Fitting double-glazed units to a hardwood door

[Corazones]

Hello everybody,
I have bought a hardwood back door which is intended to have six double-glazed units, and I have also found a supplier for the units. The door is primed and painted, ready to fit them.
My question concerns exactly how the units are fitted, and what clearance should I allow.
I assume that the units are best fitted by embedding them in mastic or clear silicone sealant, and then securing them in place with the loose beading supplied. Is this correct? and how much undersize should I order? I am wary of silicone as it could make repainting difficult.
Many thanks, Alec.

 

[northernchappy]

Hello. I had large units fitted to a hardwood frame. Black security glazing tape was used to keep weather out and the unit seated on spacers to help keep the unit ventilated with vents also cut into the recess between spacers at bottom to allow moisture escape.. Basically emulating a pvc frame. Apparently silicone will stop moisture escaping and help unit fail according to bloke who fitted them

 

[northernchappy]

Hello. I had large units fitted to a hardwood frame. Black security glazing tape was used to keep weather out and the unit seated on spacers to help keep the unit ventilated with vents also cut into the recess between spacers at bottom to allow moisture escape.. Basically emulating a pvc frame. Apparently silicone will stop moisture escaping and help unit fail according to bloke who fitted them

 

[Corazones]

Thanks, northernchappy,

I can understand that as I know faulty assembly with the sealing strips in uPVC can cause premature breakdown and misting, hence my question.

Your reply is very helpful but that was with a large unit; I'm not sure how six small ones can be fitted that way. How large were the spacers, and what did they look like?

 

[northernchappy]

They are plastic, come in different thicknesses, think he used 3mm thick ones. They are wide enough to support each pane of glass yet flush so as not to protrude and interfere with the beading and about 10cm long. Upvc frames have vent holes but not sure how you'd vent the ones your fitting. Could you copy a upvc design? Btw i know some dg units have an inside and outside pane so be careful to look out for stickers. My units are big! 8ft x 5ft so a tad bigger than yours lol

 

[Corazones]

Thanks for that; I read elsewhere that 2mm spacers are often used. Fortunately my door will be largely protected by an overhanging roof, and I think I will fit it with the removable beading inside (for security), so I am hoping that I can avoid the misting-up problem.
Alec.

 

[northernchappy]

Sounds like your in luck if its sheltered. OP may help you out here, looking at the security tape, it may also be breathable.. don't quote me though. sorry i couldn't be more helpful