Ross M
10-26-2002, 01:58 AM
Author Topic: CPES
JoJo
posted 01-27-2000 12:15 AM
--------------------------------------------------------------------------------
In all my travels on this forum, I've read an awefull lot about CPES. It just suddenly hit me. I don't know what the heck the stuff is. To tell the truth I am only really familiar with epoxy as far as boatbuilding is concerned. We have used the WEST SYSTEM on all or our boats so far. So... can anyone tell me what CPES is? Is it similar to epoxy?
Allen Foote
posted 01-27-2000 12:31 PM
--------------------------------------------------------------------------------
Don't feel like you're alone on this CPES stuff. I've been working with West for years and the first time hearing of CPES was on this forum. I still haven't seen any of it yet. Sounds like it's a thinned version of West...but don't try anymore than 10% and make sure it's a Methol Ethal Keytone and not acetone. Did I get that right? Seriously, I use thinned West instead of buying another product. I've got enough stuff cluttering up my paint locker. That might not answer your question but I know where you're comming from.
Bob Cleek
posted 01-27-2000 02:00 PM
--------------------------------------------------------------------------------
There have been previous posts which went into great detail discussing CPES. Check them out.
CPES is Clear Penetrating Epoxy SEALER. It is NOT thinned epoxy resin, West, System 3 or otherwise, but rather a very specialized product made by Smith and Co. Industrial Coatings of Richmond CA. It can also be purchased at WestMarine and off the net at Rotdoctor.com or something like that, repackaged as "Restors-it" at a much higher price than Smith sells it at the factory.
While "Restors-it" is marketed as a miracle cure you paint on rotten wood to turn it into epoxy, that is pure BS. CPES is a specially formulated product that contains specialized solvents which permit the penetration of particular penetrating epoxy compounds into the wood surface. It is a sealer used under traditional or more modern coating systems. It is the "industry standard" on the West Coast for this purpose. Good stuff, check it out... nobody who does ever goes without it again!
Bill Sterling
posted 01-27-2000 04:08 PM
--------------------------------------------------------------------------------
Apparently WestMarine dropped CPES 'cause Smith didn't want to expand production to supply all their stores but they recommend the product highly.
Scott Rosen
posted 01-27-2000 07:09 PM
--------------------------------------------------------------------------------
Waste Marine recommends CPES. One more reason not to use it. (No offense, Bill.)
Bob Cleek
posted 01-28-2000 12:30 AM
--------------------------------------------------------------------------------
Puleeeeeze, Scott! Just try a taste... you'll dig it, man!
Ross Miller
posted 01-28-2000 12:56 AM
--------------------------------------------------------------------------------
Set me straight, O apostles of CPES. If I were building a traditional lapstrake or carvel boat, are you recommending that I slather everything with this product? Keel, frames, planks, clamps and logs? Inside and out? Each piece prior to assembly? Do tell.
Bob Cleek
posted 01-28-2000 01:08 AM
--------------------------------------------------------------------------------
Each piece when you build it and the whole shebang when she's done... then paint or varnish as usual.
Ross Miller
posted 01-28-2000 01:58 AM
--------------------------------------------------------------------------------
How does this affect swelling and shrinking?
Art Read
posted 01-28-2000 01:00 PM
--------------------------------------------------------------------------------
Warning... "Hearsay" ahead... Suposedly, CPES will slow down the natural shrinking/swelling cycle, but in no way "halt" it. I guess the idea is that changes will not be as extreme or rapid as with untreated materials. This is my first project using it, (hell, first boatbuilding project, period....) I have seen it's advantages when looked at simply as a "primer/sealer" coat, and the wood I've put it on has remained remarkably stable... so far... But as the vessel in question has yet to leave the building stocks in our garage/basement, I can't vouch for its long term "stabalizing" or protective qualities. Hope you're right, Bob! ;-}
[This message has been edited by Art Read (edited 01-28-2000).]
steve sparhawk
posted 01-28-2000 02:01 PM
--------------------------------------------------------------------------------
Why foola around. Just call ole Steve Smith and ask him to send you his propaganda. He'll go through the whole chemistry/physiology of wood and the treatment of it by various methods and convince you of the CPES appropriateness. His stuff contains solvent to handle oils AND moisture in the wood as well. It is not a miricle cure for everything but a product that significantly enhances the properties of wood in the fight against the moist environment and the beasties that lurk there. I have found it very good for preparing the wood to receive adhesives as well as coatings. Even if I didn't intend to use epoxies for gluing or coating, I would use CPES for its advantages under paint. I'm ready for my next order about now.
