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?
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.
Nothing sticks to silicone, and silicone sticks to nothing.
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?
We used 5200 on boats for things like thru hulls because it sets up like glue. Very hard to remove.
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.
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
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.
Is this our version of a caulk-us? Oh well I try.
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
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 (http://www.mcmaster.com/#8694k124/=11bt7xo)
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.
Use Butyl tape
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
Forget the Butyl tape, it just oozes out in the heat.