Window Caulking - Exterior

[George7941]

I am very good at caulking showers and tubs and have done hundreds of them. I needed to caulk a window and, as per my usual procedure for showers, started to remove the old caulk on the window. turned out to be very difficult because the old caulk was sticky and balled up when scraped. I gave up and am thinking of just caulking over the existing bead, which fortunately is quite thin and won't make the new bead excessively large. The bead split in the middle because of excessive sag of the window sill.

The old caulk is nothing like silicone. I am guessing it is a polyurethane caulk. I picked up this caulk from Home Depot and am going to apply it over the old bead

https://www.homedepot.ca/product/lepage-quad-max-280ml-black-003-all-weather-flexible-window-door-siding-sealant/1001520530

 

[dlundblad]

Will a new razor blade help?

 

[doitmyself]

It's anyone's guess. The results, quality, and durability of most of these types of jobs usually revolves around the prep work. The very best quality paint will fail on an improperly prepared substrate. You can see where I am leaning, but I have perfectionist tendencies - do it once, correctly.

Have you tried a little bit of heat to assist removal of old caulk?

 

[PontiacHO]

I am very good at caulking showers and tubs and have done hundreds of them. I needed to caulk a window and, as per my usual procedure for showers, started to remove the old caulk on the window. turned out to be very difficult because the old caulk was sticky and balled up when scraped. I gave up and am thinking of just caulking over the existing bead, which fortunately is quite thin and won't make the new bead excessively large. The bead split in the middle because of excessive sag of the window sill.

The old caulk is nothing like silicone. I am guessing it is a polyurethane caulk. I picked up this caulk from Home Depot and am going to apply it over the old bead

https://www.homedepot.ca/product/lepage-quad-max-280ml-black-003-all-weather-flexible-window-door-siding-sealant/1001520530

View attachment 151344

Personally-I’ve found that attempts to remove old caulk (especially exterior) is damaging to the area that actually needs it. New caulk applied over it with care and a quality product (3M) yields an acceptable result.

 

[LazyDog]

The other alternative is to visit a windows company to see if they will sell you a tube.

Some commercials caulks are very flexible even in cold weather.

 

[George7941]

Heat helps when the caulk is hard, whereas the issue here was stickiness.

I have lots of spare razor blades and a new blade did not help.

I am going to caulk it this afternoon, let us see how it turns out.

 

[George7941]

Caulked the windows today. Pics show the windows, old split caulk and the fresh black caulk I applied today.