3m5200

[bgould]

Folks,
Under what conditions could I use 3M5200, sold as bedding compound, as glue, as opposed to using epoxy?
It is said that it "just won't let go". Opinions?
Bob

[G.Sherman]

Sounds like famous last words....

What other things are you willing to substitute for the correct material?
Need more information about what you've got planned…

[Bill Huson]

Folks,
Under what conditions could I use 3M5200, sold as bedding compound, as glue, as opposed to using epoxy?
It is said that it "just won't let go". Opinions?
Bob

I've used both 3M4200 and 3M5200. 4200 is for stuff you may have to remove in the future, and 5200 is for stuff you have no intention of removing because it does stick.

Local tale: Guy wanted to remove the dive platform (also the OB engine set-back mount) from his Parker boat so he could have the battered aluminum platform dressed out and re-powder coated. He removed more'n a dozen big honking SS bolts, but the platform which was bedded in 3M5200 wouldn't gives under the persuasion of large pry bars. He lashed the boat down, ran a chain from the dive platform transom to the hitch on his Ford pickemup truck, put the Ford in low lock 4WD and juiced the gas. Story goes he ripped the trailer hitch off the truck and the platform didn't even wiggle.

Even if this a legend, my experience is that 3M5200 has serious sticky power. After replacing a rotted transom on my aluminum Starcraft I used 3M5200 to caulk the splash well when I pop riveted it back in place. However, it is not an epoxy resin designed to glue various wood boat parts together. I would not *build* a wood boat with 5200.

[Cuyahoga Chuck]

There are tens of thousands of small boats out there that are held together by nothing but epoxy. If anyone has tried that with 5200 the results have not been made public. I suspect there are none.
The problem is every possible material that can be used in building a boat has a list of physical properties and swapping this for that is only possible if the required properties are present in both materials. One little deficiency can turn your craft into a raft.
If you search this web site you will find threads with every conceiveable scheme for avoiding epoxy. It's as if there are those that have a genetic inclination to take the path least likely to work.
Epoxy works. It is used on aircraft, spacecraft, watercraft, yada yada, yada. If you have an epoxy allergy you, of course, must use something different but 5200 isn't it.
One of the downsides of many glues is "creep". The glue will work as long as the joint in not under continuous strain. Unfortunately, boat hulls are full of elements are that are literally sprung into place. If you are going to glue that stuff the glue had better be exactly what is required.
There is one glue that is a close substitute for epoxy. It is resorcinol. It is expensive, has a short shelf life, is temperature sensative and requires very thin glue lines. If you have no experience with it you will have to learn the drill. Epoxy gluing can be blundered thru' with a fair degree of success. That is not so with resorcinol.

[Lucky Luke]

Welcome bgould,

5200 is great stuff. Period. But does it perform miracles? Not really.
It' bonding is extremely strong, and it glues wood just a well as fiberglass or stainless steel to a point where it can become impossible to separate them if it may one day be needed. Therefore, it should not really qualify as "bedding compound", but as glue. It is then only for structural elements that are supposed to be there "for life". It is slow curing and long skin time which is usually a good thing, although if needed the fast curing version, 5200FC, is fast....too fast a times (and exists only in white)!

Contrary too what is said above -sorry- boats have been built using 5200 as a major glue. Sparkman and Stephens recommend it for some applications, and that should be a sufficient reference. These applications are when materials that will behave differently are to be glued together, like fiberglass or plywood to solid wood ...or of course solid wood to solid wood, where the (small) elasticity of this PU glue is beneficial. It has to be kept rather thick: about 2mm.

If similar materials that do not vary dimensionally are to be glued together, like ply to ply or thin solid wood, epoxy will be better: thinner, cheaper, and a bit stronger too (mind it though: 5200 is VERY strong!)

In short: bonding: No. Betteruse 4100 or others. "Normal" gluing like strip planking, plywood boat: No. Go for epoxies. Caulking: No, it is not at all designed for that and does not accept prolonged (I mean a decade) of constant immersion. Caulking is caulking, that's all. Gluing a thick, solid wood cabin side to a plywood deck: yes. Gluing a plywood deck to the top of solid (or big strip) planking: yes.

