How to fix Putty: Guide for Beginners

I’m a give-it-a-go DIYer and recently got stuck into puttying – a first for me.

We have a 100 year old villa and many of the windows are original, poor condition yes, but original!  Understandably, over decades of summers (and multiple applications of paint), despite obvious maintenance, some putty had cracked and fallen off.

This summer our aim was to completely repaint the exterior weatherboards and windows…a big task. The absence of putty in a few windows was holding us back somewhat but I decided that surely, puttying wasn’t just a big deal? I found out first hand.

Disclaimer – This was my first season of puttying, so I admit that a glazier would probably raise an eyebrow at my work – but if I can do it with good results, so can you!

Puttying Advice I Ignored

I had never puttied before so got advice from my local hardware store.  It involved buying disposable gloves so as to mould the putty into a thin sausage before applying to the window. I would not recommend this myself, it’s completely unnecessary. You don’t need to touch the putty at all with bare nor gloved hands…you just need a putty knife. (To be fair – the advice about the gloves has some merit as the oil on your hands will transfer to the putty and be potentially prone to mould at a later date).  But…no gloves, no oily hands…stick with a putty knife and you’ll be just fine.

Puttying Guide for Beginners

Puttying wasn’t so scary I found out. You just need a putty knife and workable putty. By the latter, I mean a fresh pot or one that has been well sealed as you need the putty to like a tough dough and not like concrete.

Step 1:

Remove any cracked putty by gently easing the edge of your putty knife into the crack and giving it a bit of a wiggle. Don’t be too rough or you may crack the window pane. Easy does it. If your old window is missing putty altogether (it may have fallen out ages ago) and if there is exposed wood, paint with an oil primer first and allow to dry before applying putty.

Step 2:

Slap on the putty. Apply a generous amount of putty on the tip of your putty knife and, using a downwards motion, squish the putty into the gap: ensure it is at similar proportion and height to the rest of the puttied sides for consistency when it comes to painting later. You’ll find a natural guide line to match the inside of the window.

Step 3:

Dip the end of the putty knife in mineral turpentine. Such a handy tip! This will soften the putty and allow for you to smooth the surface. Use the edge of the window frame as a guide and run the knife flat along the putty. If you spot any gaps or aren’t happy with the coverage, repeat Step 2 and 3 until you have a smooth line.

Step 4:

Use the tip of the putty knife to tidy the lines. If any excess putty has gathered on the window frame, simply scrape it off. Don’t make it hard for yourself. Use the edge of the window frame as your guide.

Step 5:

Allow two weeks for the putty to cure before painting. Regular putty requires this, although rapid-dry putty is available that cures within 48 hours (possibly a trade-grade putty if you can get your hands on it). Any thin film of putty residue on the glass can be scraped off using a paint scraper later, once it has hardened.

See, that wasn’t so daunting was it!

Have fun. Give it a go!