JoJo
posted 01-28-2000 06:18 PM
--------------------------------------------------------------------------------
Are you saying that you coat EVERYTHING inside and out with this stuff? What does that do for the wheight of the finished project?
Don Z.
posted 01-28-2000 06:28 PM
--------------------------------------------------------------------------------
Bob, I think we're going about this the wrong way. See, what we need to do is buy some stuff from Smith, and then re-label it as "Varnish Primer". That way Scott won't know it's epoxy, and he'll try it...Similar to making baby aspirin taste like candy...
Bob Cleek
posted 01-28-2000 08:56 PM
--------------------------------------------------------------------------------
Jojo... you coat all bare wood with CPES... it weighs practically nothing, since the solids are few and the solvents evaporate. The weight of it on a boat would be negligible. It isn't like googe which is syrupy and leaves a thich coat. It is like painting water or turpentine on the wood. Nothing to it at all... but it sure works. Maybe somebody with a can handy will post Smith's phone number so you can call for his info and a sample. (I'm too lazy to walk out to the shop and look, but will if nobody else does! LOL)
Art Read
posted 01-28-2000 09:27 PM
--------------------------------------------------------------------------------
Jojo... Bob's right. Putting this stuff on is about the same as putting on a coat "Deks Olja" or linseed oil. How much does THAT weigh? It isn't a "barrier" skin... It just soaks in and chemically alters the exposed layers of wood. Good, bad or indifferent, I'm not sure yet. I do like the way paint goes on over it, and I've found that I do better scraping the "gunk" my lumberyard put on the end grain of my stock and slapping on some of this stuff to prevent checking.... The pieces I've cut and treated with CPES have held up a lot better than the endcuts that I just left with the beeswax or whatever it was they used.
[This message has been edited by Art Read (edited 01-28-2000).]
Bo Curtis
posted 01-29-2000 12:47 AM
--------------------------------------------------------------------------------
In Canada there's a product called S-1 sealer, made by Industrial Formulators of Burnaby, B.C. I've used it a lot, and it must be similar to CPES. It's a water-thin 2-part epoxy sealer that has done a great job of sealing everything from boat parts to my yellow-cedar shower stall at home (!). I'm not sure how you'd get it in the states, but Lee Valley tools sells it, and I think they market in the states out of NY.
JoJo
posted 01-29-2000 07:48 PM
--------------------------------------------------------------------------------
Sound pretty interesting. Kinda like Thomson Water Seal but a lot better. I'm assuming it will not effect how epoxy takes to the wood. Will it still let epoxy soak in for a good joint?
[This message has been edited by JoJo (edited 01-29-2000).]
Bob Cleek
posted 01-29-2000 10:02 PM
--------------------------------------------------------------------------------
Jojo... you don't have to worry about epoxy soaking into a joint with CPES because if you CPES it, the epoxy will already be there. The googe will bond molecularly to the CPES, which will sink deeper into the wood than the googe ever will. Get Smith's tech data... he describes this at length!
Don Marik
posted 01-29-2000 10:13 PM
--------------------------------------------------------------------------------
JoJo, call Smith & Co in Richmond, CA at 510-237-6842. They are all very helpful and their product is great!
Don Danenberg
posted 01-30-2000 01:08 AM
--------------------------------------------------------------------------------
JoJo, I have extensively restored over 100 wooden boats to date. Started with sailboats 12 to 117 foot but came to specialize in Mahogany runabouts. I have learned from the disassembly phase to never-ever use hard epoxy glues on traditionally built wooden boats. If you are gluing together wood over 1/8" thickness, 10-15 years is the best you'll get. Only true cold-molded hulls of 1/16" vacuum bagged veneers (a fiberglass hull; with wood fibers in place of glass fibers) will last longer than that. Sea-kindly sailboats that are softly used do not see the kind of punishing jarring vibrations that lightly built Mahogany inboards see with their early flat planing bottom designs.
$100,000.00 "replicas" are coming apart after six years.
