5200 before epoxy?

[bird]

Hello. I am wondering if anyone has any thoughts or experience on using 5200 over an entire surface area, not just in seams and joints. I am wondering about coating an entire hull with 5200, before applying epoxy over that, in the hopes that it would provide a better surface area for epoxy to adhere to. Is it possible this could prolong the life of the epoxy? That it would hold to the hull longer?

[KMacDonald]

great idea !!!!!!!!!!!!!!!!!!

[James McMullen]

Be sure to use at least 1/4 square notch trowel to apply that 5200 so that there will be plenty of "tooth" for the epoxy to adhere to.

[willmarsh3]

The only time I've seen 5200 used is to bond something to something else - either double planking or bonding teak to steel or any number of fittings that someone didn't plan on ever removing.
Presuming you are coating wood the epoxy would work better over the wood. I haven't tried it but given the nature of 5200 I'm not sure if epoxy would stick to it well. But 5200 does stick well to already cured epoxy.
I see this is your first post. Welcome to the Woodenboat Forum. Would you mind sharing pictures of your project?

[Thorne]

Nope.

The general concept has been mentioned before, I think in reference to PL Premium. That stuff, along with 5200, is a GLUE or ADHESIVE, designed to attach one thing to another. As this sort of product gets more and more flexible, it becomes more of a SEALANT than GLUE.

It adds nothing positive to a hull to cover it with either glues or sealants, and would make the epoxy (another great glue that works well with fiber layers like fiberglass cloth) not stick well.

The only alternative I've heard of to epoxy and glass cloth, (and one not nearly as waterproof/durable) is thick layers of paint with polyester fabric embedded in it.

Why do you ask, and for what boat/materials/function?

[pcford]

I think the original poster should note that some of the repliers are joshing him.

[Tom Robb]

Is the question serious?

[TimH]

WOW. This is amazing. HAS to be a joke :)

[Thorne]

I treat all questions as serious, all guns as loaded, and all other drivers on the roadway as homicidal morons -- and end up being right far too often.

Question could easily be serious, after all epoxy is also a glue that you use to cover hulls with, right? Who knows...

[bird]

5200 is a forgiving transitional marriage between moving wood and the unmoving epoxy skin. There would be dynel fabric laid into the 5200, and epoxy over the dynel. This is no joke. This has occurred many times in Florida to patch wooden hulls. Does anyone have experience to do this on an entire hull?
It's a 40 ft. hull, strip planked with long leaf yellow pine. hand built over the last 30 years.

[Peter Malcolm Jardine]

I use a tube of 5200 about once every five years or so, but then, I have wooden boats. I suppose you could coat the hull with 5200... but why wouldn't you just buy a fibreglass boat?

[pcford]

Hello, Dutch.

[Chris Coose]

There would be dynel fabric laid into the 5200, and epoxy over the dynel. This is no joke..

How do you dress for safe sex?

[Bob Cleek]

5200 is a forgiving transitional marriage between moving wood and the unmoving epoxy skin. There would be dynel fabric laid into the 5200, and epoxy over the dynel. This is no joke. This has occurred many times in Florida to patch wooden hulls. Does anyone have experience to do this on an entire hull?
It's a 40 ft. hull, strip planked with long leaf yellow pine. hand built over the last 30 years.

Ah! Full details are so much more helpful. A 40' STRIP PLANKED LONG LEAF YELLOW PINE HULL, HAND BUILT OVER THE LAST 30 YEARS is a whole different matter! The Dynel and epoxy sheathing is a very important fact. Without the Dynel, the flexibility of the wooden hull and the 5200 would cause the less flexible epoxy to crack!

Here's what you do:

First, and VERY IMPORTANTLY, you want to be sure and use the "FAST CURE" 3M 5200. This stuff dries tack-free in an hour and cures fully in 24 hours. This will save you a ton of time. You'd have to sit on your hands for weeks watching regular 5200 curing before you could apply your Dynel and epoxy and with yard lay-day fees being what they are these days, that can get expensive.

Second, figure out the underwater surface area of that 40' hull in square footage and then multiply that by the thickness of the 5200 you are going to apply so you know how much to buy. You'll need a 1/4" thick coat if you want to make sure it's really fair and will fill the bumps and hollows and provide enough flexibility and "cushioning" in the event the boat runs aground. Otherwise, you risk breaking through the Dynel and epxoy sheathing, which wouldn't be a good thing, and, of course, defeat your intended purpose.

