom
http://www.boatartgallery.com
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
- Don Vogt
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Re: Epoxy bottoms
talking to a major boat restorer who uses an epoxy bottom, which includes the chine plank. They have absolutely no reason to believe that this type of bottom will affect the hull sides provided they are in proper condition, refastened,etc. in their view the expoy enhances the stability of the boat vs. other types of bottoms, which promotes longevity to the rest of the boat.
1938 Chris Craft 17' Deluxe Runabout "Jennifer II"
- steve bunda
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Re: Epoxy bottoms
From my experience of 30 years, considering the bottoms are done correctly, the region is key to the success of the new bottom. In the mid west we have huge temperature and humidity changes. Every failure I have seen of the epoxy bottom was due to cracking from our seasonal changes. The cracks allowed water to wick in , but gave it no opportunity to drain out. This condition was easy to see when the mushroom farm started. I am not picking on the epoxy bottoms , as they work in dry environments, but they Do Not work in the Midwest.
Re: Epoxy bottoms
The thing that confuses me about the D 5200 bottom is it calls for planks to be sealed with CPES which allows for some moisture transfer, but also speciifies that a Barrier Coat be applied prior to bottom paint to keep all moisture out and that if the barrier coat is damaged in any way it must be repaired. To my knowledge barrier coats are basically two part epoxy coatings. Doing the CPES to allow moisture out and then applying a barrier coat that could trap moisture in is somewhat of a contradiction. Why would a barrier coat even be necessary? I don't get it.
Re: Epoxy bottoms
The barrier coat is NOT waterproof. In fact, fiberglass is not waterproof. A solid core fiberglass hull will still allow water in although at a low rate. Osmosis still takes place. The point is to slow the process of water absorption, and therefore it is water-resistant, not water-proof.
Steve said it well, the inevitable cracking that takes place in a hard epoxy shell allows water in where it will stagnate if not allowed out. The wood rot fungus thrives in warm stagnant water with wood available to feed on.
Steve said it well, the inevitable cracking that takes place in a hard epoxy shell allows water in where it will stagnate if not allowed out. The wood rot fungus thrives in warm stagnant water with wood available to feed on.
http://www.boatartgallery.com
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
Re: Epoxy bottoms
Steve and Tom, thanks for your input and the info on barrier coats. I'm NOT a professional boat restorer, but I am a professional restoration (Old House) contractor so I've seen my share of rotted wood. I've learned over the years that dry wood doesn't rot, wood that gets wet and is able to dry before the mold spores take over doesn't rot, wood that gets damp and stays damp rots like crazy. Ok for the wood to get wet, but if the moisture wicks in and can't get back out sooner than later the wood eaters take over.
The plan for the Red and White after the bottom replacement and restoration is to leave her in an open slip for six months and shed stored on the hard for six months. This has worked well with my 1948 cruiser with original bottom. There have been lots of repairs and refastenings during her time and she's always been well maintained. Her planks always take up well and are solid and rot free.
Unfortunately the Red and White sat out uncovered for a long time with leaves and moisture in the bilge and has extensive rot damage.
Are there any professional restorers doing CC double planked bottoms with the canvas as originally designed and built?
The plan for the Red and White after the bottom replacement and restoration is to leave her in an open slip for six months and shed stored on the hard for six months. This has worked well with my 1948 cruiser with original bottom. There have been lots of repairs and refastenings during her time and she's always been well maintained. Her planks always take up well and are solid and rot free.
Unfortunately the Red and White sat out uncovered for a long time with leaves and moisture in the bilge and has extensive rot damage.
Are there any professional restorers doing CC double planked bottoms with the canvas as originally designed and built?
Re: Epoxy bottoms
I believe there are, but keep in mind that those bottoms were not meant to last decades. At the time they were expecting owners would replace the boat with a new better model.
Re: Epoxy bottoms
"Are there any professional restorers doing CC double planked bottoms with the canvas as originally designed and built?"
