Interesting discussion regarding hybrids and caulk.
What is the best caulk I can buy? Or should I go for EB25 and use that everywhere instead?
Over the years, I have used several different brands of caulk. Some were pretty good, some were awful. Some started off a good and then became awful.
I look for a caulk that isn't too thin but not so thick that you cannot smooth it with a wet finger. The taste is also quite important- seriously, some leave a very unpleasant aftertaste in your mouth when you lick your finger again. I have come across some brands that, annoyingly, had micro bubbles in them that resulted in mini craters in the finish.
Personally, I do not apply caulk until the two surfaces have been primed. I don't want the water in the caulk to be sucked into the substrate before I can smooth the edges of it. Nevertheless, some brands leave rough edges unless you apply them over completely waterproof substrates.
Longevity and reaction to paints are ultimately the more important factors. Caulk, if applied correctly and under the correct circumstances, should not crack. I recently made the mistake of working for a builder that likes to cut corners. He places his regular decorator under unrealistic time frames. The guy would caulk skirtings, paint emulsion over them within the hour and then an hour later, cut in with the waterbased eggshell. Naturally, the paint over the caulk cracked after a couple of days.
Over the three weeks that I worked there, there were proper cracks in the caulk, but that was the result of the heating being finally installed, causing the skirtings to contract.
For a long time I used Dow Corning Painter's Mate. Then they changed the formulation and I found that emulsions would crack when applied over it. I eventually started using Everbuild 125. It was every bit as good as the older version of Painter's Mate but (at the time) up to 3 times cheaper at Toolstation.
At a guess, 125 has been my go to for about 10 years. Unfortunately, Toolstation no longer sell it, they now sell a different caulk from the same manufacturer which I really dislike. The edges ripple and emulsion always cracks over it.
My only gripe with the 125 is that it now oozes out of the gun slightly when I release the trigger on the Cox no flow gun. In the old days the small tubes would discharge about 3mm, now the discharge is about 10mm. The larger tubes however will release up to 10cm, even if you remove the tube from the gun. Fortunately, I do not like the thicker (read: rigid) nozzles on larger capacity tubes and accordingly stick with the smaller ones.
As with caulks, not all emulsions are created equal. I tend to use Dulux Trade emulsion. I am confident that if I use 125 and paint over it the following day, the Dulux Trade emulsion will not crack. If I use a different brand of paint that I know will crack, I first apply a coat of shellac paint. It prevents the cracking and can be overcoated with emulsion in less than than an hour.
