corner miters in window/door trim

[harry_]

part 1:
I Just finished reading about 3 hours worth of articles re: topic, prompted by Brice's article/review of Jim Chestnut's Clam Clamps . What I am wondering is why is there not a 'field tool' for installing the (I am going to call it a metal spline) like they do on door casings for 'cased, pre-hung doors? I can get my miters tight when installing trim,... keeping them tight for years to come is another matter entirely.

As I look around the house that I live in which is a modular (delivered in 2 pieces) and has a large amount of winter/summer shift, all the trim remains relatively tight with few exceptions. All casings have this 'spline'.

Thoughts on this?

Part 2:
when installing stain grade millwork, I tend to shy away from glue out of fear that squeeze out will throw the painters (read: stainers) a fit when their turn comes. I somehow I end up with the actual staining as part of my bid, I almost always do my stain & sealer prior to installation to eliminate this problem/worry.

Thoughts on this?

Part 3:
One technique that I have employed in the past in both stain & paint grade work is to nail my 'head case' (no, I'm not referring to my ex-wife [doh]) in place. Then nail the legs in place only at the miters. Returning later to finish nailing off after the glue has had time to cure. This allows me to put some tension on things (if necessary) without the glue giving up. In the end I can only wonder how long these stay tight before the glue fails. I also tend to not like working the same thing twice. So over time I stopped the method.

Thoughts on this?

 

[Chuck Kiser]

part 1:
I Just finished reading about 3 hours worth of articles re: topic, prompted by Brice's article/review of Jim Chestnut's Clam Clamps . What I am wondering is why is there not a 'field tool' for installing the (I am going to call it a metal spline) like they do on door casings for 'cased, pre-hung doors? I can get my miters tight when installing trim,... keeping them tight for years to come is another matter entirely.

As I look around the house that I live in which is a modular (delivered in 2 pieces) and has a large amount of winter/summer shift, all the trim remains relatively tight with few exceptions. All casings have this 'spline'.

Thoughts on this?

There is such a tool. It is called a biscuit joiner or a Domino. Many folks use this technique. However, a properly made miter if glued and clamped will last a very, very,very long time without opening. Assuming no excessive external forces. Your modular home is a prime example of external forces. As in the transport and installation of same.

Part 2:
when installing stain grade millwork, I tend to shy away from glue out of fear that squeeze out will throw the painters (read: stainers) a fit when their turn comes. I somehow I end up with the actual staining as part of my bid, I almost always do my stain & sealer prior to installation to eliminate this problem/worry.

Thoughts on this?

Always, always glue a miter joint. I carry a damp rag and wipe away any excess after clamping. The glue not only bonds the pieces together it also serves to seal the end grain which minimizes moisture absorption. Which as you know is the primary culprit in seasonal wood movement

Part 3:
One technique that I have employed in the past in both stain & paint grade work is to nail my 'head case' (no, I'm not referring to my ex-wife [doh]) in place. Then nail the legs in place only at the miters. Returning later to finish nailing off after the glue has had time to cure. This allows me to put some tension on things (if necessary) without the glue giving up. In the end I can only wonder how long these stay tight before the glue fails. I also tend to not like working the same thing twice. So over time I stopped the method.

Thoughts on this?

After getting all my measurements, I build my door and window casing frames on the ground, glued and clamped. After dry time I install, 18 gauge thru the thin part of the casing into the jams and 16 gauge in the thick part of the casing into (hopefully) a stud or two.

 

[harry_]

There is such a tool. It is called a biscuit joiner or a Domino.

No. I am talking about the 'spline' that is 'shot' in. I have a biscuiter,... and some day will have a domino, but neither is that to which I was referring.

 

[Chuck Kiser]

Do you mean the wavy metal type?

 

[harry_]

well them too, but no.

The ones I am thinking of are 1 1/2 inches (give or take). The slightly resemble a a tall, narrow I-beam, cut on the flat side to a 90deg. point on each end, one being an inside 90, the other being an outside. They are shot in from the outside corner of the miter, 'pronged' end first.

I will see if i have a loose one floating about and post a pic.

 

[harry_]

well them too, but no.

The ones I am thinking of are 1 1/2 inches (give or take). The slightly resemble a a tall, narrow I-beam, cut on the flat side to a 90deg. point on each end, one being an inside 90, the other being an outside. They are shot in from the outside corner of the miter, 'pronged' end first.