Flexible bedding compounds must be used for anything but true cold-molded construction such as boats like "AirForce" (WoodenBoat #68:72) (of course the keel bolts were 'potted' in epoxy and they and the keel fell off and the boat sunk...).
Smith's CPES is nothing at all like a hard epoxy glue, it can't even be used as a glue.
It is formulated of wood resins, not space-age plastic. When it sets up in the mixing pot or in the wood it remains flexible. The wood can suffer expansion/contraction due to seasonal temperature differences, or the jarring vibrations of an inboard speedboat, that would creat 'zipper cracks' in hard epoxy coatings. It slows down the movement of moisture but will not entrap it. Write WoodenBoat magazine contributing writer/gurus like Ed McClave, Richard Jeagels, Aime Ontario Fraser and ask them if there is a place in a wooden boat for hard plastic glues and they'll probably all say: "geez, not this again, read my last 20 articles".
Seal everything with CPES and then use proper bedding compounds like 3M-5200. Don
wandiwise
posted 01-30-2000 02:31 PM
--------------------------------------------------------------------------------
This to Don Danenberg: That was a very interesting post, very informative and forthright, obviously based upon practical experience, and not an attempt to bolster a point of view.
Have you any thoughts, based upon this same work, regarding the resorcinols, whether the English Aerodux or the old-fashioned purple glues we are all familiar with?
This is assuming glued construction, with or without additional fastenings. I don't know whether I'm asking a 'versus' type question or not; hadn't intended to, such as CPES/5200 vs resorcinols w/wo fasteners.
Let's ask it this way: In the CPES/5200 recommendation, is this 'glued up' construction, or is the 5200 there for a sealer?
Thank you, and I hope you can make better sense of my question than I did.
www
Don Danenberg
posted 01-30-2000 04:08 PM
--------------------------------------------------------------------------------
WWW, I disassemble and rebuild Mahogany runabouts 16-30 foot and get to see what lasts and what doesn't. Chris Craft glued the 15/16 mahogany single-sawn-sistered frame futtocks in their postwar boats with purple resorcinol (#8x1-1/2 bronze screws every 3" or so). I've removed rotted, fractured, split frames but I've never seen failure at this joint. Century Boat Co. laminated frame members with Weldwood Plastic Resin glue and this stuff just plain disappeared after 30 years, leaving the brass screws holding the now-rotting frames together.
Every previous repair I've seen done with a hard epoxy glue either has already popped apart before I got to it or a screwdriver wedged into one end will pop the entire glued joint.
I have never had any experience with Aerodux glue.
The one adhesive/bedding that lasts for decades is 3M-5200. It allows component motion without popping free as hard epoxy glues eventually do.
Glued-up construction, in my experience, will only last if the expansion coeffecient of the wood (at 10%) is less than the glueline. Hard epoxies saturate the wood surface about 1/100". The wood being laminated, therefore, should be no larger than 1/16" veneer, as Gougeon builds them.
I've simply seen too much failure to believe otherwise.
CPES as a sealer and 3M-5200 as an adhesive/bedding still requires traditional screws to keep things together. Wooden boats work and move whether you believe you've encapsulated them or not.
Sorry, sure makes construction easy though, doesn't it. Don
Bob Cleek
posted 01-30-2000 08:30 PM
--------------------------------------------------------------------------------
Don, it sure is nice to see that I'm not the only one preaching this word! Well put! And, it isn't about "bolstering a point of view" at all. Some of us have been doing this stuff long enough to know what works and what falls apart. Sometimes, we've even tried the newly espoused methods ourselves and had them fail. Other times, it's another guy's grief.
pwilling
posted 01-31-2000 01:22 PM
--------------------------------------------------------------------------------
Has anyone tried to slow down wood electrolysis with this stuff? Situation: teak planking over teak ribs, Copper rivet fastened; iron straps on blocks between ribs. Iron straps showing some rust, and have fuzzed up the blocks with electrolytic crystals. My notions: 1) re-connect iron straps to bonding system (yah I know that is another whole theological discussion elsewhere); 2) treat fuzzed wood with white vinegar or citric acid; 3) get everything dried out and blow off all the rust; 4) run some kind of gnome sweat into the porous wood to displace the water and break up my battery action; and 5) paint the works. Does CPES have a place in this scene?
Thanks
By the way, notifications of new posts are carrying a 1969 date on them -- makes 'em a bit hard to find . . .