It's just a guess, but a relatively flat hard chine 40' powerboat hull is going to draw maybe four feet and have a 15' beam so you are in the range of 920 square feet of underwater surface. Allow for some waste and whatnot and figure you will need to buy enough 5200 to cover about 950 square feet. No matter how neat you are, there will always be some you can't get out of the tube, or that continues to ooze out of the nozzle after you've quit pumping, and like that. You'll need more if it's a sail boat hull with a keel, and beam is an addtional factor, but you can do more exact measuring and math yourself. 3M's spec sheet says that at 1/4" thickness, a tube will cover one square foot of surface area. (Convenient when doing the math, but, really, that's what they say.) At 950 square feet, then, you'll need 950 1/10-gallon tubes. You can get these at WestMarine for $25.00 per tube (maybe a bit less if you shop around). So, your 5200 is going to run you about $23,750.00, plus tax. (That would come to $25,650 with tax in CA... I don't know what your sales tax is. You might beat the sales tax if you bought it on line from someplace that doesn't charge sales tax, but then, you'd be paying the shipping, so...)

The WEST data sheet indicates a pound of WEST epoxy will saturate 13 square feet of your basic 9 oz. Dynel fabric. You'll need 73 pounds of epoxy for 950 square feet of hull, allowing for waste, and maybe 1000 square feet of Dynel, since you're going to have more waste with the fabric off cuts than you will with your 5200 and epoxy. A gallon "kit" of WEST epoxy weights about 12 pounds, so you'll need about six one-gallon kits. At around $150 a gallon, you will need about $900 worth of epoxy. (You'll spend more, adding pumps, containers, applicators and all that, but I'm not counting that stuff, since it's "chump change.") You'll need about 70 yards of 55" bolt Dynel at about $10.00 a yard, totalling $700.00 for the Dynel.

So, your total cost for materials will be $25,350.00, plus tax and shipping charges. This may sound like a lot of money, but, remember, if you do all the work yourself, there's a HUGE SAVINGS in labor costs!

Here's how you do it yourself:

The easiest way to apply 3M 5200 evenly over large surface areas is to SPRAY IT. What you do is first remove it from the applicator tubes it comes in, which only have small holes in the nozzles, and transfer it to an applicator with a LARGER ORIFICE. Unfortunately, this requires a minor intermediate handling step, but no big deal. First, pump your 5200 from the original tube into one of these bottles (after you empty it.)

http://www.assetchemist.co.uk/images/uploads/fleet.jpg

Then, empty the refilled bottle full of 5200 as per the package instructions that come with the bottle. Then, with your back facing the bottom of your boat, bend over and let it fly!

[bird]

Wow.
I am amazed at how quick some of you folks at the wooden boat forum have been to insult me.
There is lots of conjecture out there. Is there anyone with direct experience?

[Bob Cleek]

If you want more experience than what I just gave you in the post above, you'd be better off calling 3M and talking to one of their product reps. Beyond what I've given you, I don't think there's anything more I could say that might be helpful.

[Todd Bradshaw]

If you are serious, the answer is pretty much don't do it. You would be using all three materials in roles that they are neither designed for or particularly good at.

Epoxy doesn't need "a better surface area to adhere to" and adding one made of flexible goo will do little other than prevent the epoxy from doing its job properly. Suspending a thin layer of any epoxy (or epoxy saturated cloth) over a layer of rubbery stuff is just asking for trouble. You soon run into a scenario where unless your epoxy section is nearly strong enough to stand alone as a hull, it's just excess weight and wasted money.

If your wood is moving, the boat's construction may well fall into the category where thin epoxy coating or sheathing don't work well. This is not uncommon with many traditional planking methods. Unless, again, the epoxy/composite layers are nearly thick enough to stand alone (you're probably looking at maybe 40-50 ounces of combined fabric weight, or better, on a boat that size) they are generally not strong enough to stabilize or survive moving planking. Folks who try to stabilize old planked wooden hulls with a thin layer of epoxy/fiberglass often find this out when their glass skin splits open and their planks rot.

Some of the ski companies played with the basic idea of laminating fiberglass skis with a rubbery layer between the core and the glass layers to absorb vibration and prevent the sheer forces from delaminating the fiberglass when the skis bent. It worked reasonably well, but they probably had 50 ounces of composite stuff on either side of the core, even on a two-pound cross country ski. In this case, the glass layers were the load-bearing ones and the core was just a spacer, which is why it worked, Trying the same on a 40' boat with a light layer of epoxy/fiberglass or a brittle layer of epoxy resin alone is a formula for disaster.

