What's the best outdoor sealant/caulk?

[John]

Hey everyone,

I'm about to paint my house (200 years old) and there are gaps all over the trim that need to be sealed before painting.

What's the best sealant/caulk to use? Needs to be paintable, durable etc. I've used LEXEL with good success in smaller projects and was thinking of using it again for this.

Any suggestions for something better?

Thanks for any advice

[Mikepier]

I've always had good results using GE silicones.

[John Willis]

On Wed, 4 May 2005 07:41:30 -0400, "John" scribbled this interesting note:

Depends on what your goals are. Do you just want a good exterior caulk or do you want better? I've had very good results with the 50 year DAP painter's caulk-clear. I've found the clear, as opposed to the white or other colors, works better and cracks less. On the other hand, if you don't mind the extra mess, you could go with a one part urethane caulk. These are flexible and resist the weather. The come in different colors so one might be a close match to your paint color.

Good luck.

-- John Willis (Remove the Primes before e-mailing me)

[Robert Allison]

That is like asking what is the best truck!

If you are just needing cosmetic coverage, then any good latex caulk will work well and is easy to apply and work with. If you are looking for something that will truly be a sealant, then I would go with something like a Vulkem product, or a Geocell product like Geocell 2300. PL2000 is another good product if you can find it.

Be aware that all of the products in the second category are adhesive sealants and if you use them, you are NOT going to be able to remove them easily. They are also more difficult to work than the latexes.

I would stay away from silicone as it is not paintable and I have had serious problems with its adhesive qualities on wood and masonry.

Here is a site for Vulkem (use the urethanes):

Geocell is available at most roofing suppliers and I haven't been able to find PL2000 in a while.

[John Willis]

On Wed, 04 May 2005 15:01:24 GMT, Robert Allison scribbled this interesting note:

What we typically use is NP-1, which is another one part urethane caulk or sealer. More difficult to work than painter's caulk, but it does its job wonderfully. As with what you recommend, we buy NP-1 at the roofing supply house.

-- John Willis (Remove the Primes before e-mailing me)

[Eric and Megan Swope]

GE actually makes a paintable silicone now, I just used it to seal around my french doors and painted over it. Looks pretty good.

[DanG]

Avoid silicones like the plague, unless you use Dow Corning 795. I would suggest Sonneborn's NP1 or any of several other one part urethanes. Silicone does not paint. Silicone does not stick in the long haul.

(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) [e-mail]

[Hopkins]

I agree wholeheartedly. I'm sure there's a "paintable" silicone available, but my experience with silicone adhering to wood and masonry is that it doesn't. I hate to see it on a house, but if it needs to be ripped out it's great. It comes out out in nice long strings.

[Hopkins]

I should add that I'm in the one-part urethane camp. It's hard to work but it's great stuff.

[Bob]

Of course, nothing else will adhere where the silicone was. Urethane for me.

Bob

[John]

This all good information. I definately want a sealant, one that lasts.

I'm going to look for some of the one part polyurethane products mentioned.

No one recommends Lexel?

I'm not even sure what it's classified as but it seems to be real sticky. When cured it feels very rubbery and stretchy. Not sure of the longterm use since I moved.

Thanks again for the info..

Johnny

[Hopkins]

I haven't used Lexel but I have to admit, from the link, it sounds like an interesting product. Sounds like it's along the lines of urethane -- great adhesion and stays flexible.