Bill Sterling
posted 01-31-2000 04:46 PM
--------------------------------------------------------------------------------
Does this talk about not using hard epoxies apply to the edge joints of a transom (it'll have the bronze drifts)? Would you use 5200 there instead of epoxy?! What about strip plank edges?
Dale Harvey
posted 01-31-2000 07:58 PM
--------------------------------------------------------------------------------
It might be a good idea to do a simple litmus paper test on a moistened area of the fuzzy wood to determine if it is an acidic or base condition that is eating the wood. Phosphoric acid based products neutalize rust on steel. Should be scrubbed on with a stainless brush after chipping. Nuetralize wood with soda solution afterward. CPES is a good idea for primer, but red lead is the only thing I've seen stop fuzzyrot. Good on Iron too.
pwilling
posted 02-03-2000 08:49 PM
--------------------------------------------------------------------------------
Thanks Dale -- you send me off in some useful directions -- I will do a bit of nondestructive investigation first. About the red lead -- is it still available? There is a lot in the boat already --
chemist
posted 03-12-2000 12:22 PM
--------------------------------------------------------------------------------
Any isolated piece of metal can corrode if one of two conditions are present.
First, if that piece of metal is chemically unstable in the presence of oxygen (the air) and the salt water. (test: put it in a plastic or glass container with salt water. Cover it, let it sit and see if it does anything.) If it corrodes, dissolves, or otherwise provides entertainment, then it is chemically unstable and should not be used in the first place. However, sometimes they are.
Second, if there is a dissimilar metal present and a path conductive to electricity exists between the two, then there can be "electrolytic corrosion", named because the dissimilar metals have inherently a potential difference between them, and that causes a current to flow and electroplates in reverse, dissolving the fastener away.
It follows that wood with a bit of water and the most minute amount of salt present is an electrical conductor, even over tens of feet and through fasteners that penetrate separate pieces of wood. This flow of current also causes a decomposition of the wood surrounding the target fastener, where the concentration of current is the highest. Imagine the electrolytic current concentrated all down onto one little fastener, then spreading radially out to a hundred times that area as it flows through the entire cross section of the wood member.
If the wood can be dried in the area of the fastener, so that it is not waterlogged, and then impregnated with something that raises the electrical resistance of the wood and encapsulates the salt crystals in a hydrophobic material (an epoxy product such as CPES does this...if the wood is dry enough and you do not need the water-dissolving feature of CPES, most epoxy products are in principle capable of doing this) then electrolytic corrosion stops because essentially no current can flow to or from the fastener, it now being surrounded by an insulator rather than a conductor of electricity.
Treating iron fasteners with a phosphoric-acid-containing product converts the iron oxide (rust) to iron phosphate which is grey rather than black or red. The rust thus appears to go away. These products help paint and glue to stick better to iron but are not anticorrosive treatments in and of themselves. Corrosion-inhibiting products are also required. Many amine-cured epoxy products may serve this purpose, since amines are mild corrosion inhibitors . You should evaluate each product carefully, since epoxy/amine systems by themselves are not often designed to take advantage of this feature.
[This message has been edited by chemist (edited 03-12-2000).]
Bob Cleek
posted 03-12-2000 02:29 PM
--------------------------------------------------------------------------------
I got a "D" in college chemistry, so... but I can tell you this, Chemist knows his stuff when it comes to chemistry and wooden boats. I don't know all the technical reasons why things do the things they do, but I can confirm from dirty fingernail experience that what he says is true. Thanks, Chemist, for explaining what really goes on with these materials! A lot of us have been saying the same things for a long while, based on nothing more than our own playing around with this stuff, without any scientific bases. Your posts really hit the nails on the head!
dasboat
posted 03-12-2000 05:01 PM
--------------------------------------------------------------------------------
Way to go chemist.I 2nd Bobs remarks.I didnt take chem.in college(I couldn't make myself play with tinkertoys)so I took a real serious major (psych.)and now I really really really understand what life is about...WOOD BOATS.
I dont need to know how something works before I use it,but I sure do like to know if its possible.It allows me to try out ideas from a knowledge base.
This forum is for me alot like having a bunch of bright friends who know how to have fun and learn at the same time.What a find!
