Quick Tip: How to Caulk Before Painting

Caulking is a must in most houses, new and old before getting the paint out. But first, you should do all your preparation work, because you cannot sandpaper caulk in any way! Nope, don’t even try it.

Get everything washed down with a well wrung out sponge and some pre-decorating cleaner (bedrooms etc. don’t need much, but kitchens and bathrooms, hallways etc., need a lot!). Wipe away the cleaner with a big microfiber cloth and a bucket of clean water. Change the water often. Once dry again, sandpaper everything down to flatten any nibs and scratch the old paint surface to provide a good ‘key’ for the new paint. Wipe or dust everything down again to remove the sandpapering dust. Seal any stains with a good primer/sealer coat.

All done? Now you’re ready to caulk those pesky gaps. Well, unless you’re painting a new, previously unpainted surface, then I’d get the first coat/primer etc. on first. Caulk sits better on a painted or primed surface (it slows the drying out and you get less shrinkage over time you see). Okay, some tips then…

  1. Only buy really good quality caulk, ignore the cheap stuff if you want to job to last years. The more expensive it is, the better it will perform (like anything else in life really, if you think about it…).
  2. Grab yourself a ‘heavy duty’ caulk gun, the cheap ones are terrible to use and a really good gun doesn’t cost the earth, will last forever and is well worth the extra outlay for it’s improved ease of use.  
  3. heavy duty or professional caulking gun

  4. Cut the sealant tube inner nozzle straight off at the top using a sharp craft knife and screw on the long nozzle.
  5. Cut the caulk nozzle at 45 degrees

    Most nozzles have lines around the tip to guide you.

  6. Cut the long nozzle at around 45 degrees and usually as close to the end as you can. Most times you only need the smallest of beads. If you need a thick bead, cut a spare nozzle bigger and then keep it for future use.
  7. mark nozzle with marker pen for easy caulking

  8. Grab a permanent marker and draw a line back from the nozzle tip on the longest side. This helps no end when trying to ‘find’ which way around the nozzle is when there is some excess caulk around the tip.
  9. excess caulk on nozzle tip

  10. Get the angled end of the nozzle parallel with the gap you’re filling, this stops wasting lots of caulk and forces it deep into the crack/gap.
  11. Pump the caulk whilst moving along the crack/gap. Look at the line of caulk as it leaves the nozzle. It shouldn’t be too high or too low along the line. Too high and you’ll scrape most of it off and too low, well, it’s not enough.
  12. Wet a finger (or thumb) with a damp rag and smooth out the line of caulk, pressing it back to where you want it. Usually as small as possible. Use the damp rag to tidy up any excess caulk from places you don’t want it. Fold the rag over if you’ve got sealant on it, to avoid getting sealant everywhere. Rinse out the rag every few runs.
  13. Wipe any excess sealant on your finger onto the top of the gun (to save your trousers/rag etc.), and just cut it off once in a while…
  14. Where to wipe excess sealant or caulk

  15. Wait before painting. Overnight is best. Or rigidly follow the instructions on the tube.
  16. If you’re getting a lot of caulk on your finger, adjust your angle, trigger pressure or technique to apply less caulk.
  17. Nope, that’s it, you’re done.

Hope that helps with your caulking, especially the tip about marking the tip with a sharpie, it’s a boon on the job!

Let me know how you get on in the comments…
Stay well

P.S. pretty much all of the above also applies when using any sealant such as silicone etc.

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