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Rich VanValkenburg
04-02-2010, 08:13 AM
I've been invited to think about getting my tools ready to start some restorations in a small venture that could get bigger, so I did some reading about current technique i.e. Chris Craft bottom rebuild. I found that most if not all were being done as a 5200 sandwich. I've always hated 5200 because once you used that on something that big, it's almost impossible to do a repair or plank replacement. I tend to look down the road and wonder how in hell would I get a plank off that was glued in with 5200 if the boat struck a log or rock and needed more bottom work.

What's the experience around here with using that stuff in that manner?

erster
04-02-2010, 08:23 AM
For some reason this seems to be the rage these days. Unless I truely needed the money and someone signed a waiver like a hardheaded owner, this is one project that I would not be involved in myself. And I have done some crazy stuff in boats. There are better ways to repair and preserve the original hulls even though there are indeed some seasoned guys using this method. Now if you are redoing using new woods, cold mould with finish cloth is the only way to go IMO.

Dale Genther
04-02-2010, 09:34 AM
When we put a new bottom on our 1952 Chris Craft Sportsman, I investigated the 5200 bottom method and the less common West System method. I dismissed the 5200 bottom because the method just seemed flawed to me. No particular reason, it's just the more I though about it the more I didn't like it. I want with the West System method which was cold molding with 3 layers of 6 mm ocume plywood, then covered with a layer of glass, followed by several coats of InterProtect 2000. I no longer own the boat but a friend of mine does. It has heldup very well in sprite of the fact that the engine in it has over twice the horsepower the original engine had. The boat will do over 40 knots and hitting any chop, wakes, etc. at that speed would have, by now, caused problems iif they were going to happen.

chuckt
04-02-2010, 10:00 AM
I kinda railed against 5200 when I had to remove some planking that had been previously applied with the stuff. I'm doing a replacement cold molded (maybe West System is the better phrase) on a 30 foot boat and 5200 may be the only thing I would trust to attach to oak given oak's rep for epoxy issues. Like Dale, I've got a Chris Craft utility with three layers of plywood. The first layer is attached with 5200 (and screws) to oak framing. She also has an oversized engine (230 hp vs orginal 130 hp) and we have driven this boat hard through lots of chop, as did the prior owner. No signs of any issues with the 5200 and the bottom looks brand spanking new 7 years later. I know I will be creating a dificult repair situation on my current project if my work needs to be revisited but this should last a very long time. But then again, it is doable to cut between the ply and frames through the 5200--which is how I will be using it. But I don't think I would ever do a true 5200 bottom. Like Dale, I felt it just didn't seem right and i wonder how do you cut out a plank bedded in 5200? I imagine that would be horrible. We could be totally wrong and guys with infinitely more knowledge and experience than I swear by this method. I really respect Don Danenburg and he literally wrote the book on 5200 bottoms.

Erster and Dale--Would you use 5200 to attach your ply to frames? If not, how would you do it?

Dale Genther
04-02-2010, 10:07 AM
chuckt - I don't remember what I used b/t the ply and frames. It was 6 years ago. It may have bee 5200 or 4200 or LifeCaulk. I know I screwed the first layer of ply to the frames with bronze screws. Then attached the next two layers with some screws to the frames, some bronze ring nails, and lots of monel staples. Oh, and the epoxy, of course.

Dale Genther
04-02-2010, 10:16 AM
I just called my freind, who now owns the boat. He told my I used 5200. It's a sad state of affairs when they guy who didn't do the work remembers what was done better than the guy who did the work.

Peter Malcolm Jardine
04-02-2010, 10:36 AM
I am a amateur restorer. Despite years of working on woodenboats, and various other things, I am still an amateur in my own opinion. I've stated my case before, but here it goes again:

First of all, I think a lot of restorers look at 5200 or west system as a method of making an old boat stop leaking. This is true. 5200 and west system bottoms also make the boat more ridgid. Also true.

