The Offshore Voyaging Reference Site

Goop and Goo, and Why I Hate 5200

no-5200

Recently, while helping member Henning make a decision on which way to go in replacing the seacocks on his boat, we were discussing various options in the comments. All was going along fine with lots of good options being proposed…and then someone mentioned…I have to pause and take a deep breath to repeat this…OK, I can do it…5200, and I saw red.

Yea, I know, it’s available in every marine store and is much loved by some. And I certainly don’t blame the member who mentioned it…but I do hate the stuff.

A Sad Story

Let me tell you why. Back some 35 years ago, I had just bought a new-to-me, but in fact very tired, 45-foot sailboat. And, like most hard-used boats, most every port, hatch and fitting in the boat leaked because working of the hull and time had broken the goop-seal between those hardware items and the hull.

So, like any soon-to-be-demented-refitting-boat-owner, I removed all those fittings and re-bedded them with…wait, I have to pause to collect myself again before saying it…5200. And yes, I followed the directions faithfully.

The task itself went reasonably well, or at least as well as it does for me with any of these goops. (Has anyone else noticed that no matter what you do, five minutes after you take the cap off it’s in your hair, and ten minutes after that it’s on the salon upholstery, even though you are working at the top of the mast? Or is it just me?)

That Got Sadder

I digress…I finally got the whole job done and went sailing and everything was fine…for about a year. And then a good third of those hatches, ports and deck fittings bedded, or in fact not, with 5200 started to leak. Not a lot, just a few drops, and only when there was a lot of water around, but a leak is a leak.

So I started to remove each piece of leaking hardware…or at least tried to. And that’s when I found out about the other characteristic of 5200: it sticks…I mean, it really sticks. To the point that I ruined two expensive hatches by bending them while removing them and actually bent a small pry bar. Not to speak of tearing the gelcoat off the laminate in some places.

I ask you, how can a material both stick like hell and leak? Beats me, but that’s what happened.

Maybe it’s just me. Maybe 5200 works great for everyone else. Maybe I just hurt its feelings with all that colourful language when it got in my hair and it decided to get even.

A Real Problem?

But maybe not. Since then I have spoken with several experienced managers who won’t allow the stuff past the gates of their boatyards because they have had the same sort of experiences.

No, I don’t have any proof that the stuff don’t-work-worth-a-damn, but the gun doth smoke. No tube of 5200 will ever touch Morgan’s Cloud, at least as long as I’m around to protect her from the diabolical stuff.

I really don’t know why 5200 leaked on my old boat. Perhaps it’s not a good idea to have a bedding compound that sticks too aggressively? Perhaps that causes fractures as the boat flexes? I really don’t know. (Do any of you engineers have a theory? If so, please leave a comment, I would simply love to know.)

What I do know for sure is that bedding any fitting with 5200 that you, or some other poor sod, may ever have to remove is a really bad idea, because crowbars will quickly become involved, and maybe explosives too.

A Clue?

Yes, I know about the spray stuff that purports to break the stiction, but is that really going to work with a large fitting and a lot of 5200? And if it does, that brings up another worry: If the removal stuff is as innocuous as the makers would have you believe, and especially since it’s water-based, what does that tell us?

Maybe the effectiveness of this removal stuff—assuming it is effective, I have never tried it and it was not available when I was rupturing myself—might be the clue to the cause of the leaking problem?

lifecalk_cartirdge_white_1__83844.1377245946.1280.1280Alternatives

So what do I use instead of 5200? Good old Life-Calk polysulfide, a goop that was once called Thiokol, back in the day when it was developed to patch bullet holes in bombers…in World War II.

Yup, it ain’t new and it ain’t sexy, but I redid all the 5200 bedding that failed on that old boat and never had a leak, and it hasn’t let me down since, above or below the waterline. And while it’s pretty sticky, you can get stuff apart that you bedded with it without too much foul language.

lifeseal_cartridge_white__38775.1377245961.1280.1280

Oh yes, one admission, I do use Life-Seal, a combination of silicon and the same chemistry as 5200 (polyurethane) if, and only if, I’m bedding Lexan—for example, the clear plastic in a hatch—and it works well.

Two Warnings

So there it is. Use whatever you like, but if it’s 5200, don’t bring it near me as I tend to react instinctively by throwing it into deep water, and the stuff is expensive and probably a pollutant too.

Also, never tell a boatyard that you are a 5200 user if you are soliciting a quote from them for a job that requires removing even one fitting. If you do, they will triple the price in the hopes that you will take your boat down the road to the next boatyard…the one they hate.

Further Reading

Comments

Any one else had a bad experience with 5200…or even a good experence? What goops and goos do you like and why? Please leave a comment.

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Max

I caught, just in time, a mechanic in a Mexican yard about to 5200 the custom made, impossible to find a replacement for, rubber bellows over the rudder post bearing. The yard manager took him off boats and put him behind the parts desk after that (might not have been his first offense though) .

Thanks all the great e-books.

Cheers,

Max
SV Fluenta
Presently Vuda Point, Fiji

Chris

Having heard the horror stories regarding 5200, we avoided the stuff during our refit and went to the opposite extreme-butyl tape. Easy to work with, but doesn’t stick all that well after a while. In the future I think I would go with a polysulfide sealant as written above.

