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Topic: Exterior Caulk - silicone or siliconized latex? (Read 966 times) previous topic - next topic

Exterior Caulk - silicone or siliconized latex?

just wanted some opinions on caulk,
 I am going to remove the fenders to replace the air bags and need a good caulk to use when replacing the trim above the bay doors. Too many choices at the local hardware store.
What works best?

Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Exterior Caulk - silicone or siliconized latex?

Reply #1 –
I use 3M 5200 on permanent joints ( roof seems and such) it finishes nice and doesn't mildew. A word of caution it is very hard to remove. For joints I might need to remove you might try 3m 4000, I used it in the shower no mildew in over a year and according to 3m it is removable. Most boat supply stores have the 3m caulk. I have not had good luck with big box store stuff, silicone is great stuff but it doesn't like to adhear to old silicone. If you decide to go that route make sure all the old stuff is cleaned off. I'm sure others with more experience will chime in.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Exterior Caulk - silicone or siliconized latex?

Reply #2 –
Nothing sticks to silicone, and silicone sticks to nothing.
Dave W. (AKA Toyman )
'03, 270, 36', Build 6095, Pulling whatever I hook it to.

"Don't cry because it's over. Smile because it happened."
Dr Seuss

Re: Exterior Caulk - silicone or siliconized latex?

Reply #3 –
I agree with Bruce.  The 3M 4000 series have a UV resistant variety that works well where it is exposed to the sun.  Both are available at Amazon and other places. The 5200 series is very tough.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Exterior Caulk - silicone or siliconized latex?

Reply #4 –
Quote from: Roger & Susan in Home2 –
I agree with Bruce.  The 3M 4000 series have a UV resistant variety that works well where it is exposed to the sun.  Both are available at Amazon and other places. The 5200 series is very tough.
do you know if the 5200 series protects from UV?
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Exterior Caulk - silicone or siliconized latex?

Reply #5 –
We used 5200 on boats for things like thru hulls because it sets up like glue.  Very hard to remove.
George and Steph
1997 U270 36 Build 5081 "Honu"
1180w Solar 400A lithium all Victron house system
Motorcade 17670, SKP 128300, FMCA F459019
73 VW Camper, 79 VW Camper, 2363 Sunline, and an Arctic Fox 25P

Re: Exterior Caulk - silicone or siliconized latex?

Reply #6 –
The 5200 specs do not show UV resistance as a property.  The 4000 UV specifically does "Superior UV resistance properties makes this an ideal cosmetic adhesive sealant". The 4000 UV makes a great sealant that doesn't attract dirt, seal through holes well and with some work is removable.

The 5200 is an adhesive as well. I have used it to glue down deck boards on a "no fastener" deck.  90% of those joints are tight after 15 years in MN.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Exterior Caulk - silicone or siliconized latex?

Reply #7 –
Having removed the panels many times and that strip I would not use anything that is not easily removed and it is not needed to secure that strip in a permanent manner. I use a clear Polyurethane and it does a good job. I DO NOT caulk along the bottom edge so as to allow any moister an escape route. You do not want water (if it gets there) to be trapped as it will follow screws into the flooring etc. Screws should also have a dab of it when replacing them too.
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Exterior Caulk - silicone or siliconized latex?

Reply #8 –
3M 5200 is permanent.  Do NOT use it unless you positively know something will never have to be removed.

Yes, I am a fan of 4000UV both on boat and RV.
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: Exterior Caulk - silicone or siliconized latex?

Reply #9 –
Is this our version of a caulk-us?  Oh well I try.
1995 U320 40', 2013 chevy sonic toad, my real love are corvettes have owned 30

Re: Exterior Caulk - silicone or siliconized latex?

Reply #10 –
A simple thought on caulks
If you think you might remove use silicone
If you want adhesion and don't think you will need to remove use poly sulfide (boat life is a brand)
If you never want to remove 5200 is great.
I would avoid the latex silicone for exterior use.
That is what someone more knowledgeable than I advised,  so far after some time I have found it sound advice.
Best of travels
Best of Travels

Re: Exterior Caulk - silicone or siliconized latex?

Reply #11 –
I'm like Mr. Haygarth and find myself removing the trim every once and a while.  Removing the old caulking from the trim piece and side wall is one of the chores I dislike the most.  I have always used silicone and they do sell a silicone remover but it is just barely better than nothing.  Maybe there is a good one for 3M 4200UV, but it also needs to be gentle enough not to harm the trim or sidewall.

Next time, I want to try using a closed cell foam strip (self-adhesive on one side) under the trim piece and not use any sealant except for the screw heads.  I'm thinking of an EPDM material that's 3/16" thick by about 1/4" wide:  McMaster-Carr
3/16" thick because there is 1/8" notch on the back side of the trim piece and 1/4" wide because that is the narrowest.  If it's too wide it could make the trim budge out between each screw depending on how stiff the foam is.
But it will be a while before I do it so I can't recommend something I haven't tried myself.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Exterior Caulk - silicone or siliconized latex?

Reply #12 –
Use Butyl tape
1998 U270 34'

Re: Exterior Caulk - silicone or siliconized latex?

Reply #13 –
A further word of warning re: silicone sealants. silicone will react with aluminum, causing worse corrosion.
After rigging boats for 20 years I've seen it all.  :thumbsup:
5200 is indeed PERMANENT!
Cheers - Ric
Previously:'66 VW Bus"Turtle 1";'65 VW Riviera Camper "Turtle 2";
';'91 VW Syncro Camper"Syn";'92 Barth 30' -"The Big Easy"
Currently: 2000 FT U270 40', #5634 -
"Le Bons Temps"; 2003 CRV
Ric & Leslie
"Laissez les bons temps rouler!"

Re: Exterior Caulk - silicone or siliconized latex?

Reply #14 –
Forget the Butyl tape, it just oozes out in the heat.
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094