I did them in the long past (60's and early 70's) and have done several since at the request of owners. One big difference is that the "white lead" we used in the early days is now illegal and not available, as are some of the other preservatives we used then.
The 5200 was developed in the 60's for the space program and became the "go to" replacement.
The "5200" bottom as we know it now evolved over the years and was finally documented by Don Dannenberg in his book. He is the first to say that he didnt develop it, he just documented it and in my opinion he did a great job.
I think you have a good handle on what is going on and we want to see pics of your work as it progresses!
I did them in the long past (60's and early 70's) and have done several since at the request of owners. One big difference is that the "white lead" we used in the early days is now illegal and not available, as are some of the other preservatives we used then.
The 5200 was developed in the 60's for the space program and became the "go to" replacement.
The "5200" bottom as we know it now evolved over the years and was finally documented by Don Dannenberg in his book. He is the first to say that he didnt develop it, he just documented it and in my opinion he did a great job.
I think you have a good handle on what is going on and we want to see pics of your work as it progresses!
http://www.boatartgallery.com
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
Re: Epoxy bottoms
"Unfortunately the Red and White sat out uncovered for a long time with leaves and moisture in the bilge and has extensive rot damage. "
Unfortunately, that is often the case! Bilge debris also clogs the limber holes and creates great little pockets of rot which translates into much of the frame repairs that are necessary.
Cruisers tend to be worse for "topside water" in that they tend to rot from the top down. Hidden out of the way pockets are harder to get to in cruisers and rainwater collects and does its dirty work.
I own a '56 Connie 46' and the previous owner had glued rubber roofing membrane on the entire bottom to make for a cheap bottom repair! Needless to say I spent months under it chiseling off the "rubber underpants" and replacing 400 bf of new planking plus 6 frames. Check it out on my website.
http://boatartgallery.com/Past_Projects.php
Unfortunately, that is often the case! Bilge debris also clogs the limber holes and creates great little pockets of rot which translates into much of the frame repairs that are necessary.
Cruisers tend to be worse for "topside water" in that they tend to rot from the top down. Hidden out of the way pockets are harder to get to in cruisers and rainwater collects and does its dirty work.
I own a '56 Connie 46' and the previous owner had glued rubber roofing membrane on the entire bottom to make for a cheap bottom repair! Needless to say I spent months under it chiseling off the "rubber underpants" and replacing 400 bf of new planking plus 6 frames. Check it out on my website.
http://boatartgallery.com/Past_Projects.php
http://www.boatartgallery.com
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
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Re: Epoxy bottoms
Its been awhile since I have been active in the marine industry so my perceptions and experience may have been updated by more current technology. That being said we were active during the explosive awareness of fiberglass hull blistering and the rush to solve , treat, and prevent the problem that may occur with polyester resin laminates.
One element of the correction and prevention process involved coating the bare hull's surface with an epoxy barrier coat(multiple applications) prior to the application of the antifouling bottom paint. According to the narrative of the manufacturers of these products (including Pettit and Interlux), this barrier coat was indeed intended to be water proof and non permeable.
Since some of the "barrier coat" products I see recommended for application on 5200 bottoms seem to be the same or similar products we were using as preventative medicine on glass hulls. I am curious as to how this product would not retain its waterproof characteristics on wood.
Have the manufacturers changed their narrative or have the products changed?
I have no dog in this hunt and believe the effectiveness of the popular methods are dependent on proper application.
I find this discussion very interesting and feel that there have been some contradictory opinions offered worthy of additional comment and clarification. I am as interested as anyone in hearing from any authority that can enlighten us with the current science to back it up.
One element of the correction and prevention process involved coating the bare hull's surface with an epoxy barrier coat(multiple applications) prior to the application of the antifouling bottom paint. According to the narrative of the manufacturers of these products (including Pettit and Interlux), this barrier coat was indeed intended to be water proof and non permeable.
Since some of the "barrier coat" products I see recommended for application on 5200 bottoms seem to be the same or similar products we were using as preventative medicine on glass hulls. I am curious as to how this product would not retain its waterproof characteristics on wood.