Regards,Darryl
Scott Rosen
posted 03-12-2000 05:09 PM
--------------------------------------------------------------------------------
Triple dittos for me, Chemist. Thanks for the education.
JoJo
posted 01-27-2000 12:15 AM
--------------------------------------------------------------------------------
In all my travels on this forum, I've read an awefull lot about CPES. It just suddenly hit me. I don't know what the heck the stuff is. To tell the truth I am only really familiar with epoxy as far as boatbuilding is concerned. We have used the WEST SYSTEM on all or our boats so far. So... can anyone tell me what CPES is? Is it similar to epoxy?
Allen Foote
posted 01-27-2000 12:31 PM
--------------------------------------------------------------------------------
Don't feel like you're alone on this CPES stuff. I've been working with West for years and the first time hearing of CPES was on this forum. I still haven't seen any of it yet. Sounds like it's a thinned version of West...but don't try anymore than 10% and make sure it's a Methol Ethal Keytone and not acetone. Did I get that right? Seriously, I use thinned West instead of buying another product. I've got enough stuff cluttering up my paint locker. That might not answer your question but I know where you're comming from.
Bob Cleek
posted 01-27-2000 02:00 PM
--------------------------------------------------------------------------------
There have been previous posts which went into great detail discussing CPES. Check them out.
CPES is Clear Penetrating Epoxy SEALER. It is NOT thinned epoxy resin, West, System 3 or otherwise, but rather a very specialized product made by Smith and Co. Industrial Coatings of Richmond CA. It can also be purchased at WestMarine and off the net at Rotdoctor.com or something like that, repackaged as "Restors-it" at a much higher price than Smith sells it at the factory.
While "Restors-it" is marketed as a miracle cure you paint on rotten wood to turn it into epoxy, that is pure BS. CPES is a specially formulated product that contains specialized solvents which permit the penetration of particular penetrating epoxy compounds into the wood surface. It is a sealer used under traditional or more modern coating systems. It is the "industry standard" on the West Coast for this purpose. Good stuff, check it out... nobody who does ever goes without it again!
Bill Sterling
posted 01-27-2000 04:08 PM
--------------------------------------------------------------------------------
Apparently WestMarine dropped CPES 'cause Smith didn't want to expand production to supply all their stores but they recommend the product highly.
Scott Rosen
posted 01-27-2000 07:09 PM
--------------------------------------------------------------------------------
Waste Marine recommends CPES. One more reason not to use it. (No offense, Bill.)
Bob Cleek
posted 01-28-2000 12:30 AM
--------------------------------------------------------------------------------
Puleeeeeze, Scott! Just try a taste... you'll dig it, man!
Ross Miller
posted 01-28-2000 12:56 AM
--------------------------------------------------------------------------------
Set me straight, O apostles of CPES. If I were building a traditional lapstrake or carvel boat, are you recommending that I slather everything with this product? Keel, frames, planks, clamps and logs? Inside and out? Each piece prior to assembly? Do tell.
Bob Cleek
posted 01-28-2000 01:08 AM
--------------------------------------------------------------------------------
Each piece when you build it and the whole shebang when she's done... then paint or varnish as usual.
Ross Miller
posted 01-28-2000 01:58 AM
--------------------------------------------------------------------------------
How does this affect swelling and shrinking?
Art Read
posted 01-28-2000 01:00 PM
--------------------------------------------------------------------------------
Warning... "Hearsay" ahead... Suposedly, CPES will slow down the natural shrinking/swelling cycle, but in no way "halt" it. I guess the idea is that changes will not be as extreme or rapid as with untreated materials. This is my first project using it, (hell, first boatbuilding project, period....) I have seen it's advantages when looked at simply as a "primer/sealer" coat, and the wood I've put it on has remained remarkably stable... so far... But as the vessel in question has yet to leave the building stocks in our garage/basement, I can't vouch for its long term "stabalizing" or protective qualities. Hope you're right, Bob! ;-}
[This message has been edited by Art Read (edited 01-28-2000).]
steve sparhawk
posted 01-28-2000 02:01 PM
--------------------------------------------------------------------------------
Why foola around. Just call ole Steve Smith and ask him to send you his propaganda. He'll go through the whole chemistry/physiology of wood and the treatment of it by various methods and convince you of the CPES appropriateness. His stuff contains solvent to handle oils AND moisture in the wood as well. It is not a miricle cure for everything but a product that significantly enhances the properties of wood in the fight against the moist environment and the beasties that lurk there. I have found it very good for preparing the wood to receive adhesives as well as coatings. Even if I didn't intend to use epoxies for gluing or coating, I would use CPES for its advantages under paint. I'm ready for my next order about now.
