Removing 5200?

[tkeithlu]

I need to replace my stanchions, which currently are 0.85" O.D. steel pipes bedded with 3M 5200 in 1.0" I.D. tubes. The 5200 has had years to harden. I've tried heat at the propane torch level, but given that my boat is a very large steel heat sink, all I got was a little charring. I could try an oxy/acetylene torch. The gap isn't big enough for the chemical releasers to get in there, I suspect.

In the photo the gunwale with cut off stanchion is surrounded by 5200 and blistered paint; the outer tube is visible below the gunwale to the right.

Any ideas from someone who has been there and done that?

[Shenandoah52]

Read your post and became curious myself. A google search for removing that stuff showed this link. Don't know of this helps, but it was an interesting read.
https://www.boatingmag.com/marine-so...removing-5200/

[Woodland Hills]

Mapp gas or oxy acetylene, you need a lot more heat.....

[MicHughV]

3M 5200 is a beast....it gets it's deserved reputation that it never lets go.

In the past I also owned a steel boat and that 5200 seemed to bond especially good to a steel hull due to the many microscopic dents, bumps and dings on steel plate.

I have had to use a knife, scraper, sandpaper and dremel tool with a steel burring bit to dig away at it.
It's a tedious process, requiring at least a six-pack of beer, which is key to the whole process, as it takes time and patience to remove it.

In the end, after scraping, sanding and dremeling the bulk of it, I found that a rag dipped in Acetone was able to remove the last stubborn bits, but it requires diligent rubbing. Be sure to wear rubber gloves.

Hope this helps.

[Lake-Effect]

I believe that hardened 5200 can only be removed mechanically - cut/scrape/file/etc.


I can also share a tip for removing still-gooey 5200 from self, tools, boat: WD40.

[john61ct]

Just in case it isn't clear for those learning from the mistakes of others.

Never use 5200 (or similar Sikaflex 292) on components that will **ever** need re-doing.

Good reason to avoid buying a boat.

Sika 291, 3M 4200 much more reasonable adhesion.

[a64pilot]

Usually 5200 isn’t all the bad. I gained experience removing aircraft fuel tank sealer, which is pretty much a two part 5200 and even tougher than 5200.
Very often 5200 is the preferred go to, even on items that will one day be removed, thru hulls for instance. I trust 5200 below the waterline, I don’t trust anything else myself.
Depending on what is glued together you can often get a piece of leader wire and cut the 5200 between the two pieces, or maybe cut it apart with a knife, lift an edge with a screwdriver, sometimes just time with parts being pried apart will cause it to let loose.
I’ve never used heat myself.

There are solvents for aircraft fuel tank sealer too, but they do more to make a God awful gooey mess than remove it, I’d suspect the 5200 solvent may be the same.

[Woodland Hills]

Originally Posted by a64pilot

Usually 5200 isn’t all the bad. I gained experience removing aircraft fuel tank sealer, which is pretty much a two part 5200 and even tougher than 5200.
Very often 5200 is the preferred go to, even on items that will one day be removed, thru hulls for instance. I trust 5200 below the waterline, I don’t trust anything else myself.
Depending on what is glued together you can often get a piece of leader wire and cut the 5200 between the two pieces, or maybe cut it apart with a knife, lift an edge with a screwdriver, sometimes just time with parts being pried apart will cause it to let loose.
I’ve never used heat myself.

There are solvents for aircraft fuel tank sealer too, but they do more to make a God awful gooey mess than remove it, I’d suspect the 5200 solvent may be the same.

ProSeal 890 or 1422? I’ve found that a piece of .020 safety wire with a few knots in it will work as a saw when dragged back and forth between the structure and the part. Polysulfite sealants are tough stuff!

With a steel boat you can get the structure red hot and only have to worry about repainting later. It’s not like aluminum which is heat treated......

[hpeer]

Can you get a 0.85” diameter drill bit? Ream it out?

[JPA Cate]

@tkeithlu:

The only way we've ever removed 5200 has been by meticulous scraping, then finishing with acetone, as described above. I have no idea whatsoever how to remove it from the inside of a pipe! other than scraping down carefully with a small blade screwdriver. It's going to be so hard, I think I might just try bedding over the 5200 with 4200, and hope for the best. This is purely a guess.


For the outside, sand it off with 40 grit, finish with acetone. You're going to be going to bare metal, and will have to renew the coatings.

Good luck with it, it looks like a real bear!

Ann

[Rod B]

Post #3 has it right, heat. Is the 1" id tube open at the bottom and would a piece of 3/4" or 5/8" threaded rod fit through the remains of the .85" od stanchion if it is open allowing you to rig up some means of pulling on it?
I had to remove parts from my boat which were bedded in 5200 fourty years ago and my limited experience suggests that it doesn't actually harden w age and that sufficient heat will soften it.
Drilling it out is an option as mentioned, I think that by cutting it off flush you may have done yourself a disservice. I would try heating the next stanchion with a decent sized pipe wrench on it, keep a force on the wrench while heating (the stanchion) with a torch and see if it loosens up. Take your time, get it good and hot and keep a load on it. Good luck!

[Lake-Effect]

Originally Posted by tkeithlu

I need to replace my stanchions, which currently are 0.85" O.D. steel pipes bedded with 3M 5200 in 1.0" I.D. tubes.

Just throwing some ideas out.

Are you certain that the stanchions were bedded in 5200, and it's not just something applied at the top as a sealant?

Rod's idea above seems like something worth trying, but there's lots to heat. I would want to turn (twist) the stanchion with the pipe wrench while heating, if the design permits that.

Carefully drilling out the remnant of stanchion with successively larger bits would be tedious, but it would work, if nothing else does.

[wkearney99]

I'd wonder about some sort of threaded jig to help pull on the inserted pipe? It'd be some welding, a piece of pipe threaded to fit into those threads, and then have a bracket over it with a threaded bolt to allow cranking on it to pull it out. Sorta like the way you'd remove a pulley from a shaft.

[thinwater]

In fact, there are some effective removers.
https://www.practical-sailor.com/iss...0_12286-1.html
But they are not "all purpose". Some work for silicone. Some for polyurethane. And you have to follow the instructions.

[Nicholson58]

I have used a sharp chisel on open surfaces. Heat is the only way I know to weaken the bond in a confined spot.