Have the manufacturers changed their narrative or have the products changed?
I have no dog in this hunt and believe the effectiveness of the popular methods are dependent on proper application.
I find this discussion very interesting and feel that there have been some contradictory opinions offered worthy of additional comment and clarification. I am as interested as anyone in hearing from any authority that can enlighten us with the current science to back it up.
Greg Wallace 23 Custom 22166 former Chris-Craft dealer Russells Point, Oh.
Re: Epoxy bottoms
Don,
Just to clarify I have done one 5200 bottom and have yet to get it wet (hopefully soon).
I followed the process detailed in Don Danenberg's book as I believe it to be a valid process.
He was asked the same question today on his forum and his response was similar to mine but much more specific - as would be expected from someone who has restored many boats versus one.
I am no expert. I just try and help other by relaying information that I believe in so they can form their own opinions.
Mark
Just to clarify I have done one 5200 bottom and have yet to get it wet (hopefully soon).
I followed the process detailed in Don Danenberg's book as I believe it to be a valid process.
He was asked the same question today on his forum and his response was similar to mine but much more specific - as would be expected from someone who has restored many boats versus one.
I am no expert. I just try and help other by relaying information that I believe in so they can form their own opinions.
Mark
1953 CC Rocket Runabout "Rocket Man"
- Don Vogt
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Re: Epoxy bottoms
thanks, Mark, as I mentioned,i dont have a dog in the fight. I think a number of excellent points have been raised, and people will need to decide for themselves what they think will be best for them. If i werent going traditional, i would have gone epoxy. One thing that hasnt been mentioned is that I believe epoxy bottom boats enjoy higher resale value than those with a bottom that needs soaking.
1938 Chris Craft 17' Deluxe Runabout "Jennifer II"
Re: Epoxy bottoms
I have the impression that a well documented 5200 bottom has the highest resale value. That might vary by location.
Re: Epoxy bottoms
I've been doing 5200 bottoms for 19 years now. I have several customers who leave their boat in the water all summer. Which down here is about 7 to 9 months. I have not seen any problems with these boats. There pretty much done to the Dannenberg method. On the first ones I used red lead instead of barrier coat.
I have ridden in most models and most brands of reproductions. The boats restored with 5200 ride much better and are not as noisy. The epoxy boats tend to amplify the noise of the water hitting the bottom of the hull. I even rode in one of the high end reproduction brand boats and it resonated the engine noise through the hull at around 3500 rpm.
Another thing I can add about the epoxy bottoms is. Where I went to boat building school Meade Gougeon was on one of the boards of the school. After he gave a lecture on West System I asked him about putting epoxy bottoms on traditional built powerboats. He said it was best if you were going to put an epoxy bottom on to rebuild the whole boat using epoxy. This was in the mid 90's and there were several lawsuits going on with them and Hackercraft so Meade could not talk about it much.
Also over the course of 19 years I have seen more problems with epoxy bottoms then 5200 bottoms. But a lot of those problems stem from the bottoms not being done correctly. But not all of them.
One other thing. Chris Craft started using a early version of what became 5200 to assemble the Sea Skiff hulls. Where the 5200 was used has held up well in these boats that have been well maintained over the years.
I have ridden in most models and most brands of reproductions. The boats restored with 5200 ride much better and are not as noisy. The epoxy boats tend to amplify the noise of the water hitting the bottom of the hull. I even rode in one of the high end reproduction brand boats and it resonated the engine noise through the hull at around 3500 rpm.
Another thing I can add about the epoxy bottoms is. Where I went to boat building school Meade Gougeon was on one of the boards of the school. After he gave a lecture on West System I asked him about putting epoxy bottoms on traditional built powerboats. He said it was best if you were going to put an epoxy bottom on to rebuild the whole boat using epoxy. This was in the mid 90's and there were several lawsuits going on with them and Hackercraft so Meade could not talk about it much.