JoJo
posted 01-28-2000 06:18 PM
--------------------------------------------------------------------------------
Are you saying that you coat EVERYTHING inside and out with this stuff? What does that do for the wheight of the finished project?
Don Z.
posted 01-28-2000 06:28 PM
--------------------------------------------------------------------------------
Bob, I think we're going about this the wrong way. See, what we need to do is buy some stuff from Smith, and then re-label it as "Varnish Primer". That way Scott won't know it's epoxy, and he'll try it...Similar to making baby aspirin taste like candy...
Bob Cleek
posted 01-28-2000 08:56 PM
--------------------------------------------------------------------------------
Jojo... you coat all bare wood with CPES... it weighs practically nothing, since the solids are few and the solvents evaporate. The weight of it on a boat would be negligible. It isn't like googe which is syrupy and leaves a thich coat. It is like painting water or turpentine on the wood. Nothing to it at all... but it sure works. Maybe somebody with a can handy will post Smith's phone number so you can call for his info and a sample. (I'm too lazy to walk out to the shop and look, but will if nobody else does! LOL)
Art Read
posted 01-28-2000 09:27 PM
--------------------------------------------------------------------------------
Jojo... Bob's right. Putting this stuff on is about the same as putting on a coat "Deks Olja" or linseed oil. How much does THAT weigh? It isn't a "barrier" skin... It just soaks in and chemically alters the exposed layers of wood. Good, bad or indifferent, I'm not sure yet. I do like the way paint goes on over it, and I've found that I do better scraping the "gunk" my lumberyard put on the end grain of my stock and slapping on some of this stuff to prevent checking.... The pieces I've cut and treated with CPES have held up a lot better than the endcuts that I just left with the beeswax or whatever it was they used.
[This message has been edited by Art Read (edited 01-28-2000).]
Bo Curtis
posted 01-29-2000 12:47 AM
--------------------------------------------------------------------------------
In Canada there's a product called S-1 sealer, made by Industrial Formulators of Burnaby, B.C. I've used it a lot, and it must be similar to CPES. It's a water-thin 2-part epoxy sealer that has done a great job of sealing everything from boat parts to my yellow-cedar shower stall at home (!). I'm not sure how you'd get it in the states, but Lee Valley tools sells it, and I think they market in the states out of NY.
JoJo
posted 01-29-2000 07:48 PM
--------------------------------------------------------------------------------
Sound pretty interesting. Kinda like Thomson Water Seal but a lot better. I'm assuming it will not effect how epoxy takes to the wood. Will it still let epoxy soak in for a good joint?
[This message has been edited by JoJo (edited 01-29-2000).]
Bob Cleek
posted 01-29-2000 10:02 PM
--------------------------------------------------------------------------------
Jojo... you don't have to worry about epoxy soaking into a joint with CPES because if you CPES it, the epoxy will already be there. The googe will bond molecularly to the CPES, which will sink deeper into the wood than the googe ever will. Get Smith's tech data... he describes this at length!
Don Marik
posted 01-29-2000 10:13 PM
--------------------------------------------------------------------------------
JoJo, call Smith & Co in Richmond, CA at 510-237-6842. They are all very helpful and their product is great!
Don Danenberg
posted 01-30-2000 01:08 AM
--------------------------------------------------------------------------------
JoJo, I have extensively restored over 100 wooden boats to date. Started with sailboats 12 to 117 foot but came to specialize in Mahogany runabouts. I have learned from the disassembly phase to never-ever use hard epoxy glues on traditionally built wooden boats. If you are gluing together wood over 1/8" thickness, 10-15 years is the best you'll get. Only true cold-molded hulls of 1/16" vacuum bagged veneers (a fiberglass hull; with wood fibers in place of glass fibers) will last longer than that. Sea-kindly sailboats that are softly used do not see the kind of punishing jarring vibrations that lightly built Mahogany inboards see with their early flat planing bottom designs.
$100,000.00 "replicas" are coming apart after six years.