Dynel saturated with 5200 should maintain good fabric tear strength, but probably loses most of its other characteristics (like abrasion resistance, impact resistance and what rigidity it can offer) and most likely relegates it to the "big waste of money for very limited benefits" category. If you are looking to cover the hull with Dynel and take full advantage of the benefits Dynel can offer, your best bet, by far, is normal, fiberglass-style sheathing using epoxy resin, combined with doing everything possible to stabilize the wood inside and out (which might even include cold-molding veneer over the strip-planked core first).

As far as what they do in Florida to "patch" hulls, there are plenty of really bad boat repairs out there, some done by "professionals" (or at least guys who work in boat yards and like to call themselves professionals). That does not mean that they are proper repairs and is perhaps one of the main reasons that most of the folks on this forum build, repair and restore their boats themselves.

[AstoriaDave]

Bird,

That is such a bad idea that most responders did not think you serious. I could not believe you were serious, either.

Others have provided careful, thoughtful answers detailing the limits on that idea. I consider the treatment benevolent, in the face of the idea.

[bird]

Thank you very much for all your replies. I realize the very question itself sounds insane to most.
I am also looking into other options such as copper sheeting for the hull.
Again, thank you for all your time.

[ccx2]

I treat all questions as serious, all guns as loaded, and all other drivers on the roadway as homicidal morons -- and end up being right far too often.

Question could easily be serious, after all epoxy is also a glue that you use to cover hulls with, right? Who knows...
Good answer Thorne, good observation:D

[Bob Triggs]

Read the instructions.

[Bob Cleek]

Yes, serious, perhaps. But a question can easily be serious and ridiculous at the same time. It was unanimous. He got nine negative answers in various degrees, running from kind, patient, and accurate explanations (e.g. Thorne's) to flat out sarcastic. Only after all that does the poster come back trying to argue about why he thinks it's a good idea. Thorne treats every question as "serious." I do too, but only until it becomes apparent beyond a reasonable doubt that it is also worthy of ridicule. I've never known Father Neptune to be any more forgiving of any mariner than the worst of the crotchety curmudgeons in this snake pit!

[RodB]

I think the poster is getting his ideas from the current administration in Washington?????

RodB

[Todd Bradshaw]

Not sure what that is in reference to, but it could probably just as easily be aimed at any administration, current or previous, depending on your personal point of view. That stuff is best relegated to the bilge, where it belongs. In the mean time, what would the function of the copper be? Anti-fouling? Worm resistance? etc? I don't remember ever hearing much about coppered strip-plankers, but maybe I missed something. It would also be interesting to know what the designer called for in the first place.

[bird]

To be honest, I posted this question for a friend of mine who does not currently have access to a computer. Again, I realize most of you have thought the question to be completely ridiculous, but he is not a stupid man. He has hand built this entire boat, including cutting the trees and milling the wood himself for part of it. Every inch of it has been done with meticulous care. Perhaps tomorrow I will try to post a picture of of the boat for him. It is a work of art. If anyone is near the St. Paul area and wanted to take a look, I am sure he would welcome it.
Again, thank you all very much.
Bird.
by the by, I re-posted for him after several replies to clarify about the dynel. According to his pricing, it came to a couple thousand dollars, not the stated 9000.
Again, thank you for input, even if you thought it was stupid.

[bird]

The copper I believe, is intended for longevity. To minimize hauling out for repairs to the hull. Requiring also less toxic substance in the "long haul". The design of the boat he pulled out of a Smithsonian. From the 1700's I believe. A boat built for Ocean crossing. And modified that design slightly to his preferences.

[kc8pql]

Actually, I've heard of this before, maybe 7 or 8 years ago on the old Buehler builders Yahoo site. As I recall, someone asked about using 5200 to glue glass to the hull to give a better bond for the polyester resin. The idea was that the polyester wetted out the fabric and formed the sheathing and the 5200 stuck it all to the hull. He also said he'd seen this done on wooden hulls in Florida. The answers were about the same as above.

[outofthenorm]

Okay,Bird, if you are serious, then the serious answer is that it's just about the dumbest and most wrong-headed use of a perfectly good product I've ever heard of, and I've heard a lot of 'em. Not only will it not accomplish the objective, it will be pretty well ruin what otherwise might be a good boat. Wood-epoxy-cloth is a proven system that doesn't much need "improvement".