Also over the course of 19 years I have seen more problems with epoxy bottoms then 5200 bottoms. But a lot of those problems stem from the bottoms not being done correctly. But not all of them.
One other thing. Chris Craft started using a early version of what became 5200 to assemble the Sea Skiff hulls. Where the 5200 was used has held up well in these boats that have been well maintained over the years.
Re: Epoxy bottoms
"He said it was best if you were going to put an epoxy bottom on to rebuild the whole boat using epoxy."
Jim G....this reverts to my point earlier. When you do an epoxy bottom on a traditional boat, you have a marriage of the 2 systems. That convergence will create problems. I have seen it on numerous occasions. That is exactly why he suggested doing the entire boat in epoxy.
I also agree with you on the noise and the flexibility issue (better ride).
Tom
Jim G....this reverts to my point earlier. When you do an epoxy bottom on a traditional boat, you have a marriage of the 2 systems. That convergence will create problems. I have seen it on numerous occasions. That is exactly why he suggested doing the entire boat in epoxy.
I also agree with you on the noise and the flexibility issue (better ride).
Tom
http://www.boatartgallery.com
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
1956 CC Connie 47'
1959 Caulkins bartender
1965 Cheoy Lee Frisco Flyer
1953 Chris Craft Holiday
1941 Chris Craft Deluxe
Plus 8-12 customer boats at any time
God don't count the days spent messing around in wood boats.
Re: Epoxy bottoms
Hi Tom,boat_art wrote:"He said it was best if you were going to put an epoxy bottom on to rebuild the whole boat using epoxy."
Jim G....this reverts to my point earlier. When you do an epoxy bottom on a traditional boat, you have a marriage of the 2 systems. That convergence will create problems. I have seen it on numerous occasions. That is exactly why he suggested doing the entire boat in epoxy.
I also agree with you on the noise and the flexibility issue (better ride).
Tom
I agree with you. I wanted to post what Meade told me years ago.
For those of you who don't know. Meade Gougeon is one of the Gougeon brothers who developed West System Epoxy.
- steve bunda
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Re: Epoxy bottoms
In all the years that I have messed with wood boats, and have given rides and rode in many. The number one comment from guests is, how nice the wood boat rides on the lake. The gleam of varnished mahogany, and and sound of the flathead engine are unique and recognized, but everyone comments on the feel and smoothness of the ride. The original double planked wood boat bottoms move, and provide a soft ride due to the flexibility of the wood.
The 5200 bottom still allows the boat to feel like an original bottom without the worry of soaking. A bonus of the 5200 bottom is the fact that a laminate is much more stronger with a flexible 5200 adhesive , than the original layer of lead soaked canvas.
The 5200 bottom still allows the boat to feel like an original bottom without the worry of soaking. A bonus of the 5200 bottom is the fact that a laminate is much more stronger with a flexible 5200 adhesive , than the original layer of lead soaked canvas.
Re: Epoxy bottoms
Great debate guys. What do you think about my idea for a new type bottom system????
Goes like this.
1. Boats flipped, all frame and structural members replaced or repaired.
2. 1/4 inch 1088 marine plywood inner bottom cut, fitted, red lead primed inside, 5200 and tack fastened to frame.
3. Outside of inner plywood sheathed with layer of dynel and epoxy.
4. Outer mahogany planks cut and fitted as originals, back primed with red lead.
5. Outer planks installed and bronze fastened on a full coat of traditional bedding compound.
6. First upper chine plank 5200 to chine and frames and bronze fastened.
7. Bottom red lead primed and ablative bottom coated.
8. Primed bilge finished with oil based bilge coat.
Breathable, Leak Free, Flexible, Epoxy Reinfourced, 5200 Attached, Bronze Fastened, Enhanced Original Bottom.
Could it be the next best way to do a bottom/or a catastrophic fail.
Goes like this.
1. Boats flipped, all frame and structural members replaced or repaired.
2. 1/4 inch 1088 marine plywood inner bottom cut, fitted, red lead primed inside, 5200 and tack fastened to frame.
