3M 5200 as a gasket?

[Art Reinhert]

I have 2 steel tanks with lids that are hinged open to one side and need a gasket to keep them leak free. The tanks are not under pressure, one operates at a slight vacuum. The lids clamps down hard on an 1/8" wide metal lips. A rubber gasket has not worked well here. It tends to get cut or dislodged. The liquid insde is an emulsion that does not attack Buna N rubber, or polyurethane.
I'm thinking of making a "cast in place" non removeable gasket on the lids from 3200.
Anyone here have experience doing this? Thanks, Art.

[Garret]

Art -

First off - you started 2 identical threads - might want to delete one.

Presuming you'll need to open these, I can't see how 5200 (if you could create a gasket that wasn't stuck to both sides) would be anywhere near as strong as a neoprene or rubber. Is there any way you can make the gasket flange wider so the rubber/neoprene, etc. won't cut so easily?

[Art Reinhert]

Sorry about the extra thread,I had not noticed. I'm inexperienced in this forum format. I'll try to delete it.

As for the flange, no I cannot make it wider without some major cutting and welding modifications. The narrowness of the flange is the problem we are trying to work around until a total replacement of the tanks.

Extra thread deleted, thanks for the heads up.

[Garret]

Sure.

Do you have to be able to open the tanks often? If only once a season or some such, then maybe the 5200 would work - though it is susceptible to various solvents & heat (300F or so IIRC?).

[Breakaway]

5200 can work as a gasket. When I install permanent deck hardware I'll typically bed with it but not crank down the fasteners all the way. Just enough to give the goop a slight smoosh. Than about 5 days later, when its cured, I torque the fasteners to where they want to be be. Provides a better seal, in my view, used this way.

For your purposes, you would need to line the lid that makes contact with the flange with plastic ( or some other release agent--I don't know, not having done exactly what you propose before). Apply the 5200, close the lid without dogging it down, and then wait for it to cure. When cured, remove the release film. If it works great; if not you can remove it with heat and a scraper, which shouldnt be that hard on metal tanks.

kevin

[Art Reinhert]

Thanks, guys. No heat problems, summer weather temps only. No nasty solvents. Lids opened a few times a day for about 100 days a year.

The 5200 can affixed to the lid permanently and if it needs to be removed we can take it off with a pneumatic scraper or by sandblasting.

[wizbang 13]

5200 can work as a gasket. When I install permanent deck hardware I'll typically bed with it but not crank down the fasteners all the way. Just enough to give the goop a slight smoosh. Than about 5 days later, when its cured, I torque the fasteners to where they want to be be. Provides a better seal, in my view, used this way.

For your purposes, you would need to line the lid that makes contact with the flange with plastic ( or some other release agent--I don't know, not having done exactly what you propose before). Apply the 5200, close the lid without dogging it down, and then wait for it to cure. When cured, remove the release film. If it works great; if not you can remove it with heat and a scraper, which shouldnt be that hard on metal tanks.

kevin

Plus one

[NickW]

Art

As long as you don't plan to paint them, I've had some success with ordinary bathroom silcone sealant gunned around the edge then gently closed on to some release agent say clingfilm put on the lips. Once cured, carry on as usual. If the seal goes, it's easy enough to replace without too much effort.

Nick

[KAIROS]

I've used 5200 and polysulfide (Boatlife Life-Caulk) to make custom fitted gaskets, with cling film on one flange. Works well. If the result is a bit too thick you can sand it down slightly, in place. The polysulfide is spongier, not as hard, and easier to modify in place. As said above, don't dog the lid down tight when the goop is curing, but you want enough pressure to make it work just so when it is dogged down. Carefully prep the surface you want it to stick to.