# Glue type for exterior door mortise/tenon joint



## whattodo (Jan 24, 2011)

Hi All,
I am looking for suggestions for the BEST glues for gluing up rails/stiles on an exterior door project. I am building with mortise and tenon joints. I need to have a long (about an hour) for open time so that I am not rushed during assembling time. Must be water proof (living in south florida).
I am not sure if I need gap filling or not. My tenons are fitting pretty well but what is considered a gap? I have a few notches on the inside of the mortise where the router kind of got a way and there are saw marks on the tenons from the dado blades. When fitting the tenon to the mortise I can slip it in with pressure about half way in but need to apply more force to get fully inserted. So does this sound like a candidate for gap filling epoxy? What is considered a gag?

Thanks in advance,

John


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## cabinetman (Jul 5, 2007)

If there are gaps in the joinery, a 2 part epoxy would be my recommendation. If the joint is a good fit, I would use a resorcinol glue.








 







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## Steve Neul (Sep 2, 2011)

+1 on Cabinetmans suggestions for glue. If you mean it's a entry door as far as your joints, unless it's a through mortice the mortice and tennon joint isn't enough. You will also need to drill and install 5" long 1/2" dowels in the joints. You would need two in the top rail, three in the lock rail and four in the bottom rail.


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## J.C. (Jan 20, 2012)

A urea resin glue would also be a good choice. It can have a long open time, is gap filling, water and solvent resistant, and creates a rigid strong glue joint. I prefer Unibond 800 which is a 2 part glue but you can also get it in powder form and mix with water. Here's a good article about it ureaglue.pdf
http://www.veneersystems.com/index.php/action/item/id/220/prevaction/pricelist/


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## whattodo (Jan 24, 2011)

After researching and finally finishing up fitting my tenons I am leaning towards using the Dap Weldwood plastic resin. My tenons are slide into the mortise until about 3/4 of the way down and then taps from a deadblow is needed to seat it. I would guess that there are some gaps within the interior of the mortise of about 1/32 to 1/16 in a few places line the ends where the radius is not the same due to sanding/rasping the tenons. I also need a longer open time because when pressed for time I tend to get a little spastic and crazy and I start yelling at the helper(wife) to hurry. So with the small gaps and the open time needed Weldwood seems to be a good fit. 
Does this choice seem logical?
I have used Pro-Glue in the past with good results for lamination which I believe is the same but with less Formaldehyde.
Just to recap this for mortise / Tenon made of honduran mahogany for an exterior door.
Thanks


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## Steve Neul (Sep 2, 2011)

In the late 1970's I worked for a custom entry door company. We used the Weldwood Plastic Resin glue exclusively. I think if you finish the door good you won't have any problem with it. It's not completely water proof but is pretty close. One of the reasons it was used there is it gave more open time for assembly. There were many doors which had a lot of parts to get together before it set up. On the joints on your door where you know are loose, you can mix a separate batch that is a lot thicker so it doesn't run out on you. I will today buy a can of the resin glue from time to time. Every once in a while I will get a can that has set in the store too long. It will appear to be just fine but when you try to mix it, it will not completely dissolve. It should mix up looking like carpenters glue only brown. If there is anything that looks like curdled milk in it don't use the glue.


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## cabinetman (Jul 5, 2007)

Plastic Resin Glue (urea formaldehyde), and phenol formaldehyde glues are rated at "water resistant", both are used for plywood lamination. Urea formaldehyde is used mostly for interior applications, phenol formaldehyde is used for more exterior use. Marine grade plywood lamination...for example.

For your application, a good exterior grade 2 part epoxy might be a better bet, as you aren't sure how the mating surfaces are to each other. A caveat about epoxy is that it works best when it has some thickness to the mating surfaces. That doesn't mean it won't work with a well fitted joint. I would prefer to use it if there were gaps.










 







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