Dick Stevenson

Hi all, I know of a marine parts distributor who said that he made a mess with 5200 just ordering it on the phone.
Dick Stevenson, s/v Alchemy

Dick Stevenson

Hi Chris, John and all
With regards to butyl rubber as a bedding/caulking material, I have read that not all butyl rubber is the same and have gotten all of my BR from a marine source I trust, http://www.pbase.com/mainecruising/boat_projects (and where there are superb “how to” articles on thru-hulls as well as many other common marine projects). And for the project John is referring to, I am unsure of BR’s use as an underwater bedding/caulk compound. And, Chris, I am not sure what you mean by “doesn’t stick all that well after a while”. Although quite sticky, BR is not to be considered an adhesive.
That said, I have been using BR for almost all, maybe all, deck bedding/caulking for 6-8 years now and have been very pleased: easy to work, clean, not unattractive in the grey or black. It is my research that it will last virtually forever (and unlike the traditional caulking/bedding, the BR I have had stored in the bilge for years is as good as new, not hard in the tubes-or out of expiry- as 5200 and Life- Caulk etc. would be, especially if opened). One of my earliest uses was to bed chainplates. I am recently replacing my chainplates and I pulled one that was bedded in BR 6+ years ago and the BR looked and felt virtually new to the extent that I was tempted to re-use it (I resisted this unreasonably frugal side of my nature).
Not any of my BR bedding has failed yet nor shown any signs they are likely to. A fingernail into the edges still shows the BR to be soft and flexible as when new. It is my understanding that most traditional bedding/caulking compounds (polysulfides and polyurethanes) are considered to have a lifespan: they dry out and shrink, and it is recommended that the bedding be re-placed every now and again (10 years comes to mind, read the manufacturer’s fine print). In the scheme of re-bedding portlights, for example, 10 years is not a long time, and not a chore I wish to do even once a decade. And they (I know from personal experience) can leak undetected into a balsa core whereas many leaks are mere nuisance and announce themselves quickly.
Enough for now: more on working with BR if wished for.
My best to all, Dick Stevenson, s/v Alchemy

Marc Dacey

Dick, the butyl tape I have on my 1973 FG sloop is still pliable, as I discovered after someone collided with me and I had to remove a sterncorner extrusion. I have keep a couple of rolls aboard. As for 5200, while I think it MIGHT have a use in bonding keels to keel stubs, it’s the stopped clock of marine glues. I prefer 4200 where I must prefer it.

Alan Bradley

Hi Dick,
I always enjoy reading your comments, lots of good stuff there. I’m looking at re-bedding a couple of ports with BR. Any helpful tips would be greatly appreciated. I’m not sure how to take a discussion like this off-line, but my email is of course included in this comment.
Thanks,
Alan

Dick Stevenson

Hi Alan,
Thanks for the kind words.
I am on the road, so have limited time.
That said, in looking over the stream of comments, I think everything has been covered. The web site Compass Marine mentioned by me and others is a wealth of knowledge and definitely should be consulted. It will give you a feel for the material and what it can do. Not related to BR, but often neglected, if the deck is cored, ensure the core is reefed back and filled with an epoxy slurry well past the bolt/screw holes.
Let us know how your project works out.
My best, Dick Stevenson, s/v Alchemy

Alan Bradley

Hi Dick,
Thanks for the quick follow-up and thanks for the tip on prepping the core area below the screw holes.
Best regards,
Alan Bradley, s/v Vivacia

pat synge

I haven’t used 3M’s 5200 but have used gallons of various other single component polyurethane sealant/adhesives by Sikaflex and Bostik and have had good results. I’ve just finished glueing down a timber floor onto a (well cured) concrete slab.

Yes, you have to be careful to avoid making a mess but that’s mostly preparation (good fitting gloves, masking tape, mineral turpentine and lots and lots of rags into a big plastic lined bin). In many situations (decking) it’s best to leave any excess to cure in place and remove it with a blade.

Usually leaks are the result of over-tightening and squeezing most of the sealant out. It can’t do its job if it’s not there. The right primer is essential with acrylic and polycarbonate.

It has a specific % of elasticity (depending on the grade) and so if there’s going to be thermal expansion differential (ie with plastic glazing) or movement due to flex you have to allow enough thickness of sealant to absorb this. I usually use a 3mm double sided foam tape as a spacer when glazing.

Removal of fittings: difficult. It has to be carefully cut to remove the fitting and then the residue carefully removed (ie with a chisel or very sharp scraper).

I removed a fairly large surface area aluminium gooseneck fitting from an epoxy painted aluminium mast. It had been in place more than 25 years. The bolts came out fine but I had to carefully wedge the fitting away from the mast cutting away at the sealant with a fine blade as I went. Amazingly, at the centre the sealant had not fully cured after all that time. I reckon the bolts probably weren’t needed.

Great stuff!!

Marc Dacey

John, I wore out 11 blades (!) on my sabre saw cutting through a bead of 5200 that a previous, delusional owner had used to seal my aluminum pilothouse roof from my mild steel pilothouse framing. It took me ages. It didn’t even accomplish the basic goal of isolating dissimilar metals. We are talking about maybe 20 linear feet. So I have felt your pain.

pat synge

As I said, John, I haven’t used 3M’s 5200. It may be harder with less elasticity and be more difficult to remove.

I’m not saying I haven’t ever made a mess – far from it! But I’ve learned how not to and it’s not that difficult if you prepare well and take care. As soon as I get any on the vinyl gloves I peel them off and put on a new pair (the contaminated ones can usually be used later for other jobs – especially if promptly blown the right way out)

The advantage of fitting relatively high load fittings (like goosenecks) with adhesive is that loads are distributed over a larger area and not concentrated at the fastenings. I was impressed that the thread cut into the aluminium was clean and shiny after 25+ years.