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Topic: 3M 4000 Marine Adhesive Sealant (Read 702 times) previous topic - next topic

3M 4000 Marine Adhesive Sealant

After replacing my shocks, I need to reseal the snap-in weather stripping that runs the length of the coach. I used silicone last time and am considering switching to 3M 4000 this time around: https://www.3m.com/3M/en_US/p/d/b40066991/

The silicone gets dirty real easy and cleans equally easy, so I don't hate it but I'd prefer something that doesn't dirty as fast. For those of you that have used 3M 4000, are you happy with it? Regrets?

Any tricks to applying it? With silicone I apply the caulk and then spray it with ammonia-free window cleaning foam, then wipe it all off and it results in a perfect seam every time.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: 3M 4000 Marine Adhesive Sealant

Reply #1 –
Elliott pondering this myself I wonder how a foam backed adhesive tape would work like a 1/8"x1" they say it supposed to be water proof just thinking about having to take it off later
1999 36 ft U270
Build 5465

Re: 3M 4000 Marine Adhesive Sealant

Reply #2 –
The 3M 4000UV sealant is my "go to" sealant. I've been very pleased with it. The only caveat would be that it cures quickly and so any smoothing or cleanup also need to be accomplished quickly.
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: 3M 4000 Marine Adhesive Sealant

Reply #3 –
I got rid of the sealant altogether and applied a strip of adhesive backed foam to the trim piece.  I don't remember what I used but I ordered it.  It was closed cell.  Most stuff at the home stores is open cell and OK for blocking air but for water I think closed cell is better. Note that I keep my coach in a garage so I can't say it's really stood the test of time being in such a protected environment.

Another protection to add if using foam is to put a light coat of silicone on the screw flat heads that are just under the trim piece.  And also put just a tiny dab of silicone under the head of each screw that holds the trim piece too.

BTW, I recall some 3M 5200 I used on the coach getting dirty on the surface (after a few years) and not being able to clean it (at least easily).  4200 is a similar compound.  I think either is far too strong for something you need to expect to remove in the future.  You want to be able to scrape it off easily for a clean install next time.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: 3M 4000 Marine Adhesive Sealant

Reply #4 –
Quote from: JohnFitz –
BTW, I recall some 3M 5200 I used on the coach getting dirty on the surface (after a few years) and not being able to clean it (at least easily).  4200 is a similar compound.  I think either is far too strong for something you need to expect to remove in the future.  You want to be able to scrape it off easily for a clean install next time.
Thanks John. The 4000 does say "High performance, medium strength bonding allows for disassembly" but I don't know exactly how easy that would be. I might order a tube of it and play around with it a bit before jumping in. Right now I'm just taping over the weather stripping to keep it dry until I figure out what direction I want to go.

Like I said, the silicone gets dirty fast but is easy to clean. I'd hate to go with something harder to dirty but not able to be cleaned in the future... and there isn't a good way to test that really
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: 3M 4000 Marine Adhesive Sealant

Reply #5 –
Isn't 5200 forever.  Whatever you use it on you'll have to cut it off. 
  Silkaflex is good.  Cleans easy and the factory used it on our vintage of coach.  27 years and still working where it's not disturbed.
Robert and Susan
 1995 36' 280 WTBI 8.3 3060r
 1200 watts on the roof, 720 Ah of lithium's
 Build # 4637. Motorcade # 17599
        FMCA  # 451505
        18  Wrangler JLUR

Re: 3M 4000 Marine Adhesive Sealant

Reply #6 –
3M 4000UV is a significantly different formulation than 4200 or 5200. In my experience it has excellent UV resistance and it removable when required.
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: 3M 4000 Marine Adhesive Sealant

Reply #7 –

I called my buddy that runs a body shop and asked him what they use to remove silicone from paint/gel coat. He put me on to this: Amazon.com: 3M General Purpose Adhesive Cleaner, Quart, 08984 : Health &...

I went out and tried it today and it awesome! All it takes is a little squirt and then let it sit for a minute and the silicone just starts separating from the paint. Looking forward to finally getting this cleaned up.

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1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: 3M 4000 Marine Adhesive Sealant

Reply #8 –
That's a lot of caulk.  Someone's not aware of the blue tape method.
Robert and Susan
 1995 36' 280 WTBI 8.3 3060r
 1200 watts on the roof, 720 Ah of lithium's
 Build # 4637. Motorcade # 17599
        FMCA  # 451505
        18  Wrangler JLUR

Re: 3M 4000 Marine Adhesive Sealant

Reply #9 –
Quote from: Bob & Sue –
That's a lot of caulk.  Someone's not aware of the blue tape method.

Yup, NOT a reasonable job.  Blue tape method does give a professional look:

Put blue painter's tape immediately above and below the area to be caulked. Keep the gap/clearance small and uniform.

Run a section of caulk.

Immediately use gloved finger to push the caulk down into the gap and give a uniform thickness.

Immediately remove the tape.

Immediately resmooth with gloved finger.  If silicone, use a wet finger.  For other caulks, experiment with what gives the best results.

Haven't done that in 4 days (yes project at home).
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: 3M 4000 Marine Adhesive Sealant

Reply #10 –
Yep there are a few spots like that where it's quite thick and therefore much more noticeable when it gets dirty.

I use the ammonia free glass cleaner trick, which yields the same results as the tape method you describe. Apply the caulk, spray the glass cleaner right over the top of it while it's still wet, and then wipe it with a cloth. everything but the caulk right in the gap you're trying to seal comes right off.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.
 

Re: 3M 4000 Marine Adhesive Sealant

Reply #11 –
Here's what someone did to our 295.  Smeared over an inch wide in places.  At least it cleans up easily.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon