Active Mike

What is everyone using between the 3m 5200 Polyurethane or the 4200 Polyurethane.
I'm reinstalling my trim tabs and not sure what the difference is or the better between the two.

mcollinstn

5200 will never come off. It will pull the gelcoat off the glass.

4200 will come off if you pry hard enough.

There is a chemical solvent that will work to soften 5200 to the point where you can get it off, but on an area as large as a K-plane mount plate, you would still be in danger of ripping a chunk out of the boat to remove it.

4200 for trim mounts.
Or Lifeseal/Lifecalk is a good alternative.

You gotta decide if all you want is a SEAL or if you want the caulk to work as an adhesive too. If SEAL is your goal, a silicone like Lifecalk will work great. If you want adhesive properties to boot, 4200.

If you are attaching something that should never ever be removed, then use 5200.

mcollinstn

To give you an idea where I am coming from, on a molded fiberglass cockpit entry door on my Sea Ray sundancer, it had large stainless hinge plates, appx 4" wide where it bolted to the heavy glass door and the boat itself. At idle, the low rumble of the diesels would make the hinge plates touch and rattle. The stick on rubber bumpers put on at the factory wouldn't stand up to the heat and pressure. I decided to run a bead of 5200 down the gap and close the door 90% and let it cure. That way I would have a built-in bumper pad that would preload the door when latched and be quiet and pretty.

To prep the area, I thoroughly cleaned both stainless surfaces. Then I rubbed a thick coating of wheel bearing grease on the side with the door, and smoothed it with a plastic spreader to about .050" thick (blue waterproof BelRay bearing grease). Then I put an even bead of 5200 about 1/4" wide x 1/4" thick. I shut the door to where the latch was 1" away from closed position. I watched the bead spread as I closed it and it was about 3/8" to 1/2" wide from being squished. I duct taped it in place and let it set for 4 days.

Grease or not, I thought I would NEVER be able to open that door again. This is the 3 1/2' high rear entry door. I messed with it for a couple of hours, resorting to using a trailer winch to pull on it hard enough to where I could slip a screwdriver tip into the gap to start working the bond loose a little at a time. At this point, the original 1/8" gap was stretched to 3/8" and was holding tight enough that I was honestly concerned that I was going to tear the glass off the boat (there was of course no way to get to the bolts, and the hinge pin couldn't be pulled up). After 30 minutes with a long Craftsman small tip screwdriver blade, I had made it 3" down from the top of the bead of 5200. I left at that point, convinced that I could make a stiff tool out of spring steel to do the job. I returned with a custom tool and was able to finish the job in another half hour.

The surface that it was so tenaciously attached to was smooth polished stainless steel with axle grease smeared heavily on it.

Even after sitting open for a week after that, If you shut the door it would stick to it hard enough that it was scary. I ended up applying talc to the surface ten or twenty times until the talc had finally inpregnated the stickyness enough that it stopped grabbing the hinge plate when closed.

Has worked wonderfully since then. I would advise this fix for anybody, but next time I will put saran wrap on the side I dont want it sticking to and then trim it with a razor later.

I promise you that 5200 is tenacious stuff.

Mr. Demeanor

Talked to a guy who paints boats and had to remove the keel off a sailboat. The keel was bolted and 5200 was used. They had to cut the bottom of the boat out and repair the hole. 4200 is great stuff that I used on my exhaust tips. Its stays very "rubbery". I also used it when I put a new shower enclosure in my bathroom and I never has to recaulk it. Its easy to work with as well.

Falcon

I like to use 3M Marine Sealant 101. Easy to work with and leaves your parts removable. Probably similar to Lifeseal.

Danny_Ocean

FYI - Here's a 5200 remover on E-Stink:

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2459368343

D. Ocean
Pompano Beach, FLA

Active Mike

West marine has a solvent that they say removes the 5200. I purchased some but have not had a chance to try it. I think that my K plans were put on with 5200 before. When I removed them I had all of the bolts out and could not get it to leave go by jumping on the tabs.
I end up working a 3" putty knife around the edge and in as far as I could get it, still no luck. At that point I placed a floor jack and a block of wood under the tab and started to jack up against the tab. It end up lifting the back of the boat off of the trailer and me jarring the boat around before it stated to leave go. I then stated to lower the jack before she left completely go and the boat would drop back to the trailer. One of them did take a chunk of the gel coat but I was getting the transom regel coated anyway.
I purchased the 4200 already I just wanted to make sure before I used it.
Thanks for the information.
Mike

Cord

iTrader: (2)

The 3m adhesive remover takes it off. Mind you it doesn't just melt it away. It kinda softens it so you can scrape at it with a nail. The really thin spots will just wipe off with a rag. This stuff also works great to clean up after applying the 5200. Wait for it to fully cure and then just wipe the area down.