Flexible bedding compounds must be used for anything but true cold-molded construction such as boats like "AirForce" (WoodenBoat #68:72) (of course the keel bolts were 'potted' in epoxy and they and the keel fell off and the boat sunk...).
Smith's CPES is nothing at all like a hard epoxy glue, it can't even be used as a glue.
It is formulated of wood resins, not space-age plastic. When it sets up in the mixing pot or in the wood it remains flexible. The wood can suffer expansion/contraction due to seasonal temperature differences, or the jarring vibrations of an inboard speedboat, that would creat 'zipper cracks' in hard epoxy coatings. It slows down the movement of moisture but will not entrap it. Write WoodenBoat magazine contributing writer/gurus like Ed McClave, Richard Jeagels, Aime Ontario Fraser and ask them if there is a place in a wooden boat for hard plastic glues and they'll probably all say: "geez, not this again, read my last 20 articles".
Seal everything with CPES and then use proper bedding compounds like 3M-5200. Don
wandiwise
posted 01-30-2000 02:31 PM
--------------------------------------------------------------------------------
This to Don Danenberg: That was a very interesting post, very informative and forthright, obviously based upon practical experience, and not an attempt to bolster a point of view.
Have you any thoughts, based upon this same work, regarding the resorcinols, whether the English Aerodux or the old-fashioned purple glues we are all familiar with?
This is assuming glued construction, with or without additional fastenings. I don't know whether I'm asking a 'versus' type question or not; hadn't intended to, such as CPES/5200 vs resorcinols w/wo fasteners.
Let's ask it this way: In the CPES/5200 recommendation, is this 'glued up' construction, or is the 5200 there for a sealer?
Thank you, and I hope you can make better sense of my question than I did.
www
Don Danenberg
posted 01-30-2000 04:08 PM
--------------------------------------------------------------------------------
WWW, I disassemble and rebuild Mahogany runabouts 16-30 foot and get to see what lasts and what doesn't. Chris Craft glued the 15/16 mahogany single-sawn-sistered frame futtocks in their postwar boats with purple resorcinol (#8x1-1/2 bronze screws every 3" or so). I've removed rotted, fractured, split frames but I've never seen failure at this joint. Century Boat Co. laminated frame members with Weldwood Plastic Resin glue and this stuff just plain disappeared after 30 years, leaving the brass screws holding the now-rotting frames together.
Every previous repair I've seen done with a hard epoxy glue either has already popped apart before I got to it or a screwdriver wedged into one end will pop the entire glued joint.
I have never had any experience with Aerodux glue.
The one adhesive/bedding that lasts for decades is 3M-5200. It allows component motion without popping free as hard epoxy glues eventually do.
Glued-up construction, in my experience, will only last if the expansion coeffecient of the wood (at 10%) is less than the glueline. Hard epoxies saturate the wood surface about 1/100". The wood being laminated, therefore, should be no larger than 1/16" veneer, as Gougeon builds them.
I've simply seen too much failure to believe otherwise.
CPES as a sealer and 3M-5200 as an adhesive/bedding still requires traditional screws to keep things together. Wooden boats work and move whether you believe you've encapsulated them or not.
Sorry, sure makes construction easy though, doesn't it. Don
Bob Cleek
posted 01-30-2000 08:30 PM
--------------------------------------------------------------------------------
Don, it sure is nice to see that I'm not the only one preaching this word! Well put! And, it isn't about "bolstering a point of view" at all. Some of us have been doing this stuff long enough to know what works and what falls apart. Sometimes, we've even tried the newly espoused methods ourselves and had them fail. Other times, it's another guy's grief.
pwilling
posted 01-31-2000 01:22 PM
--------------------------------------------------------------------------------
Has anyone tried to slow down wood electrolysis with this stuff? Situation: teak planking over teak ribs, Copper rivet fastened; iron straps on blocks between ribs. Iron straps showing some rust, and have fuzzed up the blocks with electrolytic crystals. My notions: 1) re-connect iron straps to bonding system (yah I know that is another whole theological discussion elsewhere); 2) treat fuzzed wood with white vinegar or citric acid; 3) get everything dried out and blow off all the rust; 4) run some kind of gnome sweat into the porous wood to displace the water and break up my battery action; and 5) paint the works. Does CPES have a place in this scene?
