So i'm looking for a specific gasketing product but can't seem to find it with my Google skills. I have an application where I need to seal an enclosure to create a dust and water barrier. We've been testing a EPDM/SBR/Neoprene foam blend with a PSA backer but there seems to be water intrusion at the corners where there are seams. I could use sealant at the corners but that is not optimal for production. What I'm trying to find is material that can be dispensed in a bead around the sealing surface and once cured will act like a foam which will compress when the cover is installed making a water tight seal. I've seen this used before but don't know where to source it. I've searched for gasket makers but they all seem to be a one use gasket. I need this gasket to withstand several cycles of removing and attaching the cover. Any help would be appreciated.

1/23/2013 9:30:29 AM

Will this enclosure be certified, does it need to be a NEMA type or anything? NEMA has specific requirements for gasket materials, so if you need to do testing pay attention to that.

in NEMA 250-2003 section 5.14 covers gaskets. Elongation (5.14.1) and Oil Immersion (5.14.3) come to mind for consideration with regards to material selection

[Edited on January 23, 2013 at 10:35 AM. Reason : .]

1/23/2013 10:35:42 AM

This will not be NEMA rated but it will be UL certified and we are shooting for IP 67 rating.

Anyway, I found what I was looking for. It's called a formed in place foam gasket. It looks like it would work for my application but it has to be machined applied, no hand application, which pretty much throws it out the window for me. Anyway, now exploring other gasket methods or a geometry change to make a better sealing surface.

1/24/2013 9:22:20 AM

would a permanent tape work ?

1/24/2013 9:52:39 AM

http://www.findtape.com/product368/JVCC-SCF-02-Single-Coated-Foam-Tape.aspx?sid=cVuHIchfEsk5BAWmFFOq1iC%2fvyWy07l7MJ2fT6KbN2lsIjzOxH83srzIzRnIWRrD

1/24/2013 10:53:25 AM

Not to hijack, but this is also a gasket question.

I developed a bunch of exhaust leaks on my Valiant where the manifold meets the block. Its a slant six, so if anyone is familiar with it you know the gasket is very long and is also the intake gasket at the same time.

Also unique to the motor (I think) is the hardware required to mount them, and the fact they are torqued to a low value. The heat and cooling cycles require all of these things to move a decent amount in order not to crack, but the tradeoff is using a very thin steel gasket.

This car is no spring chicken, and it seems the exhaust manifold isnt perfectly flat across all the runners. Ive already changed all these gaskets twice and dont want to do it again, but I have an extremely tiny gap on one cylinder, maybe 1/32 of an inch, and 1 inch long.

A very tiny amount of exhaust gas comes out of here when cold, along with just a bit of coolant (we're talking a few drops). Its discoloring a little bit (I dont care) and seems to go away once warmed up, but I was wondering if there is some liquid product to take care of this?

A high temperature silicone maybe? Or do you have another recommendation? This is not a powerful motor, or high compression. I was hoping someone had a good experience with something I could grab at a generic parts store.

Thanks!

1/24/2013 11:35:27 AM

Is the surface flat? If so just cut a gasket yourself out of rubber.

1/25/2013 8:53:09 AM

^ no worriers y0

^^ my original design uses a EPDM/SBR/Neoprene foam blend with a PSA backer but the joints (the sealing surface is rectangular and had a raised curved section) are a potential area for water intrusion. I am going to test the foam tape but don't have a lot of confidence. If it fails I think I'm just going to go with a molded gasket or O-ring that sits in a groove.

1/25/2013 8:56:30 AM

Why does the one you found can't be machine-applied? Cost? We have a vendor that makes all sorts of custom industrial enclosures and panels w/ IS5 rating on all their stuff that uses exactly what you need but it looks to either done by a steady hand or machine and looks to be a foam form in place. Try McMaster-Carr.

For the Valiant gasket I'd recommend the same on McMaster; I definitely saw a high temp gasket sealer rating for something ridiculous like 1500F and specifically called out exhaust systems. Only thing I would check with it is glycol resistance so the coolant doesnt degrade it.

1/25/2013 10:41:13 AM

yowilly, permatex ultra copper is the best one that's widely available. I'm thinking manifolds get to 1000+ when running though, so it may be out of the question. Feel free to try

I've got that stuff on my mani-to-turbo connection with zero problems.

If that doesn't work, I'd cut the gasket into individual ones

1/25/2013 5:52:16 PM

I believe thats what I used when I installed them, both on the flange side and head side.

It did very good on every other cylinder, I can only assume this one is fucked up by being slightly non-square.

Can this stuff be used after the fact? Squirted into a gap instead of used as an initial sealer? That goes for any products already discussed...

Thanks guys,

(again, the idea is NOT removing the gasket again. If you're familiar with this engine design its one of the biggest pains in the ass ever).

[Edited on January 25, 2013 at 9:18 PM. Reason : -]

1/25/2013 9:16:02 PM

Monkey Snot. All you need. End thread

1/25/2013 11:23:09 PM

^^Seriously, you need to take it off and have it and the intake manifold resurfaced together. Not a terrible job. Not fun, I admit. But you need to start with a surface that's straight and true. There is no goop that'll stay put there. Too much variation during heat cycling, and you have positive pressure behind it to boot.

1/27/2013 11:19:30 PM

ah god damn it

1/27/2013 11:31:21 PM

sparky, sounds like you need me working alongside you. Hook a brotha up; I'm seriously underemployed where I'm at now.

1/28/2013 6:39:50 PM

^ you would have to move to Houston TX!

Quote :

"Why does the one you found can't be machine-applied? Cost?"

no the problem is that it HAS to be machine applied and out contract manufacturer in China does not have that capability.

1/29/2013 8:46:49 AM