More door making questions

[Joe Hendershott]

Moving ahead with a flush panel exterior door project and would like some more opinions.

It will be flush door covered with a single sheet of commercial ribbon striped mahogany and have several round glass windows.

The core is baltic birch 1/2 inch on either side with another 2 layers of 3/8 and 1/4 to get me close to a final thickness of 1 5/8 inches. Planning to bond it all together with epoxy or Weldwood 2 part plastic resin glue. Opinions on which is better? Pretty sure most will say the epoxy. Will glue it up in a vacuum bag.

Considering making it more hollow with some rigid foam insulation that would bump the door R value up a bit and of course make it lighter. The house is a 50 year old mid century modern that has been improved but not nearly as tight as newer homes so the insulating value isn't that huge of a deal. Locally available sheets are not 5/8 inch so that is another concern.

Finally, the glass will most likely just be 3/8 laminated glass . IGU I have priced are about twice the price and may not matter that much.

So the questions or concerns would be:

1. Epoxy or plastic resin glue?

2. Hollow-ish with foam, and what kind, where to source it, etc. or solid?

3. How much larger than the glass should the window openings be and how (aside from silicone) to center the glass in the openings? Would you use IGU's?

[Wayne Lomman]

First question, if it is not getting direct rain, a good crosslinking PVA glue will work. TB3 is an example. Otherwise resorcinol or failing that, epoxy.
More answers soon. Cheers

[Wayne Lomman]

Sorry, I was waiting outside a dress fabric shop and my wife came back astonish early...

How much you insulate your door depends on your weather and how good the rest of the house is. Make it solid all the way through. You will get reasonable insulation anyway, more benefit will come from good draft exclusion through the gaps and a solid heavy door increases the value of your house. If the door is solid and heavy, everything else appears to be as well.

Leave 2mm all round for the gap between the edges of the glass and the timber. The simplest method for centring the glass is to make identical bead inside and out if it doesn't get direct weather. A better way is to rebate the outside and bead it on the outside.

IGUs I assume are insulated glass units ie double-glazed units? They will transfer less heat but your budget is the final decider on this. I do my own double glazing using 5.38 and 3mm glass. The difference in thickness is to improve sound deadening. Cheers

[Joe Hendershott]

First question, if it is not getting direct rain, a good crosslinking PVA glue will work. TB3 is an example. Otherwise resorcinol or failing that, epoxy.
More answers soon. Cheers

Thanks Wayne. I've decided just to go with the epoxy. Only downside for me is it's a little more messy to work with, or at least cleaning up. I know people use the TB3 a lot with success outside but epoxy is still a better choice when used correctly.

Also will make the door 1 3/4" thick and insert some foam between the exterior panels.

I have a test piece glued up waiting for a final cure and then finish. So far it is good.

[Joe Hendershott]

I do my own double glazing using 5.38 and 3mm glass. The difference in thickness is to improve sound deadening. Cheers

Would love to hear your process for making the units yourself.

The exterior will be rabbeted and a stop on the interior side.

[Wayne Lomman]

Epoxy will work OK. TB3 would be OK in this situation because you are laminating layers rather than framing with timber at right angles where the glue line fails in the direct weather.

Double glazing needs desiccant between the glass layers so you have to design in a small cavity to take a couple of teaspoons of desiccant with some 1mm holes linking the desiccant chamber to the space between the glass. This stops condensation where you can't get to it.

I make a finished opening the size I want and rebate both faces just deep enough to take the thickness of the glass and silicone to set it. No beading required as the silicone is very secure. The colour of the silicone varies depending on the job. Mask up with tape to fill the 2mm gap between edge of glass and the surrounding timber. I'll post a picture of a pair I just did for the metrology lab at work when I can find it. Cheers

[Wayne Lomman]