Thanks
By the way, notifications of new posts are carrying a 1969 date on them -- makes 'em a bit hard to find . . .
Bill Sterling
posted 01-31-2000 04:46 PM
--------------------------------------------------------------------------------
Does this talk about not using hard epoxies apply to the edge joints of a transom (it'll have the bronze drifts)? Would you use 5200 there instead of epoxy?! What about strip plank edges?
Dale Harvey
posted 01-31-2000 07:58 PM
--------------------------------------------------------------------------------
It might be a good idea to do a simple litmus paper test on a moistened area of the fuzzy wood to determine if it is an acidic or base condition that is eating the wood. Phosphoric acid based products neutalize rust on steel. Should be scrubbed on with a stainless brush after chipping. Nuetralize wood with soda solution afterward. CPES is a good idea for primer, but red lead is the only thing I've seen stop fuzzyrot. Good on Iron too.
pwilling
posted 02-03-2000 08:49 PM
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Thanks Dale -- you send me off in some useful directions -- I will do a bit of nondestructive investigation first. About the red lead -- is it still available? There is a lot in the boat already --
chemist
posted 03-12-2000 12:22 PM
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Any isolated piece of metal can corrode if one of two conditions are present.
First, if that piece of metal is chemically unstable in the presence of oxygen (the air) and the salt water. (test: put it in a plastic or glass container with salt water. Cover it, let it sit and see if it does anything.) If it corrodes, dissolves, or otherwise provides entertainment, then it is chemically unstable and should not be used in the first place. However, sometimes they are.
Second, if there is a dissimilar metal present and a path conductive to electricity exists between the two, then there can be "electrolytic corrosion", named because the dissimilar metals have inherently a potential difference between them, and that causes a current to flow and electroplates in reverse, dissolving the fastener away.
It follows that wood with a bit of water and the most minute amount of salt present is an electrical conductor, even over tens of feet and through fasteners that penetrate separate pieces of wood. This flow of current also causes a decomposition of the wood surrounding the target fastener, where the concentration of current is the highest. Imagine the electrolytic current concentrated all down onto one little fastener, then spreading radially out to a hundred times that area as it flows through the entire cross section of the wood member.
If the wood can be dried in the area of the fastener, so that it is not waterlogged, and then impregnated with something that raises the electrical resistance of the wood and encapsulates the salt crystals in a hydrophobic material (an epoxy product such as CPES does this...if the wood is dry enough and you do not need the water-dissolving feature of CPES, most epoxy products are in principle capable of doing this) then electrolytic corrosion stops because essentially no current can flow to or from the fastener, it now being surrounded by an insulator rather than a conductor of electricity.
Treating iron fasteners with a phosphoric-acid-containing product converts the iron oxide (rust) to iron phosphate which is grey rather than black or red. The rust thus appears to go away. These products help paint and glue to stick better to iron but are not anticorrosive treatments in and of themselves. Corrosion-inhibiting products are also required. Many amine-cured epoxy products may serve this purpose, since amines are mild corrosion inhibitors . You should evaluate each product carefully, since epoxy/amine systems by themselves are not often designed to take advantage of this feature.
[This message has been edited by chemist (edited 03-12-2000).]
Bob Cleek
posted 03-12-2000 02:29 PM
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I got a "D" in college chemistry, so... but I can tell you this, Chemist knows his stuff when it comes to chemistry and wooden boats. I don't know all the technical reasons why things do the things they do, but I can confirm from dirty fingernail experience that what he says is true. Thanks, Chemist, for explaining what really goes on with these materials! A lot of us have been saying the same things for a long while, based on nothing more than our own playing around with this stuff, without any scientific bases. Your posts really hit the nails on the head!
dasboat
posted 03-12-2000 05:01 PM
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Way to go chemist.I 2nd Bobs remarks.I didnt take chem.in college(I couldn't make myself play with tinkertoys)so I took a real serious major (psych.)and now I really really really understand what life is about...WOOD BOATS.
I dont need to know how something works before I use it,but I sure do like to know if its possible.It allows me to try out ideas from a knowledge base.
This forum is for me alot like having a bunch of bright friends who know how to have fun and learn at the same time.What a find!
Regards,Darryl
Scott Rosen
posted 03-12-2000 05:09 PM
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Triple dittos for me, Chemist. Thanks for the education.