Deck hand rail face 90 joint (2 pieces @ 45 miter) IPE- reinforce with Domino?

[redknife]

Situation/Background: Contracted work starts tomorrow to tear down our second story deck and install new design. Decking and hand railing will be constructed of Ipe. I was talking with our GC and he highlighted that there will be some areas of rail that will form a 90 degree angle in the same plane (45 each). He highlighted that those joints tend to look perfect when they leave but separate and/or warp over time as each board moves. They structure other joints to hide the movement but face 90's are a problem. If I inadequately described - looking at the face place from above you'd see an "L" configuration with 45 degree cuts across the face plane of each.

I wonder if inserting a couple Domino tenons might mitigate some of that disparate movement over time. I have a domino 500 and could acquire the appropriate outdoor tenons. A complicating factor, I think, is that the Ipe does not take glue well from what I understand. So: domino, leave it, other?

Thanks

 

[Skymaster]

they make locking plates for biscuit jointer :} If you have to capability mill a spline from the Ipe, slot the ends with a biscuit jointer or 5/32 slot cutter. drive the spline home and at least the ends will remain level with each other. Also polyurethane glue may work. wipe good with alcohol b4 gluing may help

 

[redknife]

Yeah, wondered about using a spline instead. Would have to use a slot cutter as I don't have a biscuit cutter. Could dimension some splines from leftover ipe. I'm coming across West system Gflex 655 as a potential adhesive.

 

[Skymaster]

heck most likely 5/4 for deck so i wood go 1/4 spline. leave it long on both inside and outside then trim/cope to conform to the miter :}

 

[JohnW]

Chris,
I have an IPE deck and have built a screen door out of IPE. For the door, the flexible epoxy worked for me. I used System 3 G2 formula and left the joints a little sloppy so I could get a good amount of epoxy in them. (System 3 recommended this) The door takes the pounding of a typical spring hinged open/shut routine and the mortise/tenon joints are staying firm. It's about 1.5 years in use.

My deck is 3 years old and is under roof on a screened in deck. The railings sill is made from 5/4 x 6" IPE and gets exposure to rain and sun. My corner joints are not 45* because I have a post in each corner. I used a jig saw and cut the ends of the sill to fit around the posts. So while it's not a 45*, it is a joint of sorts closely resembling a butt joint, and while there is a little bit of shrinkage, it's not near as much as I had with pressure treated lumber from the borg.

I like the idea of using a 1/4" slot/tenon at the joint. Even is there is a bit of shrinkage, this should help keep everything lined up. I'd consider using a slot cutter and using IPE as the tenon with a flexible epoxy.

 

[CrealBilly]

Lumber in general does not shrink or swell much along its length so I think if you epoxied and pinned a stainless steel dowel it would work pretty well. Besides doweling is a lot easier than a spline.

 

[redknife]

OK. Good ideas. I haven't worked with this deck guy before but I can't see he'd mind if I grooved or doweled a few joints. Don't think any of those options would be hard or time consuming. With those thoughts in mind, I'll work something out.

 

[mkepke]

Instead of a domino loose tenon you could make the joint a combo bridle joint + miter joint..I've done this before on a deck. The miter makes it look nice but the bridle joint provides a lot of surface area for gluing and screwing (from the underside).

Or you could cut a traditional 45 degree miter and reinforce it with (deep) butterfly splines across the miter.

That said weather proof tenons should be fine..you could even pin them.

-Mark

 

[Bob Carreiro]

I really hate to be the bearer of contrary news, but...
No matter what you use - dominos, splines, dowels or biscuts, you ARE NOT going to keep the 45 tight at the heel. As the width of the boards move in season, it reflects 2-fold at the joints heel. Even while the toe remains tight, the heel will be left open a few months out of the year. I speak from first-hand experience, and a few second-hand experiences of "I told you so's" since my own experience. Use simple butt joints, with pocket screws from beneath (screw into edge, not end grain) if you can manage it, or one of the afore mentioned methods.
REMEMBER, I told you so! You are without excuses!