DSC_0220.jpgPhoto of a pair of double glazed windows/supervisor spy holes for the metrology lab. These ones are inside the main building and needed for insulation as the lab is maintained at 20C all year round. 100mm gap between the panes. Frame is MDF painted black. Trim is left over bright aluminium tile edge we had lying around. It was needed to cover the grinder-cut opening in the insulated panel. For the windows at home, everything is flush fitted. Polycarbonate instead of glass for impact resistance in the workshop. The dark panel to the left is a glass note board. Best 'whiteboard' I have ever used. Cheers

[Tom M King]

Wayne, I'm assuming custom insulated glass units are hard to come by there. Here, not so hard. I recently put 10 custom skylights in a standing seam metal roof. We formed the curbs out of, and into the panels, but that's another story. The glass units were 1" thick 2' x 4'. Top layer was 1/4" tempered bronze, 1/2" spacer, and inner glass was 1/4" Safety glass, filled with Argon. Cost per double insulated unit was a few dollars less than $200 delivered.

[Malcolm McLeod]

I recently moved; house was built in the 50's, but has been remodeled a couple of times. Part of the charm is they kept some of the nicer old details, like the kitchen>patio door. But since it has single pane lights, they sweat like pigs! I'm not sure the 'charm' is worth the worry about the door rotting - - and the lockset is 90% of said charm anyway.

When the proverbial roundtoit arrives, I will look for IGUs.

Not sure this will impact your decision, but food for thought.

[Tom M King]

In the historic houses I work on, if the inside of sash are painted, with single pane glass, they need to be painted with exterior paint, and the paint touching the glass like you do on the outside. They will condense water on the inside when the conditions are right, which come fairly often around here.

[Wayne Lomman]

Tom, insulated glass panels are readily available. I just make my own for the hell of it. The ones pictured cost about $8 and some time. Also, the ones I make produce a slimline appearance in timber. Cheers

[Mark Bolton]

I'm assuming custom insulated glass units are hard to come by there.

We could never get away with a shop built IGU on any work and I cant honestly say I would ever even consider making an argon filled IGU with approved thermal break, low e, tempering, and so on. We couldnt even deal with the shop side of the components, adhesive, and so on, for $8 unless it was all found/salvaged. Heck, new 1/8" plate glass is more than that.

We are in the same boat. We did some 2'x3' 3/4" IGU's clear, tempered, and they were a shade over 100 bucks a piece.

[Wayne Lomman]

Mark, I don't make them for a living, nor would I suggest anyone try to match my costs. I just happen to have the appropriate materials available from doing other types of work. An engineering shop has interesting resources if one applies a bit of creativity to the design process. Creativity in design is the point.

It also needs to be noted that the OP was comparing an IGU with a single pane of glass. Even a half-hearted double glazed unit is better than a single pane. Cheers

[Mark Bolton]

Mark, I don't make them for a living, nor would I suggest anyone try to match my costs. I just happen to have the appropriate materials available from doing other types of work. An engineering shop has interesting resources if one applies a bit of creativity to the design process. Creativity in design is the point.

It also needs to be noted that the OP was comparing an IGU with a single pane of glass. Even a half-hearted double glazed unit is better than a single pane. Cheers

Oh for sure, no argument there. When you have lots of bits and pieces available to you that are drops, scraps, pretty much free, things can get very fun on your own time. I understand the comparison to the single pane however for an exterior door, I guess you can call me a chicken, I would never venture to roll the dice on a shop made IGU. Air tight, argon, modern glass coatings,.. I know it may be something that sparks consideration when comparing the cost of a piece of double strength glass to a purchased IGU.

With that, Ive swapped my fair share of failed IGUs as well lol. Most commonly due to poor installation and having shear loads on the IGU or adhesive interactions with what the IGU mfr. used. I have a feeling I would have swapped a lot more in exterior applications had I made my own. In our climate (basically humidity central) if you couldnt keep the air space dead tight (hermetically sealed) I dont think any type of desiccant would save you.

[Wayne Lomman]

Mark, its not rolling the dice. To be accurate, I don't do glazing for a living these days but it was a significant part of my life for years when I lived in the tropical north. Double glazing is not difficult. IGU suppliers just want us to think it is plus buy all the options they are peddling. Never had a failure other than spectacular disintegration from stray impact. Cheers