Replies

1. 
   Riversong | Dec 31, 2008 03:27am | #1

   If you're looking for a clear, highly flexible, long-lasting caulk with great adhesion and that's paintable, I would recommend Lexal - far superior to silicone in every way.

   What is the application? That makes all the difference.

    

   Riversong HouseWright

   Design *  * Build *  * Renovate *  * Consult
   Solar & Super-Insulated Healthy Homes
1. 
   Bpawb | Dec 31, 2008 04:45am | #2

      Thanks for your reply....The application is general caulk/adhesive for interior trims and moldings. In which the primer and paint will be oil base

      I know most people will say use a acrylic latex type caulk but in past experiences it seems to dry out and crack over time.

1. 
   DonCanDo | Dec 31, 2008 05:06am | #3

   I'm not familiar with GE Silicone II XST, but I've been stung far too many times on paint jobs by the use of silicone caulk by the trades that preceded me.  I really don't understand the fascination/overuse of silicone caulk and I very rarely use it myself.

   If you're using caulk just as a gap filler between moldings (or molding and wall), I don't think you're going to have any cracking issues with latex caulk unless you're filling HUGE gaps.

   And if you're using it as an adhesive to secure small pieces of molding, it doesn't really matter if it cracks because you won't see it.  It's not likely to lose it's adhesion, but if you want a little extra insurance, try Loctite Power Grab.

1. 
   Bpawb | Dec 31, 2008 05:16am | #4

       DCD, Is "Loctite Power Grab" a caulk like consistency  ( white )  Or is it more like construction adhesive  (brown) ?

    

     Have you used it before...if so how old is the project you used it on?

    

   thanks...paul...

    

1. 
   BillHartmann | Dec 31, 2008 05:21am | #5

   Power Grab is a white acrylic, water based product. But it has much more body that regular caulk.When I use it to attach stuff that will be painted I don't worry about squeeze out as I can just wipe it off with a damp sponge.But I find it too stiff to be used as a caulk. So I don't over apply it so that I get continous squeeze out that I can tool.If I need a neat line after I get done I use a quality acrylic caulk..
   William the Geezer, the sequel to Billy the Kid - Shoe

2. 
   DonCanDo | Dec 31, 2008 05:59am | #6

   Yup, what he said.

   The stuff hasn't been around that long so the oldest job I used it on might be about 5 years ago.  I really don't know how it's holding up, but since I only ever use it where there wouldn't be any structural forces (that's where construction adhesives are used), I have every confidence that no small pieces of baseboard have fallen off the wall.  You know, like that little 2" piece that fits between the door casing and the corner that has no stud to nail it into.

   You should experiment with the stuff.  Just take 2 pieces of scrap with some Power Grab between them and a few pounds of weight on top.  After a few days, try and pull them apart.  Let us know, but I think you'll find that it holds pretty good.

2. 
   Riversong | Dec 31, 2008 07:05am | #9

   The application is general caulk/adhesive for interior trims and moldings. In which the primer and paint will be oil base

   Silicone is the last thing I would use for interior trim. There are excellent quality siliconized acrylic latex caulks that have far more elasticity and life than the old painter's caulk.

   Other good water-based caulks with more adhesive strength are Phenoseal and Geocel.

   All latex caulks, unlike silicones, can be applied to unpainted wood. They adhere to both porous and non-porous materials. I caulk first, then prime, then spackle, then topcoat. 

   Riversong HouseWright

   Design *  * Build *  * Renovate *  * ConsultSolar & Super-Insulated Healthy Homes

2. 
   procrazyman | Dec 31, 2008 06:13am | #7

   I usually prime first, then caulk with acrylic latex, followed by any type of paint.  Cracking is caused by shrinking of caulk or movement of the wood. 

   Moisture content within the structure has alot to do with cracking (movement of wood).  In my part of the country readings can range from 35% to 70%.  This is bad for wood.  I monitor my moisture content with a hydrometer and adjust my humidifier accordingly to maintain about 40%.

1. 
   Riversong | Dec 31, 2008 06:58am | #8

   Moisture content within the structure has alot to do with cracking (movement of wood).  In my part of the country readings can range from 35% to 70%.  This is bad for wood.  I monitor my moisture content with a hydrometer and adjust my humidifier accordingly to maintain about 40%.

   You mean relative humidity. Moisture content is the percentage of water by weight compared to the weight of oven-dry wood. Interior wood typically stabilizes at about 6%-8% MC at 30%-40% RH. 

   Riversong HouseWright

   Design *  * Build *  * Renovate *  * ConsultSolar & Super-Insulated Healthy Homes

1. 
   procrazyman | Jan 01, 2009 01:54am | #10

   Oops!   Your right. Relative humidity.

3. 
   arcflash | Jan 01, 2009 02:32am | #11

   I have used it. I don't think that it is quite as paintable as they claim. At least, not with latex paints. Maybe try polyurethane caulk?

   Silicon is far supreme to most other sealants. It is more flexible, stands up to weather better, and bonds to just about anything. You just can't paint it.

   Polyurethane seems a bit extreme for interiors. Have you tried siliconized acrylic latex?

4. 
   KenHill3 | Jan 01, 2009 03:00am | #12

   I have gone from siliconized acryics ie. Alex II to Polyseamseal, which also has adhesive qualities. Does my plumbing fixtures as well.

5. 
   Matt | Jan 01, 2009 03:21am | #13

   I've used it, including on my own house, but not under oil paint.  That was in a bathroom environment where there was a definite possibility of moisture.  Worked fine and has held up good although not the easiest thing to work with.  

   For general interior caulking you shouldn't really have too much trouble with cracking unless there is a lot of movement, provided you are using a GOOD QUALITY caulk - some are named above.  I also think it's important that the raw wood be primed before it is caulked. 

   On the houses I build I have had some problems with the base cap applied to the top of the stair skirt board cracking at the drywall connection - not sure why this is.  Obviously there is some movement.  For this application I went to the SW paint store and asked what they recommend.  They recommended SW Sher-max Ultra as their most flexible and paintable caulk which I have used and liked the way it worked.   Time will tell how it lasts - a little pricey at around $5 but they had it on sale for $2 something.  I'd say this is overkill for general caulking though.  Really though, any new house is going to require some re-caulking after it has gone through it's first complete set of season changes.

   Really though I don't use oil paints, so maybe I'm out of my element here.

6. 
   Marson | Jan 01, 2009 04:58am | #14

   As others have said, where's the beef with latex caulks? Maybe you haven't used good ones. I like "Big Stretch", made by Sashco (same outfit that makes Lexel.