If you're not serious, well ... nuff said above.

- Norm

[bird]

Thank you very much, Norm, and everyone else.

[RodB]

A serious reply re... copper on the bottom...

I once had a conversation with Phil Bolger and his wife concerning shallow water boats... (my Presto idea) and they recommended any shallow water hull could withstand the impact from lifting waves etc... much better with copper sheeting attached to the bottom of the hull. They were talking about reasonable thickness (correction) sheets of copper attached with some fasteners and an adhesive like 3M 5200.

One of the forumites here did apply this copper sheeting to the bottom of his Egret... sharpie.

The results is a strong protective bottom both for impact, abrasion, and of course critters.

RodB

[Todd Bradshaw]

1/4" sheets????? Christ, I'd certainly hope that would protect the bottom. Just solder them together and leave out the wood to save weight.

[Todd Bradshaw]

...it'd make one hell of a ground plane for your electronics though...:)

[RodB]

Jeesh!! every part of every statement has to be qualified or someone criticizes... and this by someone who won't even consider graphite in epoxy as an exterior coating on a hull.

Perhaps I was mistaken in remembering a proper thickness of copper plating... but its been a long time since I had that conversation... you get the idea... thick enough to offer enough protection as a tough barrier for grounding etc. It sure as hell wasn't 1/16 th... How thick would you want the plate if the hull was lifted up by a wave and slammed down on a sharp rock... ???

I need to remember to not put any dimension or amount if I can't remember...for sure.


what would the function of the copper be? Anti-fouling? Worm resistance? etc?

Everything a strong bottom would offer including impact resistance and anti-fouling. The Bolgers implied that most folks did not consider the amount of force that a bottom of a hull would be subjected to when lifted up by water and let down on the bottom... ie, in shallows. Another point expressed was that shallow draft craft were just so much more versatile in a coastal craft... thus an option to be strongly considered.

R

[James McMullen]

The design of the boat he pulled out of a Smithsonian. From the 1700's I believe. A boat built for Ocean crossing. And modified that design slightly to his preferences.

Oh my God! I just realized he must be talking about Raw Faith II! Coat that sucker with 5200 and copper plates, quick! Can't be too careful!

[Yeadon]

I've many times considered heating up 5200 in a crab cooker, then evenly distributing it across the exterior of my boat with an air-driven paint sprayer.

The same can be done with the epoxy, though you'll need to thin versus heat the goo.

Be sure to wear a respirator, and eye protection.

[Todd Bradshaw]

Rod, A quickie estimate would put the weight of a 4'x8' sheet of the 1/4" copper plate which you originally specified somewhere around 372 lbs. - and you're surprised that it caught my attention when you might be talking about needing three or four of them just to cover the bottom of a typical small-to-medium-sized boat, let alone a 40' strip-planked hull? Like it or not, that idea fits beautifully into this thread with all the other crazy ones. You should know by now that when you make an inaccurate statement on this forum, somebody is likely to call attention to it. If I hadn't caught it, somebody else would have and this department of the forum would be totally worthless to folks looking for accurate information if it that type of thing didn't happen. Even at the weight of 1/16" sheet, I suspect that impact and/or structural strength from slamming a hull down on a rock would be better with the same weight of composites than copper sheet. Go slam a Grumman canoe into a few rocks and then do it with a well-built Kevlar whitewater boat and see which one still looks like a canoe the longest - and the Kevlar boat will probably be 15-20 lbs. lighter than aluminum and even more so if you happened to have a Grumman made from copper.

As for my dislike of graphite bottom coating, it's based on tests I ran for my own use where I dragged weighted samples over real rocks. The graphite-filled epoxy samples exhbited less friction than unfilled resin (took somewhat less force to drag) but with the same amount of downforce (as in - a boat with the same momentum and amount of weight in it) the graphite suffered noticably deeper damage and wore through faster than plain resin. The addition of cabosil or aluminum powder to the graphite samples helped somewhat with its hardness, but aluminum tends to stick on rocks and the cabosil seemed to also defeat some of the low-friction properties as its ratio was increased to improve hardness.