My question is always this: What was it like originally, when it was new? Chris Craft made over 100,000 boats. To my knowledge they were not known to be leaky, in fact the opposite was true. So, if the boat was not originally leaky, and it's construction method was considered to be sound, what improvements would either 5200 or west system give me that an original construction in good condition would not. Ridgidity is one of those things, although I would say that a 5200 bottom is not usually compared to an original bottom that is brand new. Weight? Nope. Ease of additional repair? Absolutely not, in either case. That is always my big question. Can I repair it again, with reasonable methods. A 5200 bottom the way a lot of the open boat restorers do it, would be a complete reconstruction of the boat. They 5200 the ply to the frames, then trowel 5200 on the ply, then fasten the plank down. You would need a sawzall to get this construction apart. I suppose the length of life is substantial on this bottom if the boat is a trailer queen, but I use my boats and they stay in the water.

My concerns about west system are based on mixing new construction with old. Cold molding a new boat, as Erster says, is very successful. Mixing west system with a traditional method? .. Hmmm heard stories about success and failure.

I still think Chris Craft knew more about boat construction than I do. So I copy what they do, and bring the boat back to original build standard. I have a 36 foot CC cruiser. It is the original bottom. It doesn't leak much, even after spring launch. If it did, something would be wrong. I'm sticking with the traditional stuff.

erster
04-02-2010, 11:36 AM
For me personally to use 5200 or any other simular product on aged wood, I would remove and plane each and every piece down to clean and smoothe wood grain to make sure that I did have a true bond. This is almost impossible to do on old and aged planking.
If I was to go that route, I would still not use it between the planks if I was doing this on any original boat in a restoration of a true original built boat such as the Chris Craft and feel good about it when representing the boat as an original.

Having said that if the boat was for my own original use and I did not want to be completely in touch with the puriests, then I would indeed go the cold moulded method if I went to all the trouble to pull a bottom off, or any layer of a bottom and sand, clean and glue up. This is just my own personal opinion.


The absolute worse thing you can have is water trapped between the layers and not knowing what areas are simular when gluing older woods and you find one place that has not bonded well. I want to positively have faith in what is under me and my guests for sure.

Chuck, 5200 is not a gap filler even though folks forget this when building or rebuilding. When using fasteners for plywood and frame construction, as long as your fits are proper, the added expense makes no sense these days when there are simular materials for less. In plywood boats and when the need for repair comes up, its pretty easy to deal with the repairs because the plywood or even framess has reached the soup or pulp stage. So what have you truely accomplished if you have built using fasteners for holding bits and pieces together and the overpriced 5200?


When it was created, it was the only game in town for sure replacing many of the bedding compounds and saw lots of uses originally in fiberglass boats where the moisture issues did not come into play and some structural ,maintaince and refinishing was reduced until folks thought that they could reinvent the wheel on wooden boats forgoing actually going back with the original building methods, IMO.

As people began to do their own work, ignorance sometimes was bliss but the results has been disasterous for almost anyone going behind some of those folks.

chuckt
04-02-2010, 11:44 AM
Cant really argue with you Peter. I personally believe a cold molded replacement bottom--properly done--is going to last a whole lot longer than a traditional bottom. My boat will be in and out of the water a lot so there is an advantage there avoiding the soaking-in wait everytime I launch. And my boat is not rare in any sense so I don't feel compelled to be historically pristine. That's why I decided on this method for my restoration--in another situation I might go traditional.

Erster--I wouldn't be using 5200 as a "gap filler" although someone in the history of my boat did. I have a lot (understatement) of frame repair to do--all the frames in the forward half of my boat need varying levels of repair and the rest are contaminated with oil and may or may not require repalcement. The bottom is completely off my boat for a total replacement of the bottom.
http://i571.photobucket.com/albums/ss151/cmeke0870/work%20begins/IMG00087-20100313-1505.jpg[/IMG]
Unfortunately, I have a lot of frame, keel, stem, and gripe repair to do before I get to ply or planking--sigh. sigh again.