Chuck: sorry, but the similarity you describe between epoxies and resorcinol is not valid: these are very different glues and to be used a very different way. Resorcinlol is now almost only for plywood, where perfect control, very thin (almost zero) joint, high pressure is possible.

[jclays]

Walter Barron at Old Warf Dory uses Sikaflex 291 for the assembly of his boats instead of epoxy. Is this simlar to 5200?

[Lucky Luke]

Walter Barron at Old Warf Dory uses Sikaflex 291 for the assembly of his boats instead of epoxy. Is this simlar to 5200?

Not at all "similar": 291 is a general bonding polyurethane, not for structural gluing like 5200. In the Sikaflex range, only the 292 ( or, better, the 252= exactly the same stuff but for industrial use, and then cheaper!) is somehow comparable, with much faster curing, slightly less resistance, "quite probably" (?) lower bonding, and more elasticity. It does not exist in "mahogany" color like 5200, but black or white only, which may sometimes be less desirable. Good stuff though!

[RodB]

Folks,
Under what conditions could I use 3M5200, sold as bedding compound, as glue, as opposed to using epoxy?
It is said that it "just won't let go". Opinions?
Bob

The builder of Peterson's "Susan" used 5200 to glue the entryway rails to the cabin top.... along with through bolts. He said the flexability of the 5200 would be better for this area where there would be lots of stress over time with the entryway hatch being opened and closed over time.

http://i40.photobucket.com/albums/e239/Prestoboat/Susan%20const%203/entrywayrailsmounted-72.jpg

Can you think of any other special situations where 5200 offers some really good advantages?

RodB

[Rich VanValkenburg]

A found this recently. They claim to be able to remove 5200. http://marineformula.com/uses.htm

I wouldn't use 5200 on a wooden boat as glue anyway.

[One Mule Team]

Off point but the thread seems to be headed there anyway . . . I seem to recall hearing that hitting 3M 5200 "deathpaste" with a heat gun helped to loosen its tenacious hold. Anyone tried that?

[Dan McCosh]

The builder of Peterson's "Susan" used 5200 to glue the entryway rails to the cabin top.... along with through bolts. He said the flexability of the 5200 would be better for this area where there would be lots of stress over time with the entryway hatch being opened and closed over time.

http://i40.photobucket.com/albums/e239/Prestoboat/Susan%20const%203/entrywayrailsmounted-72.jpg

Can you think of any other special situations where 5200 offers some really good advantages?

RodB

We replaced the trim strip around the top of the cabin house about 10 years ago. I started to screw and bed the trim, then realized that all the rot had started around the plugged screws, where the bedding had broken down, cracks to let water in, etc. I ended up gluing the strip on with 5200, figuring if it ever had to come off I would just cut it off. It's done fine now for about 10 years.

[dmg]

RodB

One of the biggest asset's of 5200 is the very long working time allowed. Planking or frame parts with tedious clamping arrangements, or, lots of fasteners, can easily be done with 5200.

Dave

[Jay Greer]

I was called upon to replace a sliding scuttle hatch and rails on a Spitzgatter a few years ago. The owner had fastened the rails down on the canvas coach roof with 5200. The removal of the rails was a nightmare! The removal of the old rails, without damaging the coach roof canvas, required nearly thirty six hours of work!!! We had "Quite Tune" at our dock and the owner had fastened the Barient winches down in a bed of 5200. He also opted for setting the canvas deck in epoxy, which ended up cracking along the plank lines. The bright work was finished with a clear synthetic finish. The result was that the deck covering had to be replaced, the clear finish bleached out the wood beneath and the Barient winches were so stuck that their bases were bent during removal! Does anyone have a comment here in favor of traditonal methods of construction?
Jay

[RodB]

I hardly ever use 5200 except in situations where it is undoubtedly the product of choice.

RodB

[willmarsh3]

I've been able to remove parts fastened by 5200 only if I can get a thin knife in the joint and cut it.

I just used some tonight to fasten a piece of velcro cloth the size of a stamp to the overhead. The sticky side of the cloth had failed to adhere. The velcro is to hold a small battery powered light.