They weren't super-sophisticated tests, but I couldn't find anybody else who had done a similar comparison and I wanted to make an intelligent decision for my own boats - so I did my own tests. When I combined my results with the potential for heat buildup that some graphite-bottomed car-topable boats might have in the sun, and the fact that many epoxy boat resins start to seriously weaken and degrade at about 140 degrees F, I decided not to use graphite coatings on my boats. I'm not sure why my views on this, based on my own tests, continue to bug you so much, many months after the original discussion - other than perhaps the fact that you slathered the stuff all over the bottom of that nice powerboat you built and feel that you need to somehow justify it to yourself. No problems here. You're free to put whatever you want on your boat's bottom (graphite, 1/4" copper plate or anything else that trips your trigger) and it won't bug me. But it also won't change my mind on the stuff or make me believe that my tests didn't happen, or that it actually makes for a tougher boat bottom.

[Chris Coose]

Wow.

There is lots of conjecture out there.

No **** Sherlock. Ask a stupid question.............

This is the most absurd thread I've seen since being here. Don't matter if Dutch is serious or not.

[RodB]

Todd,

My bad on the thickness of the plate... and you may be right about what the weight trade off is on copper plating vs a modern composites bottom and how they would react to impact trauma. I was just relating the Bolgers comments as best as I remember... This would be an interesting test... copper plating vs composite materials... with cost and weight figured into the equation... with performance value clearly illustrated. Oh yea, the anti-fouling properties of the copper were also considered.

The graphite subject was just a comment in jest... where we have some differences (although less than you may think). Besides, if you used graphite on a hull of a smaller craft that was exposed to the sun during transport, heat would be a factor to consider... and would probably deter me from using it also. I won't rehash the subject again, except it does increase the lubricity of the surface allowing it to slide over objects a bit easier, even if it is a teeny bit softer than straight cabosil and epoxy. It also allows one to have an opaque surface (that is easily touched up) and one can avoid painting (a prime feature for some us).

I always value your analytical and objective input...

Rod

[Captain Intrepid]

Go slam a Grumman canoe into a few rocks and then do it with a well-built Kevlar whitewater boat and see which one still looks like a canoe the longest

Yeah, but when you're done, you can grab a rock off the shoreside and beat the grumman back into canoe shape. :D

[bird]

keel fritz, did you refasten before skinning it with glass?..the glass is only as strong as the frame with your application...i've never seen a planked boat glassed that way and i'm interested in how it will hold up with the seasons...i've seen planked boats get glassed two ways: c-flex works great but is pricey....most common is a 'scratch coat' of 5200 on a dry hull then lay heavy mat on top on it...once the 5200 cures they build the glass out from the mat..the idea is the 5200 allows for normal expansion and contraction of the planks throughout the seasons without delaminating the glass...i'm not sure how your hard shell is going to hold up....anyway,make sure the keel bolts get replaced...darn near all of them were shot on mine....i'd hate to be turning 30kts and lose a keel...

[MiddleAgesMan]

Thank you very much for all your replies. I realize the very question itself sounds insane to most.
I am also looking into other options such as copper sheeting for the hull.
Again, thank you for all your time.

Go for it and take lots of pictures. ;)

Oh, yes, go for the copper, too. In sequence--5200 (1/4 inch layer per Cleek), copper (at least 10 gauge), epoxy/dynel (24 ounce if you can find it), another copper layer (say, 14 gauge). With the double copper you'll never have to put bottom paint on again. ;)

[RodB]

Copper Mariner II

Launched in 1983, the 76-foot shrimp boat Copper Mariner II currently is in service off the Western Coast of Mexico.

Built in Salina Cruz, Mexico, its hull incorporates composite 90-10 copper-nickel plate, .078 inch thick, metallurgically bonded to steel.

According to its owner, the copper-nickel hull always has remained free of fouling and corrosion.

[Bob Adams]

Gary E offered a possibility....as I recall, the Sea Flex sheathing method used 5200 applied with a notched trowel and Monel staples to attach the fiberglass to the hull prior to impregnation with resin. Best used, in my opinion, only to try and get a few more years out of a tired hull.

[bird]

Gary E offered a possibility....as I recall, the Sea Flex sheathing method used 5200 applied with a notched trowel and Monel staples to attach the fiberglass to the hull prior to impregnation with resin. Best used, in my opinion, only to try and get a few more years out of a tired hull.


So, if used to try and get a few more years out of a tired hull, why do you think it might not work to extend and protect the life of any hull, lowering maintenance?

[bird]

Read about the Copper Mariner...posted by Gary E

Interesting link. Thank you.
The main problem, I think, in this case, is that there is already galvanized iron nails in the hull. Trouble of getting around those.

[Candyfloss]

GALVINIZED IRON NAILS? "A house is but a boat so poorly built, you daren't put to sea in it" Att. to Nat Herreshoff.