Best putty for old Crittall (steel) windows?

[ChrisOxford]

My house was built in 1950, and has ungalvanised, steel "Crittall-style" windows which are generally in good condition and which suit the style of the house so well that I've kept them even though all the neighbours are on their 2nd, 3rd or even 4th lot of uPVC replacements.

Unsurprisingly, every few years, a pane will crack because of rust developing in the rebate where the putty has failed. Replacement of the pane is fairly quick and easy - hack out old glass and putty, sand/wire brush rusty area, metal primer and undercoat, fit glass, then topcoat.

My question is: what kind of putty should I be using? I've always used a multipurpose/universal putty from the shop where I buy the glass or from one of the usual DIY sheds, which is described as "suitable for timber and metal windows" and it all looks great to start with. But a year or two down the line, the paint and putty's gone crinkly and and sometimes there's an oily gunge seeping from the rebate. Very annoying after taking a lot of care to do a nice neat job.

I've experimented with leaving the putty to well and truely go off properly for several weeks before overpainting, but the same thing always happens. I did try a synthetic glazing putty in a gun cartridge too, but found it was far too runny for this kind of application.

Any ideas, anyone (other than double glazing )

Cheers,
Chris.

 

[KenGMac]

Chris, Hi.

I believe the "preferred" replacement putty is a formulation that does not contain linseed Oil.

There are available "Metal casement putties" that are especially developed / designed for steel casement windows.

Try a Google for this material and a supplier near you.

Cheers.

Ken

 

[ChrisOxford]

Thanks, Ken, much appreciated!

It seems quite hard to find these days though. Googling showed that a company called Hodgson Sealants seems to do it, though obtaining a small quantity might be hard. Certainly my local glass merchants fobbed me off with "Universal" stuff which went messy after a few months.

Cheers,
Chris.

 

[KenGMac]

Chris, Hi.

As a bit of a long shot?

Try asking Crittal, if they still exist in some form? find a web site and ask them if there are any suppliers that can and are willing to supply a Kilogram but not half a Tonne of the correct material to you? Or there may be some "newer" formulation that will sort the problem for you?

Another searching area may be with "conservation Groups" or groups that are involved with large projects that contain a lot of steen framed windows, they may have tame suppliers that can supply a small amount ?

Must admit it is a very, very long number of years since I used this particular type of "Putty" The early / mid 60s as I recall.

I was told then that Linseed putty had the tendency / charisteristic to "leach" into the surrounding timber, in doing so it formed a sort of bond with wood. The "specialized" casement putty, which I seem to remember as being a "harder / less pliable" material would form a surface skin, yet remain really quite soft / pliable under this skin, just what you need when the steel frame expanded in sunshine, or as you know only too well rust bubbles form.

Good luck in the search.

Ken.