3. Outside of inner plywood sheathed with layer of dynel and epoxy.
4. Outer mahogany planks cut and fitted as originals, back primed with red lead.
5. Outer planks installed and bronze fastened on a full coat of traditional bedding compound.
6. First upper chine plank 5200 to chine and frames and bronze fastened.
7. Bottom red lead primed and ablative bottom coated.
8. Primed bilge finished with oil based bilge coat.
Breathable, Leak Free, Flexible, Epoxy Reinfourced, 5200 Attached, Bronze Fastened, Enhanced Original Bottom.
Could it be the next best way to do a bottom/or a catastrophic fail.
Re: Epoxy bottoms
If you prime the plywood before 5200 its not going to adhere very well. As the paint fills and seals the grain. You want the 5200 against raw wood for the best adhesion.joanroy wrote:Great debate guys. What do you think about my idea for a new type bottom system????
Goes like this.
1. Boats flipped, all frame and structural members replaced or repaired.
2. 1/4 inch 1088 marine plywood inner bottom cut, fitted, red lead primed inside, 5200 and tack fastened to frame.
3. Outside of inner plywood sheathed with layer of dynel and epoxy.
4. Outer mahogany planks cut and fitted as originals, back primed with red lead.
5. Outer planks installed and bronze fastened on a full coat of traditional bedding compound.
6. First upper chine plank 5200 to chine and frames and bronze fastened.
7. Bottom red lead primed and ablative bottom coated.
8. Primed bilge finished with oil based bilge coat.
Breathable, Leak Free, Flexible, Epoxy Reinfourced, 5200 Attached, Bronze Fastened, Enhanced Original Bottom.
Could it be the next best way to do a bottom/or a catastrophic fail.
Once the dynel soaked in epoxy cures. Its going to be hard. My opinion is that when the hull flexes over the waves the hard epoxy is going to crack. Which in a few years will let water in as the bedding compound will have dried out and started turning to dust and washing out.
The reason Chris Craft put canvas between the bottoms was to give the bedding compound something to attach itself to.
Here are a couple of pictures of 5200 applied between the inner and outer bottom after the wood had be painted. Beside the fact that the restorer did not use close to the correct amount of 5200. When I took it back apart to redo the bottom the 5200 that was there just popped loose.
Re: Epoxy bottoms
Jim, thanks for the photos. I'm sure your right about the 5200 having better adhesion to raw wood. It would be better to prime and paint the bilge after she's flipped back upright. The 5200 against the frame would offer some flex and cushioning as the hull moves.
The traditional paints in the bilge should allow for drying when it gets wet inside from any rain and spray.
My thinking with the dynel sheathing. I've used it before on decks with great success. It's a really tough fabric, great abrasion resistance, and when epoxy bedded totally water proof. It doesn't add a lot of structural strength, but is somewhat flexible and super impact and wear resistant. Little difficult to soak up with the epoxy and has some texture when cured that resembles traditional canvas.
The texture should help hold the traditional bedding compound under the outer planking.
This is all just an idea that been rattling around in my head. This is my first CC complete bottom replacement and I can see it's going to be a bear of a job. I admire you guys who do this for a living. House carpentry has its challenges, but boat carpentry takes it to a whole other level.
The traditional paints in the bilge should allow for drying when it gets wet inside from any rain and spray.
My thinking with the dynel sheathing. I've used it before on decks with great success. It's a really tough fabric, great abrasion resistance, and when epoxy bedded totally water proof. It doesn't add a lot of structural strength, but is somewhat flexible and super impact and wear resistant. Little difficult to soak up with the epoxy and has some texture when cured that resembles traditional canvas.
The texture should help hold the traditional bedding compound under the outer planking.
This is all just an idea that been rattling around in my head. This is my first CC complete bottom replacement and I can see it's going to be a bear of a job. I admire you guys who do this for a living. House carpentry has its challenges, but boat carpentry takes it to a whole other level.
Last edited by joanroy on Wed Mar 09, 2016 6:33 am, edited 2 times in total.
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