I will see if i have a loose one floating about and post a pic.

Well I checked my 'obvious' places for one. It appear to now be a 'stumble-upon' item (won't find it until I stumble upon it).
but here is a pic [attachthumb=#]

 

[tDot]

I've seen the spline that you are talking about. The picture that you have shown is the side profile view. You should post an end profile view, it makes the spline make more sense.  The top and botom portion of the "I" provide physical resistance to prevent the miter from opening.  I think the major limitation to installing those on site would be the amount of force required to install them. I believe in shops they are installed with a pneumatic gun that is larger then a framng gun.

Glued dominos and biscuits should provide close to the same resistance. 

 

[Holzhacker]

I always nail the legs in first and then the header. This allows me to push the top casing down into the legs for a bit of tension. Years ago I used to use corrugated nails for miters with 3/4" stock. Something I learned in play production. Corrugated nails take time and don't work well with newer trim.
Nowadays if the job calls for it, I pre-drill and put in a #1 square drive screw from the top down. This system works great for me. I can trim out all the openings and then go back, drill and insert the screw. Miters stay tight. Since the screw is on the top coming down a little colored wood putty and no one ever knows.

 

[harry_]

I've seen the spline that you are talking about. The picture that you have shown is the side profile view. You should post an end profile view, it makes the spline make more sense. 

The view you see is exactly how it goes into the miter, pointy end towards the outside of the joint. a drawing of the end profile is in the same image, right next to it.

I think the major limitation to installing those on site would be the amount of force required to install them. I believe in shops they are installed with a pneumatic gun that is larger then a framng gun.

That could be a problem, but i could always do it on my new MFT which would eliminate clearance issues with the gun.
So, who makes the gun? I don't even know what one would call it

Glued dominos and biscuits should provide close to the same resistance. 

My 'bread & butter' work is paint grade new construction. Dominos and/or biscuits quite simply, are not going to happen, too much time. The bids for this type of work cannot spare it. I think my joints are pretty tight, definitely above par for paint grade.

Dominos and/or biscuits would be more appropriate for my stain grade and/or custom work where my margin runs a little higher.

 

[Forrest Anderson]

The view you see is exactly how it goes into the miter, pointy end towards the outside of the joint. a drawing of the end profile is in the same image, right next to it.

So it looks kinda like this..?

[attachimg=1]

I haven't seen one personally, but maybe other members might recognise it.

Forrest

 

[peter halle]

Dan Rush and I talked at the first training class about how to use 4 mm dominoes to pin together door trim from above where you might not even need glue.  Sorry, I can't describe right now, I haven't opened presents yet.  That is NOW.  I'll be back later.

Peter

 

[Forrest Anderson]

The Estad Stamping & Mfg Company has this image on their website which seems to be the thing you're looking for:

[attachimg=2]

And McFeely's has various sizes of this:

[attachimg=1]

However, note the way that McFeely's nails are being inserted into the joint.

A Google search for "Clamp Nails" or "Joint Nails" comes up with various hits.

Forrest

 

[mastercabman]

I know what you are talking about.It is also used on cabinet doors construction.(mitered picture frame)
I don't know the real name for them.As for the tool,I'm not sure where you can get it.I would try an industrial tool supplier.

 

[harry_]

Yes Forrest, the funky shaped ones!

Couldn't find any place else that sells them or a gun to shoot them with

 

[danrush]

Harry,

Try checking with a local door manufacturer.  My lumber yard has an in-house door shop and uses them.  I'll check with them after the holidays, if you like.   My guess would be that the pressure needed for the gun will be greater than any site compressor can handle.  In 25+ years, I have never seen those guns on a jobsite.

I agree with Chuck, always glue the joints.  With quality glue, they are unlikely to break.  I also try to build the casings on the table, then install.

Dan

 

[WarnerConstCo.]

If you guys like to build them down and then install them in one unit, I do this when I can.

Look into the collins miter clamps.  You can use them for a multitude of tasks.

They leave a pin prick about the size of an 18ga.

http://www.collinstool.com/base.php?page=collins_miter_clamps.htm

 

[Kevin Stricker]

Here are a few alternative ideas:

Gary Katz Stitched Miters

2P-10 Review

Collins Mitertite

I like using the Collins clamps for Crown and Base, don't know why I don't use them on casement.  With Paint grade trim I think 2P-10 will be your best bet.