CharlieCobra
04-02-2010, 01:14 PM
I would guess you could say that Oh Joy has a 5200 hull, considering that's what they used to apply the C-Flex cloth to the wood prior to wetting it in. That and random Monel staples. Stripping the stuff off ain't bad if ya use a multitool to slice under the sheathing and followup with the "5200 de-bonding agent" to clean it up. One thing's for sure. None of the glass has lifted or delaminated. Replacing that strip looks to be interesting though...

cap'nRod
04-02-2010, 02:10 PM
Another interesting use for 5200 that I've discovered is as a wood surface waterproofer. Smear the surface of the wood liberally with 5200, then immediately wipe it off with dry papertowels until you're back to the bare wood. The 5200 has now sealed the wood's surface, giving it a slightly 'whitewashed' look. It works great for traditionally difficult-to-properly-seal areas such as wood ends, too.

erster
04-02-2010, 02:20 PM
Erster--I wouldn't be using 5200 as a "gap filler" although someone in the history of my boat did. I have a lot (understatement) of frame repair to do--all the frames in the forward half of my boat need varying levels of repair and the rest are contaminated with oil and may or may not require repalcement. The bottom is completely off my boat for a total replacement of the bottom.

Is it possible to skin back the frames if the frames are so soiled and then glue back some fresh wood for spacers, shimming them back and then refastening the bottom through the shims into the good frame sealing the seam with good bedding? Try to drill an exploratory hole with a forstener bit or even a paddle blade type and see what you have under the surface. Simple green works wonders on oil.


Try some undiluted whisk detergent too on the faces. In some of the chesepeake bay deadrise boats we just use roofing tar, or plastic cement for bedding which skin cures. You really only need something to take up the space to stem off water if the fits are proper.

chuckt
04-02-2010, 06:27 PM
Erster: What's "simple green?" I can't tell if someone applied something deliberately or not. It is very widespread and thick in some places to just be an accident. Its definitely petroleum based. Interesting that you mentioned roofing tar because that is what it smells like. I will definitely be conducting clean up experiments soon so thanks for the suggestions. And sorry for the thread drift

erster
04-02-2010, 06:56 PM
Erster: What's "simple green?" I can't tell if someone applied something deliberately or not. It is very widespread and thick in some places to just be an accident. Its definitely petroleum based. Interesting that you mentioned roofing tar because that is what it smells like. I will definitely be conducting clean up experiments soon so thanks for the suggestions. And sorry for the thread drift

Take your pick. Look around at your local hardware store. Locally the grocery stores carry it too, the general formula.
http://industrial.simplegreen.com/

Try scraping the faces with a rigid putty knife and see if you can remove any residue. If you think its roofing tar, you are in business. This also preserves the wood even though its a bit messy. Other heavy duty work boats from years ago used motor oil when they changed their engine oils in lieu of any paint to preserve cedars and pine framing. Do you have what appears to be rot or are your frames just nasty?

Rich VanValkenburg
04-02-2010, 07:52 PM
It might be worth it for me to rattle some chains of the guys that I know are doing this type (5200) of bottom rebuild. I don't think they're looking down the road at future repairs, and that begs to pose that question to them.

chuckt
04-02-2010, 09:16 PM
Yeah, I'd be interested in how long they last. They sure look nice when first done.

Erster--I think I will start a thread on oil removal.

Rich VanValkenburg
04-02-2010, 10:31 PM
LOL!!! I'm still laughing at the response I just received from my email. I posed the question to a professional restorer, I won't mention the name, and you want to hear the answer?

in part "....... I hope I never get one that hits a huge rock or log, etc. We can do it, but would rather not. Are you trying to give me nightmares?"

So much for repairing a 5200 bottom. Many customers insist on it, but have no idea.

chuckt
04-03-2010, 08:13 AM
LOL! Danenburg has a forum on his website. If you search through there you will see he admits repairs are problematic-- however insists it is doable

erster
04-03-2010, 09:22 AM
:D:D Thats a riot for sure.

pcford
04-03-2010, 09:53 PM
Really don't understand the non traditional bottom...The original ones lasted sixty years...how long are these guys going to live?

nextse7en
04-03-2010, 11:15 PM
5200 is an absolute nightmare. Here is another vote for a cold molded bottom.

I'm assuming you are talking about a runabout, and not a 50' cruiser. The game gets a bit different then.

Cold molding is time consuming, but very forgiving for the beginner.